000
FXUS61 KPBZ 230253
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
953 PM EST SUN NOV 22 2009

.SYNOPSIS...
LOW PRESSURE MOVING FROM LOUISIANA TONIGHT TO THE VIRGINIA COAST
MONDAY NIGHT MAY SPREAD SHOWERS AS FAR WEST AS THE UPPER OHIO
VALLEY MONDAY AND MONDAY NIGHT. A LOW PRESSURE SYSTEM COMING FROM
THE CANADIAN ROCKIES WILL STRENGTHEN WHEN IT MOVES THROUGH THE
GREAT LAKES WEDNESDAY AND THANKSGIVING DAY TO GIVE THE UPPER OHIO
VALLEY COLDER TEMPERATURES AND RAIN AND SNOW SHOWERS INTO THE
WEEKEND.

&&

.NEAR TERM /THROUGH MONDAY/...
AS LOW PRESSURE SYSTEM FROM LOUISIANA HEADS TOWARD THE VIRGINIA
COAST...CLOUDS WILL INCREASE EAST TO WEST ACROSS THE UPPER OHIO
VALLEY LATE TONIGHT AND MONDAY.

AS CONTINUED TO BE SHOWN BY SREF MODEL OUTPUT...THERE IS A CHANCE
THAT SHOWERS FROM THE COASTAL SYSTEM COULD SPREAD WESTWARD ACROSS
THE UPPER OHIO VALLEY MONDAY.

FORECASTED CONTINUED MILD TEMPERATURES THIS PERIOD USING A BLEND
OF CLOSELY CONCURRING GFS AND NAM MOS VALUES.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
SEVERAL SREF MODEL MEMBERS INCLUDING OPERATIONAL NAM MODEL OUTPUT CONTINUE
TO SHOW SHOWERS FROM THE COASTAL SYSTEM BRINGING SHOWERS TO THE
UPPER OHIO VALLEY MONDAY NIGHT INTO TUESDAY. HOWEVER OPERATIONAL
GFS AND ECMWF MODEL OUTPUT SHOW NO RAIN FOR THE AREA. OUR CURRENT
SOLUTION WAS TO KEEP MENTION OF A CHANCE OF SHOWERS MONDAY NIGHT FOR
MOST AREAS...BUT FOR ONLY LOCATIONS NEAR THE MOUNTAINS DAYTIME
TUESDAY.

BASED ON RECENT BLEND OF SREF AND GEFS MODEL OUTPUT...EXPECT THE
FIRST SHOWERS WITH THE INCOMING WESTERN SYSTEM TO BEGIN TO SPREAD
ACROSS THE UPPER OHIO VALLEY TUESDAY NIGHT AND WEDNESDAY.

FOR TEMPERATURES...PREFERRED SLIGHTLY MILDER GFS MOS VALUES THIS
PERIOD.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
LITTLE CHANGE IN THE EXTENDED FORECAST COMPARED TO YESTERDAY. UPPER
LEVEL LOW WILL SLOWLY MOVE FROM THE CENTRAL PLAINS WEDNESDAY NIGHT
TO NEW ENGLAND FRIDAY NIGHT. EXPECTED SCATTERED SHOWERS TO PERSIST
THROUGH MUCH OF THIS TIME PERIOD. TEMPERATURES WILL DROP TO NEAR OR
SLIGHTLY BELOW FREEZING THURSDAY AND FRIDAY NIGHTS...BUT WITH THESE
BEING THE FIRST TWO NIGHTS IN SOME TIME WITH BELOW FREEZING
TEMPERATURES...AT THIS POINT DO NOT THINK THERE WOULD BE ANY
ACCUMULATING SNOW.

MODELS HAVE SURFACE LOW PRESSURE DEVELOPING OFF THE NEW ENGLAND
COAST FRIDAY NIGHT...BUT THIS SYSTEM SHOULD BE TOO FAR TO THE EAST
TO AFFECT LOCAL WEATHER. AS THE UPPER LOW MOVES TO THE EAST FRIDAY
NIGHT...NORTHWEST FLOW SHOULD ALLOW FOR THE DEVELOPMENT OF SOME
LAKE EFFECT SHOWERS INTO SATURDAY. CONDITIONS SHOULD DRY OUT
SATURDAY NIGHT AS HIGH PRESSURE MOVES IN FROM THE SOUTHWEST.
TEMPERATURES WILL BE BELOW NORMAL THROUGH THIS TIME PERIOD.

&&

.AVIATION /03Z MONDAY THROUGH FRIDAY/...
WINDS WILL DECREASE A FEW KNOTS OVERNIGHT...BUT REMAIN STEADY OUT
OF THE EAST AROUND 5 KTS OVERNIGHT. EXPECT CIRRUS SHIELD TO MOVE
IN OVERNIGHT FROM THE SOUTH WITH A DEVELOPING LOW PRESSURE SYSTEM
OFF THE SOUTHEAST COAST.

THE LOW MOVING UP THE EAST COAST ON MONDAY WILL BRING THE NEXT
CHANCE FOR SHOWERS WITH REDUCED CEILINGS EXPECTED...ESPECIALLY
SOUTHEAST OF A KMGW-KLBE LINE. FOR NOW...WILL JUST KEEP LOW VFR
CEILINGS AT MOST SITES.

A LOW PRESSURE SYSTEM ACROSS THE MISSOURI VALLEY WILL DEVELOP ON
TUESDAY...STRENGTHENING AS IT MOVES INTO THE GREAT LAKES BY
WEDNESDAY. THIS SYSTEM AND ITS ASSOCIATED COLD FRONT WILL RETURN
THE CHANCE FOR REDUCED CEILINGS ACROSS THE AREA FOR THE REST OF
THE WEEK.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.

&&

$$

000
FXUS61 KPHI 230145
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
845 PM EST SUN NOV 22 2009

.SYNOPSIS...
HIGH PRESSURE, LOCATED OVER NEW ENGLAND EARLY THIS EVENING, WILL
DRIFT TO THE EAST AND OFF THE COAST ON MONDAY. MEANWHILE, LOW
PRESSURE IS EXPECTED TO DEVELOP OFF THE SOUTHEAST COAST TONIGHT.
THE LOW SHOULD PROGRESS TO THE NORTHEAST AND IT IS EXPECTED TO
PASS WELL TO THE EAST OF DELAWARE AND NEW JERSEY ON MONDAY NIGHT.
A COLD FRONT FROM THE WEST IS ANTICIPATED TO ARRIVE ON THURSDAY.
LOW PRESSURE IS FORECAST TO DEVELOP OFF THE SOUTHEAST COAST ON
THURSDAY AND IT SHOULD MOVE UP INTO NEW ENGLAND ON FRIDAY. HIGH
PRESSURE IS EXPECTED TO BUILD SLOWLY INTO OUR REGION FROM THE WEST
DURING THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
SKIES CLEARED ACROSS A GOOD PART OF THE CFA AND ARE SLOW TO RETURN
SO HAVE BACKED OFF ON THE CLOUDING UP ESPECIALLY NORTHERN AREAS.
THE SATELLITE DOES SHOW THE MID AND HIGH LEVEL CLOUDS MOVING IN
FROM THE SOUTH AND JUST NOW TO NORTHERN VIRGINIA WHILE THE LOW
CLOUDS ON THE CURVE ARE ADVECTING IN ON AN EAST TO NORTHEAST FLOW
AND ARE SCATTERED OVER SNJ.

WITH THAT...HAVE ALSO BACKED OFF ON THE PRECIPITATION UP NORTH AND
DELAYED SOUTH FOR A COUPLE HOURS. NEAREST TO US IS THE TIDEWATER
AREA AND MOVING SLOWLY NORTHNORTHEAST.

ALL IN ALL, WE SHOULD SEE AN INCREASE IN CLOUD COVER LATER TONIGHT
AS ADDITIONAL LOW CLOUDS CONTINUE TO DRIFT IN FROM THE OCEAN, AND
MID AND HIGH LEVEL CLOUDS BUILD UP FROM THE SOUTH. WE WILL BEGIN
TO MENTION CHANCE POPS FOR OUR SOUTHERN COUNTIES FOR VERY LATE
TONIGHT.

TEMPERATURES TONIGHT SHOULD DROP INTO THE 40S IN MUCH OF OUR
REGION, WITH SOME 30S POSSIBLE UP NORTH.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/...
AS HIGH PRESSURE DRIFTS OFF THE COAST OF CANADA`S MARITIME
PROVINCES ON MONDAY, A SURFACE RIDGE WILL REMAIN ALONG THE EAST
COAST. THE RIDGE AXIS IS FORECAST TO DRIFT FARTHER INLAND ON
MONDAY AND TUESDAY BEFORE WORKING ITS WAY BACK TOWARD THE COAST ON
WEDNESDAY.

IN REGARD TO THE COASTAL LOW, THE 12 UTC GFS AND THE 12 UTC ECMWF
ARE SIMILAR IN THEIR HANDLING OF THE FEATURE. THE 12 UTC NAM
REMAINS THE OUTLIER. THE LOW SHOULD PASS OFF CAPE HATTERAS ON
MONDAY EVENING BEFORE PASSING WELL TO OUR EAST ON MONDAY NIGHT.

MEANWHILE, THE REMNANTS OF THE UPPER SYSTEM THAT WAS OVER THE
TENNESSEE RIVER VALLEY AND THE LOWER APPALACHIANS THIS AFTERNOON
SHOULD LIFT OVER OUR REGION LATE ON MONDAY. SOME OF THE ENERGY
ASSOCIATED WITH THE SHORT WAVE OVER THE CENTRAL PLAINS THIS
AFTERNOON SHOULD PASS OVERHEAD ON TUESDAY MORNING.

WE ARE EXPECTING RAIN TO CONTINUE BUILDING UP FROM THE SOUTH AND
INTO OUR REGION ON MONDAY. THE RAIN WILL PERSIST THROUGH MONDAY
NIGHT AND INTO EARLY TUESDAY. AFTER THE UPPER LEVEL SHORT WAVE
PASSES OVERHEAD ON TUESDAY MORNING, THE CHANCES FOR RAIN SHOULD
BEGIN TO DECREASE.

IT APPEARS AS THOUGH SOME LOW LEVEL MOISTURE MAY LINGER FOR
TUESDAY NIGHT INTO WEDNESDAY, SO WE ARE NOT INDICATING A GREAT
DEAL OF CLEARING FOR THE MID WEEK PERIOD, ESPECIALLY WITH OUR NEXT
WEATHER SYSTEM APPROACHING FROM THE WEST.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
A PATTERN CHANGE WILL CONTINUE TO GET UNDERWAY AS WE START THIS
PERIOD. THE COMPUTER MODELS ARE IN GOOD AGREEMENT THAT A TROUGH
WILL AMPLIFY ACROSS THE NORTHERN PLAINS AND GREAT LAKES REGION AS
STRONG ENERGY DIVES SOUTHEASTWARD. THE SHORT WAVE ENERGY, COUPLED
WITH THE JET STREAM POSITIONING, WILL TEND TO LEAD TO A CLOSED LOW
FROM THE GREAT LAKES REGION DOWN TO THE OHIO VALLEY. WHILE THIS
SYNOPTIC EVOLUTION IS AGREED UPON FAIRLY WELL BY THE COMPUTER
GUIDANCE, DETAILS ESPECIALLY FROM LATE THURSDAY INTO SATURDAY
BECOMES MORE DIFFICULT ALONG WITH LOWER CONFIDENCE AS TO THE
LOCATION AND TRACK OF A CLOSED MIDLEVEL CENTER /AS IT MOVES EAST
AND NORTHEASTWARD THROUGH THE CENTRAL APPALACHIANS AND NORTHEAST/.
GIVEN THE UNCERTAINTY, WE INITIALIZED THE DATABASE WITH HPC
GUIDANCE /COMPRISED OF THE ECMWF FOR WEDNESDAY NIGHT THROUGH
THURSDAY NIGHT, THEN THE ECMWF/GFS ENSEMBLE MEANS FOR FRIDAY
THROUGH SUNDAY/. WE DID MAKE SOME ADJUSTMENTS THOUGH AFTER
ADDITIONAL COLLABORATION WITH OUR SURROUNDING OFFICES.

BASED ON THE ABOVE, AN INITIAL COLD FRONT WILL BE ARRIVING
WEDNESDAY NIGHT AS THE UPPER-LEVEL TROUGH AMPLIFIES TO OUR WEST.
AS THE SYSTEM CLOSES OFF AND SLIDES EASTWARD, ENERGY ROTATING
AROUND THIS WILL TEND TO KEEP THE CHC OF AT LEAST SOME SHOWERS ON
THURSDAY. THERE IS SOME HINTS IN SOME OF THE MODEL GUIDANCE THAT
AN INVERTED TROUGH MAY EXTEND ACROSS PORTIONS OF OUR AREA LATE
THURSDAY INTO FRIDAY AS A NEW SURFACE LOW FORMS TO OUR EAST. IF
THIS IS PRESENT, THEN PRECIPITATION COULD BE ENHANCED SOME
ESPECIALLY AS THE MIDLEVEL LOW APPROACHES. FOR FRIDAY, THE SURFACE
LOW IS FORECAST TO BE PULLING UP INTO THE VICINITY OF SOUTHERN NEW
ENGLAND AND OUR AREA WILL BE UNDER A COLDER CYCLONIC FLOW. GIVEN
THE COLDER AIR ARRIVING ALOFT, WE CANNOT RULE OUT SHOWERS
/CONVECTIVE?/ WITH EVEN SOME SNOW POSSIBLE ESPECIALLY ACROSS THE
NORTHERN AREAS. FOR NOW, WE JUST KEPT THE MENTION OF SNOW ACROSS
THE FAR NORTHERN ZONES. IF ENOUGH MOISTURE AND INSTABILITY IS
AROUND AS THE CLOSED LOW MOVES BY, WOULD NOT RULE OUT SOME SMALL
HAIL/GRAUPEL WITH SOME SHOWERS. A BRISK NORTHWEST FLOW IS FORECAST
TO SETUP AS WE GO THROUGH FRIDAY AND SATURDAY. THIS COULD KEEP
SOME RAIN/SNOW SHOWERS GOING SATURDAY ESPECIALLY ACROSS THE FAR
NORTHERN ZONES AS SOME LAKE ERIE/ONTARIO MOISTURE COULD GET PULLED
SOUTHEASTWARD IN THE FORM OF STREAMERS. HIGH PRESSURE THEN BUILDS
TO OUR SOUTH SUNDAY WITH THE NORTHWESTERLY FLOW GRADUALLY ON THE
DECREASE.

&&

.AVIATION /02Z MONDAY THROUGH FRIDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.

HIGH PRESSURE CENTERED OVER NORTHERN NEW ENGLAND EARLY THIS EVENING
WILL SLIDE EASTWARD OVERNIGHT, GIVING WAY TO AN AREA OF LOW PRESSURE
ACROSS THE SOUTHEASTERN UNITED STATES. AS THIS OCCURS, AN EASTERLY
FLOW WILL STRENGTHEN AND ALLOW THE LOW-LEVEL MOISTURE TO INCREASE.
THIS IS STARTING TO HAPPEN WITH STRATOCUMULUS MOVING WESTWARD FROM
THE OCEAN INTO NEW JERSEY. SATELLITE TRENDS SHOW THIS CLOUDINESS
BREAKING UP SOME AS IT SPREADS INLAND, HOWEVER AN INCREASING TREND
IS EXPECTED EVERYWHERE THROUGH THE NIGHT. OUR CONFIDENCE IS ON THE
LOWER SIDE REGARDING HOW QUICKLY THE CEILINGS LOWER BELOW VFR. WE
TOOK CONTINUITY INTO ACCOUNT, BUT DID MAKE SOME ADJUSTMENTS BASED ON
TRENDS AND SOME NEWER COMPUTER GUIDANCE. AS THE MOISTURE DEEPENS
THROUGH THE OVERNIGHT, SOME DRIZZLE MAY BEGIN TO OCCUR ESPECIALLY
FROM THE KPHL AREA SOUTH AND EASTWARD. SOME LOCAL VISIBILITIES MAY
LOWER SOME LATER TONIGHT AS THE MOISTURE INCREASES, HOWEVER THIS
DOES NOT APPEAR TO BE SIGNIFICANT AT THIS TIME. WE BROUGHT SOME
DRIZZLE IN FROM SOUTH TO NORTH LATE TONIGHT AND MONDAY MORNING, THEN
AS AN AREA OF LOW PRESSURE TRACKS FROM THE CAROLINAS TO OUR EAST
MONDAY, SOME RAIN IS EXPECTED TO OVERSPREAD THE AREA. WE GRADUALLY
STEPPED DOWN THE VISIBILITIES AS SOMEWHAT MORE ORGANIZED RAIN LOOKS
TO MOVE THROUGH MONDAY.

A NORTHEASTERLY WIND WILL TEND TO SETTLE SOME FOR A WHILE TONIGHT AS
WE GET SOME DECOUPLING, HOWEVER AS THE FLOW INCREASES ABOVE THE
SURFACE, THE SURFACE WINDS SHOULD INCREASE A BIT LATER TONIGHT AND
MONDAY MORNING. WHILE THERE COULD BE SOME WIND GUSTS, WE CARRIED
GUSTS JUST AT KACY AND KMIV MONDAY FOR NOW GIVEN THE SURFACE WIND
TRAJECTORY. FOR THE KPHL METRO AREA, WE INCREASED THE SUSTAINED
WINDS A BIT.

OUTLOOK...
AS THE STORM SYSTEM TRACKS AWAY FROM OUR AREA MONDAY NIGHT, A
NORTHEASTERLY FLOW LOOKS TO CONTINUE. THIS LOOKS TO LINGER THE
LOW-LEVEL MOISTURE IN PLACE, THEREFORE LOW CEILINGS AND/OR
VISIBILITIES ALONG WITH SOME RAIN AND DRIZZLE WILL CONTINUE. WE MAY
HAVE TO DEAL WITH A PROLONGED PERIOD OF LOWER CEILINGS TUESDAY AND
WEDNESDAY AS MOISTURE POTENTIALLY GETS TRAPPED. A FRONTAL BOUNDARY
IS FORECAST TO APPROACH LATE WEDNESDAY, THEN A STORM SYSTEM IS
FORECAST TO DEVELOP TO OUR EAST LATER IN THE WEEK. THIS POTENTIALLY
TO BRING SOME WIND AND RAIN TO THE AREA.

&&

.MARINE...
A PERSISTENT NORTHEAST FLOW WILL HELP THE SEAS BUILD OVER THE NEXT
SEVERAL DAYS, STARTING TONIGHT. AS AN AREA OF LOW PRESSURE MOVES
TOWARD THE COASTAL WATERS ON MONDAY, AND HIGH PRESSURE REMAINS TO
OUR NORTHEAST, THE PRESSURE GRADIENT WILL TIGHTEN, ALLOWING WINDS TO
INCREASE AS WELL. SMALL CRAFT ADVISORIES ARE IN EFFECT NOW FOR THE
COASTAL WATERS. THE LOWER BAY MAY GET SOME GUSTS UP TO 25 KT TONIGHT
INTO MONDAY AS WELL, SO WE HAVE A SMALL CRAFT ADVISORY THERE AS
WELL. THE LOW PRESSURE SYSTEM WILL CONTINUE MOVING TO OUR NORTHEAST
AND OUT OF THE AREA LATE TUESDAY, LEADING TO A BRIEF REPRIEVE FOR
LATE TUESDAY INTO EARLY WEDNESDAY. HOWEVER, CONDITIONS WILL LIKELY
DIMINISH ONCE AGAIN LATE WEDNESDAY THROUGH THE LATTER PART OF THE
WEEK AS A FRONTAL BOUNDARY IS EXPECTED TO APPROACH THE AREA, WITH
ANOTHER COASTAL LOW DEVELOPING AND MOVING NEAR OUR AREA. SMALL CRAFT
ADVISORIES COULD BE POSSIBLE AGAIN FOR THE END OF THE WEEK.

&&

.TIDES/COASTAL FLOODING...
THE EAST TO NORTHEAST FLOW IS ON AND THE TIDES ARE RUNNING ABOUT
1.2 FEET ABOVE THE MRPSSE WHICH WOULD GIVE US A 4.5 FT MLLW HEIGHT
FOR THE SOUTHERN END OF NJ AND DE AT THE 1 AM TIDE. WILL CONTINUE
TO WATCH THE DEPARTURES WHICH COULD APPROACH THE LEVEL OF MINOR
ESPECIALLY IN DE WITH THE EARLY AFTERNOON HIGH TIDE AND REACH
SOMEWHERE AROUND 5.5 TO 5.8 FT WITH MINOR BEING 6.0 THE THRESHOLD
BEFORE THE VETERANS DAY STORM COULD BE A BIT LOWER WHERE THE
EROSION OCCURRED.

WE WILL CONTINUE TO MONITOR THE SITUATION IN CASE THINGS CHANGE
OVER THE NEXT FEW FORECASTS. THE TIDE HEIGHTS AT 44009 ARE ONLY
FORECAST TO BE 7-8 FEET WHICH TRANSLATES TO ABOUT A 3.5 FT
BREAKING ON THE BEACH. QUITE A BIT DIFFERENT THAN THE 12-13 FT OF
LAST WEEK.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST TUESDAY FOR ANZ450>455.
     SMALL CRAFT ADVISORY UNTIL 6 PM EST MONDAY FOR ANZ431.

&&

$$
SYNOPSIS...EBERWINE/IOVINO
NEAR TERM...EBERWINE/IOVINO
SHORT TERM...IOVINO
LONG TERM...GORSE
AVIATION...GORSE
MARINE...ROBERTSON
TIDES/COASTAL FLOODING...EBERWINE

000
FXUS61 KCTP 230003
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
703 PM EST SUN NOV 22 2009

.SYNOPSIS...
WEAK HIGH PRESSURE OVER THE REGION WILL SLOWLY RETREAT TO THE
NORTHEAST. AS THE HIGH MOVES AWAY...IT WILL ALLOW A SERIES OF LOW
PRESSURE SYSTEMS TO MOVE THROUGH DURING THE WEEK. LIGHT
PRECIPITATION IS POSSIBLE ALMOST EVERY DAY THIS WEEK. TEMPERATURES
WILL COOL DOWN BELOW THE SEASONAL NORMALS FOR THE LONG HOLIDAY
WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
SKIES HAVE CLEARED OUT...AND TEMPS ARE DROPPING RAPIDLY TOWARD THE
DEWPOINTS. WITH NO WIND TO SPEAK OF...TEMPS WILL CONTINUE TO FALL
AND COULD PUSH THE DEWPOINTS DOWN LOWER THAN WHERE THEY ARE ATTM.
AN INCREASE IN LLVL MSTR IS SEEN IN THE POST- MIDNIGHT HOURS AS AN
ERLY FLOW DEVELOPS JUST ALOFT. THIS SHOULD HELP TO LEVEL TEMPS
OFF. MINS SHOULD DIP INTO THE U20S IN THE NRN VALLEYS AND 30S
ELSEWHERE...BEFORE POSSIBLY RISING AGAIN LATE TONIGHT.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
THE STORY REMAINS THE SAME FOR MONDAY AS 1034+ MB SFC HIGH PUSHES
OFF THE NEW ENG COAST...DEVELOPING MOIST...EASTERLY FLOW OVR THE
MID ATLANTIC. STRATOCU WILL DRIFT NORTHWARD ALONG THE APPALACHIANS
WITH SOME PATCHY LIGHT RAIN AND DRIZZLE SPREADING NORTHWARD AS
WELL THROUGHOUT THE DAY. OVERALL VERY LITTLE QPF EXPECTED WITH
THIS SYSTEM...DESPITE THE DEEP EASTERLY FLOW. HOWEVER...BY LATE
MONDAY A BETTER CHANCE OF SOME MEASURABLE BUT STILL OVERALL LIGHT
RAIN WILL ARRIVE AS EASTERLY WIND AND PWAT ANOMALIES SHIFT NORTH
INTO PA. TEMPS WILL STRUGGLE TO RISE THROUGH THE 40S TOMORROW WITH
FAR SOUTHEAST SECTIONS PERHAPS REACHING THE LOWER 50S.

&&

.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
MODELS HAVE MOISTURE MOVING IN FASTER ON MONDAY THAN WHAT I SAW
YESTERDAY. THIS IS SUPPORTED BY SATELLITE DATA ETC. SEE SHORT
TERM SECTION ABOVE FOR MORE DETAILS.

ON THE FLIP SIDE...TUESDAY LOOKS LESS OF A CHC OF RAIN...AND
THERE MAY BE SOME PARTIAL CLEARING IN THE AFTERNOON...MAINLY
WESTERN SECTIONS.

AS WAS THE CASE YESTERDAY...STILL A LOT OF VARIATION ON TIMING
OF FROPA ON WED AND THU. IT LOOKS LIKE FRONT MAY MOVE RATHER
FAST ON WED. HOWEVER...A WAVE IS NOW LIKELY TO FORM AND DEVELOP
THU NIGHT. AT THE CURRENT TIME...IT LOOKS LIKE WE WOULD BE TOO
FAR WEST AND SOUTH TO GET MUCH...BUT DID UP POPS SOME FOR THU
INTO FRIDAY. SOME MINOR AMTS OF SNOW POSSIBLE LATE THURSDAY
NIGHT INTO FRIDAY EVENING ACROSS THE MTS AND HIGHER ELEVATIONS
OF CENTRAL PA.

I DID EDGE TEMPS DOWN SOME FROM THU INTO SAT...MAINLY MAX
TEMPS.

IT STILL LOOKS LIKE THE FLOW WOULD BACK MORE TO THE WEST NEXT
SUNDAY...BRINGING A MODERATING TREND TO THE AREA.

OTHERWISE...OTHER THAN THE MINOR CHANGES NOTED ABOVE...LEFT
PACKAGE CLOSE TO WHAT WE HAD.

WITH THE TENDENCY FOR A WESTERN RIDGE AND A WEAK NEGATIVE NAO...
A TREND TO COOLER CONDITIONS LIKELY OVERALL. NOT SO CLEAR CUT
ON STORM POTENTIAL ETC.

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/...
IR IMAGERY INDICATES VFR CONDS FOR MUCH OF CENTRAL PA
AIRFIELDS...HOWEVER ARND 09Z MID- LVL MOISTURE APPROACHES
JST/AOO FROM THE SOUTH. GUIDANCE SUGGESTS A HIGH CONFIDENCE THAT
MVFR CIGS WILL DEVELOP...WITH A TEMPO IFR CONDS BTWN 10-13Z FOR
JST/AOO/UNV. BFD SHUD REMAIN VFR POSSIBLY THRU 00Z TUE WITH CIGS
ARND 4KFT AGL. SUSQ-VALLEY AIRFIELDS WILL SEE PATCHY MVFR BY 12Z
THEN TREND TOWARDS SOLID MVFR LCL IFR CONDS ARND 18Z. EXPECT
PRECIP TO REMAIN SOUTH OF PA AIRFIELDS UNTIL CLOSER TO 00Z TUE.
JST/AOO/UNV COULD SEE ISO SHRA BTWN 18-21Z...HOWEVER OVERALL
HIGHER CONFIDENCE IN VCSH FOR MOST SITES.

OUTLOOK...
TUE...MVFR/IFR CIGS. SHRA IN THE AM.
WED...MVFR TO VFR.
THU-FRI...MVFR WITH CHC -SHRASN.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO
SHORT TERM...DEVOIR
LONG TERM...MARTIN
AVIATION...BEACHLER

000
FXUS61 KCTP 222354
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
654 PM EST SUN NOV 22 2009

.SYNOPSIS...
WEAK HIGH PRESSURE OVER THE REGION WILL SLOWLY RETREAT TO THE
NORTHEAST. AS THE HIGH MOVES AWAY...IT WILL ALLOW A SERIES OF LOW
PRESSURE SYSTEMS TO MOVE THROUGH DURING THE WEEK. LIGHT
PRECIPITATION IS POSSIBLE ALMOST EVERY DAY THIS WEEK. TEMPERATURES
WILL COOL DOWN BELOW THE SEASONAL NORMALS FOR THE LONG HOLIDAY
WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
SKIES HAVE CLEARED OUT...AND TEMPS ARE DROPPING RAPIDLY TOWARD THE
DEWPOINTS. WITH NO WIND TO SPEAK OF...TEMPS WILL CONTINUE TO FALL
AND COULD PUSH THE DEWPOINTS DOWN LOWER THAN WHERE THEY ARE ATTM.
AN INCREASE IN LLVL MSTR IS SEEN IN THE POST- MIDNIGHT HOURS AS AN
ERLY FLOW DEVELOPS JUST ALOFT. THIS SHOULD HELP TO LEVEL TEMPS
OFF. MINS SHOULD DIP INTO THE U20S IN THE NRN VALLEYS AND 30S
ELSEWHERE...BEFORE POSSIBLY RISING AGAIN LATE TONIGHT.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
THE STORY REMAINS THE SAME FOR MONDAY AS 1034+ MB SFC HIGH PUSHES
OFF THE NEW ENG COAST...DEVELOPING MOIST...EASTERLY FLOW OVR THE
MID ATLANTIC. STRATOCU WILL DRIFT NORTHWARD ALONG THE APPALACHIANS
WITH SOME PATCHY LIGHT RAIN AND DRIZZLE SPREADING NORTHWARD AS
WELL THROUGHOUT THE DAY. OVERALL VERY LITTLE QPF EXPECTED WITH
THIS SYSTEM...DESPITE THE DEEP EASTERLY FLOW. HOWEVER...BY LATE
MONDAY A BETTER CHANCE OF SOME MEASURABLE BUT STILL OVERALL LIGHT
RAIN WILL ARRIVE AS EASTERLY WIND AND PWAT ANOMALIES SHIFT NORTH
INTO PA. TEMPS WILL STRUGGLE TO RISE THROUGH THE 40S TOMORROW WITH
FAR SOUTHEAST SECTIONS PERHAPS REACHING THE LOWER 50S.

&&

.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
MODELS HAVE MOISTURE MOVING IN FASTER ON MONDAY THAN WHAT I SAW
YESTERDAY. THIS IS SUPPORTED BY SATELLITE DATA ETC. SEE SHORT
TERM SECTION ABOVE FOR MORE DETAILS.

ON THE FLIP SIDE...TUESDAY LOOKS LESS OF A CHC OF RAIN...AND
THERE MAY BE SOME PARTIAL CLEARING IN THE AFTERNOON...MAINLY
WESTERN SECTIONS.

AS WAS THE CASE YESTERDAY...STILL A LOT OF VARIATION ON TIMING
OF FROPA ON WED AND THU. IT LOOKS LIKE FRONT MAY MOVE RATHER
FAST ON WED. HOWEVER...A WAVE IS NOW LIKELY TO FORM AND DEVELOP
THU NIGHT. AT THE CURRENT TIME...IT LOOKS LIKE WE WOULD BE TOO
FAR WEST AND SOUTH TO GET MUCH...BUT DID UP POPS SOME FOR THU
INTO FRIDAY. SOME MINOR AMTS OF SNOW POSSIBLE LATE THURSDAY
NIGHT INTO FRIDAY EVENING ACROSS THE MTS AND HIGHER ELEVATIONS
OF CENTRAL PA.

I DID EDGE TEMPS DOWN SOME FROM THU INTO SAT...MAINLY MAX
TEMPS.

IT STILL LOOKS LIKE THE FLOW WOULD BACK MORE TO THE WEST NEXT
SUNDAY...BRINGING A MODERATING TREND TO THE AREA.

OTHERWISE...OTHER THAN THE MINOR CHANGES NOTED ABOVE...LEFT
PACKAGE CLOSE TO WHAT WE HAD.

WITH THE TENDENCY FOR A WESTERN RIDGE AND A WEAK NEGATIVE NAO...
A TREND TO COOLER CONDITIONS LIKELY OVERALL. NOT SO CLEAR CUT
ON STORM POTENTIAL ETC.

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/...
MVFR CIGS DISSIPATING FINALLY OVER THE CENTRAL MOUNTAIN REGION
THIS EVENING...FOLLOWED BY MOSTLY VFR MID TO LATE AS HIGH CLOUDS
STREAM NORTHWARD FROM ADVANCING MID ATLANTIC/CENTRAL APPALACHIAN
WEATHER SYSTEM

FLOW TURNS SE LATE THIS EVENING...AND MOISTURE WILL QUICKLY RETURN
OVERNIGHT IN THE FORM OF AN EXPANDING MVFR STRATOCU DECK FROM S TO
N. BY 12Z CLOUDS WILL LIKELY LOWER TO IFR ACROSS SOUTHERN TIER.
FORCING REMAINS LIGHT...BUT COULD EVEN SEE SOME PATCHY DRIZZLE
/MAINLY AROUND KJST-KAOO/ BY 12Z.

STARTING MONDAY...THE REGION WILL BE IN FOR AN EXTENDED PERIOD OF
POOR FLYING CONDITIONS.

OUTLOOK...
MON...MVFR LCL IFR. PSBL SHRA IN THE AFTN.
TUE...MVFR/IFR CIGS. SHRA IN THE AM.
WED...MVFR TO VFR.
THU-FRI...MVFR WITH CHC -SHRASN.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO
SHORT TERM...DEVOIR
LONG TERM...MARTIN
AVIATION...DEVOIR/RXR

000
FXUS61 KPHI 222336
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
636 PM EST SUN NOV 22 2009

.SYNOPSIS...
HIGH PRESSURE, LOCATED OVER NEW ENGLAND EARLY THIS EVENING, WILL
DRIFT TO THE EAST AND OFF THE COAST ON MONDAY. MEANWHILE, LOW
PRESSURE IS EXPECTED TO DEVELOP OFF THE SOUTHEAST COAST TONIGHT.
THE LOW SHOULD PROGRESS TO THE NORTHEAST AND IT IS EXPECTED TO
PASS WELL TO THE EAST OF DELAWARE AND NEW JERSEY ON MONDAY NIGHT.
A COLD FRONT FROM THE WEST IS ANTICIPATED TO ARRIVE ON THURSDAY.
LOW PRESSURE IS FORECAST TO DEVELOP OFF THE SOUTHEAST COAST ON
THURSDAY AND IT SHOULD MOVE UP INTO NEW ENGLAND ON FRIDAY. HIGH
PRESSURE IS EXPECTED TO BUILD SLOWLY INTO OUR REGION FROM THE WEST
DURING THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
THE CLOUDS OVER OUR NORTHERN COUNTIES AND OUR SOUTHERN COUNTIES
WERE A BIT MORE STUBBORN THAN WE THOUGHT THEY WOULD BE EARLIER IN
THE DAY. HOWEVER, THE CLOUDS HAVE BEEN SHOWING SIGNS OF DISSIPATING.
THERE WERE ADDITIONAL CLOUDS DRIFTING OFF THE OCEAN AND ONTO THE
NEW JERSEY COAST.

ALL IN ALL, WE SHOULD SEE AN INCREASE IN CLOUD COVER TONIGHT AS
ADDITIONAL LOW CLOUDS DRIFT OFF THE OCEAN, AND MID AND HIGH LEVEL
CLOUDS BUILD UP FROM THE SOUTH. WE WILL BEGIN TO MENTION CHANCE
POPS FOR OUR SOUTHERN COUNTIES FOR LATE TONIGHT AS THE
PRECIPITATION THAT WAS OVER THE SOUTHEASTERN STATES THIS AFTERNOON
CONTINUES TO LIFT TO THE NORTH.

TEMPERATURES TONIGHT SHOULD DROP INTO THE 40S IN MUCH OF OUR
REGION, WITH SOME 30S POSSIBLE UP NORTH.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/...
AS HIGH PRESSURE DRIFTS OFF THE COAST OF CANADA`S MARITIME
PROVINCES ON MONDAY, A SURFACE RIDGE WILL REMAIN ALONG THE EAST
COAST. THE RIDGE AXIS IS FORECAST TO DRIFT FARTHER INLAND ON
MONDAY AND TUESDAY BEFORE WORKING ITS WAY BACK TOWARD THE COAST ON
WEDNESDAY.

IN REGARD TO THE COASTAL LOW, THE 12 UTC GFS AND THE 12 UTC ECMWF
ARE SIMILAR IN THEIR HANDLING OF THE FEATURE. THE 12 UTC NAM
REMAINS THE OUTLIER. THE LOW SHOULD PASS OFF CAPE HATTERAS ON
MONDAY EVENING BEFORE PASSING WELL TO OUR EAST ON MONDAY NIGHT.

MEANWHILE, THE REMNANTS OF THE UPPER SYSTEM THAT WAS OVER THE
TENNESSEE RIVER VALLEY AND THE LOWER APPALACHIANS THIS AFTERNOON
SHOULD LIFT OVER OUR REGION LATE ON MONDAY. SOME OF THE ENERGY
ASSOCIATED WITH THE SHORT WAVE OVER THE CENTRAL PLAINS THIS
AFTERNOON SHOULD PASS OVERHEAD ON TUESDAY MORNING.

WE ARE EXPECTING RAIN TO CONTINUE BUILDING UP FROM THE SOUTH AND
INTO OUR REGION ON MONDAY. THE RAIN WILL PERSIST THROUGH MONDAY
NIGHT AND INTO EARLY TUESDAY. AFTER THE UPPER LEVEL SHORT WAVE
PASSES OVERHEAD ON TUESDAY MORNING, THE CHANCES FOR RAIN SHOULD
BEGIN TO DECREASE.

IT APPEARS AS THOUGH SOME LOW LEVEL MOISTURE MAY LINGER FOR
TUESDAY NIGHT INTO WEDNESDAY, SO WE ARE NOT INDICATING A GREAT
DEAL OF CLEARING FOR THE MID WEEK PERIOD, ESPECIALLY WITH OUR NEXT
WEATHER SYSTEM APPROACHING FROM THE WEST.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
A PATTERN CHANGE WILL CONTINUE TO GET UNDERWAY AS WE START THIS
PERIOD. THE COMPUTER MODELS ARE IN GOOD AGREEMENT THAT A TROUGH
WILL AMPLIFY ACROSS THE NORTHERN PLAINS AND GREAT LAKES REGION AS
STRONG ENERGY DIVES SOUTHEASTWARD. THE SHORT WAVE ENERGY, COUPLED
WITH THE JET STREAM POSITIONING, WILL TEND TO LEAD TO A CLOSED LOW
FROM THE GREAT LAKES REGION DOWN TO THE OHIO VALLEY. WHILE THIS
SYNOPTIC EVOLUTION IS AGREED UPON FAIRLY WELL BY THE COMPUTER
GUIDANCE, DETAILS ESPECIALLY FROM LATE THURSDAY INTO SATURDAY
BECOMES MORE DIFFICULT ALONG WITH LOWER CONFIDENCE AS TO THE
LOCATION AND TRACK OF A CLOSED MIDLEVEL CENTER /AS IT MOVES EAST
AND NORTHEASTWARD THROUGH THE CENTRAL APPALACHIANS AND NORTHEAST/.
GIVEN THE UNCERTAINTY, WE INITIALIZED THE DATABASE WITH HPC
GUIDANCE /COMPRISED OF THE ECMWF FOR WEDNESDAY NIGHT THROUGH
THURSDAY NIGHT, THEN THE ECMWF/GFS ENSEMBLE MEANS FOR FRIDAY
THROUGH SUNDAY/. WE DID MAKE SOME ADJUSTMENTS THOUGH AFTER
ADDITIONAL COLLABORATION WITH OUR SURROUNDING OFFICES.

BASED ON THE ABOVE, AN INITIAL COLD FRONT WILL BE ARRIVING
WEDNESDAY NIGHT AS THE UPPER-LEVEL TROUGH AMPLIFIES TO OUR WEST.
AS THE SYSTEM CLOSES OFF AND SLIDES EASTWARD, ENERGY ROTATING
AROUND THIS WILL TEND TO KEEP THE CHC OF AT LEAST SOME SHOWERS ON
THURSDAY. THERE IS SOME HINTS IN SOME OF THE MODEL GUIDANCE THAT
AN INVERTED TROUGH MAY EXTEND ACROSS PORTIONS OF OUR AREA LATE
THURSDAY INTO FRIDAY AS A NEW SURFACE LOW FORMS TO OUR EAST. IF
THIS IS PRESENT, THEN PRECIPITATION COULD BE ENHANCED SOME
ESPECIALLY AS THE MIDLEVEL LOW APPROACHES. FOR FRIDAY, THE SURFACE
LOW IS FORECAST TO BE PULLING UP INTO THE VICINITY OF SOUTHERN NEW
ENGLAND AND OUR AREA WILL BE UNDER A COLDER CYCLONIC FLOW. GIVEN
THE COLDER AIR ARRIVING ALOFT, WE CANNOT RULE OUT SHOWERS
/CONVECTIVE?/ WITH EVEN SOME SNOW POSSIBLE ESPECIALLY ACROSS THE
NORTHERN AREAS. FOR NOW, WE JUST KEPT THE MENTION OF SNOW ACROSS
THE FAR NORTHERN ZONES. IF ENOUGH MOISTURE AND INSTABILITY IS
AROUND AS THE CLOSED LOW MOVES BY, WOULD NOT RULE OUT SOME SMALL
HAIL/GRAUPEL WITH SOME SHOWERS. A BRISK NORTHWEST FLOW IS FORECAST
TO SETUP AS WE GO THROUGH FRIDAY AND SATURDAY. THIS COULD KEEP
SOME RAIN/SNOW SHOWERS GOING SATURDAY ESPECIALLY ACROSS THE FAR
NORTHERN ZONES AS SOME LAKE ERIE/ONTARIO MOISTURE COULD GET PULLED
SOUTHEASTWARD IN THE FORM OF STREAMERS. HIGH PRESSURE THEN BUILDS
TO OUR SOUTH SUNDAY WITH THE NORTHWESTERLY FLOW GRADUALLY ON THE
DECREASE.

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.

HIGH PRESSURE CENTERED OVER NORTHERN NEW ENGLAND EARLY THIS EVENING
WILL SLIDE EASTWARD OVERNIGHT, GIVING WAY TO AN AREA OF LOW PRESSURE
ACROSS THE SOUTHEASTERN UNITED STATES. AS THIS OCCURS, AN EASTERLY
FLOW WILL STRENGTHEN AND ALLOW THE LOW-LEVEL MOISTURE TO INCREASE.
THIS IS STARTING TO HAPPEN WITH STRATOCUMULUS MOVING WESTWARD FROM
THE OCEAN INTO NEW JERSEY. SATELLITE TRENDS SHOW THIS CLOUDINESS
BREAKING UP SOME AS IT SPREADS INLAND, HOWEVER AN INCREASING TREND
IS EXPECTED EVERYWHERE THROUGH THE NIGHT. OUR CONFIDENCE IS ON THE
LOWER SIDE REGARDING HOW QUICKLY THE CEILINGS LOWER BELOW VFR. WE
TOOK CONTINUITY INTO ACCOUNT, BUT DID MAKE SOME ADJUSTMENTS BASED ON
TRENDS AND SOME NEWER COMPUTER GUIDANCE. AS THE MOISTURE DEEPENS
THROUGH THE OVERNIGHT, SOME DRIZZLE MAY BEGIN TO OCCUR ESPECIALLY
FROM THE KPHL AREA SOUTH AND EASTWARD. SOME LOCAL VISIBILITIES MAY
LOWER SOME LATER TONIGHT AS THE MOISTURE INCREASES, HOWEVER THIS
DOES NOT APPEAR TO BE SIGNIFICANT AT THIS TIME. WE BROUGHT SOME
DRIZZLE IN FROM SOUTH TO NORTH LATE TONIGHT AND MONDAY MORNING, THEN
AS AN AREA OF LOW PRESSURE TRACKS FROM THE CAROLINAS TO OUR EAST
MONDAY, SOME RAIN IS EXPECTED TO OVERSPREAD THE AREA. WE GRADUALLY
STEPPED DOWN THE VISIBILITIES AS SOMEWHAT MORE ORGANIZED RAIN LOOKS
TO MOVE THROUGH MONDAY.

A NORTHEASTERLY WIND WILL TEND TO SETTLE SOME FOR A WHILE TONIGHT AS
WE GET SOME DECOUPLING, HOWEVER AS THE FLOW INCREASES ABOVE THE
SURFACE, THE SURFACE WINDS SHOULD INCREASE A BIT LATER TONIGHT AND
MONDAY MORNING. WHILE THERE COULD BE SOME WIND GUSTS, WE CARRIED
GUSTS JUST AT KACY AND KMIV MONDAY FOR NOW GIVEN THE SURFACE WIND
TRAJECTORY. FOR THE KPHL METRO AREA, WE INCREASED THE SUSTAINED
WINDS A BIT.

OUTLOOK...
AS THE STORM SYSTEM TRACKS AWAY FROM OUR AREA MONDAY NIGHT, A
NORTHEASTERLY FLOW LOOKS TO CONTINUE. THIS LOOKS TO LINGER THE
LOW-LEVEL MOISTURE IN PLACE, THEREFORE LOW CEILINGS AND/OR
VISIBILITIES ALONG WITH SOME RAIN AND DRIZZLE WILL CONTINUE. WE MAY
HAVE TO DEAL WITH A PROLONGED PERIOD OF LOWER CEILINGS TUESDAY AND
WEDNESDAY AS MOISTURE POTENTIALLY GETS TRAPPED. A FRONTAL BOUNDARY
IS FORECAST TO APPROACH LATE WEDNESDAY, THEN A STORM SYSTEM IS
FORECAST TO DEVELOP TO OUR EAST LATER IN THE WEEK. THIS POTENTIALLY
TO BRING SOME WIND AND RAIN TO THE AREA.

&&

.MARINE...
A PERSISTENT NORTHEAST FLOW WILL HELP THE SEAS BUILD OVER THE NEXT
SEVERAL DAYS, STARTING TONIGHT. AS AN AREA OF LOW PRESSURE MOVES
TOWARD THE COASTAL WATERS ON MONDAY, AND HIGH PRESSURE REMAINS TO
OUR NORTHEAST, THE PRESSURE GRADIENT WILL TIGHTEN, ALLOWING WINDS TO
INCREASE AS WELL. SMALL CRAFT ADVISORIES ARE IN EFFECT NOW FOR THE
COASTAL WATERS. THE LOWER BAY MAY GET SOME GUSTS UP TO 25 KT TONIGHT
INTO MONDAY AS WELL, SO WE HAVE A SMALL CRAFT ADVISORY THERE AS
WELL. THE LOW PRESSURE SYSTEM WILL CONTINUE MOVING TO OUR NORTHEAST
AND OUT OF THE AREA LATE TUESDAY, LEADING TO A BRIEF REPRIEVE FOR
LATE TUESDAY INTO EARLY WEDNESDAY. HOWEVER, CONDITIONS WILL LIKELY
DIMINISH ONCE AGAIN LATE WEDNESDAY THROUGH THE LATTER PART OF THE
WEEK AS A FRONTAL BOUNDARY IS EXPECTED TO APPROACH THE AREA, WITH
ANOTHER COASTAL LOW DEVELOPING AND MOVING NEAR OUR AREA. SMALL CRAFT
ADVISORIES COULD BE POSSIBLE AGAIN FOR THE END OF THE WEEK.

&&

.TIDES/COASTAL FLOODING...
A PERSISTENT NORTHEAST FLOW WILL REMAIN ACROSS THE AREA FOR THE NEXT
SEVERAL DAYS. THIS WILL CAUSE THE TIDES TO BE HIGHER THAN THE
CURRENT ASTRONOMICAL FORECASTS. WE WOULD STILL NEED AROUND A 1.5 TO
2.0 FT TIDAL SURGE ABOVE THE ASTRONOMICAL TIDE, BUT THE FORECAST
MODELS ARE ONLY PRODUCING 1.0 TO 1.5 FT TIDAL SURGES AT THIS TIME.
SO THE CURRENT FORECAST IS THAT WE WILL REMAIN ABOUT 0.5 TO 1.0 FT
BELOW MINOR FLOOD STAGE. WE WILL CONTINUE TO MONITOR THE SITUATION
IN CASE THINGS CHANGE OVER THE NEXT FEW FORECASTS.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST TUESDAY FOR ANZ450>455.
     SMALL CRAFT ADVISORY UNTIL 6 PM EST MONDAY FOR ANZ431.

&&

$$
SYNOPSIS...IOVINO
NEAR TERM...IOVINO
SHORT TERM...IOVINO
LONG TERM...GORSE
AVIATION...GORSE
MARINE...ROBERTSON
TIDES/COASTAL FLOODING...ROBERTSON

000
FXUS61 KPBZ 222111
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
411 PM EST SUN NOV 22 2009

.SYNOPSIS...
LOW PRESSURE MOVING FROM LOUISIANA TONIGHT TO THE VIRGINIA COAST
MONDAY NIGHT MAY SPREAD SHOWERS AS FAR WEST AS THE UPPER OHIO
VALLEY MONDAY AND MONDAY NIGHT. A LOW PRESSURE SYSTEM COMING FROM
THE CANADIAN ROCKIES WILL STRENGTHEN WHEN IT MOVES THROUGH THE
GREAT LAKES WEDNESDAY AND THANKSGIVING DAY TO GIVE THE UPPER OHIO
VALLEY COLDER TEMPERATURES AND RAIN AND SNOW SHOWERS INTO THE
WEEKEND.

&&

.NEAR TERM /THROUGH MONDAY/...
AS INDICATED BY RECENT SATELLITE IMAGES EXPECT FEW CLOUDS ACROSS
THE UPPER OHIO VALLEY THIS EVENING. AS LOW PRESSURE SYSTEM FROM
LOUISIANA HEADS TOWARD THE VIRGINIA COAST...CLOUDS WILL INCREASE
EAST TO WEST ACROSS THE UPPER OHIO VALLEY LATE TONIGHT AND MONDAY.

AS CONTINUED TO BE SHOWN BY SREF MODEL OUTPUT...THERE IS A CHANCE
THAT SHOWERS FROM THE COASTAL SYSTEM COULD SPREAD WESTWARD ACROSS
THE UPPER OHIO VALLEY MONDAY.

FORECASTED CONTINUED MILD TEMPERATURES THIS PERIOD USING A BLEND
OF CLOSELY CONCURRING GFS AND NAM MOS VALUES.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
SEVERAL SREF MODEL MEMBERS INCLUDING OPERATIONAL NAM MODEL OUTPUT CONTINUE
TO SHOW SHOWERS FROM THE COASTAL SYSTEM BRINGING SHOWERS TO THE
UPPER OHIO VALLEY MONDAY NIGHT INTO TUESDAY. HOWEVER OPERATIONAL
GFS AND ECMWF MODEL OUTPUT SHOW NO RAIN FOR THE AREA. OUR CURRENT
SOLUTION WAS TO KEEP MENTION OF A CHANCE OF SHOWERS MONDAY NIGHT FOR
MOST AREAS...BUT FOR ONLY LOCATIONS NEAR THE MOUNTAINS DAYTIME
TUESDAY.

BASED ON RECENT BLEND OF SREF AND GEFS MODEL OUTPUT...EXPECT THE
FIRST SHOWERS WITH THE INCOMING WESTERN SYSTEM TO BEGIN TO SPREAD
ACROSS THE UPPER OHIO VALLEY TUESDAY NIGHT AND WEDNESDAY.

FOR TEMPERATURES...PREFERRED SLIGHTLY MILDER GFS MOS VALUES THIS
PERIOD.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
LITTLE CHANGE IN THE EXTENDED FORECAST COMPARED TO YESTERDAY. UPPER
LEVEL LOW WILL SLOWLY MOVE FROM THE CENTRAL PLAINS WEDNESDAY NIGHT
TO NEW ENGLAND FRIDAY NIGHT. EXPECTED SCATTERED SHOWERS TO PERSIST
THROUGH MUCH OF THIS TIME PERIOD. TEMPERATURES WILL DROP TO NEAR OR
SLIGHTLY BELOW FREEZING THURSDAY AND FRIDAY NIGHTS...BUT WITH THESE
BEING THE FIRST TWO NIGHTS IN SOME TIME WITH BELOW FREEZING
TEMPERATURES...AT THIS POINT DO NOT THINK THERE WOULD BE ANY
ACCUMULATING SNOW.

MODELS HAVE SURFACE LOW PRESSURE DEVELOPING OFF THE NEW ENGLAND
COAST FRIDAY NIGHT...BUT THIS SYSTEM SHOULD BE TOO FAR TO THE EAST
TO AFFECT LOCAL WEATHER. AS THE UPPER LOW MOVES TO THE EAST FRIDAY
NIGHT...NORTHWEST FLOW SHOULD ALLOW FOR THE DEVELOPMENT OF SOME
LAKE EFFECT SHOWERS INTO SATURDAY. CONDITIONS SHOULD DRY OUT
SATURDAY NIGHT AS HIGH PRESSURE MOVES IN FROM THE SOUTHWEST.
TEMPERATURES WILL BE BELOW NORMAL THROUGH THIS TIME PERIOD.

&&

.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
CLOUDS HAVE FINALLY SCATTERED OUT ACROSS THE AREA...WITH CONDITIONS
EXPECTED TO BE COMPLETELY CLEAR BY SUNSET. WINDS WILL DECREASE A FEW
KNOTS OVERNIGHT...BUT REMAIN STEADY OUT OF THE EAST AROUND 5 KTS
OVERNIGHT. EXPECT CIRRUS SHIELD TO MOVE IN OVERNIGHT WITH A
DEVELOPING LOW PRESSURE SYSTEM OFF THE SOUTHEAST COAST.

THE LOW MOVING UP THE EAST COAST ON MONDAY WILL BRING THE NEXT
CHANCE FOR SHOWERS WITH REDUCED CEILINGS EXPECTED...ESPECIALLY
SOUTHEAST OF A KMGW-KLBE LINE. FOR NOW...WILL JUST KEEP LOW VFR
CEILINGS AT MOST SITES.

A LOW PRESSURE SYSTEM ACROSS THE MISSOURI VALLEY WILL DEVELOP ON
TUESDAY...STRENGTHENING AS IT MOVES INTO THE GREAT LAKES BY
WEDNESDAY. THIS SYSTEM AND ITS ASSOCIATED COLD FRONT WILL RETURN
THE CHANCE FOR REDUCED CEILINGS ACROSS THE AREA FOR THE REST OF
THE WEEK.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.

&&

$$

000
FXUS61 KPHI 222030
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
330 PM EST SUN NOV 22 2009

.SYNOPSIS...
HIGH PRESSURE, LOCATED OVER THE SAINT LAWRENCE RIVER VALLEY THIS
AFTERNOON, WILL DRIFT TO THE EAST AND OFF THE COAST ON MONDAY.
MEANWHILE, LOW PRESSURE IS EXPECTED TO DEVELOP OFF THE SOUTHEAST
COAST TONIGHT. THE LOW SHOULD PROGRESS TO THE NORTHEAST AND IT IS
EXPECTED TO PASS WELL TO THE EAST OF DELAWARE AND NEW JERSEY ON
MONDAY NIGHT. A COLD FRONT FROM THE WEST IS ANTICIPATED TO ARRIVE
ON THURSDAY. LOW PRESSURE IS FORECAST TO DEVELOP OFF THE SOUTHEAST
COAST ON THURSDAY AND IT SHOULD MOVE UP INTO NEW ENGLAND ON
FRIDAY. HIGH PRESSURE IS EXPECTED TO BUILD SLOWLY INTO OUR REGION
FROM THE WEST DURING THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
AT 3:00 PM, THERE WAS A NORTHEAST WIND AND TEMPERATURES WERE
MAINLY IN THE 50S IN OUR REGION. THE POCONOS AND PARTS OF FAR
NORTHERN NEW JERSEY WERE IN THE 40S.

THE CLOUDS OVER OUR NORTHERN COUNTIES AND OUR SOUTHERN COUNTIES
WERE A BIT MORE STUBBORN THAN WE THOUGHT THEY WOULD BE EARLIER IN
THE DAY. HOWEVER, AT MID AFTERNOON THE CLOUDS WERE SHOWING SIGNS
OF DISSIPATING. THERE WERE ADDITIONAL CLOUDS DRIFTING OFF THE
OCEAN AND TOWARD THE NEW JERSEY COAST.

ALL IN ALL, WE SHOULD SEE AN INCREASE IN CLOUD COVER TONIGHT AS
ADDITIONAL LOW CLOUDS DRIFT OFF THE OCEAN, AND MID AND HIGH LEVEL
CLOUDS BUILD UP FROM THE SOUTH. WE WILL BEGIN TO MENTION CHANCE
POPS FOR OUR SOUTHERN COUNTIES FOR LATE TONIGHT AS THE
PRECIPITATION THAT WAS OVER THE SOUTHEASTERN STATES THIS AFTERNOON
CONTINUES TO LIFT TO THE NORTH.

TEMPERATURES TONIGHT SHOULD DROP INTO THE 40S IN MUCH OF OUR
REGION, WITH SOME 30S POSSIBLE UP NORTH.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/...
AS HIGH PRESSURE DRIFTS OFF THE COAST OF CANADA`S MARITIME
PROVINCES ON MONDAY, A SURFACE RIDGE WILL REMAIN ALONG THE EAST
COAST. THE RIDGE AXIS IS FORECAST TO DRIFT FARTHER INLAND ON
MONDAY AND TUESDAY BEFORE WORKING ITS WAY BACK TOWARD THE COAST ON
WEDNESDAY.

IN REGARD TO THE COASTAL LOW, THE 12 UTC GFS AND THE 12 UTC ECMWF
ARE SIMILAR IN THEIR HANDLING OF THE FEATURE. THE 12 UTC NAM
REMAINS THE OUTLIER. THE LOW SHOULD PASS OFF CAPE HATTERAS ON
MONDAY EVENING BEFORE PASSING WELL TO OUR EAST ON MONDAY NIGHT.

MEANWHILE, THE REMNANTS OF THE UPPER SYSTEM THAT WAS OVER THE
TENNESSEE RIVER VALLEY AND THE LOWER APPALACHIANS THIS AFTERNOON
SHOULD LIFT OVER OUR REGION LATE ON MONDAY. SOME OF THE ENERGY
ASSOCIATED WITH THE SHORT WAVE OVER THE CENTRAL PLAINS THIS
AFTERNOON SHOULD PASS OVERHEAD ON TUESDAY MORNING.

WE ARE EXPECTING RAIN TO CONTINUE BUILDING UP FROM THE SOUTH AND
INTO OUR REGION ON MONDAY. THE RAIN WILL PERSIST THROUGH MONDAY
NIGHT AND INTO EARLY TUESDAY. AFTER THE UPPER LEVEL SHORT WAVE
PASSES OVERHEAD ON TUESDAY MORNING, THE CHANCES FOR RAIN SHOULD
BEGIN TO DECREASE.

IT APPEARS AS THOUGH SOME LOW LEVEL MOISTURE MAY LINGER FOR
TUESDAY NIGHT INTO WEDNESDAY, SO WE ARE NOT INDICATING A GREAT
DEAL OF CLEARING FOR THE MID WEEK PERIOD, ESPECIALLY WITH OUR NEXT
WEATHER SYSTEM APPROACHING FROM THE WEST.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
A PATTERN CHANGE WILL CONTINUE TO GET UNDERWAY AS WE START THIS
PERIOD. THE COMPUTER MODELS ARE IN GOOD AGREEMENT THAT A TROUGH
WILL AMPLIFY ACROSS THE NORTHERN PLAINS AND GREAT LAKES REGION AS
STRONG ENERGY DIVES SOUTHEASTWARD. THE SHORT WAVE ENERGY, COUPLED
WITH THE JET STREAM POSITIONING, WILL TEND TO LEAD TO A CLOSED LOW
FROM THE GREAT LAKES REGION DOWN TO THE OHIO VALLEY. WHILE THIS
SYNOPTIC EVOLUTION IS AGREED UPON FAIRLY WELL BY THE COMPUTER
GUIDANCE, DETAILS ESPECIALLY FROM LATE THURSDAY INTO SATURDAY
BECOMES MORE DIFFICULT ALONG WITH LOWER CONFIDENCE AS TO THE
LOCATION AND TRACK OF A CLOSED MIDLEVEL CENTER /AS IT MOVES EAST
AND NORTHEASTWARD THROUGH THE CENTRAL APPALACHIANS AND NORTHEAST/.
GIVEN THE UNCERTAINTY, WE INITIALIZED THE DATABASE WITH HPC
GUIDANCE /COMPRISED OF THE ECMWF FOR WEDNESDAY NIGHT THROUGH
THURSDAY NIGHT, THEN THE ECMWF/GFS ENSEMBLE MEANS FOR FRIDAY
THROUGH SUNDAY/. WE DID MAKE SOME ADJUSTMENTS THOUGH AFTER
ADDITIONAL COLLABORATION WITH OUR SURROUNDING OFFICES.

BASED ON THE ABOVE, AN INITIAL COLD FRONT WILL BE ARRIVING
WEDNESDAY NIGHT AS THE UPPER-LEVEL TROUGH AMPLIFIES TO OUR WEST.
AS THE SYSTEM CLOSES OFF AND SLIDES EASTWARD, ENERGY ROTATING
AROUND THIS WILL TEND TO KEEP THE CHC OF AT LEAST SOME SHOWERS ON
THURSDAY. THERE IS SOME HINTS IN SOME OF THE MODEL GUIDANCE THAT
AN INVERTED TROUGH MAY EXTEND ACROSS PORTIONS OF OUR AREA LATE
THURSDAY INTO FRIDAY AS A NEW SURFACE LOW FORMS TO OUR EAST. IF
THIS IS PRESENT, THEN PRECIPITATION COULD BE ENHANCED SOME
ESPECIALLY AS THE MIDLEVEL LOW APPROACHES. FOR FRIDAY, THE SURFACE
LOW IS FORECAST TO BE PULLING UP INTO THE VICINITY OF SOUTHERN NEW
ENGLAND AND OUR AREA WILL BE UNDER A COLDER CYCLONIC FLOW. GIVEN
THE COLDER AIR ARRIVING ALOFT, WE CANNOT RULE OUT SHOWERS
/CONVECTIVE?/ WITH EVEN SOME SNOW POSSIBLE ESPECIALLY ACROSS THE
NORTHERN AREAS. FOR NOW, WE JUST KEPT THE MENTION OF SNOW ACROSS
THE FAR NORTHERN ZONES. IF ENOUGH MOISTURE AND INSTABILITY IS
AROUND AS THE CLOSED LOW MOVES BY, WOULD NOT RULE OUT SOME SMALL
HAIL/GRAUPEL WITH SOME SHOWERS. A BRISK NORTHWEST FLOW IS FORECAST
TO SETUP AS WE GO THROUGH FRIDAY AND SATURDAY. THIS COULD KEEP
SOME RAIN/SNOW SHOWERS GOING SATURDAY ESPECIALLY ACROSS THE FAR
NORTHERN ZONES AS SOME LAKE ERIE/ONTARIO MOISTURE COULD GET PULLED
SOUTHEASTWARD IN THE FORM OF STREAMERS. HIGH PRESSURE THEN BUILDS
TO OUR SOUTH SUNDAY WITH THE NORTHWESTERLY FLOW GRADUALLY ON THE
DECREASE.

&&

.AVIATION /21Z SUNDAY THROUGH FRIDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.

VFR CONDITIONS WILL START THE FORECAST LATE THIS AFTERNOON INTO
THE EARLY EVENING. HOWEVER, CLOUDS WILL BEGIN TO DEVELOP ACROSS
THE AREA AS MOIST NORTHEASTERLY FLOW CONTINUES ACROSS THE AREA.
CLOUDS SHOULD BEGIN FORMING AFTER SUNDOWN AND THICKEN THROUGH THE
NIGHT. MVFR CEILINGS ARE EXPECTED TO START AROUND OR AFTER
MIDNIGHT FOR THE MAJORITY OF THE AREA, AND THEN LOWER TO IFR BY
SUNRISE TOMORROW. AS AN AREA OF LOW PRESSURE RIDES UP THE EAST
COAST DURING THE DAY TOMORROW, RAIN CHANCES SHOULD INCREASE FROM
SOUTH TO NORTH. WINDS WILL REMAIN MOSTLY NORTHEAST THROUGH THE TAF
PERIOD, POSSIBLY INCREASING DURING THE DAY TOMORROW. LOW CEILINGS,
VISIBILITIES, AND RAINY CONDITIONS WILL CONTINUE THROUGH MONDAY
NIGHT.

OUTLOOK...
THE LOW PRESSURE SYSTEM MOVES OUT OF THE AREA ON TUESDAY, WHICH
COULD PROVIDE A BRIEF REPRIEVE LAST TUESDAY INTO EARLY WEDNESDAY.
HOWEVER, A FRONTAL BOUNDARY AND ANOTHER COASTAL LOW ARE EXPECTED
TO IMPACT THE AREA FOR THE LATTER PART OF THE WEEK.

&&

.MARINE...
A PERSISTENT NORTHEAST FLOW WILL HELP THE SEAS BUILD OVER THE NEXT
SEVERAL DAYS, STARTING TONIGHT. AS AN AREA OF LOW PRESSURE MOVES
TOWARD THE COASTAL WATERS ON MONDAY, AND HIGH PRESSURE REMAINS TO
OUR NORTHEAST, THE PRESSURE GRADIENT WILL TIGHTEN, ALLOWING WINDS
TO INCREASE AS WELL. SMALL CRAFT ADVISORIES ARE IN EFFECT NOW FOR
THE COASTAL WATERS. THE LOWER BAY MAY GET SOME GUSTA UP TO 25 KT
LATER TONIGHT INTO TOMORROW AS WELL, SO WE HAVE A SMALL CRAFT
ADVISORY THERE AS WELL. THE LOW PRESSURE SYSTEM WILL CONTINUE
MOVING TO OUR NORTHEAST AND OUT OF THE AREA LATE TUESDAY, LEADING
TO A BRIEF REPRIEVE FOR LATE TUESDAY INTO EARLY WEDNESDAY.
HOWEVER, CONDITIONS WILL LIKELY DIMINISH ONCE AGAIN LATE WEDNESDAY
THROUGH THE LATTER PART OF THE WEEK AS A FRONTAL BOUNDARY IS
EXPECTED TO APPROACH THE AREA, WITH ANOTHER COASTAL LOW DEVELOPING
AND MOVING NEAR OUR AREA. SMALL CRAFT ADVISORIES COULD BE POSSIBLE
AGAIN FOR THE END OF THE WORK WEEK.

&&

.TIDES/COASTAL FLOODING...
A PERSISTENT NORTHEAST FLOW WILL REMAIN ACROSS THE AREA FOR THE
NEXT SEVERAL DAYS. THIS WILL CAUSE THE TIDES TO BE HIGHER THAN THE
CURRENT ASTRONOMICAL FORECASTS. WE WOULD STILL NEED AROUND A 1.5
TO 2 FT TIDAL SURGE ABOVE THE ASTRONOMICAL TIDE, BUT THE FORECAST
MODELS ARE ONLY PRODUCING 1 TO 1.5 FT TIDAL SURGES AT THIS TIME.
SO THE CURRENT FORECAST IS THAT WE WILL REMAIN ABOUT .5 TO 1.0 FT
BELOW MINOR FLOOD STAGE. WE WILL CONTINUE TO MONITOR THE SITUATION
IN CASE THINGS CHANCE OVER THE NEXT FEW FORECASTS.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST TUESDAY FOR ANZ450>455.
     SMALL CRAFT ADVISORY UNTIL 6 PM EST MONDAY FOR ANZ431.

&&

$$

SYNOPSIS/NEAR TERM/SHORT TERM...IOVINO
LONG TERM...GORSE
AVIATION/MARINE...ROBERTSON
TIDES/COASTAL FLOODING...ROBERTSON

000
FXUS61 KCTP 222016
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
316 PM EST SUN NOV 22 2009

.SYNOPSIS...
AN ANOMALOUS STRONG UPPER RIDGE WILL DOMINATE OUR WEATHER THROUGH
MID-WEEK. THEN A SERIES OF WAVES WILL CARVE OUT A TROUGH OVER
EASTERN NORTH AMERICA BEGINNING ABOUT THANKSGIVING. THE STRONG
TROUGH WHICH DEVELOPS BY THE WEEKEND AND THE RIDGE OVER WESTERN
NORTH AMERICA. IT WILL TURN COLDER AROUND THANKSGIVING.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
GREATER THAN 65% OF CENTRAL PA HAS BROKEN INTO THE CLEARING WITH
THE CENTRAL MOUNTAIN REGION AND MIDDLE SUSQ. RIVER VALLEY THE LAST
PLACES TO BE RID OF THE LOW CLOUDS. EVEN HERE...EXPECT CLEARING
BEFORE THE SUN SETS...BUT THE DAY ENDED UP A LOT GRAYER THAN HOPED
THANKS TO WEAKER AND SLOWER MIXING THAN ANTICIPATED.

THE CLEARING WILL BE SHORTLIVED AS MID TO HIGH CLOUDS INCREASE
QUICKLY OVERNIGHT...AND MORE IMPORTANTLY A DEEP FETCH OF ATALANTIC
MOISTURE WILL ARRIVE ON A DEEP EASTERLY FETCH BRINGING A CHANCE OF
PATCHY LIGHT RAIN AND DRIZZLE TO SOUTHERN BORDER AREAS BY DAWN ON
MONDAY.

WITH MUCH OF THE NIGHT SEEING ONLY MID TO HIGH CLOUD COVER STATEWIDE...
IT WILL GET COLD...LAND EXPECT MINS TO RANGE THROUGH THE 30S
CENTRAL AND NORTH TO AROUND 40 OVER MY SOUTHEAST COUNTIES. STAYED
FAIRLY CLOSE TO MOS BIAS CORRECTED NUMBERS FOR MINS.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
THE STORY REMAINS THE SAME FOR MONDAY AS 1034+ MB SFC HIGH PUSHES
OFF THE NEW ENG COAST...DEVELOPING MOIST...EASTERLY FLOW OVR THE
MID ATLANTIC. STRATOCU WILL DRIFT NORTHWARD ALONG THE
APPALACHIANS WITH SOME PATCHY LIGHT RAIN AND DRIZZLE SPREADING
NORTHWARD AS WELL THROUGHOUT THE DAY. OVERALL VERY LITTLE QPF
EXPECTED WITH THIS SYSTEM...DESPITE THE DEEP EASTERLY FLOW.
HOWEVER...BY LATE MONDAY A BETTER CHANCE OF SOME MEASURABLE BUT
STILL OVERALL LIGHT RAIN WILL ARRIVE AS EASTERLY WIND AND PWAT
ANOMALIES SHIFT NORTH INTO PA. TEMPS WILL STRUGGLE TO RISE
THROUGH THE 40S TOMORROW WITH FAR SOUTHEAST SECTIONS PERHAPS
REACHING THE LOWER 50S.

&&

.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
MODELS HAVE MOISTURE MOVING IN FASTER ON MONDAY THAN WHAT I SAW
YESTERDAY. THIS IS SUPPORTED BY SATELLITE DATA ETC. SEE SHORT
TERM SECTION ABOVE FOR MORE DETAILS.

ON THE FLIP SIDE...TUESDAY LOOKS LESS OF A CHC OF RAIN...AND
THERE MAY BE SOME PARTIAL CLEARING IN THE AFTERNOON...MAINLY
WESTERN SECTIONS.

AS WAS THE CASE YESTERDAY...STILL A LOT OF VARIATION ON TIMING
OF FROPA ON WED AND THU. IT LOOKS LIKE FRONT MAY MOVE RATHER
FAST ON WED. HOWEVER...A WAVE IS NOW LIKELY TO FORM AND DEVELOP
THU NIGHT. AT THE CURRENT TIME...IT LOOKS LIKE WE WOULD BE TOO
FAR WEST AND SOUTH TO GET MUCH...BUT DID UP POPS SOME FOR THU
INTO FRIDAY. SOME MINOR AMTS OF SNOW POSSIBLE LATE THURSDAY
NIGHT INTO FRIDAY EVENING ACROSS THE MTS AND HIGHER ELEVATIONS
OF CENTRAL PA.

I DID EDGE TEMPS DOWN SOME FROM THU INTO SAT...MAINLY MAX
TEMPS.

IT STILL LOOKS LIKE THE FLOW WOULD BACK MORE TO THE WEST NEXT
SUNDAY...BRINGING A MODERATING TREND TO THE AREA.

OTHERWISE...OTHER THAN THE MINOR CHANGES NOTED ABOVE...LEFT
PACKAGE CLOSE TO WHAT WE HAD.

WITH THE TENDENCY FOR A WESTERN RIDGE AND A WEAK NEGATIVE NAO...
A TREND TO COOLER CONDITIONS LIKELY OVERALL. NOT SO CLEAR CUT
ON STORM POTENTIAL ETC.

&&

.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
MVFR CIGS DISSIPATING FINALLY OVER THE CENTRAL MOUNTAIN REGION
THIS EVENING...FOLLOWED BY MOSTLY VFR MID TO LATE AS HIGH CLOUDS
STREAM NORTHWARD FROM ADVANCING MID ATLANTIC/CENTRAL APPALACHIAN
WEATHER SYSTEM

FLOW TURNS SE LATE THIS EVENING...AND MOISTURE WILL QUICKLY RETURN
OVERNIGHT IN THE FORM OF AN EXPANDING MVFR STRATOCU DECK FROM S TO
N. BY 12Z CLOUDS WILL LIKELY LOWER TO IFR ACROSS SOUTHERN TIER.
FORCING REMAINS LIGHT...BUT COULD EVEN SEE SOME PATCHY DRIZZLE
/MAINLY AROUND KJST-KAOO/ BY 12Z.

STARTING MONDAY...THE REGION WILL BE IN FOR AN EXTENDED PERIOD OF
POOR FLYING CONDITIONS.

OUTLOOK...
MON...MVFR LCL IFR. PSBL SHRA IN THE AFTN.
TUE...MVFR/IFR CIGS. SHRA IN THE AM.
WED...MVFR TO VFR.
THU-FRI...MVFR WITH CHC -SHRASN.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...DEVOIR
NEAR TERM...DEVOIR
SHORT TERM...DEVOIR
LONG TERM...MARTIN
AVIATION...DEVOIR/RXR

000
FXUS61 KCTP 221928
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
228 PM EST SUN NOV 22 2009

.SYNOPSIS...
AN ANOMALOUS STRONG UPPER RIDGE WILL DOMINATE OUR WEATHER THROUGH
MID-WEEK. THEN A SERIES OF WAVES WILL CARVE OUT A TROUGH OVER
EASTERN NORTH AMERICA BEGINNING ABOUT THANKSGIVING. THE STRONG
TROUGH WHICH DEVELOPS BY THE WEEKEND AND THE RIDGE OVER WESTERN
NORTH AMERICA. IT WILL TURN COLDER AROUND THANKSGIVING.

&&

.NEAR TERM /THROUGH TONIGHT/...
GREATER THAN 65% OF CENTRAL PA HAS BROKEN INTO THE CLEARING WITH
THE CENTRAL MOUNTAIN REGION AND MIDDLE SUSQ. RIVER VALLEY THE LAST
PLACES TO BE RID OF THE LOW CLOUDS. EVEN HERE...EXPECT CLEARING
BEFORE THE SUN SETS...BUT THE DAY ENDED UP A LOT GRAYER THAN HOPED
THANKS TO WEAKER AND SLOWER MIXING THAN ANTICIPATED.

THE CLEARING WILL BE SHORTLIVED AS MID TO HIGH CLOUDS INCREASE
QUICKLY OVERNIGHT...AND MORE IMPORTANTLY A DEEP FETCH OF ATALANTIC
MOISTURE WILL ARRIVE ON A DEEP EASTERLY FETCH BRINGING A CHANCE OF
PATCHY LIGHT RAIN AND DRIZZLE TO SOUTHERN BORDER AREAS BY DAWN ON
MONDAY.

WITH MUCH OF THE NIGHT SEEING ONLY MID TO HIGH CLOUD COVER STATEWIDE...
IT WILL GET COLD...LAND EXPECT MINS TO RANGE THROUGH THE 30S
CENTRAL AND NORTH TO AROUND 40 OVER MY SOUTHEAST COUNTIES. STAYED
FAIRLY CLOSE TO MOS BIAS CORRECTED NUMBERS FOR MINS.

&&

.SHORT TERM /MONDAY/...
THE STORY REMAINS THE SAME FOR MONDAY AS 1034+ MB SFC HIGH PUSHES
OFF THE NEW ENG COAST...DEVELOPING MOIST...EASTERLY FLOW OVR THE
MID ATLANTIC. STRATOCU WILL DRIFT NORTHWARD ALONG THE
APPALACHIANS WITH SOME PATCHY LIGHT RAIN AND DRIZZLE SPREADING
NORTHWARD AS WELL THROUGHOUT THE DAY. OVERALL VERY LITTLE QPF
EXPECTED WITH THIS SYSTEM...DESPITE THE DEEP EASTERLY FLOW.
HOWEVER...BY LATE MONDAY A BETTER CHANCE OF SOME MEASURABLE BUT
STILL OVERALL LIGHT RAIN WILL ARRIVE AS EASTERLY WIND AND PWAT
ANOMALIES SHIFT NORTH INTO PA. TEMPS WILL STRUGGLE TO RISE
THROUGH THE 40S TOMORROW WITH FAR SOUTHEAST SECTIONS PERHAPS
REACHING THE LOWER 50S.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
HAVE INCREASED POPS FOR THE MON NITE/EARLY TUESDAY TIMEFRAME TO
COINCIDE WITH PASSAGE OF SHORTWAVE AND ANOMALOUS PWATS. RIDGING AT
SFC AND ALOFT SUPPORTS A LULL IN THE PRECIP TUE NITE. HOWEVER...A
SERIES OF SHORTWAVES WILL BEGIN DIGGING OUT A DEEP TROF OVR THE
MIDWEST DURING THE SECOND HALF OF THE WEEK. WED/THU APPEAR
UNSETTLED/SHOWERY AHEAD OF THIS FEATURE. HOWEVER...EXACT TIMING OF TROF
REMAINS UNCERTAIN...SO WILL KEEP POPS IN THE CHC CATEGORY FOR NOW.

AS ANOMALOUS TROF MOVES OVR THE NORTHEAST CONUS...LAKE EFFECT SNOW
SHWRS LOOKING MORE LIKELY FOR FRI/SAT. 500MB TRAJECTORIES SUGGEST
LATE WEEK AIR MASS WILL BE A MIX OF PACIFIC AND POLAR...SO ONLY
SEASONABLE CHILL EXPECTED. GEFS MEAN 850 TEMPS ARND -6C SUGGEST
HIGHS FRI/SAT FROM U30S MTNS TO M40S SUSQ VALLEY.

&&

.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
MVFR CIGS DISSIPATING FINALLY OVER THE CENTRAL MOUNTAIN REGION
THIS EVENING...FOLLOWED BY MOSTLY VFR MID TO LATE AS HIGH CLOUDS
STREAM NORTHWARD FROM ADVANCING MID ATLANTIC/CENTRAL APPALACHIAN
WEATHER SYSTEM

FLOW TURNS SE LATE THIS EVENING...AND MOISTURE WILL QUICKLY RETURN
OVERNIGHT IN THE FORM OF AN EXPANDING MVFR STRATOCU DECK FROM S TO
N. BY 12Z CLOUDS WILL LIKELY LOWER TO IFR ACROSS SOUTHERN TIER.
FORCING REMAINS LIGHT...BUT COULD EVEN SEE SOME PATCHY DRIZZLE
/MAINLY AROUND KJST-KAOO/ BY 12Z.

STARTING MONDAY...THE REGION WILL BE IN FOR AN EXTENDED PERIOD OF
POOR FLYING CONDITIONS.

OUTLOOK...
MON...MVFR LCL IFR. PSBL SHRA IN THE AFTN.
TUE...MVFR/IFR CIGS. SHRA IN THE AM.
WED...MVFR TO VFR.
THU-FRI...MVFR WITH CHC -SHRASN.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...DEVOIR
NEAR TERM...DEVOIR
SHORT TERM...DEVOIR
LONG TERM...FITZGERALD/MARTIN
AVIATION...DEVOIR/RXR

000
FXUS61 KPBZ 221715
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
1215 PM EST SUN NOV 22 2009

.SYNOPSIS...
HIGH PRESSURE MOVING TO NEW ENGLAND TODAY WILL BRING SUNSHINE THIS
AFTERNOON TO THE UPPER OHIO VALLEY. LOW PRESSURE MOVING TOWARD
THE MID ATLANTIC COAST WILL BRING THE CHANCE FOR SHOWERS LATER
MONDAY INTO EARLY TUESDAY BEFORE MOVING EAST. DEEPENING LOW
PRESSURE MOVING INTO THE GREAT LAKES WILL BRING COLDER
TEMPERATURES AND RAIN AND SNOW SHOWERS INTO THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
WITH SATELLITE IMAGERY, IMAGES SHOWING STRATOCUMULUS CLOUDS
DISSIPATING...EXPECT MOSTLY SUNNY SKIES ACROSS THE UPPER OHIO
VALLEY THIS AFTERNOON. TEMPERATURES ADJUSTED SLIGHTLY LOWER BASED
ON RECENT SURFACE DATA AND RUC OUTPUT.

CONTINUE TO EXPECT CLOUDS TO INCREASE LATE TONIGHT FROM SYSTEM
COMING FROM THE SOUTH.

&&

.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
MAJOR CHANGE TO FORECAST IS INCREASE IN POPS ACROSS ENTIRE CWA
MONDAY INTO EARLY TUESDAY AS SHORTWAVES MOVE ACROSS THE
APPALACHIANS TO THE MID ATLANTIC WITH LOW PRESSURE MOVING
OFFSHORE. MODEL POPS IN THE LIKELY RANGE BUT WILL NOT GO THAT FAR
WITH HIGH CHANCE POPS SOUTH AND CHANCE NORTH. LEFTOVER SHOWERS
EARLY TUESDAY AS SYSTEM EXITS EAST WITH A DRY PERIOD LATER TUESDAY
INTO TUESDAY EVENING. BY LATER TUESDAY NIGHT CLOSED LOW WILL BE
APPROACHING LOWER OHIO VALLEY WITH CLOUDS AND SHOWERS INTO
WEDNESDAY. TEMPERATURES WILL CONTINUE TO AVERAGE ABOVE NORMAL INTO
WEDNESDAY.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
DEEP AND COLD CLOSED LOW WILL AFFECT THE REGION THROUGH THE PERIOD
AS IT MOVES EAST ACROSS THE OHIO VALLEY TO THE EAST COAST. MODEL
THICKNESS STILL SHOWS TEMPERATURES TO BE WARM ENOUGH FOR ALL RAIN
WEDNESDAY NIGHT AND THURSDAY THEN LOWER FOR A CHANGE OVER TO SNOW
SHOWERS THURSDAY NIGHT AND A MIX FOR FRIDAY. LEFT SATURDAY DRY FOR
NOW BUT NEW RUN OF ECMWF AGREES WITH GFS FOR SNOW SHOWERS IN
NORTHWEST FLOW. WILL LET DAY SHIFT REEVALUATE SNOW CHANCES FOR THE
WEEKEND. TEMPERATURES WILL FALL WELL BELOW NORMAL FOR LATE WEEK
INTO THE WEEKEND AND MEX MOS MAY NOT BE COLD ENOUGH BASED ON MODEL THICKNESS
AND 850MB TEMPS.

&&

.AVIATION /17Z SUNDAY THROUGH THURSDAY/...
MVFR CEILINGS WILL FINALLY BEGIN TO BREAK BY LATE MORNING
EVERYWHERE EXCEPT KFKL/KDUJ WHERE CIGS WILL CONTINUE TO PREVAIL
INTO THIS AFTERNOON. WITH RIDGING ALOFT CENTERED ACROSS THE
AREA...VFR CONDITIONS WITH PREVAIL THROUGH SUNDAY NIGHT.

A LOW PRESSURE SYSTEM MOVING UP THE EAST COAST ON MONDAY WILL
BRING THE NEXT CHANCE FOR SHOWERS WITH REDUCED CEILINGS
EXPECTED...ESPECIALLY ALONG AND EAST OF A KMGW-KDUJ LINE. A LOW
PRESSURE SYSTEM ACROSS THE MISSOURI VALLEY WILL DEVELOP ON
TUESDAY...STRENGTHENING AS IT MOVES INTO THE GREAT LAKES BY
WEDNESDAY. THIS SYSTEM AND ITS ASSOCIATED COLD FRONT WILL RETURN
THE CHANCE FOR REDUCED CEILINGS ACROSS THE AREA TUESDAY THROUGH
THURSDAY.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.

&&

$$

000
FXUS61 KPHI 221615
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1115 AM EST SUN NOV 22 2009

.SYNOPSIS...
HIGH PRESSURE OVER SOUTHERN QUEBEC WILL STRENGTHEN AND MOVE TO
THE CANADIAN MARITIMES BY MONDAY MORNING AND THEN RECEDE EAST.
FAIRLY WEAK LOW PRESSURE DEVELOPING NEAR THE GULF COAST WILL MOVE
OFF THE SOUTHEAST COAST BY MONDAY MORNING AND THEN LIFT NORTHEAST.
THE LOW WILL PASS BY TO OUR EAST ON TUESDAY. A COLD FRONT FROM THE
WEST IS EXPECTED TO ARRIVE ON THURSDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HIGH PRESSURE WAS CENTERED IN SOUTHERN QUEBEC THIS MORNING AND IT
WILL DRIFT TO THE EAST. A SURFACE RIDGE WAS CONTINUING TO POKE
DOWN THE EAST COAST. THE RESULTING SURFACE CIRCULATION HAS CAUSED
A NORTH TO NORTHEAST WIND TO DEVELOP ALONG THE COAST.

A PATCH OF STRATOCUMULUS REMAINED OVER OUR SOUTHEASTERN COUNTIES
LATE THIS MORNING. WE EXPECT THE CLOUDS TO DISSIPATE A BIT DURING
THE AFTERNOON.

MEANWHILE, THE MASS OF CLOUDS TO OUR NORTHWEST SHOULD BEGIN TO
RECEDE THIS AFTERNOON.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
THE MID LEVEL REX BLOCK IS PROGGED BY ALL MODELS TO BEGIN TO
WEAKEN AND LIFT AWAY TONIGHT. STILL, IT IS THIS FEATURE THAT MAKES
US CONTINUE TO KEEP OUR SECOND PERIOD FORECAST MAINLY DRY WITH
ONLY SOME SLIGHT CHANCE POPS SOUTH. THE SURFACE FLOW STARTS TO
VEER JUST A LITTLE AND STRENGTHEN A BIT MORE, PERHAPS ENOUGH TO BRING
IN SOME LOWER LEVEL MOISTURE AND LOW CLOUDS. CERTAINLY, MID AND
HIGH LEVEL CLOUDS WILL BE ON THE INCREASE AS THE MID LEVEL WEAK
RIDGE AXIS UPSTREAM OF THE BLOCK WEAKENS FURTHER. GUIDANCE AND
CONTINUITY WERE ALL PRETTY CLOSE ON MINS AND WERE FOLLOWED.

ON MONDAY AND MONDAY NIGHT, WE START TO SEE AND THEN DO SEE
INGREDIENTS FOR RAIN COME TOGETHER OVER AT LEAST THE EASTERN PART
OF THE FORECAST AREA. IT SHOULD BE NOTED THAT THE NAM PUSHES
EVERYTHING A BIT FURTHER TO THE WEST THAN THE ECMWF DOES DESPITE
THEIR GOOD AGREEMENT ON THE SURFACE AND H5 FORECASTS. THEY BOTH
HAVE Q-VECTOR CONVERGENCE AND FRONTOGENESIS WITH DECENT ISENTROPIC
LIFT AND THETA-E ADVECTION, BUT THE ECMWF WANTS ALL THIS MORE
FOCUSED NEAR THE COAST AND OVER THE OPEN WATER THAN THE NAM. SINCE
THE MAV POPS WERE LOWER THAN THE MET POPS, WE HAVE COME DOWN IN
BETWEEN THE TWO TO REFLECT THE POSSIBILITY THAT THE NAM IS TOO FAR
WEST WITH THE ACTION. IN PARTING DEFERENCE TO THE LIFTING AND
WEAKENING REX BLOCK, WE START THE DAY WITH ONLY SLIGHT CHANCE
POPS NEAR AND NORTHWEST OF THE I-95 CORRIDOR AND THEN INCREASE
THEM IN THE AFTERNOON. FURTHER SOUTHEAST, WE START WITH CHANCE POPS
AND THEN INCREASE THEM. AM NOT SEEING ANY SIGNS OF INSTABILITY
WITH THIS SYSTEM OVER OUR AREA, SO HAVE NOT HIT THE QPF VALUES VERY
HARD.

OUR MAX TEMPERATURES ON MONDAY ARE A BLEND OF CONTINUITY AND THE
MEAN OF THE DISPARATE STAT GUIDANCE, PERHAPS LEANING A BIT ON THE
MILD SIDE WHERE PRECIPITATION IS LESS LIKELY OR WILL START LAST
AND ON THE COOLER SIDE FURTHER SOUTHEAST. OUR MIN TEMPS FOR MONDAY
NIGHT TRY TO SHRINK THE DIURNAL OSCILLATION. FOR NOW, WE HAVE
DISREGARDED THE POSSIBILITY THAT WARMER AIR RIDING OVER THE
SURFACE WILL MAKE IT DOWN.

THERE SHOULD BE A DECENT NORTHEAST WIND THANKS TO THE GRADIENT
BETWEEN THE RECEDING HIGH AND THE ADVANCING LOW, BUT NOT THE SAME
IN STRENGTH OR PERSISTENCE AS THE ONE WE EXPERIENCED JUST AFTER
VETERAN`S DAY.

MODELS SOUNDINGS SHOW TRAPPED MOISTURE AND THE HINT OF A TRAILING
WAVE FOR TUESDAY, AND SO WE CONTINUE WITH THE CHANCE OF
PRECIPITATION. WE TRY TO CARVE OUT SOME SORT OF BREAK ON TUESDAY
NIGHT. WE SHOULD SEE THE WINDS BEGIN TO DECREASE ON TUESDAY AND
CONTINUE TO DO SO ON TUESDAY NIGHT. TEMPERATURES WERE A BLEND OF
GUIDANCE AND CONTINUITY.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
ALL MODELS AGREE THAT A SIGNIFICANT CHANGE IN THE PATTERN OCCURS
DURING THE END OF THE WEEK. WE START OFF WITH A BROAD SW FLOW ON
THE EASTERN PORTION OF A MIDWEST TROUGH ON TUESDAY
NIGHT...EVENTUALLY THE MIDWEST TROUGH MOVES EAST, BUT DEEPENS AS
IT HEADS EAST. THE UPPER TROUGH THEN BECOMES CLOSED OFF AS IT
MOVES THROUGH THE REGION.

THIS MEANS THAT WE HAVE QUITE A BIT OF CLOUDS AND POSSIBLE
SHOWERS LATE TUESDAY NIGHT AND WEDNESDAY DUE TO MOISTURE SPREADING
OVER THE REGION WITHIN THE SW FLOW ALOFT. WEDNESDAY NIGHT THROUGH
THANKSGIVING AND INTO THURSDAY NIGHT, WE COULD SEE RAIN AS A
FRONTAL SYSTEM ASSOCIATED WITH THE UPPER TROUGH MOVES THROUGH FROM
THE WEST. THEN ON FRIDAY, COOLER DRIER AIR ARRIVES, BUT WE STILL
COULD HAVE RAIN SHOWERS WITH THE CYCLONIC FLOW ALOFT. FRIDAY NIGHT
AND SATURDAY, IT GETS COLD ENOUGH THAT SOME SNOW SHOWERS ARE
POSSIBLE NORTH, BUT THE REST OF THE AREA SHOULD BE DRY WITH
DOWNSLOPE NW FLOW. ALSO ON SATURDAY, IT SHOULD BE BREEZY/WINDY
WITH THE NW FLOW.

HPC PROGS HAVE THE SITUATION WELL IN HAND AND IN GENERAL THEIR
GUIDANCE HAS BEEN FOLLOWED.

&&

.AVIATION /16Z SUNDAY THROUGH THURSDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.

SURFACE HIGH PRESSURE OVER SOUTHEASTERN CANADA WILL MOVE
NORTHEASTWARD. THE UPPER TROUGH FROM NEW ENGLAND TO THE OHIO
VALLEY ABOVE THE SURFACE HIGH WAS MOVING EAST-SOUTHEASTWARD...AND
THE BETTER FLOW TO THE SOUTHEAST OF THE TROUGH WAS WHERE THE HIGH
CLOUDS HAD BEEN GENERATED YESTERDAY. THESE MOVED OFF EARLY
SATURDAY NIGHT. THIS SET-UP WAS LEAVING OUR REGION IN A CLOUD-FREE
AREA THIS MORNING...EXCEPT FOR AN AREA OF STRATOCUMULUS AROUND
KACY AND KMIV WHICH SHOULD DISSIPATE A BIT FOR THIS AFTERNOON.

AS THE LOW LEVEL FLOW VEERS FROM NORTH TO NORTHEAST TODAY...THE
ONSHORE FLOW WILL BRING IN MOISTURE TONIGHT. MOS GUIDANCE IS IN
AGREEMENT ON BRINGING IN LOW CLOUDS OVERNIGHT...WITH THE NAM MOS
BEING MORE PESSIMISTIC THAN THE GFS. FOR NOW, CEILINGS WILL BE
LOWERED TO MARGINAL VFR IN THE AREA OF MIDNIGHT, WITH JUST A MENTION
OF SCATTERED 8 HUNDRED AND LOW MARGINAL VFR OVERCAST FOR THE LATE
NIGHT PERIOD AND TOWARD MONDAY MORNING. SOUTHERN TAF SITES MAY STAND
A SMALL CHANCE OF RAIN OVERNIGHT...BUT WITH SUCH A SMALL CHANCE, AND
VISIBILITIES LIKELY NOT BEING AFFECTED, THIS WILL BE LEFT OUT OF THE
KMIV, KACY, AND KILG TAFS FOR NOW.

OUTLOOK...
MONDAY SHOULD BE THE TIME PERIOD WHEN CEILINGS ARE MARGINAL VFR TO
EVEN IFR IN DEVELOPING RAIN, AS LOW PRESSURE LIFTS SLOWLY OFF THE
MID ATLANTIC COAST. THE LOW WILL LINGER IN OUR AREA INTO OR POSSIBLY
THROUGH TUESDAY...WITH UNSETTLED CONDITIONS LOITERING WEDNESDAY AS
WELL.

&&

.MARINE...
SURFACE HIGH PRESSURE OVER THE EASTERN GREAT LAKES AND SOUTHEASTERN
CANADA WILL MOVE NORTHEASTWARD MORE FULLY INTO SOUTHEASTERN CANADA
THIS MORNING. AS LOW PRESSURE DEVELOPS OFF THE U.S. EAST COAST AND
LIFTS NORTHWARD TODAY...A BETTER GRADIENT BETWEEN THE LOW TO THE
SOUTH AND THE HIGH TO THE NORTH WILL FORM OVER OUR AREA DURING THIS
AFTERNOON AND BE IN PLACE TONIGHT AND MONDAY, AND PERHAPS INTO
TUESDAY AS WELL. IF THE NAM PRESSURE PATTERN TURNS OUT TO A BETTER
SOLUTION THAN THE GFS, WHICH SHOWS THE LOW CLOSER TO THE COAST ALONG
WITH A STRONGER GRADIENT, THEN WINDS AND GUSTS MAY BE A BIT STRONGER
THAN SMALL CRAFT ADVISORY TERRITORY. THE 00Z ECMWF SEEMS TO BE MORE
IN LINE WITH THE 00Z GFS, AND NOT AS PRONOUNCED AS THE NAM WHICH
APPARENTLY HAS OVERCOOKED THE TROUGH ALOFT. FOR NOW, THE SMALL CRAFT
ADVISORY THAT WILL BE COMING INTO EFFECT SOUTH THIS AFTERNOON AND
NORTH THIS EVENING, AND WHICH CURRENTLY EXTENDS THROUGH MONDAY, WILL
BE STRETCHED THROUGH MONDAY NIGHT. ADVISORY LEVEL SEAS, AND MAYBE
WINDS, COULD BE IN EFFECT FOR A GOOD PART OF THIS WEEK AS THERE ARE
SEVERAL LOWS WHICH LOOK TO IMPACT OUR AREA. PRESENTLY, CONDITIONS
ARE NOT FORECAST TO REACH ADVISORY LEVELS OVER DELAWARE BAY.
HOWEVER, THE FORECAST WILL BE BROUGHT TO NEAR ADVISORY TERRITORY
THERE, AND FUTURE FORECASTERS MAY NEED TO FOLD AT LEAST LOWER
DELAWARE BAY INTO THE ADVISORY IF CONDITIONS ARE A BIT STRONGER THAN
FORECAST.

&&

.TIDES/COASTAL FLOODING...
A PERSISTENT NORTHEAST FLOW OVER THE NEXT SEVERAL DAYS WILL CAUSE
ABOVE NORMAL WATER LEVELS. AS LOW PRESSURE LIFTS NORTHWARD ALONG THE
MID ATLANTIC COAST, A FRESH ONSHORE FLOW STARTING TONIGHT AND
PERSISTING AT LEAST INTO TUESDAY WILL BEAR WATCHING. AVIATION STORM
SURGE GUIDANCE IS NOT CREATING DRAMATIC EFFECTS, BUT IT MAY BE
UNDERDONE AS IT ONLY BRINGS ANOMALIES OF A HALF FOOT ABOVE NORMAL.
TIDE LEVELS MAY BE MORE LIKE 1.0 TO 1.5 FEET ABOVE NORMAL, AND, WITH
RECENT SEVERE BEACH EROSION, THIS MAY CAUSE SOME PROBLEMS IN A FEW
AREAS. IF CONFIDENCE BUILDS IN THIS SCENARIO, SOME TYPE OF COASTAL
PRODUCT MAY NEED TO BE ISSUED ON TODAY`S DAY SHIFT. FOR NOW,
THE SITUATION WILL CONTINUE TO BE MONITORED.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST TUESDAY FOR ANZ452>455.
     SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 6 AM EST
     TUESDAY FOR ANZ450-451.

&&

$$

SYNOPSIS...DELISI
NEAR TERM...IOVINO
SHORT TERM...DELISI
LONG TERM...STAUBER

000
FXUS61 KCTP 221546
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1046 AM EST SUN NOV 22 2009

.SYNOPSIS...
AN ANOMALOUS STRONG UPPER RIDGE WILL DOMINATE OUR WEATHER THROUGH
MID-WEEK. THEN A SERIES OF WAVES WILL CARVE OUT A TROUGH OVER
EASTERN NORTH AMERICA BEGINNING ABOUT THANKSGIVING. THE STRONG
TROUGH WHICH DEVELOPS BY THE WEEKEND AND THE RIDGE OVER WESTERN
NORTH AMERICA. IT WILL TURN COLDER AROUND THANKSGIVING.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LARGE SCALE SUBSIDENCE HELPING TO ERODE THE SHALLOW ~1K FOOT
INVERSION AND STRATO-CU DECK ACROSS CENTRAL...WESTERN AND NORTHERN
PORTIONS OF MY AREA. THIS IS SLOWER THAN FORECAST...SO DID ADJUST
THE SKY GRIDS INTO EARLY THIS AFTERNOON. EASTERLY FLOW AND
ASSOCIATED OROGRAPHIC UPLIFT OVR THE LAURELS WILL MAKE THEM THE
LAST TO COMPLETELY CLEAR.

MODEL 900MB TEMPS STILL SUPPORT A FAIRLY MILD DAY. SUNSHINE WILL
HELP TEMPS REACH THE LOWER TO MIDDLE 50S ACROSS MUCH OF THE
CENTRAL AND SOUTH WITH HIGHS AROUND 50 IN THE NORTH.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
AS SFC HIGH PUSHES OFF THE NEW ENG COAST...DEVELOPING MOIST...EASTERLY
FLOW OVR THE MID ATLANTIC WILL LIKELY RESULT IN STRATOCU CREEPING
NORTHWRD ALONG THE APPALACHIANS. THE NCEP ENSEMBLES SUGGEST THAT
A BIT OF LGT RAIN/DZ MAY DEVELOP AS EARLY AS 12Z MONDAY OVR THE
SC MTNS. HOWEVER...LATEST SREF INDICATES A BETTER CHC OF RAIN
ACROSS SOUTHERN PA BY LATE MONDAY...AS EASTERLY WIND AND PWAT ANOMALIES
SHIFT NORTH INTO PA. LG SCALE/QG FORCING REMAINS WEAK THROUGH
MONDAY...SUPPORTING IDEA OF VERY LIGHT QPF.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
HAVE INCREASED POPS FOR THE MON NITE/EARLY TUESDAY TIMEFRAME TO
COINCIDE WITH PASSAGE OF SHORTWAVE AND ANOMALOUS PWATS. RIDGING AT
SFC AND ALOFT SUPPORTS A LULL IN THE PRECIP TUE NITE. HOWEVER...A
SERIES OF SHORTWAVES WILL BEGIN DIGGING OUT A DEEP TROF OVR THE
MIDWEST DURING THE SECOND HALF OF THE WEEK. WED/THU APPEAR
UNSETTLED/SHOWERY AHEAD OF THIS FEATURE. HOWEVER...EXACT TIMING OF TROF
REMAINS UNCERTAIN...SO WILL KEEP POPS IN THE CHC CATEGORY FOR NOW.

AS ANOMALOUS TROF MOVES OVR THE NORTHEAST CONUS...LAKE EFFECT SNOW
SHWRS LOOKING MORE LIKELY FOR FRI/SAT. 500MB TRAJECTORIES SUGGEST
LATE WEEK AIR MASS WILL BE A MIX OF PACIFIC AND POLAR...SO ONLY
SEASONABLE CHILL EXPECTED. GEFS MEAN 850 TEMPS ARND -6C SUGGEST
HIGHS FRI/SAT FROM U30S MTNS TO M40S SUSQ VALLEY.

&&

.AVIATION /16Z SUNDAY THROUGH THURSDAY/...
MVFR/IFR STRATOCU DECK WILL HANG ON ACROSS MUCH OF CENTRAL PA
/EXCEPT LOWER SUSQ/ THROUGH MID MORNING BEFORE RAPIDLY
DIMINISHING. LOWER SUSQ WILL HAVE SHORT-LIVED LIGHT FOG THIS
MORNING WITH A QUICK RETURN TO VFR CONDITIONS.

FLOW TURNS SE THROUGH THE DAY AND EVENING...AND MOISTURE WILL
QUICKLY RETURN OVERNIGHT IN THE FORM OF AN EXPANDING MVFR STRATOCU
DECK FROM S TO N. BY 12Z CLOUDS WILL LIKELY LOWER TO IFR ACROSS
SOUTHERN TIER. FORCING REMAINS LIGHT...BUT COULD EVEN SEE SOME
PATCHY DRIZZLE /MAINLY AROUND KJST-KAOO/ BY 12Z.

STARTING MONDAY...THE REGION WILL BE IN FOR AN EXTENDED PERIOD OF
POOR FLYING CONDITIONS.

OUTLOOK...
MON...MVFR LCL IFR. PSBL SHRA IN THE AFTN.
TUE...MVFR/IFR CIGS. SHRA IN THE AM.
WED...MVFR TO VFR.
THU...MVFR WITH CHC -SHRASN.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...GRUMM
NEAR TERM...DEVOIR/FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD/MARTIN
AVIATION...RXR

000
FXUS61 KPHI 221325
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
825 AM EST SUN NOV 22 2009

.SYNOPSIS...
HIGH PRESSURE OVER THE EASTERN GREAT LAKES REGION WILL STRENGTHEN
AND MOVE TO THE CANADIAN MARITIMES BY MONDAY MORNING AND THEN
RECEDE EAST. FAIRLY WEAK LOW PRESSURE DEVELOPING NEAR THE GULF
COAST WILL MOVE OFF THE SOUTHEAST COAST BY MONDAY MORNING AND THEN
LIFT NORTHEAST. THE LOW WILL PASS BY TO OUR EAST ON TUESDAY. A
COLD FRONT FROM THE WEST IS EXPECTED TO ARRIVE ON THURSDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HIGH PRESSURE WAS CENTERED IN SOUTHERN QUEBEC THIS MORNING AND IT
WILL DRIFT TO THE EAST. A SURFACE RIDGE WAS CONTINUING TO POKE
DOWN THE EAST COAST. THE RESULTING SURFACE CIRCULATION HAS CAUSED
A NORTH TO NORTHEAST WIND TO DEVELOP ALONG THE COAST.

A PATCH OF STRATOCUMULUS DEVELOPED OFF THE SOUTHERN NEW JERSEY AND
DELAWARE COAST EARLY THIS MORNING. AT 8:00 AM, THE CLOUDS WERE
CONTINUING TO MAKE THEIR WAY INLAND. WE HAVE ADDED SOME ADDITIONAL
CLOUD COVER TO THE FORECAST FOR EXTREME SOUTHERN NEW JERSEY AND
SOUTHEASTERN DELAWARE. HOWEVER, WE EXPECT THE CLOUDS TO BEGIN
DISSIPATING THIS MORNING.

MEANWHILE, THE MASS OF CLOUDS TO OUR NORTHWEST SHOULD BEGIN TO
RECEDE THIS MORNING. AS A RESULT, OUR NORTHERN COUNTIES WILL LIKELY
RECEIVE A GOOD AMOUNT OF SUNSHINE FOR TODAY.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
THE MID LEVEL REX BLOCK IS PROGGED BY ALL MODELS TO BEGIN TO
WEAKEN AND LIFT AWAY TONIGHT. STILL, IT IS THIS FEATURE THAT MAKES
US CONTINUE TO KEEP OUR SECOND PERIOD FORECAST MAINLY DRY WITH
ONLY SOME SLIGHT CHANCE POPS SOUTH. THE SURFACE FLOW STARTS TO
VEER JUST A LITTLE AND STRENGTHEN A BIT MORE, PERHAPS ENOUGH TO BRING
IN SOME LOWER LEVEL MOISTURE AND LOW CLOUDS. CERTAINLY, MID AND
HIGH LEVEL CLOUDS WILL BE ON THE INCREASE AS THE MID LEVEL WEAK
RIDGE AXIS UPSTREAM OF THE BLOCK WEAKENS FURTHER. GUIDANCE AND
CONTINUITY WERE ALL PRETTY CLOSE ON MINS AND WERE FOLLOWED.

ON MONDAY AND MONDAY NIGHT, WE START TO SEE AND THEN DO SEE
INGREDIENTS FOR RAIN COME TOGETHER OVER AT LEAST THE EASTERN PART
OF THE FORECAST AREA. IT SHOULD BE NOTED THAT THE NAM PUSHES
EVERYTHING A BIT FURTHER TO THE WEST THAN THE ECMWF DOES DESPITE
THEIR GOOD AGREEMENT ON THE SURFACE AND H5 FORECASTS. THEY BOTH
HAVE Q-VECTOR CONVERGENCE AND FRONTOGENESIS WITH DECENT ISENTROPIC
LIFT AND THETA-E ADVECTION, BUT THE ECMWF WANTS ALL THIS MORE
FOCUSED NEAR THE COAST AND OVER THE OPEN WATER THAN THE NAM. SINCE
THE MAV POPS WERE LOWER THAN THE MET POPS, WE HAVE COME DOWN IN
BETWEEN THE TWO TO REFLECT THE POSSIBILITY THAT THE NAM IS TOO FAR
WEST WITH THE ACTION. IN PARTING DEFERENCE TO THE LIFTING AND
WEAKENING REX BLOCK, WE START THE DAY WITH ONLY SLIGHT CHANCE
POPS NEAR AND NORTHWEST OF THE I-95 CORRIDOR AND THEN INCREASE
THEM IN THE AFTERNOON. FURTHER SOUTHEAST, WE START WITH CHANCE POPS
AND THEN INCREASE THEM. AM NOT SEEING ANY SIGNS OF INSTABILITY
WITH THIS SYSTEM OVER OUR AREA, SO HAVE NOT HIT THE QPF VALUES VERY
HARD.

OUR MAX TEMPERATURES ON MONDAY ARE A BLEND OF CONTINUITY AND THE
MEAN OF THE DISPARATE STAT GUIDANCE, PERHAPS LEANING A BIT ON THE
MILD SIDE WHERE PRECIPITATION IS LESS LIKELY OR WILL START LAST
AND ON THE COOLER SIDE FURTHER SOUTHEAST. OUR MIN TEMPS FOR MONDAY
NIGHT TRY TO SHRINK THE DIURNAL OSCILLATION. FOR NOW, WE HAVE
DISREGARDED THE POSSIBILITY THAT WARMER AIR RIDING OVER THE
SURFACE WILL MAKE IT DOWN.

THERE SHOULD BE A DECENT NORTHEAST WIND THANKS TO THE GRADIENT
BETWEEN THE RECEDING HIGH AND THE ADVANCING LOW, BUT NOT THE SAME
IN STRENGTH OR PERSISTENCE AS THE ONE WE EXPERIENCED JUST AFTER
VETERAN`S DAY.

MODELS SOUNDINGS SHOW TRAPPED MOISTURE AND THE HINT OF A TRAILING
WAVE FOR TUESDAY, AND SO WE CONTINUE WITH THE CHANCE OF
PRECIPITATION. WE TRY TO CARVE OUT SOME SORT OF BREAK ON TUESDAY
NIGHT. WE SHOULD SEE THE WINDS BEGIN TO DECREASE ON TUESDAY AND
CONTINUE TO DO SO ON TUESDAY NIGHT. TEMPERATURES WERE A BLEND OF
GUIDANCE AND CONTINUITY.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
ALL MODELS AGREE THAT A SIGNIFICANT CHANGE IN THE PATTERN OCCURS
DURING THE END OF THE WEEK. WE START OFF WITH A BROAD SW FLOW ON
THE EASTERN PORTION OF A MIDWEST TROUGH ON TUESDAY
NIGHT...EVENTUALLY THE MIDWEST TROUGH MOVES EAST, BUT DEEPENS AS
IT HEADS EAST. THE UPPER TROUGH THEN BECOMES CLOSED OFF AS IT
MOVES THROUGH THE REGION.

THIS MEANS THAT WE HAVE QUITE A BIT OF CLOUDS AND POSSIBLE
SHOWERS LATE TUESDAY NIGHT AND WEDNESDAY DUE TO MOISTURE SPREADING
OVER THE REGION WITHIN THE SW FLOW ALOFT. WEDNESDAY NIGHT THROUGH
THANKSGIVING AND INTO THURSDAY NIGHT, WE COULD SEE RAIN AS A
FRONTAL SYSTEM ASSOCIATED WITH THE UPPER TROUGH MOVES THROUGH FROM
THE WEST. THEN ON FRIDAY, COOLER DRIER AIR ARRIVES, BUT WE STILL
COULD HAVE RAIN SHOWERS WITH THE CYCLONIC FLOW ALOFT. FRIDAY NIGHT
AND SATURDAY, IT GETS COLD ENOUGH THAT SOME SNOW SHOWERS ARE
POSSIBLE NORTH, BUT THE REST OF THE AREA SHOULD BE DRY WITH
DOWNSLOPE NW FLOW. ALSO ON SATURDAY, IT SHOULD BE BREEZY/WINDY
WITH THE NW FLOW.

HPC PROGS HAVE THE SITUATION WELL IN HAND AND IN GENERAL THEIR
GUIDANCE HAS BEEN FOLLOWED.

&&

.AVIATION /13Z SUNDAY THROUGH THURSDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.

SURFACE HIGH PRESSURE OVER THE EASTERN GREAT LAKES AND SOUTHEASTERN
CANADA WILL MOVE NORTHEASTWARD MORE FULLY INTO SOUTHEASTERN CANADA
THIS MORNING. THE UPPER TROUGH FROM NEW ENGLAND TO THE OHIO VALLEY
ABOVE THE SURFACE HIGH WAS MOVING EAST-SOUTHEASTWARD...AND THE
BETTER FLOW TO THE SOUTHEAST OF THE TROUGH WAS WHERE THE HIGH CLOUDS
HAD BEEN GENERATED YESTERDAY. THESE MOVED OFF EARLY SATURDAY NIGHT.
THIS SET-UP WAS LEAVING OUR REGION IN A CLOUD-FREE AREA THIS
MORNING...EXCEPT FOR AN AREA OF STRATOCUMULUS AROUND KACY AND
KMIV WHICH SHOULD DISSIPATE FOR THIS AFTERNOON.

AS THE LOW LEVEL FLOW VEERS FROM NORTH TO NORTHEAST TODAY...THE
ONSHORE FLOW WILL BRING IN MOISTURE TONIGHT. MOS GUIDANCE IS IN
AGREEMENT ON BRINGING IN LOW CLOUDS OVERNIGHT...WITH THE NAM MOS
BEING MORE PESSIMISTIC THAN THE GFS. FOR NOW, CEILINGS WILL BE
LOWERED TO MARGINAL VFR IN THE AREA OF MIDNIGHT, WITH JUST A MENTION
OF SCATTERED 8 HUNDRED AND LOW MARGINAL VFR OVERCAST FOR THE LATE
NIGHT PERIOD AND TOWARD MONDAY MORNING. SOUTHERN TAF SITES MAY STAND
A SMALL CHANCE OF RAIN OVERNIGHT...BUT WITH SUCH A SMALL CHANCE, AND
VISIBILITIES LIKELY NOT BEING AFFECTED, THIS WILL BE LEFT OUT OF THE
KMIV, KACY, AND KILG TAFS FOR NOW.

OUTLOOK...
MONDAY SHOULD BE THE TIME PERIOD WHEN CEILINGS ARE MARGINAL VFR TO
EVEN IFR IN DEVELOPING RAIN, AS LOW PRESSURE LIFTS SLOWLY OFF THE
MID ATLANTIC COAST. THE LOW WILL LINGER IN OUR AREA INTO OR POSSIBLY
THROUGH TUESDAY...WITH UNSETTLED CONDITIONS LOITERING WEDNESDAY AS
WELL.

&&

.MARINE...
SURFACE HIGH PRESSURE OVER THE EASTERN GREAT LAKES AND SOUTHEASTERN
CANADA WILL MOVE NORTHEASTWARD MORE FULLY INTO SOUTHEASTERN CANADA
THIS MORNING. AS LOW PRESSURE DEVELOPS OFF THE U.S. EAST COAST AND
LIFTS NORTHWARD TODAY...A BETTER GRADIENT BETWEEN THE LOW TO THE
SOUTH AND THE HIGH TO THE NORTH WILL FORM OVER OUR AREA DURING THIS
AFTERNOON AND BE IN PLACE TONIGHT AND MONDAY, AND PERHAPS INTO
TUESDAY AS WELL. IF THE NAM PRESSURE PATTERN TURNS OUT TO A BETTER
SOLUTION THAN THE GFS, WHICH SHOWS THE LOW CLOSER TO THE COAST ALONG
WITH A STRONGER GRADIENT, THEN WINDS AND GUSTS MAY BE A BIT STRONGER
THAN SMALL CRAFT ADVISORY TERRITORY. THE 00Z ECMWF SEEMS TO BE MORE
IN LINE WITH THE 00Z GFS, AND NOT AS PRONOUNCED AS THE NAM WHICH
APPARENTLY HAS OVERCOOKED THE TROUGH ALOFT. FOR NOW, THE SMALL CRAFT
ADVISORY THAT WILL BE COMING INTO EFFECT SOUTH THIS AFTERNOON AND
NORTH THIS EVENING, AND WHICH CURRENTLY EXTENDS THROUGH MONDAY, WILL
BE STRETCHED THROUGH MONDAY NIGHT. ADVISORY LEVEL SEAS, AND MAYBE
WINDS, COULD BE IN EFFECT FOR A GOOD PART OF THIS WEEK AS THERE ARE
SEVERAL LOWS WHICH LOOK TO IMPACT OUR AREA. PRESENTLY, CONDITIONS
ARE NOT FORECAST TO REACH ADVISORY LEVELS OVER DELAWARE BAY.
HOWEVER, THE FORECAST WILL BE BROUGHT TO NEAR ADVISORY TERRITORY
THERE, AND FUTURE FORECASTERS MAY NEED TO FOLD AT LEAST LOWER
DELAWARE BAY INTO THE ADVISORY IF CONDITIONS ARE A BIT STRONGER THAN
FORECAST.

&&

.TIDES/COASTAL FLOODING...
A PERSISTENT NORTHEAST FLOW OVER THE NEXT SEVERAL DAYS WILL CAUSE
ABOVE NORMAL WATER LEVELS. AS LOW PRESSURE LIFTS NORTHWARD ALONG THE
MID ATLANTIC COAST, A FRESH ONSHORE FLOW STARTING TONIGHT AND
PERSISTING AT LEAST INTO TUESDAY WILL BEAR WATCHING. AVIATION STORM
SURGE GUIDANCE IS NOT CREATING DRAMATIC EFFECTS, BUT IT MAY BE
UNDERDONE AS IT ONLY BRINGS ANOMALIES OF A HALF FOOT ABOVE NORMAL.
TIDE LEVELS MAY BE MORE LIKE 1.0 TO 1.5 FEET ABOVE NORMAL, AND, WITH
RECENT SEVERE BEACH EROSION, THIS MAY CAUSE SOME PROBLEMS IN A FEW
AREAS. IF CONFIDENCE BUILDS IN THIS SCENARIO, SOME TYPE OF COASTAL
PRODUCT MAY NEED TO BE ISSUED ON TODAY`S DAY SHIFT. FOR NOW,
THE SITUATION WILL CONTINUE TO BE MONITORED.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 1 PM THIS AFTERNOON TO 6 AM EST
     TUESDAY FOR ANZ452>455.
     SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 6 AM EST
     TUESDAY FOR ANZ450-451.

&&

$$

SYNOPSIS...DELISI
NEAR TERM...IOVINO
SHORT TERM...DELISI
LONG TERM...STAUBER

000
FXUS61 KCTP 221158
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
658 AM EST SUN NOV 22 2009

.SYNOPSIS...
AN ANOMALOUS STRONG UPPER RIDGE WILL DOMINATE OUR WEATHER THROUGH
MID-WEEK. THEN A SERIES OF WAVES WILL CARVE OUT A TROUGH OVER
EASTERN NORTH AMERICA BEGINNING ABOUT THANKSGIVING. THE STRONG
TROUGH WHICH DEVELOPS BY THE WEEKEND AND THE RIDGE OVER WESTERN
NORTH AMERICA. IT WILL TURN COLDER AROUND THANKSGIVING.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
11-3.9 MICRON DATA SHOWS EXTENSIVE STRATOCU DECK OVR CENTRAL PA
EARLY THIS MORNING...WHILE DOWNSLOPING NORTHERLY FLOW RESULTING IN
CLEAR SKIES ACROSS THE LOWER SUSQ VALLEY. CLEAR SKY AND CALM WIND
MAY RESULT IN PATCHY FOG OVR THE LOWER SUSQ EARLY TDY.

LARGE SCALE SUBSIDENCE IN WAKE OF DEPARTING UPPER LVL SHORTWAVE
SHOULD RESULT IN LOWERING INVERSION AND CLEARING SKIES LATER TODAY.
LATEST NAM12/RUC13 SUGGEST FAIRLY RAPID CLEARING LATER THIS
MORNING. HOWEVER...EASTERLY FLOW AND ASSOCIATED OROGRAPHIC UPLIFT
OVR THE LAURELS COULD RESULT IN SLOWER CLEARING DOWN THERE.

MODEL 900MB TEMPS SUPPORT A FAIRLY MILD DAY...GIVEN MSUNNY SKIES.
HAVE LEANED TOWARD THE WARMER MAV GUIDANCE BASED ON THE 00Z NAEFS
DATA...WHICH INDICATE HIGHS FROM NR 50F ALLEGHENIES...TO U50S SUSQ
VALLEY.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
AS SFC HIGH PUSHES OFF THE NEW ENG COAST...DEVELOPING MOIST...EASTERLY
FLOW OVR THE MID ATLANTIC WILL LIKELY RESULT IN STRATOCU CREEPING
NORTHWRD ALONG THE APPALACHIANS. THE NCEP ENSEMBLES SUGGEST THAT
A BIT OF LGT RAIN/DZ MAY DEVELOP AS EARLY AS 12Z MONDAY OVR THE
SC MTNS. HOWEVER...LATEST SREF INDICATES A BETTER CHC OF RAIN
ACROSS SOUTHERN PA BY LATE MONDAY...AS EASTERLY WIND AND PWAT ANOMALIES
SHIFT NORTH INTO PA. LG SCALE/QG FORCING REMAINS WEAK THROUGH
MONDAY...SUPPORTING IDEA OF VERY LIGHT QPF.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
HAVE INCREASED POPS FOR THE MON NITE/EARLY TUESDAY TIMEFRAME TO
COINCIDE WITH PASSAGE OF SHORTWAVE AND ANOMALOUS PWATS. RIDGING AT
SFC AND ALOFT SUPPORTS A LULL IN THE PRECIP TUE NITE. HOWEVER...A
SERIES OF SHORTWAVES WILL BEGIN DIGGING OUT A DEEP TROF OVR THE
MIDWEST DURING THE SECOND HALF OF THE WEEK. WED/THU APPEAR
UNSETTLED/SHOWERY AHEAD OF THIS FEATURE. HOWEVER...EXACT TIMING OF TROF
REMAINS UNCERTAIN...SO WILL KEEP POPS IN THE CHC CATEGORY FOR NOW.

AS ANOMALOUS TROF MOVES OVR THE NORTHEAST CONUS...LAKE EFFECT SNOW
SHWRS LOOKING MORE LIKELY FOR FRI/SAT. 500MB TRAJECTORIES SUGGEST
LATE WEEK AIR MASS WILL BE A MIX OF PACIFIC AND POLAR...SO ONLY
SEASONABLE CHILL EXPECTED. GEFS MEAN 850 TEMPS ARND -6C SUGGEST
HIGHS FRI/SAT FROM U30S MTNS TO M40S SUSQ VALLEY.

&&

.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
MVFR/IFR STRATOCU DECK WILL HANG ON ACROSS MUCH OF CENTRAL PA
/EXCEPT LOWER SUSQ/ THROUGH MID MORNING BEFORE RAPIDLY
DIMINISHING. LOWER SUSQ WILL HAVE SHORT-LIVED LIGHT FOG THIS
MORNING WITH A QUICK RETURN TO VFR CONDITIONS.

FLOW TURNS SE THROUGH THE DAY AND EVENING...AND MOISTURE WILL
QUICKLY RETURN OVERNIGHT IN THE FORM OF AN EXPANDING MVFR STRATOCU
DECK FROM S TO N. BY 12Z CLOUDS WILL LIKELY LOWER TO IFR ACROSS
SOUTHERN TIER. FORCING REMAINS LIGHT...BUT COULD EVEN SEE SOME
PATCHY DRIZZLE /MAINLY AROUND KJST-KAOO/ BY 12Z.

STARTING MONDAY...THE REGION WILL BE IN FOR AN EXTENDED PERIOD OF
POOR FLYING CONDITIONS.

OUTLOOK...
MON...MVFR LCL IFR. PSBL SHRA IN THE AFTN.
TUE...MVFR/IFR CIGS. SHRA IN THE AM.
WED...MVFR TO VFR.
THU...MVFR WITH CHC -SHRASN.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...GRUMM
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD/MARTIN
AVIATION...RXR

000
FXUS61 KPBZ 221119
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
619 AM EST SUN NOV 22 2009

.SYNOPSIS...
HIGH PRESSURE WILL MOVE TO NEW ENGLAND TODAY WITH EARLY MORNING
CLOUDS GIVING WAY TO SUNSHINE. LOW PRESSURE MOVING TOWARD THE MID
ATLANTIC COAST WILL BRING THE CHANCE FOR SHOWERS LATER MONDAY INTO
EARLY TUESDAY BEFORE MOVING EAST. DEEPENING LOW PRESSURE MOVING
INTO THE GREAT LAKES WILL BRING COLDER TEMPERATURES AND RAIN AND
SNOW SHOWERS INTO THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
EARLY MORNING UPDATE TO INCREASE CLOUD COVERAGE OVER MUCH OF CWA
THIS MORNING AS BREAKS HAVE FILLED IN. WILL REQUIRE MIXING BY MID
MORNING TO DECREASE CLOUDS . STILL EXPECT SUNSHINE FOR THE
AFTERNOON AS SURFACE HIGH SHIFTS TO NEW ENGLAND. CLOUDS WILL THEN
INCREASE LATER TONIGHT AS SHORTWAVE IN SOUTHWEST FLOW SHEARS OUT
INTO THE MID ATLANTIC STATES PUSHING MOISTURE NORTH ACROSS REGION.
TEMPERATURES CLOSE TO MOS.

&&

.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
MAJOR CHANGE TO FORECAST IS INCREASE IN POPS ACROSS ENTIRE CWA
MONDAY INTO EARLY TUESDAY AS SHORTWAVES MOVE ACROSS THE
APPALACHIANS TO THE MID ATLANTIC WITH LOW PRESSURE MOVING
OFFSHORE. MODEL POPS IN THE LIKELY RANGE BUT WILL NOT GO THAT FAR
WITH HIGH CHANCE POPS SOUTH AND CHANCE NORTH. LEFTOVER SHOWERS
EARLY TUESDAY AS SYSTEM EXITS EAST WITH A DRY PERIOD LATER TUESDAY
INTO TUESDAY EVENING. BY LATER TUESDAY NIGHT CLOSED LOW WILL BE
APPROACHING LOWER OHIO VALLEY WITH CLOUDS AND SHOWERS INTO
WEDNESDAY. TEMPERATURES WILL CONTINUE TO AVERAGE ABOVE NORMAL INTO
WEDNESDAY.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
DEEP AND COLD CLOSED LOW WILL AFFECT THE REGION THROUGH THE PERIOD
AS IT MOVES EAST ACROSS THE OHIO VALLEY TO THE EAST COAST. MODEL
THICKNESS STILL SHOWS TEMPERATURES TO BE WARM ENOUGH FOR ALL RAIN
WEDNESDAY NIGHT AND THURSDAY THEN LOWER FOR A CHANGE OVER TO SNOW
SHOWERS THURSDAY NIGHT AND A MIX FOR FRIDAY. LEFT SATURDAY DRY FOR
NOW BUT NEW RUN OF ECMWF AGREES WITH GFS FOR SNOW SHOWERS IN
NORTHWEST FLOW. WILL LET DAY SHIFT REEVALUATE SNOW CHANCES FOR THE
WEEKEND. TEMPERATURES WILL FALL WELL BELOW NORMAL FOR LATE WEEK
INTO THE WEEKEND AND MEX MOS MAY NOT BE COLD ENOUGH BASED ON MODEL THICKNESS
AND 850MB TEMPS.

&&

.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
MVFR CEILINGS WILL FINALLY BEGIN TO BREAK BY LATE MORNING
EVERYWHERE EXCEPT KFKL/KDUJ WHERE CIGS WILL CONTINUE TO PREVAIL
INTO THIS AFTERNOON. WITH RIDGING ALOFT CENTERED ACROSS THE
AREA...VFR CONDITIONS WITH PREVAIL THROUGH SUNDAY NIGHT.

A LOW PRESSURE SYSTEM MOVING UP THE EAST COAST ON MONDAY WILL
BRING THE NEXT CHANCE FOR SHOWERS WITH REDUCED CEILINGS
EXPECTED...ESPECIALLY ALONG AND EAST OF A KMGW-KDUJ LINE. A LOW
PRESSURE SYSTEM ACROSS THE MISSOURI VALLEY WILL DEVELOP ON
TUESDAY...STRENGTHENING AS IT MOVES INTO THE GREAT LAKES BY
WEDNESDAY. THIS SYSTEM AND ITS ASSOCIATED COLD FRONT WILL RETURN
THE CHANCE FOR REDUCED CEILINGS ACROSS THE AREA TUESDAY THROUGH
THURSDAY.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.

&&

$$

000
FXUS61 KPBZ 221029
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
529 AM EST SUN NOV 22 2009

.SYNOPSIS...
HIGH PRESSURE WILL MOVE TO NEW ENGLAND TODAY WITH EARLY MORNING
CLOUDS GIVING WAY TO SUNSHINE. LOW PRESSURE MOVING TOWARD THE MID
ATLANTIC COAST WILL BRING THE CHANCE FOR SHOWERS LATER MONDAY INTO
EARLY TUESDAY BEFORE MOVING EAST. DEEPENING LOW PRESSURE MOVING
INTO THE GREAT LAKES WILL BRING COLDER TEMPERATURES AND RAIN AND
SNOW SHOWERS INTO THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
EARLY MORNING UPDATE TO INCREASE CLOUD COVERAGE OVER MUCH OF CWA
THIS MORNING AS BREAKS HAVE FILLED IN. WILL REQUIRE MIXING BY MID
MORNING TO DECREASE CLOUDS . STILL EXPECT SUNSHINE FOR THE
AFTERNOON AS SURFACE HIGH SHIFTS TO NEW ENGLAND. CLOUDS WILL THEN
INCREASE LATER TONIGHT AS SHORTWAVE IN SOUTHWEST FLOW SHEARS OUT
INTO THE MID ATLANTIC STATES PUSHING MOISTURE NORTH ACROSS REGION.
TEMPERATURES CLOSE TO MOS.

&&

.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
MAJOR CHANGE TO FORECAST IS INCREASE IN POPS ACROSS ENTIRE CWA
MONDAY INTO EARLY TUESDAY AS SHORTWAVES MOVE ACROSS THE
APPALACHIANS TO THE MID ATLANTIC WITH LOW PRESSURE MOVING
OFFSHORE. MODEL POPS IN THE LIKELY RANGE BUT WILL NOT GO THAT FAR
WITH HIGH CHANCE POPS SOUTH AND CHANCE NORTH. LEFTOVER SHOWERS
EARLY TUESDAY AS SYSTEM EXITS EAST WITH A DRY PERIOD LATER TUESDAY
INTO TUESDAY EVENING. BY LATER TUESDAY NIGHT CLOSED LOW WILL BE
APPROACHING LOWER OHIO VALLEY WITH CLOUDS AND SHOWERS INTO
WEDNESDAY. TEMPERATURES WILL CONTINUE TO AVERAGE ABOVE NORMAL INTO
WEDNESDAY.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
DEEP AND COLD CLOSED LOW WILL AFFECT THE REGION THROUGH THE PERIOD
AS IT MOVES EAST ACROSS THE OHIO VALLEY TO THE EAST COAST. MODEL
THICKNESS STILL SHOWS TEMPERATURES TO BE WARM ENOUGH FOR ALL RAIN
WEDNESDAY NIGHT AND THURSDAY THEN LOWER FOR A CHANGE OVER TO SNOW
SHOWERS THURSDAY NIGHT AND A MIX FOR FRIDAY. LEFT SATURDAY DRY FOR
NOW BUT NEW RUN OF ECMWF AGREES WITH GFS FOR SNOW SHOWERS IN
NORTHWEST FLOW. WILL LET DAY SHIFT REEVALUATE SNOW CHANCES FOR THE
WEEKEND. TEMPERATURES WILL FALL WELL BELOW NORMAL FOR LATE WEEK
INTO THE WEEKEND AND MEX MOS MAY NOT BE COLD ENOUGH BASED ON MODEL THICKNESS
AND 850MB TEMPS.

&&

.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
A POCKET OF LOW-LEVEL MOISTURE ACROSS THE TERMINALS WILL CONTINUE
TO DRIFT SLOWLY SOUTHWARD THROUGH THE PRE-DAWN HRS. THIS WILL
ALLOW FOR MVFR CIGS TO PREVAIL AT KFKL/KDUJ...WITH CIGS HOVERING
AROUND 3-4KFT OTHERWISE. TEMPO GROUPS ARE FCST FOR KFKL/KDUJ FOR CIGS
DROPPING TO LIFR-IFR LEVELS DURING THE PRE-DAWN HRS. WITH CLEARING
AT KZZV...VSBYS WILL REDUCE TO MVFR AT TIMES THROUGH 12Z. CEILINGS
WILL FINALLY BEGIN TO BREAK BY LATE MORNING AS RIDGING ALOFT
BECOMES CENTERD ACROSS THE AREA...WITH VFR CONDITIONS PREVAILING
THROUGH SUNDAY NIGHT.

A LOW PRESSURE SYSTEM MOVING UP THE EAST COAST ON MONDAY WILL
BRING THE NEXT CHANCE FOR SHOWERS WITH REDUCED CEILINGS
EXPECTED...ESPECIALLY SOUTHEAST OF A KMGW-KLBE LINE. A LOW
PRESSURE SYSTEM ACROSS THE MISSOURI VALLEY WILL DEVELOP ON
TUESDAY...STRENGTHENING AS IT MOVES INTO THE GREAT LAKES BY
WEDNESDAY. THIS SYSTEM AND ITS ASSOCIATED COLD FRONT WILL RETURN
THE CHANCE FOR REDUCED CEILINGS ACROSS THE AREA TUESDAY THROUGH
THURSDAY.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.

&&

$$

000
FXUS61 KCTP 220936
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
436 AM EST SUN NOV 22 2009

.SYNOPSIS...
AN ANOMALOUS STRONG UPPER RIDGE WILL DOMINATE OUR WEATHER THROUGH
MID-WEEK. THEN A SERIES OF WAVES WILL CARVE OUT A TROUGH OVER
EASTERN NORTH AMERICA BEGINNING ABOUT THANKSGIVING. THE STRONG
TROUGH WHICH DEVELOPS BY THE WEEKEND AND THE RIDGE OVER WESTERN
NORTH AMERICA. IT WILL TURN COLDER AROUND THANKSGIVING.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
11-3.9 MICRON DATA SHOWS EXTENSIVE STRATOCU DECK OVR CENTRAL PA
EARLY THIS MORNING...WHILE DOWNSLOPING NORTHERLY FLOW RESULTING IN
CLEAR SKIES ACROSS THE LOWER SUSQ VALLEY. CLEAR SKY AND CALM WIND
MAY RESULT IN PATCHY FOG OVR THE LOWER SUSQ EARLY TDY.

LARGE SCALE SUBSIDENCE IN WAKE OF DEPARTING UPPER LVL SHORTWAVE
SHOULD RESULT IN LOWERING INVERSION AND CLEARING SKIES LATER TODAY.
LATEST NAM12/RUC13 SUGGEST FAIRLY RAPID CLEARING LATER THIS
MORNING. HOWEVER...EASTERLY FLOW AND ASSOCIATED OROGRAPHIC UPLIFT
OVR THE LAURELS COULD RESULT IN SLOWER CLEARING DOWN THERE.

MODEL 900MB TEMPS SUPPORT A FAIRLY MILD DAY...GIVEN MSUNNY SKIES.
HAVE LEANED TOWARD THE WARMER MAV GUIDANCE BASED ON THE 00Z NAEFS
DATA...WHICH INDICATE HIGHS FROM NR 50F ALLEGHENIES...TO U50S SUSQ
VALLEY.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
AS SFC HIGH PUSHES OFF THE NEW ENG COAST...DEVELOPING MOIST...EASTERLY
FLOW OVR THE MID ATLANTIC WILL LIKELY RESULT IN STRATOCU CREEPING
NORTHWRD ALONG THE APPALACHIANS. THE NCEP ENSEMBLES SUGGEST THAT
A BIT OF LGT RAIN/DZ MAY DEVELOP AS EARLY AS 12Z MONDAY OVR THE
SC MTNS. HOWEVER...LATEST SREF INDICATES A BETTER CHC OF RAIN
ACROSS SOUTHERN PA BY LATE MONDAY...AS EASTERLY WIND AND PWAT ANOMALIES
SHIFT NORTH INTO PA. LG SCALE/QG FORCING REMAINS WEAK THROUGH
MONDAY...SUPPORTING IDEA OF VERY LIGHT QPF.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
HAVE INCREASED POPS FOR THE MON NITE/EARLY TUESDAY TIMEFRAME TO
COINCIDE WITH PASSAGE OF SHORTWAVE AND ANOMALOUS PWATS. RIDGING AT
SFC AND ALOFT SUPPORTS A LULL IN THE PRECIP TUE NITE. HOWEVER...A
SERIES OF SHORTWAVES WILL BEGIN DIGGING OUT A DEEP TROF OVR THE
MIDWEST DURING THE SECOND HALF OF THE WEEK. WED/THU APPEAR
UNSETTLED/SHOWERY AHEAD OF THIS FEATURE. HOWEVER...EXACT TIMING OF TROF
REMAINS UNCERTAIN...SO WILL KEEP POPS IN THE CHC CATEGORY FOR NOW.

AS ANOMALOUS TROF MOVES OVR THE NORTHEAST CONUS...LAKE EFFECT SNOW
SHWRS LOOKING MORE LIKELY FOR FRI/SAT. 500MB TRAJECTORIES SUGGEST
LATE WEEK AIR MASS WILL BE A MIX OF PACIFIC AND POLAR...SO ONLY
SEASONABLE CHILL EXPECTED. GEFS MEAN 850 TEMPS ARND -6C SUGGEST
HIGHS FRI/SAT FROM U30S MTNS TO M40S SUSQ VALLEY.

&&

.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
CONSIDERABLE MVFR/IFR STRATUS AND PATCHY LIGHT FOG WILL HOLD TOUGH
OVER MUCH OF PA THROUGH MID MORNING...EXCECT FOR THE SUSQ-VALLEY
WHERE IT WILL REMAIN FEW/SKC. GUIDANCE SUGGESTS AS FLOW TURNS N/NE
BNDRY LYR WILL DRY AND ERODE STRATUS DECK BTWN 12-14Z. VFR
CONDITIONS WILL THEN RETURN FOR MUCH OF THE DAY TODAY.

OUTLOOK...
MON...MVFR LCL IFR. PSBL SHRA IN THE AFTN.
TUE...MVFR/IFR CIGS. SHRA IN THE AM.
WED...MVFR TO VFR.
THU...MVFR WITH CHC -SHRASN.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...GRUMM
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD/MARTIN
AVIATION...BEACHLER/RXR

000
FXUS61 KPHI 220851
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
351 AM EST SUN NOV 22 2009

.SYNOPSIS...
HIGH PRESSURE OVER THE EASTERN GREAT LAKES REGION WILL STRENGTHEN
AND MOVE TO THE CANADIAN MARITIMES BY MONDAY MORNING AND THEN
RECEDE EAST. FAIRLY WEAK LOW PRESSURE DEVELOPING NEAR THE GULF
COAST WILL MOVE OFF THE SOUTHEAST COAST BY MONDAY MORNING AND THEN
LIFT NORTHEAST. THE LOW WILL PASS BY TO OUR EAST ON TUESDAY. A
COLD FRONT FROM THE WEST IS EXPECTED TO ARRIVE ON THURSDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WE ARE GOING TO FOLLOW THE OPTIMISTIC GUIDANCE WITH REGARD TO SKY
COVER TODAY AND KEEP THE STRATOCUMULUS CLOUDS OUT OF OUR AREA.
EVENTUALLY, SOME HIGH CLOUDS WILL BEGIN TO INVADE FROM THE SOUTH
AS THE SOUTHERN STREAM SYSTEM BEGINS TO APPROACH. SINCE WE DO SEEM
TO HAVE A MID LEVEL REX BLOCK OVER US, WE DON`T PUSH THE INCREASE
IN CLOUDS TOO MUCH.

THE WINDS TODAY WILL BEGIN TO INCREASE SOME OUT OF THE NORTHEAST
/ESPECIALLY AS ONE MOVES TOWARD THE COAST/, MORE IN RESPONSE TO SURFACE
HIGH PRESSURE STRENGTHENING TO THE NORTH THAN CYCLONGENESIS OFF
THE SOUTHEAST COAST. THE ECMWF CONTINUES TO SHOW A RATHER COOL
H925 FOR LATE THIS AFTERNOON IN RESPONSE TO THE FLOW AND THE
STRENGTHENING HIGH, SO OUR MAX TEMPERATURE FORECAST IS A BLEND OF
CONTINUITY AND THE COOLER MET GUIDANCE.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
THE MID LEVEL REX BLOCK IS PROGGED BY ALL MODELS TO BEGIN TO
WEAKEN AND LIFT AWAY TONIGHT. STILL, IT IS THIS FEATURE THAT MAKES
US CONTINUE TO KEEP OUR SECOND PERIOD FORECAST MAINLY DRY WITH
ONLY SOME SLIGHT CHANCE POPS SOUTH. THE SURFACE FLOW STARTS TO
VEER JUST A LITTLE AND STRENGTHEN A BIT MORE, PERHAPS ENOUGH TO BRING
IN SOME LOWER LEVEL MOISTURE AND LOW CLOUDS. CERTAINLY, MID AND
HIGH LEVEL CLOUDS WILL BE ON THE INCREASE AS THE MID LEVEL WEAK
RIDGE AXIS UPSTREAM OF THE BLOCK WEAKENS FURTHER. GUIDANCE AND
CONTINUITY WERE ALL PRETTY CLOSE ON MINS AND WERE FOLLOWED.

ON MONDAY AND MONDAY NIGHT, WE START TO SEE AND THEN DO SEE
INGREDIENTS FOR RAIN COME TOGETHER OVER AT LEAST THE EASTERN PART
OF THE FORECAST AREA. IT SHOULD BE NOTED THAT THE NAM PUSHES
EVERYTHING A BIT FURTHER TO THE WEST THAN THE ECMWF DOES DESPITE
THEIR GOOD AGREEMENT ON THE SURFACE AND H5 FORECASTS. THEY BOTH
HAVE Q-VECTOR CONVERGENCE AND FRONTOGENESIS WITH DECENT ISENTROPIC
LIFT AND THETA-E ADVECTION, BUT THE ECMWF WANTS ALL THIS MORE
FOCUSED NEAR THE COAST AND OVER THE OPEN WATER THAN THE NAM. SINCE
THE MAV POPS WERE LOWER THAN THE MET POPS, WE HAVE COME DOWN IN
BETWEEN THE TWO TO REFLECT THE POSSIBILITY THAT THE NAM IS TOO FAR
WEST WITH THE ACTION. IN PARTING DEFERENCE TO THE LIFTING AND
WEAKENING REX BLOCK, WE START THE DAY WITH ONLY SLIGHT CHANCE
POPS NEAR AND NORTHWEST OF THE I-95 CORRIDOR AND THEN INCREASE
THEM IN THE AFTERNOON. FURTHER SOUTHEAST, WE START WITH CHANCE POPS
AND THEN INCREASE THEM. AM NOT SEEING ANY SIGNS OF INSTABILITY
WITH THIS SYSTEM OVER OUR AREA, SO HAVE NOT HIT THE QPF VALUES VERY
HARD.

OUR MAX TEMPERATURES ON MONDAY ARE A BLEND OF CONTINUITY AND THE
MEAN OF THE DISPARATE STAT GUIDANCE, PERHAPS LEANING A BIT ON THE
MILD SIDE WHERE PRECIPITATION IS LESS LIKELY OR WILL START LAST
AND ON THE COOLER SIDE FURTHER SOUTHEAST. OUR MIN TEMPS FOR MONDAY
NIGHT TRY TO SHRINK THE DIURNAL OSCILLATION. FOR NOW, WE HAVE
DISREGARDED THE POSSIBILITY THAT WARMER AIR RIDING OVER THE
SURFACE WILL MAKE IT DOWN.

THERE SHOULD BE A DECENT NORTHEAST WIND THANKS TO THE GRADIENT
BETWEEN THE RECEDING HIGH AND THE ADVANCING LOW, BUT NOT THE SAME
IN STRENGTH OR PERSISTENCE AS THE ONE WE EXPERIENCED JUST AFTER
VETERAN`S DAY.

MODELS SOUNDINGS SHOW TRAPPED MOISTURE AND THE HINT OF A TRAILING
WAVE FOR TUESDAY, AND SO WE CONTINUE WITH THE CHANCE OF
PRECIPITATION. WE TRY TO CARVE OUT SOME SORT OF BREAK ON TUESDAY
NIGHT. WE SHOULD SEE THE WINDS BEGIN TO DECREASE ON TUESDAY AND
CONTINUE TO DO SO ON TUESDAY NIGHT. TEMPERATURES WERE A BLEND OF
GUIDANCE AND CONTINUITY.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
ALL MODELS AGREE THAT A SIGNIFICANT CHANGE IN THE PATTERN OCCURS
DURING THE END OF THE WEEK. WE START OFF WITH A BROAD SW FLOW ON
THE EASTERN PORTION OF A MIDWEST TROUGH ON TUESDAY
NIGHT...EVENTUALLY THE MIDWEST TROUGH MOVES EAST, BUT DEEPENS AS
IT HEADS EAST. THE UPPER TROUGH THEN BECOMES CLOSED OFF AS IT
MOVES THROUGH THE REGION.

THIS MEANS THAT WE HAVE QUITE A BIT OF CLOUDS AND POSSIBLE
SHOWERS LATE TUESDAY NIGHT AND WEDNESDAY DUE TO MOISTURE SPREADING
OVER THE REGION WITHIN THE SW FLOW ALOFT. WEDNESDAY NIGHT THROUGH
THANKSGIVING AND INTO THURSDAY NIGHT, WE COULD SEE RAIN AS A
FRONTAL SYSTEM ASSOCIATED WITH THE UPPER TROUGH MOVES THROUGH FROM
THE WEST. THEN ON FRIDAY, COOLER DRIER AIR ARRIVES, BUT WE STILL
COULD HAVE RAIN SHOWERS WITH THE CYCLONIC FLOW ALOFT. FRIDAY NIGHT
AND SATURDAY, IT GETS COLD ENOUGH THAT SOME SNOW SHOWERS ARE
POSSIBLE NORTH, BUT THE REST OF THE AREA SHOULD BE DRY WITH
DOWNSLOPE NW FLOW. ALSO ON SATURDAY, IT SHOULD BE BREEZY/WINDY
WITH THE NW FLOW.

HPC PROGS HAVE THE SITUATION WELL IN HAND AND IN GENERAL THEIR
GUIDANCE HAS BEEN FOLLOWED.

&&

.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.

SURFACE HIGH PRESSURE OVER THE EASTERN GREAT LAKES AND SOUTHEASTERN
CANADA WILL MOVE NORTHEASTWARD MORE FULLY INTO SOUTHEASTERN CANADA
THIS MORNING. THE UPPER TROUGH FROM NEW ENGLAND TO THE OHIO VALLEY
ABOVE THE SURFACE HIGH WAS MOVING EAST-SOUTHEASTWARD...AND THE
BETTER FLOW TO THE SOUTHEAST OF THE TROUGH WAS WHERE THE HIGH CLOUDS
HAD BEEN GENERATED YESTERDAY. THESE MOVED OFF EARLY SATURDAY NIGHT.
THIS SET-UP WAS LEAVING OUR REGION IN A CLOUD-FREE AREA THIS
MORNING...AND THIS SHOULD MOSTLY CONTINUE TODAY. ONLY KRDG HAD A
TEMPO GROUP IN ITS TAF FOR LIGHT FOG FOR THE HOURS NEAR SUNRISE
IN VIEW OF SATURDAY MORNING/S BRIEF FORAY DOWN TO 2 MILES...AND ALSO
IN VIEW OF MOS GUIDANCE AROUND 12Z.

AS THE LOW LEVEL FLOW VEERS FROM NORTH TO NORTHEAST TODAY...THE
ONSHORE FLOW WILL BRING IN MOISTURE TONIGHT. MOS GUIDANCE IS IN
AGREEMENT ON BRINGING IN LOW CLOUDS OVERNIGHT...WITH THE NAM MOS
BEING MORE PESSIMISTIC THAN THE GFS. FOR NOW, CEILINGS WILL BE
LOWERED TO MARGINAL VFR IN THE AREA OF MIDNIGHT, WITH JUST A MENTION
OF SCATTERED 8 HUNDRED AND LOW MARGINAL VFR OVERCAST FOR THE LATE
NIGHT PERIOD AND TOWARD MONDAY MORNING. SOUTHERN TAF SITES MAY STAND
A SMALL CHANCE OF RAIN OVERNIGHT...BUT WITH SUCH A SMALL CHANCE, AND
VISIBILITIES LIKELY NOT BEING AFFECTED, THIS WILL BE LEFT OUT OF THE
KMIV, KACY, AND KILG TAFS FOR NOW.

OUTLOOK...
MONDAY SHOULD BE THE TIME PERIOD WHEN CEILINGS ARE MARGINAL VFR TO
EVEN IFR IN DEVELOPING RAIN, AS LOW PRESSURE LIFTS SLOWLY OFF THE
MID ATLANTIC COAST. THE LOW WILL LINGER IN OUR AREA INTO OR POSSIBLY
THROUGH TUESDAY...WITH UNSETTLED CONDITIONS LOITERING WEDNESDAY AS
WELL.

&&

.MARINE...
SURFACE HIGH PRESSURE OVER THE EASTERN GREAT LAKES AND SOUTHEASTERN
CANADA WILL MOVE NORTHEASTWARD MORE FULLY INTO SOUTHEASTERN CANADA
THIS MORNING. AS LOW PRESSURE DEVELOPS OFF THE U.S. EAST COAST AND
LIFTS NORTHWARD TODAY...A BETTER GRADIENT BETWEEN THE LOW TO THE
SOUTH AND THE HIGH TO THE NORTH WILL FORM OVER OUR AREA DURING THIS
AFTERNOON AND BE IN PLACE TONIGHT AND MONDAY, AND PERHAPS INTO
TUESDAY AS WELL. IF THE NAM PRESSURE PATTERN TURNS OUT TO A BETTER
SOLUTION THAN THE GFS, WHICH SHOWS THE LOW CLOSER TO THE COAST ALONG
WITH A STRONGER GRADIENT, THEN WINDS AND GUSTS MAY BE A BIT STRONGER
THAN SMALL CRAFT ADVISORY TERRITORY. THE 00Z ECMWF SEEMS TO BE MORE
IN LINE WITH THE 00Z GFS, AND NOT AS PRONOUNCED AS THE NAM WHICH
APPARENTLY HAS OVERCOOKED THE TROUGH ALOFT. FOR NOW, THE SMALL CRAFT
ADVISORY THAT WILL BE COMING INTO EFFECT SOUTH THIS AFTERNOON AND
NORTH THIS EVENING, AND WHICH CURRENTLY EXTENDS THROUGH MONDAY, WILL
BE STRETCHED THROUGH MONDAY NIGHT. ADVISORY LEVEL SEAS, AND MAYBE
WINDS, COULD BE IN EFFECT FOR A GOOD PART OF THIS WEEK AS THERE ARE
SEVERAL LOWS WHICH LOOK TO IMPACT OUR AREA. PRESENTLY, CONDITIONS
ARE NOT FORECAST TO REACH ADVISORY LEVELS OVER DELAWARE BAY.
HOWEVER, THE FORECAST WILL BE BROUGHT TO NEAR ADVISORY TERRITORY
THERE, AND FUTURE FORECASTERS MAY NEED TO FOLD AT LEAST LOWER
DELAWARE BAY INTO THE ADVISORY IF CONDITIONS ARE A BIT STRONGER THAN
FORECAST.


&&

.TIDES/COASTAL FLOODING...
A PERSISTENT NORTHEAST FLOW OVER THE NEXT SEVERAL DAYS WILL CAUSE
ABOVE NORMAL WATER LEVELS. AS LOW PRESSURE LIFTS NORTHWARD ALONG THE
MID ATLANTIC COAST, A FRESH ONSHORE FLOW STARTING TONIGHT AND
PERSISTING AT LEAST INTO TUESDAY WILL BEAR WATCHING. AVIATION STORM
SURGE GUIDANCE IS NOT CREATING DRAMATIC EFFECTS, BUT IT MAY BE
UNDERDONE AS IT ONLY BRINGS ANOMALIES OF A HALF FOOT ABOVE NORMAL.
TIDE LEVELS MAY BE MORE LIKE 1.0 TO 1.5 FEET ABOVE NORMAL, AND, WITH
RECENT SEVERE BEACH EROSION, THIS MAY CAUSE SOME PROBLEMS IN A FEW
AREAS. IF CONFIDENCE BUILDS IN THIS SCENARIO, SOME TYPE OF COASTAL
PRODUCT MAY NEED TO BE ISSUED ON TODAY`S DAY SHIFT. FOR NOW,
THE SITUATION WILL CONTINUE TO BE MONITORED.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 1 PM THIS AFTERNOON TO 6 AM EST
     TUESDAY FOR ANZ452>455.
     SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 6 AM EST
     TUESDAY FOR ANZ450-451.

&&

$$
SYNOPSIS...DELISI
NEAR TERM...DELISI
SHORT TERM...DELISI
LONG TERM...STAUBER
AVIATION...
MARINE...
TIDES/COASTAL FLOODING...

000
FXUS61 KPBZ 220820
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
320 AM EST SUN NOV 22 2009

.SYNOPSIS...
HIGH PRESSURE WILL MOVE TO NEW ENGLAND TODAY WITH EARLY MORNING
CLOUDS GIVING WAY TO SUNSHINE. LOW PRESSURE MOVING TOWARD THE MID
ATLANTIC COAST WILL BRING THE CHANCE FOR SHOWERS LATER MONDAY INTO
EARLY TUESDAY BEFORE MOVING EAST. DEEPENING LOW PRESSURE MOVING
INTO THE GREAT LAKES WILL BRING COLDER TEMPERATURES AND RAIN AND
SNOW SHOWERS INTO THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
CLOUDS TRAPPED BENEATH A STRONG SUBSIDENCE INVERSION BEGINNING TO
BREAK ESPECIALLY IN THE SOUTH EARLY THIS MORNING AND THIS TREND
WILL CONTINUE PAST DAYBREAK. AS SURFACE HIGH SHIFTS TO NEW ENGLAND
TODAY CLOUDS WILL BREAK ACROSS CWA WITH NORTHERN COUNTIES BEING
THE LAST TO CLEAR. CLOUDS WILL THEN INCREASE LATER TONIGHT AS
SHORTWAVE IN SOUTHWEST FLOW SHEARS OUT INTO THE MID ATLANTIC
STATES PUSHING MOISTURE NORTH ACROSS REGION. TEMPERATURES CLOSE TO
MOS.

&&

.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
MAJOR CHANGE TO FORECAST IS INCREASE IN POPS ACROSS ENTIRE CWA
MONDAY INTO EARLY TUESDAY AS SHORTWAVES MOVE ACROSS THE
APPALACHIANS TO THE MID ATLANTIC WITH LOW PRESSURE MOVING
OFFSHORE. MODEL POPS IN THE LIKELY RANGE BUT WILL NOT GO THAT FAR
WITH HIGH CHANCE POPS SOUTH AND CHANCE NORTH. LEFTOVER SHOWERS
EARLY TUESDAY AS SYSTEM EXITS EAST WITH A DRY PERIOD LATER TUESDAY
INTO TUESDAY EVENING. BY LATER TUESDAY NIGHT CLOSED LOW WILL BE
APPROACHING LOWER OHIO VALLEY WITH CLOUDS AND SHOWERS INTO
WEDNESDAY. TEMPERATURES WILL CONTINUE TO AVERAGE ABOVE NORMAL INTO
WEDNESDAY.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
DEEP AND COLD CLOSED LOW WILL AFFECT THE REGION THROUGH THE PERIOD
AS IT MOVES EAST ACROSS THE OHIO VALLEY TO THE EAST COAST. MODEL
THICKNESS STILL SHOWS TEMPERATURES TO BE WARM ENOUGH FOR ALL RAIN
WEDNESDAY NIGHT AND THURSDAY THEN LOWER FOR A CHANGE OVER TO SNOW
SHOWERS THURSDAY NIGHT AND A MIX FOR FRIDAY. LEFT SATURDAY DRY FOR
NOW BUT NEW RUN OF ECMWF AGREES WITH GFS FOR SNOW SHOWERS IN
NORTHWEST FLOW. WILL LET DAY SHIFT REEVALUATE SNOW CHANCES FOR THE
WEEKEND. TEMPERATURES WILL FALL WELL BELOW NORMAL FOR LATE WEEK
INTO THE WEEKEND AND MEX MOS MAY NOT BE COLD ENOUGH BASED ON MODEL THICKNESS
AND 850MB TEMPS.

&&

.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
A POCKET OF LOW-LEVEL MOISTURE ACROSS THE TERMINALS WILL CONTINUE
TO DRIFT SLOWLY SOUTHWARD THROUGH THE PRE-DAWN HRS. THIS WILL
ALLOW FOR MVFR CIGS TO PREVAIL AT KFKL/KDUJ...WITH CIGS HOVERING
AROUND 3-4KFT OTHERWISE. TEMPO GROUPS ARE FCST FOR KFKL/KDUJ FOR CIGS
DROPPING TO LIFR-IFR LEVELS DURING THE PRE-DAWN HRS. WITH CLEARING
AT KZZV...VSBYS WILL REDUCE TO MVFR AT TIMES THROUGH 12Z. CEILINGS
WILL FINALLY BEGIN TO BREAK BY LATE MORNING AS RIDGING ALOFT
BECOMES CENTERD ACROSS THE AREA...WITH VFR CONDITIONS PREVAILING
THROUGH SUNDAY NIGHT.

A LOW PRESSURE SYSTEM MOVING UP THE EAST COAST ON MONDAY WILL
BRING THE NEXT CHANCE FOR SHOWERS WITH REDUCED CEILINGS
EXPECTED...ESPECIALLY SOUTHEAST OF A KMGW-KLBE LINE. A LOW
PRESSURE SYSTEM ACROSS THE MISSOURI VALLEY WILL DEVELOP ON
TUESDAY...STRENGTHENING AS IT MOVES INTO THE GREAT LAKES BY
WEDNESDAY. THIS SYSTEM AND ITS ASSOCIATED COLD FRONT WILL RETURN
THE CHANCE FOR REDUCED CEILINGS ACROSS THE AREA TUESDAY THROUGH
THURSDAY.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.

&&

$$

000
FXUS61 KCTP 220804
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
304 AM EST SUN NOV 22 2009

.SYNOPSIS...
AN ANOMALOUS STRONG UPPER RIDGE WILL DOMINATE OUR WEATHER THROUGH
MID-WEEK. THEN A SERIES OF WAVES WILL CARVE OUT A TROUGH OVER
EASTERN NORTH AMERICA BEGINNING ABOUT THANKSGIVING. THE STRONG
TROUGH WHICH DEVELOPS BY THE WEEKEND AND THE RIDGE OVER WESTERN
NORTH AMERICA. IT WILL TURN COLDER AROUND THANKSGIVING.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
UPDATED THE GRIDS AND WILL PUSH OUT A NEW ZONE SET BASED ON THESE
EDITS AS THE LOW CLOUDS ARE ERODING FAST. 3.9-11 MICRON DATA SHOWS
POTENTIAL CLEARING AS FAR NORTH AS STATE COLLEGE NOW. STILL LOTS
OF LOW CLOUDS ACROSS THE NORTH AND WEST.

PROFILES SHOW THE INVERSION NEAR 750-780 HPA WEAKENING A BIT AND
CONSIDERABLE DRYING BELOW THIS FEATURE. THIS WOULD FAVOR THE
IMPROVED WEATHER AND LESS CLOUDS OVER STATE COLLEGE AND POINTS
SOUTH AND EAST. HOWEVER THE BRADFORD PROFILE SUGGESTS IT WILL TAKE
A GOOD 6 TO 8 HOURS TO DRY OUT UP THERE.

ADDITIONALLY...THERE IS SOME POTENTIAL FOR VALLEY FOG AS THE T-TD
SPREAD IS SMALL. A GOOD PERIOD OF RADIATION WOULD HELP PRODUCE
SOME FOG. KEPT PATCHY FOG IN FORECAST.

OVERNIGHT LOWS WILL MAINLY BE UPPER 30 AND LOWER 40S. DEW POINTS
ARE MAINLY IN THE UPPER 30S AND LOWER 40S.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM MONDAY/...
ANY PATCHY FOG WILL DISSIPATE BY MID MORNING...AND WITH CONTINUED
RIDGING SFC AND ALOFT...EXPECT SKIES TO BECOME PARTLY TO MOSTLY
SUNNY EVERYWHERE WITH A RELATIVELY MILD AFTERNOON.

THE NCEP ENSEMBLES SUGGEST THAT ANY RAINFALL SHOULD HOLD OFF UNTIL
THE MONDAY-TUESDAY TIME FRAME. BOTH SYSTEMS SHOW A 1032 HIGH OVER
NEW ENGLAND AND STRONG EASTERLY FLOW DEVELOPING OVER OUR REGION.
CLOUDS SHOULD RETURN WITH EASTERLY FLOW. ANY PRECIPITATION OVER
NIGHT WOULD BE IN THE FORM OF DRIZZLE BUT THE PROBABILITY IS LOW
SO DID NOT PUT IT IN AT THIS TIME.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
MODELS HAVE WEAK SYSTEM LIFTING NE FROM THE GULF AREA LATER ON
MONDAY INTO TUE. DID SLOW THINGS DOWN SOME AND THINK BULK OF
ANY RAIN WOULD HOLD OFF TO AFT. DID CUT POPS BACK SOME. EXPECT
AMTS TO BE ON THE LIGHT SIDE.

SOME CLDS AND LIGHT RAIN...DRIZZLE FOR THE MOST PART...COULD
LINGER INTO TUE.

QUITE A BIT OF VARIATION IN MODEL SOLUTIONS. COULD SEE NORTHERN
AND WESTERN AREAS STAYING DRY.

FOR WED...CENTRAL PA IS BETWEEN SYSTEMS. GFS LOOKS FAST...
HPC NOT AS FAST... WEIGHTED FCST TO SLOWER SPEED.

OVERALL...ONLY MADE A FEW MINOR CHANGES TO THE PACKAGE.

FOR THU INTO SAT...TEMPS COOLING OFF CLOSER TO NORMAL...AS
RIDGE BUILDS ACROSS THE WESTERN STATES...AND MORE OF A TROUGH
PATTERN PREVAILS ACROSS THE EASTERN STATES. SOME RAIN AND
SNOW SHOWERS WILL BE POSSIBLE ACROSS THE MTS THU INTO FRIDAY.

ENOUGH RIDGING MAY TAKE PLACE ON SATURDAY...TO KEEP MOST OF THE
AREA DRY.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
CONSIDERABLE MVFR/IFR STRATUS AND PATCHY LIGHT FOG WILL HOLD TOUGH
OVER MUCH OF PA THROUGH MID MORNING...EXCECT FOR THE SUSQ-VALLEY
WHERE IT WILL REMAIN FEW/SKC. GUIDANCE SUGGESTS AS FLOW TURNS N/NE
BNDRY LYR WILL DRY AND ERODE STRATUS DECK BTWN 12-14Z. VFR
CONDITIONS WILL THEN RETURN FOR MUCH OF THE DAY TODAY.

OUTLOOK...
MON...MVFR LCL IFR. PSBL SHRA IN THE AFTN.
TUE...MVFR/IFR CIGS. SHRA IN THE AM.
WED...MVFR TO VFR.
THU...MVFR WITH CHC -SHRASN.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...GRUMM
NEAR TERM...GRUMM
SHORT TERM...GRUMM/DEVOIR
LONG TERM...MARTIN
AVIATION...BEACHLER/RXR

000
FXUS61 KPBZ 220552
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
1252 AM EST SUN NOV 22 2009

.SYNOPSIS...
HIGH PRESSURE WILL PROVIDE DRY CONDITIONS THROUGH SUNDAY NIGHT.
LOW PRESSURE MOVING OFF SHORE THE MID ATLANTIC WILL BRING A LOW
CHANCE FOR SHOWERS MONDAY THEN LOW PRESSURE COMING EASTWARD FROM
THE ROCKIES WILL BRING SHOWERS STARTING TUESDAY NIGHT FOLLOWED BY
COLDER TEMPERATURES FOR LATE WEEK.

&&

.NEAR TERM /THROUGH TODAY/...
CLOUDS REMAIN TRAPPED BENEATH A STRONG SUBSIDENCE INVERSION.
CLOUDS SHOULD ERODE LATER TONIGHT AND SUNDAY AS SURFACRE HIGH
SHIFTS EAST.

FORECASTED TEMPERATURES TO BE MILDER THAN NORMALS USING CLOSE TO
RECENT BLEND OF GFS AND NAM MOS VALUES ALONG WITH SREF MODEL
OUTPUT.

&&

.SHORT TERM /TONIGHT THROUGH TUESDAY/...
CONTINUE TO FORECAST A CHANCE OF SHOWERS EARLY MONDAY INTO TUESDAY NEAR
THE APPALACHIAN MOUNTAINS AS RECENT SREF MODEL OUTPUT CONTINUES TO
HAVE A FEW MEMBERS SHOWING RAIN SHOWERS FROM A COASTAL LOW
PRESSURE SYSTEM SPREADING INTO THE APPALACHIAN MOUNTAINS.

EXPECT THE REMAINDER OF THE UPPER OHIO VALLEY TO REMAIN DRY MONDAY
AND MONDAY NIGHT...BUT THERE IS A CHANCE THAT THE INITIAL SHOWERS
WITH THE LOW PRESSURE SYSTEM COMING EASTWARD FROM THE CANADIAN
ROCKIES CAN BEGIN SPREADING ACROSS THE UPPER OHIO VALLEY TUESDAY AFTERNOON.

FORECASTED TEMPERATURES TO CONTINUE WARMER THAN NORMAL AS
SUGGESTED BY RECENT GFS AND NAM MOS VALUES.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
LARGE UPPER LEVEL TROUGH WILL BE THE MAIN PLAYER IN THE EXTENDED
PORTION OF THE FORECAST. AS THE TROUGH DEVELOPS AND MOVES OVER THE
EAST COAST...THE DRY WEATHER AND ABOVE NORMAL TEMPERATURES THAT HAVE
PERSISTED FOR MUCH OF THE MONTH WILL COME TO AN END.

EVEN THOUGH MODELS ARE IN VERY GOOD AGREEMENT ABOUT THE DEVELOPMENT
OF THE UPPER LEVEL SYSTEM...THE ASSOCIATED SURFACE LOW PRESSURE
SOLUTIONS ARE QUITE VARIED IN THE MODELS. NEVERTHELESS...OVERCAST
CONDITIONS AND A CHANCE OF PRECIPITATION CAN BE EXPECTED FROM
WEDNESDAY ALL THE WAY INTO SATURDAY MORNING BEFORE HIGH PRESSURE
BUILDS IN.

TEMPERATURES SHOULD BE COLD ENOUGH THAT EACH NIGHT RAIN
MAY MIX WITH SNOW...BUT WARM GROUND TEMPERATURES WOULD LIKELY
PREVENT ANY ACCUMULATION. THE ONE EXCEPTION TO THIS COULD BE FRIDAY
NIGHT...WHEN FAVORABLE FLOW OFF LAKE ERIE WILL ALLOW FOR LAKE
ENHANCEMENT. AFTER SEASONABLE TEMPERATURES WEDNESDAY...EXPECT HIGHS
TO DROP TO 5-10 DEGREES BELOW NORMAL...WITH SEASONABLE LOW
TEMPERATURES.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
A POCKET OF LOW-LEVEL MOISTURE ACROSS THE TERMINALS WILL CONTINUE
TO DRIFT SLOWLY SOUTHWARD THROUGH THE PRE-DAWN HRS. THIS WILL
ALLOW FOR MVFR CIGS TO PREVAIL AT KFKL/KDUJ...WITH CIGS HOVERING
AROUND 3-4KFT OTHERWISE. TEMPO GROUPS ARE FCST FOR KFKL/KDUJ FOR CIGS
DROPPING TO LIFR-IFR LEVELS DURING THE PRE-DAWN HRS. WITH CLEARING
AT KZZV...VSBYS WILL REDUCE TO MVFR AT TIMES THROUGH 12Z. CEILINGS
WILL FINALLY BEGIN TO BREAK BY LATE MORNING AS RIDGING ALOFT
BECOMES CENTERD ACROSS THE AREA...WITH VFR CONDITIONS PREVAILING
THROUGH SUNDAY NIGHT.

A LOW PRESSURE SYSTEM MOVING UP THE EAST COAST ON MONDAY WILL
BRING THE NEXT CHANCE FOR SHOWERS WITH REDUCED CEILINGS
EXPECTED...ESPECIALLY SOUTHEAST OF A KMGW-KLBE LINE. A LOW
PRESSURE SYSTEM ACROSS THE MISSOURI VALLEY WILL DEVELOP ON
TUESDAY...STRENGTHENING AS IT MOVES INTO THE GREAT LAKES BY
WEDNESDAY. THIS SYSTEM AND ITS ASSOCIATED COLD FRONT WILL RETURN
THE CHANCE FOR REDUCED CEILINGS ACROSS THE AREA TUESDAY THROUGH
THURSDAY.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.

&&

$$

000
FXUS61 KPHI 220410
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1110 PM EST SAT NOV 21 2009

.SYNOPSIS...
HIGH PRESSURE WILL BUILD ACROSS THE NORTHEASTERN STATES TONIGHT
AND SUNDAY. THE HIGH SHOULD BECOME CENTERED OVER CANADA`S MARITIME
PROVINCES ON SUNDAY NIGHT BEFORE DRIFTING OFF THE COAST. WEAK LOW
PRESSURE IS FORECAST TO DEVELOP OFF THE SOUTHEAST COAST ON SUNDAY
NIGHT AND MONDAY. THE LOW IS EXPECTED TO TRACK TO THE NORTHEAST
AND IT SHOULD PASS WELL TO THE EAST OF DELAWARE AND NEW JERSEY ON
TUESDAY. A COLD FRONT FROM THE WEST IS EXPECTED TO ARRIVE ON
THURSDAY.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
SOME MIXING WAS OCCURRING OVER SOME OF THE NORMAL RADIATING SPOTS,
AND THAT WAS KEEPING SOME TEMPERATURES UP JUST A BIT LATE IN THE
EVENING. WE STILL EXPECT ENOUGH DECOUPLING TO ALLOW MOST PLACES TO
REACH THEIR FORECAST MINIMUMS, ALTHOUGH PERHAPS THE SOUTHERN
POCONOS WILL KEEP ENOUGH OF A BREEZE GOING OVERNIGHT TO WARRANT A
RAISING OF TEMPERATURES THERE. OTHERWISE, TEMPERATURES WERE
ADJUSTED TO MATCH OBSERVED VALUES AND MINIMUMS WERE ONLY TWEAKED.

THE LOWER CLOUDS IN THE NORTHWEST WERE ERODING AS PREVIOUSLY
ADVERTISED. SOME HIGHER CLOUDS WERE ADVANCING TOWARD THE SOUTHERN
ZONES. GENERALLY, HIGH PRESSURE WILL CONTINUE TO BUILD INTO OUR
REGION OVERNIGHT. TEMPERATURES SHOULD DROP INTO THE LOWER 30S TO
MID 40S RANGE.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
A STRENGTHENING HIGH IS FORECAST TO BE CENTERED UP IN THE SAINT
LAWRENCE RIVER VALLEY ON SUNDAY MORNING. IT SHOULD MOVE TO THE
CANADIAN MARITIMES FOR SUNDAY NIGHT.

WITH THE HIGH INFLUENCING OUR REGION, WE ARE ANTICIPATING A
MOSTLY SUNNY SKY FOR SUNDAY. AS THE CENTER OF THE HIGH MOVES TO
OUR NORTHEAST AND A SURFACE RIDGE BUILDS SOUTHWESTWARD ALONG THE
EAST COAST, AN ONSHORE FLOW WILL DEVELOP.

THE 12 UTC NAM AND THE 12 UTC GFS BOTH INDICATE AN INCREASE IN
LOW LEVEL MOISTURE FROM THE SOUTH ON SUNDAY NIGHT.

AS A COASTAL LOW MOVES UP FROM THE SOUTH ON MONDAY, THE PRESSURE
GRADIENT IS EXPECTED TO TIGHTEN. THE 12 UTC NAM IS A LITTLE
STRONGER AND CLOSER TO THE COAST WITH THE LOW THAN THE 12 UTC GFS
AND THE 12 UTC ECMWF. WE WILL FAVOR A COMPROMISE FOR THE TIME
BEING.

AS THE LOW APPROACHES, RAIN IS EXPECTED TO SPREAD INTO OUR REGION
FROM SOUTH TO NORTH ON MONDAY. THE RAIN SHOULD CONTINUE INTO
MONDAY NIGHT.

IT APPEARS AS THOUGH LOW LEVEL MOISTURE WILL LINGER IN OUR REGION
FOR TUESDAY. AS A RESULT, WE WILL MAINTAIN CHANCE POPS.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
ALL MODELS AGREE THAT A SIGNIFICANT CHANGE IN THE PATTERN OCCURS
DURING THE END OF THE WEEK. WE START OFF WITH A BROAD SW FLOW ON
THE EASTERN PORTION OF A MIDWEST TROUGH ON TUESDAY
NIGHT...EVENTUALLY THE MIDWEST TROUGH MOVES EAST, BUT DEEPENS AS
IT HEADS EAST. THE UPPER TROUGH THEN BECOMES CLOSED OFF AS IT
MOVES THROUGH THE REGION.

THIS MEANS THAT WE HAVE QUITE A BIT OF CLOUDS AND POSSIBLE
SHOWERS LATE TUESDAY NIGHT AND WEDNESDAY DUE TO MOISTURE SPREADING
OVER THE REGION WITHIN THE SW FLOW ALOFT. WEDNESDAY NIGHT THROUGH
THANKSGIVING AND INTO THURSDAY NIGHT, WE COULD SEE RAIN AS A
FRONTAL SYSTEM ASSOCIATED WITH THE UPPER TROUGH MOVES THROUGH FROM
THE WEST. THEN ON FRIDAY, COOLER DRIER AIR ARRIVES, BUT WE STILL
COULD HAVE RAIN SHOWERS WITH THE CYCLONIC FLOW ALOFT. FRIDAY NIGHT
AND SATURDAY, IT GETS COLD ENOUGH THAT SOME SNOW SHOWERS ARE
POSSIBLE NORTH, BUT THE REST OF THE AREA SHOULD BE DRY WITH
DOWNSLOPE NW FLOW. ALSO ON SATURDAY, IT SHOULD BE BREEZY/WINDY
WITH THE NW FLOW.

HPC PROGS HAVE THE SITUATION WELL IN HAND AND IN GENERAL THEIR
GUIDANCE HAS BEEN FOLLOWED.

&&

.AVIATION /04Z SUNDAY THROUGH THURSDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.

THE HIGH CLOUDS CLEARED AWAY EARLIER, AND SKIES ARE EXPECTED TO
REMAIN CLEAR OVERNIGHT. MOSTLY CLEAR SKIES ARE EXPECTED FOR SUNDAY
AS WELL.

OUTLOOK...
CLOUDS WILL BEGIN TO LOWER AND PRECIPITATION IS EXPECTED TO MOVE
INTO THE AREA LATE SUNDAY NIGHT AND COULD LAST THROUGH LATE
TUESDAY OR WEDNESDAY. THIS COULD BRING LOWER CEILINGS AND/OR
VISIBILITIES FOR THE SHORT TERM.

&&

.MARINE...
HIGH PRESSURE WILL MOVE TO OUR NORTHEAST TONIGHT INTO SUNDAY,
WHILE AN AREA OF LOW PRESSURE DEVELOPS NEAR THE GULF STATES. THIS
LOW IS EXPECTED TO STRENGTHEN SUNDAY INTO MONDAY, THEN MOVE UP THE
EAST COAST ON MONDAY AND INTO TUESDAY. BETWEEN THE HIGH TO OUR
NORTH AND THE LOW TO OUR SOUTH, THE GRADIENT WILL TIGHTEN AND
NORTHEAST WINDS WILL STRENGTHEN FOR SUNDAY, MONDAY, THEN BEGIN
SLACKING ON TUESDAY. A PERSISTENT NORTHEAST FETCH WILL DEVELOP,
WHICH IS EXPECTED TO INCREASE THE SEAS OVER THE NEXT SEVERAL DAYS.
THEREFORE WE HAVE ISSUED A SMALL CRAFT ADVISORY STARTING LATE
SUNDAY AND CONTINUING THROUGH MONDAY AFTERNOON. FUTURE FORECASTS
WILL LIKELY NEED TO EXTEND THE ADVISORY. IN FACT, AN ADVISORY MAY
BE POSSIBLE FOR BASICALLY THE ENTIRE FORECAST PERIOD AS THERE ARE
SEVERAL STORM SYSTEMS CURRENTLY EXPECTED TO IMPACT THE AREA
THROUGH MUCH OF NEXT WEEK. WE WILL CONTINUE TO MONITOR THE
SITUATION IN CASE THIS COMES TO FRUITION.

&&

.TIDES/COASTAL FLOODING...
A PERSISTENT NORTHEAST FLOW OVER THE NEXT SEVERAL DAYS COULD HELP
TO INCREASE TIDE LEVELS FOR SUNDAY, MONDAY, AND TUESDAY. TIDE
LEVELS WILL HAVE TO BE MORE THAN 1.5 TO 2.0 FEET ABOVE THE
PREDICTED ASTRONOMICAL TIDE IN ORDER FOR MINOR TIDAL FLOODING TO
OCCUR. CURRENTLY, THE MODELS ARE FORECASTING AROUND 1.0 TO 1.5
FEET IN TIDAL ANOMALIES, SO MINOR TIDAL FLOODING IS NOT EXPECTED
AT THIS TIME. HOWEVER, IF THE LOW PRESSURE SYSTEM STRENGTHENS, THE
POSSIBILITY OF FLOODING COULD INCREASE. WE WILL CONTINUE TO
MONITOR THE FORECAST FOR ANY CHANGES.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 1 PM SUNDAY TO 6 PM EST MONDAY FOR
     ANZ452>455.
     SMALL CRAFT ADVISORY FROM 6 PM SUNDAY TO 6 PM EST MONDAY FOR
     ANZ450-451.

&&

$$
SYNOPSIS...IOVINO
NEAR TERM...DELISI/EBERWINE/IOVINO
SHORT TERM...IOVINO
LONG TERM...STAUBER
AVIATION...ROBERTSON/STAUBER/
MARINE...ROBERTSON
TIDES/COASTAL FLOODING...ROBERTSON

000
FXUS61 KPBZ 220341
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
1041 PM EST SAT NOV 21 2009

.SYNOPSIS...
HIGH PRESSURE WILL PROVIDE DRY CONDITIONS THROUGH SUNDAY NIGHT.
LOW PRESSURE MOVING OFF SHORE THE MID ATLANTIC WILL BRING A LOW
CHANCE FOR SHOWERS MONDAY THEN LOW PRESSURE COMING EASTWARD FROM
THE ROCKIES WILL BRING SHOWERS STARTING TUESDAY NIGHT FOLLOWED BY
COLDER TEMPERATURES FOR LATE WEEK.

&&

.NEAR TERM /THROUGH SUNDAY/...
CLOUDS REMAIN TRAPPED BENEATH A STRONG SUBSIDENCE INVERSION.
CLOUDS SHOULD ERODE LATER TONIGHT AND SUNDAY AS SURFACRE HIGH
SHIFTS EAST.

FORECASTED TEMPERATURES TO BE MILDER THAN NORMALS USING CLOSE TO
RECENT BLEND OF GFS AND NAM MOS VALUES ALONG WITH SREF MODEL
OUTPUT.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
CONTINUE TO FORECAST A CHANCE OF SHOWERS EARLY MONDAY INTO TUESDAY NEAR
THE APPALACHIAN MOUNTAINS AS RECENT SREF MODEL OUTPUT CONTINUES TO
HAVE A FEW MEMBERS SHOWING RAIN SHOWERS FROM A COASTAL LOW
PRESSURE SYSTEM SPREADING INTO THE APPALACHIAN MOUNTAINS.

EXPECT THE REMAINDER OF THE UPPER OHIO VALLEY TO REMAIN DRY MONDAY
AND MONDAY NIGHT...BUT THERE IS A CHANCE THAT THE INITIAL SHOWERS
WITH THE LOW PRESSURE SYSTEM COMING EASTWARD FROM THE CANADIAN
ROCKIES CAN BEGIN SPREADING ACROSS THE UPPER OHIO VALLEY TUESDAY AFTERNOON.

FORECASTED TEMPERATURES TO CONTINUE WARMER THAN NORMAL AS
SUGGESTED BY RECENT GFS AND NAM MOS VALUES.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
LARGE UPPER LEVEL TROUGH WILL BE THE MAIN PLAYER IN THE EXTENDED
PORTION OF THE FORECAST. AS THE TROUGH DEVELOPS AND MOVES OVER THE
EAST COAST...THE DRY WEATHER AND ABOVE NORMAL TEMPERATURES THAT HAVE
PERSISTED FOR MUCH OF THE MONTH WILL COME TO AN END.

EVEN THOUGH MODELS ARE IN VERY GOOD AGREEMENT ABOUT THE DEVELOPMENT
OF THE UPPER LEVEL SYSTEM...THE ASSOCIATED SURFACE LOW PRESSURE
SOLUTIONS ARE QUITE VARIED IN THE MODELS. NEVERTHELESS...OVERCAST
CONDITIONS AND A CHANCE OF PRECIPITATION CAN BE EXPECTED FROM
WEDNESDAY ALL THE WAY INTO SATURDAY MORNING BEFORE HIGH PRESSURE
BUILDS IN.

TEMPERATURES SHOULD BE COLD ENOUGH THAT EACH NIGHT RAIN
MAY MIX WITH SNOW...BUT WARM GROUND TEMPERATURES WOULD LIKELY
PREVENT ANY ACCUMULATION. THE ONE EXCEPTION TO THIS COULD BE FRIDAY
NIGHT...WHEN FAVORABLE FLOW OFF LAKE ERIE WILL ALLOW FOR LAKE
ENHANCEMENT. AFTER SEASONABLE TEMPERATURES WEDNESDAY...EXPECT HIGHS
TO DROP TO 5-10 DEGREES BELOW NORMAL...WITH SEASONABLE LOW
TEMPERATURES.

&&

.AVIATION /04Z SUNDAY THROUGH THURSDAY/...
CEILINGS CONTINUE TO HOVER RIGHT AROUND THE 3KFT MARK AT ALL TAF
SITES. THESE CLOUDS SHOULD EVENTUALLY BEGIN TO SCATTER OUT BY
SUNSET...WITH ADVANCING HIGH PRESSURE EXPECTED TO BRING IN DRIER
AIR. MVFR CIGS MAY STILL BE POSSIBLE SUNDAY MORNING AT FAVORED
LOCATIONS TO THE NORTH. PATCHY FOG IS POSSIBLE MAINLY IN THE RIVER
VALLEYS. HIGH PRESSURE SHOULD THEN ALLOW FOR VFR CONDITIONS TO
CONTINUE FOR THE REST OF SUNDAY.

A LOW PRESSURE SYSTEM MOVING UP THE EAST COAST SUNDAY NIGHT WILL
BRING THE NEXT CHANCE FOR SHOWERS WITH REDUCED CEILINGS
EXPECTED...ESPECIALLY SOUTHEAST OF A KMGW-KLBE LINE. REDUCED
CEILINGS WILL BE POSSIBLE ACROSS THE AREA ON TUESDAY THROUGH
THURSDAY WITH AN UPPER LEVEL SYSTEM DOMINATING THE WEATHER ACROSS
THE GREAT LAKES.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.

&&

$$

000
FXUS61 KCTP 220321
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1021 PM EST SAT NOV 21 2009

.SYNOPSIS...
AN ANOMALOUS STRONG UPPER RIDGE WILL DOMINATE OUR WEATHER THROUGH
MID-WEEK. THEN A SERIES OF WAVES WILL CARVE OUT A TROUGH OVER
EASTERN NORTH AMERICA BEGINNING ABOUT THANKSGIVING. THE STRONG
TROUGH WHICH DEVELOPS BY THE WEEKEND AND THE RIDGE OVER WESTERN
NORTH AMERICA. IT WILL TURN COLDER AROUND THANKSGIVING.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
UPDATED THE GRIDS AND WILL PUSH OUT A NEW ZONE SET BASED ON THESE
EDITS AS THE LOW CLOUDS ARE ERODING FAST. 3.9-11 MICRON DATA SHOWS
POTENTIAL CLEARING AS FAR NORTH AS STATE COLLEGE NOW. STILL LOTS
OF LOW CLOUDS ACROSS THE NORTH AND WEST.

PROFILES SHOW THE INVERSION NEAR 750-780 HPA WEAKENING A BIT AND
CONSIDERABLE DRYING BELOW THIS FEATURE. THIS WOULD FAVOR THE
IMPROVED WEATHER AND LESS CLOUDS OVER STATE COLLEGE AND POINTS
SOUTH AND EAST. HOWEVER THE BRADFORD PROFILE SUGGESTS IT WILL TAKE
A GOOD 6 TO 8 HOURS TO DRY OUT UP THERE.

ADDITIONALLY...THERE IS SOME POTENTIAL FOR VALLEY FOG AS THE T-TD
SPREAD IS SMALL. A GOOD PERIOD OF RADIATION WOULD HELP PRODUCE
SOME FOG. KEPT PATCHY FOG IN FORECAST.

OVERNIGHT LOWS WILL MAINLY BE UPPER 30 AND LOWER 40S. DEW POINTS
ARE MAINLY IN THE UPPER 30S AND LOWER 40S.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
ANY PATCHY FOG WILL DISSIPATE BY MID MORNING...AND WITH CONTINUED
RIDGING SFC AND ALOFT...EXPECT SKIES TO BECOME PARTLY TO MOSTLY
SUNNY EVERYWHERE WITH A RELATIVELY MILD AFTERNOON.

THE NCEP ENSEMBLES SUGGEST THAT ANY RAINFALL SHOULD HOLD OFF UNTIL
THE MONDAY-TUESDAY TIME FRAME. BOTH SYSTEMS SHOW A 1032 HIGH OVER
NEW ENGLAND AND STRONG EASTERLY FLOW DEVELOPING OVER OUR REGION.
CLOUDS SHOULD RETURN WITH EASTERLY FLOW. ANY PRECIPITATION OVER
NIGHT WOULD BE IN THE FORM OF DRIZZLE BUT THE PROBABILITY IS LOW
SO DID NOT PUT IT IN AT THIS TIME.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
MODELS HAVE WEAK SYSTEM LIFTING NE FROM THE GULF AREA LATER ON
MONDAY INTO TUE. DID SLOW THINGS DOWN SOME AND THINK BULK OF
ANY RAIN WOULD HOLD OFF TO AFT. DID CUT POPS BACK SOME. EXPECT
AMTS TO BE ON THE LIGHT SIDE.

SOME CLDS AND LIGHT RAIN...DRIZZLE FOR THE MOST PART...COULD
LINGER INTO TUE.

QUITE A BIT OF VARIATION IN MODEL SOLUTIONS. COULD SEE NORTHERN
AND WESTERN AREAS STAYING DRY.

FOR WED...CENTRAL PA IS BETWEEN SYSTEMS. GFS LOOKS FAST...
HPC NOT AS FAST... WEIGHTED FCST TO SLOWER SPEED.

OVERALL...ONLY MADE A FEW MINOR CHANGES TO THE PACKAGE.

FOR THU INTO SAT...TEMPS COOLING OFF CLOSER TO NORMAL...AS
RIDGE BUILDS ACROSS THE WESTERN STATES...AND MORE OF A TROUGH
PATTERN PREVAILS ACROSS THE EASTERN STATES. SOME RAIN AND
SNOW SHOWERS WILL BE POSSIBLE ACROSS THE MTS THU INTO FRIDAY.

ENOUGH RIDGING MAY TAKE PLACE ON SATURDAY...TO KEEP MOST OF THE
AREA DRY.

&&

.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
IR IMAGERY INDICATING CONSIDERABLE STRATUS HOLDING ONTO THE ATMOS
OVER PA...EXPECT FOR THE SUSQ-VALLEY WHERE IT REMAINS FEW/SKC.
GUIDANCE SUGGESTS AS FLOW TURNS N/NE BNDRY LYR WILL DRY AND ERODE
STRATUS DECK BTWN 09-12Z. A FEW LOCATIONS COULD SEE PATCHY FG
DEV...HOWEVER EXPECT THIS TO BE LCL. ELSEWHERE ANTICIPATE SKIES TO
BOUNCE TO VFR CONDS AND PERSIST THRU 00Z MON.

OUTLOOK...
MON...MVFR LCL IFR. PSBL SHRA IN THE AFTN.
TUE...MVFR/IFR CIGS. SHRA IN THE AM.
WED...MVFR TO VFR.
THU...MVFR WITH CHC -SHRASN.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...GRUMM
NEAR TERM...GRUMM
SHORT TERM...GRUMM/DEVOIR
LONG TERM...MARTIN
AVIATION...BEACHLER

000
FXUS61 KPHI 220111
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
811 PM EST SAT NOV 21 2009

.SYNOPSIS...
HIGH PRESSURE WILL BUILD ACROSS THE NORTHEASTERN STATES TONIGHT
AND SUNDAY. THE HIGH SHOULD BECOME CENTERED OVER CANADA`S MARITIME
PROVINCES ON SUNDAY NIGHT, BEFORE DRIFTING OFF THE COAST. WEAK LOW
PRESSURE IS FORECAST TO DEVELOP OFF THE SOUTHEAST COAST ON SUNDAY
NIGHT AND MONDAY. THE LOW IS EXPECTED TO TRACK TO THE NORTHEAST
AND IT SHOULD PASS WELL TO THE EAST OF DELAWARE AND NEW JERSEY ON
TUESDAY. A COLD FRONT FROM THE WEST EXPECTED TO ARRIVE ON THURSDAY.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AT 8:00 PM, TEMPERATURES IN OUR REGION WERE MAINLY IN THE 40S WITH SOME
READINGS IN THE UPPER 30S IN INTER SNJ(PINE BARRENS). CLOUDS HAVE
MOVED SOUTHEAST TO THE POCONOS AND ABE AIRPORT BUT SHOULD BEGIN
ERODING IN A FEW HOURS WITH WAA AT 80H. WATER VAPOR LOOP SHOWS A
VERY THIN W-E BAND OF MID/UPPER LEVEL MOISTURE THAT IS DRYING OUT.
MOST OF THE CLOUDS ARE GENERALLY FROM 2,500 TO 4,5000 BASED CU/SC.

HIGH PRESSURE WILL CONTINUE TO BUILD INTO OUR REGION OVERNIGHT.
TEMPERATURES SHOULD DROP INTO THE MID 30S TO MID 40S RANGE.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
A STRENGTHENING HIGH IS FORECAST TO BE CENTERED UP IN THE SAINT
LAWRENCE RIVER VALLEY ON SUNDAY MORNING. IT SHOULD MOVE TO THE
CANADIAN MARITIMES FOR SUNDAY NIGHT.

WITH THE HIGH INFLUENCING OUR REGION, WE ARE ANTICIPATING A
MOSTLY SUNNY SKY FOR SUNDAY. AS THE CENTER OF THE HIGH MOVES TO
OUR NORTHEAST AND A SURFACE RIDGE BUILDS SOUTHWESTWARD ALONG THE
EAST COAST, AN ONSHORE FLOW WILL DEVELOP.

THE 12 UTC NAM AND THE 12 UTC GFS BOTH INDICATE AN INCREASE IN
LOW LEVEL MOISTURE FROM THE SOUTH ON SUNDAY NIGHT.

AS A COASTAL LOW MOVES UP FROM THE SOUTH ON MONDAY, THE PRESSURE
GRADIENT IS EXPECTED TO TIGHTEN. THE 12 UTC NAM IS A LITTLE
STRONGER AND CLOSER TO THE COAST WITH THE LOW THAN THE 12 UTC GFS
AND THE 12 UTC ECMWF. WE WILL FAVOR A COMPROMISE FOR THE TIME
BEING.

AS THE LOW APPROACHES, RAIN IS EXPECTED TO SPREAD INTO OUR REGION
FROM SOUTH TO NORTH ON MONDAY. THE RAIN SHOULD CONTINUE INTO
MONDAY NIGHT.

IT APPEARS AS THOUGH LOW LEVEL MOISTURE WILL LINGER IN OUR REGION
FOR TUESDAY. AS A RESULT, WE WILL MAINTAIN CHANCE POPS.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
ALL MODELS AGREE THAT A SIGNIFICANT CHANGE IN THE PATTERN OCCURS
DURING THE END OF THE WEEK. WE START OFF WITH A BROAD SW FLOW ON
THE EASTERN PORTION OF A MIDWEST TROUGH ON TUESDAY
NIGHT...EVENTUALLY THE MIDWEST TROUGH MOVES EAST, BUT DEEPENS AS
IT HEADS EAST. THE UPPER TROUGH THEN BECOMES CLOSED OFF AS IT
MOVES THROUGH THE REGION.

THIS MEANS THAT WE HAVE QUITE A BIT OF CLOUDS AND POSSIBLE
SHOWERS LATE TUESDAY NIGHT AND WEDNESDAY DUE TO MOISTURE SPREADING
OVER THE REGION WITHIN THE SW FLOW ALOFT. WEDNESDAY NIGHT THROUGH
THANKSGIVING AND INTO THURSDAY NIGHT, WE COULD SEE RAIN AS A
FRONTAL SYSTEM ASSOCIATED WITH THE UPPER TROUGH MOVES THROUGH FROM
THE WEST. THEN ON FRIDAY, COOLER DRIER AIR ARRIVES, BUT WE STILL
COULD HAVE RAIN SHOWERS WITH THE CYCLONIC FLOW ALOFT. FRIDAY NIGHT
AND SATURDAY, IT GETS COLD ENOUGH THAT SOME SNOW SHOWERS ARE
POSSIBLE NORTH, BUT THE REST OF THE AREA SHOULD BE DRY WITH
DOWNSLOPE NW FLOW. ALSO ON SATURDAY, IT SHOULD BE BREEZY/WINDY
WITH THE NW FLOW.

HPC PROGS HAVE THE SITUATION WELL IN HAND AND IN GENERAL THEIR
GUIDANCE HAS BEEN FOLLOWED.

&&

.AVIATION /01Z SUNDAY THROUGH THURSDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.

SOME OF THE STRATOCU FROM THE POCONOS WAS SHOWING IT WAS SPREADING
INTO AREAS NEAR ABE. THEREFORE, SCATTERED CLOUDS AROUND 25 HND FT
WILL BE FCST THERE WITH A TEMPO BKN GROUP UNTIL MIDNIGHT. THERE IS
THE POSSIBILITY OF SOME OF THESE CLOUDS GETTING INTO RDG, BUT
CONFIDENCE IS TOO LOW TO INCLUDE. OTHERWISE, SKIES HAVE CLEAR
THROUGHOUT THE REST OF THE AREA AND SHOULD REMAIN CLEAR OVERNIGHT.

THE STRATOCU NORTH SHOULD BE GONE BY MORNING, SO MOSTLY CLEAR
SKIES ARE EXPECTED FOR SUNDAY.

OUTLOOK...
CLOUDS WILL BEGIN TO LOWER AND PRECIPITATION IS EXPECTED TO MOVE
INTO THE AREA LATE SUNDAY NIGHT AND COULD LAST THROUGH LATE
TUESDAY OR WEDNESDAY. THIS COULD BRING LOWER CEILINGS AND/OR
VISIBILITIES FOR THE SHORT TERM.

&&

.MARINE...
HIGH PRESSURE WILL MOVE TO OUR NORTHEAST TONIGHT INTO SUNDAY,
WHILE AN AREA OF LOW PRESSURE DEVELOPS NEAR THE GULF STATES. THIS
LOW IS EXPECTED TO STRENGTHEN SUNDAY INTO MONDAY, THEN MOVE UP THE
EAST COAST ON MONDAY AND INTO TUESDAY. BETWEEN THE HIGH TO OUR
NORTH AND THE LOW TO OUR SOUTH, THE GRADIENT WILL TIGHTEN AND
NORTHEAST WINDS WILL STRENGTHEN FOR SUNDAY, MONDAY, THEN BEGIN
SLACKING ON TUESDAY. A PERSISTENT NORTHEAST FETCH WILL DEVELOP,
WHICH IS EXPECTED TO INCREASE THE SEAS OVER THE NEXT SEVERAL DAYS.
THEREFORE WE HAVE ISSUED A SMALL CRAFT ADVISORY STARTING LATE
SUNDAY AND CONTINUING THROUGH MONDAY AFTERNOON. FUTURE FORECASTS
WILL LIKELY NEED TO EXTEND THE ADVISORY. IN FACT, AN ADVISORY MAY
BE POSSIBLE FOR BASICALLY THE ENTIRE FORECAST PERIOD AS THERE ARE
SEVERAL STORM SYSTEMS CURRENTLY EXPECTED TO IMPACT THE AREA
THROUGH MUCH OF NEXT WEEK. WE WILL CONTINUE TO MONITOR THE
SITUATION IN CASE THIS COMES TO FRUITION.

&&

.TIDES/COASTAL FLOODING...
A PERSISTENT NORTHEAST FLOW OVER THE NEXT SEVERAL DAYS COULD HELP
TO INCREASE TIDE LEVELS FOR SUNDAY, MONDAY, AND TUESDAY. TIDE
LEVELS WILL HAVE TO BE MORE THAN 1.5 TO 2.0 FEET ABOVE THE
PREDICTED ASTRONOMICAL TIDE IN ORDER FOR MINOR TIDAL FLOODING TO
OCCUR. CURRENTLY, THE MODELS ARE FORECASTING AROUND 1.0 TO 1.5
FEET IN TIDAL ANOMALIES, SO MINOR TIDAL FLOODING IS NOT EXPECTED
AT THIS TIME. HOWEVER, IF THE LOW PRESSURE SYSTEM STRENGTHENS, THE
POSSIBILITY OF FLOODING COULD INCREASE. WE WILL CONTINUE TO
MONITOR THE FORECAST FOR ANY CHANGES.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 1 PM SUNDAY TO 6 PM EST MONDAY FOR
     ANZ452>455.
     SMALL CRAFT ADVISORY FROM 6 PM SUNDAY TO 6 PM EST MONDAY FOR
     ANZ450-451.

&&

$$
SYNOPSIS...IOVINO
NEAR TERM...EBERWINE/IOVINO
SHORT TERM...IOVINO
LONG TERM...STAUBER
AVIATION...ROBERTSON/STAUBER
MARINE...ROBERTSON
TIDES/COASTAL FLOODING...

000
FXUS61 KCTP 220058
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
758 PM EST SAT NOV 21 2009

.SYNOPSIS...

AN ANOMALOUS STRONG UPPER RIDGE WILL DOMINATE OUR WEATHER THROUGH
MID-WEEK. THEN A SERIES OF WAVES WILL CARVE OUT A TROUGH OVER
EASTERN NORTH AMERICA BEGINNING ABOUT THANKSGIVING. THE STRONG
TROUGH WHICH DEVELOPS BY THE WEEKEND AND THE RIDGE OVER WESTERN
NORTH AMERICA. IT WILL TURN COLDER AROUND THANKSGIVING.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...

UPDATED THE GRIDS AND WILL PUSH OUT A NEW ZONE SET BASED ON THESE
EDITS AS THE LOW CLOUDS ARE ERODING FAST. 3.9-11 MICRON DATA SHOWS
POTENTIAL CLEARING AS FAR NORTH AS STATE COLLEGE NOW. STILL LOTS
OF LOW CLOUDS ACROSS THE NORTH AND WEST.

PROFILES SHOW THE INVERSION NEAR 750-780 HPA WEAKENING A BIT AND
CONSIDERABLE DRYING BELOW THIS FEATURE. THIS WOULD FAVOR THE
IMPROVED WEATHER AND LESS CLOUDS OVER STATE COLLEGE AND POINTS
SOUTH AND EAST. HOWEVER THE BRADFORD PROFILE SUGGESTS IT WILL TAKE
A GOOD 6 TO 8 HOURS TO DRY OUT UP THERE.

ADDITIONALLY...THERE IS SOME POTENTIAL FOR VALLEY FOG AS THE T-TD
SPREAD IS SMALL. A GOOD PERIOD OF RADIATION WOULD HELP PRODUCE
SOME FOG. KEPT PATCHY FOG IN FORECAST.

OVERNIGHT LOWS WILL MAINLY BE UPPER 30 AND LOWER 40S. DEW POINTS
ARE MAINLY IN THE UPPER 30S AND LOWER 40S.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
MORNING PATCHY FOG WILL DISSIPATE BY MID TO LATE MORNING...AND
WITH CONTINUED RIDGING SFC AND ALOFT...EXPECT SKIES TO BECOME
PARTLY TO MOSTLY SUNNY EVERYWHERE WITH A MILDER AFTERNOON.
NAEFS GIVES HIGHER MAV MOS TEMPS...RANGING IN THE L/M50S MOST
SPOTS.

EXPECT INCREASING LLVL MOISTURE FROM DEEP EAST/SOUTHEAST FLOW
SUNDAY NIGHT AS SFC RIDGE TRACKS TOWARDS NEWFOUNDLAND BRINGING A
LARGE OVER WATER FETCH INTO THE MID ATLANTIC STATES. AT THE SAME
TIME...A DECAYING UPPER WAVE IMPINGING UPON THE UPPER RIDGE FROM
THE WEST OVER THE OHIO VALLEY WILL SPREAD DEEPER LAYER MOISTURE
ACROSS THE REGION BY LATE MONDAY. THE RESULT WILL BE A SLIGHT
CHANCE OF LIGHT RAIN BY DAWN MONDAY...WITH MUCH BETTER CHANCES
LATER MONDAY AS THE CAD IS WELL ESTABLISHED BELOW WAA ALOFT.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
MODELS HAVE WEAK SYSTEM LIFTING NE FROM THE GULF AREA LATER ON
MONDAY INTO TUE. DID SLOW THINGS DOWN SOME AND THINK BULK OF
ANY RAIN WOULD HOLD OFF TO AFT. DID CUT POPS BACK SOME. EXPECT
AMTS TO BE ON THE LIGHT SIDE.

SOME CLDS AND LIGHT RAIN...DRIZZLE FOR THE MOST PART...COULD
LINGER INTO TUE.

QUITE A BIT OF VARIATION IN MODEL SOLUTIONS. COULD SEE NORTHERN
AND WESTERN AREAS STAYING DRY.

FOR WED...CENTRAL PA IS BETWEEN SYSTEMS. GFS LOOKS FAST...
HPC NOT AS FAST... WEIGHTED FCST TO SLOWER SPEED.

OVERALL...ONLY MADE A FEW MINOR CHANGES TO THE PACKAGE.

FOR THU INTO SAT...TEMPS COOLING OFF CLOSER TO NORMAL...AS
RIDGE BUILDS ACROSS THE WESTERN STATES...AND MORE OF A TROUGH
PATTERN PREVAILS ACROSS THE EASTERN STATES. SOME RAIN AND
SNOW SHOWERS WILL BE POSSIBLE ACROSS THE MTS THU INTO FRIDAY.

ENOUGH RIDGING MAY TAKE PLACE ON SATURDAY...TO KEEP MOST OF THE
AREA DRY.

&&

.AVIATION /01Z SUNDAY THROUGH THURSDAY/...
IR IMAGERY INDICATING CONSIDERABLE STRATUS HOLDING ONTO THE ATMOS
OVER PA...EXPECT FOR THE SUSQ-VALLEY WHERE IT REMAINS FEW/SKC.
GUIDANCE SUGGESTS AS FLOW TURNS N/NE BNDRY LYR WILL DRY AND ERODE
STRATUS DECK BTWN 09-12Z. A FEW LOCATIONS COULD SEE PATCHY FG
DEV...HOWEVER EXPECT THIS TO BE LCL. ELSEWHERE ANTICIPATE SKIES TO
BOUNCE TO VFR CONDS AND PERSIST THRU 00Z MON.

OUTLOOK...
MON...MVFR LCL IFR. PSBL SHRA IN THE AFTN.
TUE...MVFR/IFR CIGS. SHRA IN THE AM.
WED...MVFR TO VFR.
THU...MVFR WITH CHC -SHRASN.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...GRUMM
NEAR TERM...GRUMM
SHORT TERM...DEVOIR
LONG TERM...MARTIN
AVIATION...BEACHLER

000
FXUS61 KCTP 212354
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
654 PM EST SAT NOV 21 2009

.SYNOPSIS...
HIGH PRESSURE WILL PROVIDE FAIR WEATHER THROUGH SUNDAY NIGHT.
STUBBORN CLOUDINESS WILL FINALLY GIVE WAY TO SUNSHINE OVER MOST
SECTIONS ON SUNDAY AHEAD OF A WEATHER SYSTEM THAT PROMISES TO
BRING RAIN STATEWIDE ON MONDAY. THIS SYSTEM WILL BE FOLLOWED BY A
SERIES OF DISTURBANCES WHICH ARE EXPECTED TO BRING COOLER WEATHER
TO THE REGION FOR THE HOLIDAY AND THROUGH THE HOLIDAY WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
NAM BUFKIT PROFILES CONTINUE TO SHOW A CLASSIC BOUNDARY LAYER
INVERSION AROUND THE 296K TO 298K LEVELS ACROSS CENTRAL AND
WESTERN PA BETWEEN 3K AND 5K FEET THIS AFTERNOON. AT THE SAME TIME...
AS CENTER OF 1023 MB SFC HIGH MOVES ONLY SLOWLY EASTWARD ACROSS THE
OHIO VALLEY...CORE OF THE COLDEST AIR AT 850 MB ASSOCIATED WITH 5H TROF
ALOFT IS SINKING SOUTHWARD TOWARDS THE LAURELS. ANY BREAKS IN THE
OVERCAST THAT DO FORM FROM THE CENTRAL AND SOUTH CENTRAL MOUNTAINS...
LAURELS...EXTENDING NWD ACROSS THE NORTHERN TIER QUICKLY FILL IN
AS A RESULT OF THE LOW LEVEL INSTABILITY. HOWEVER...THERE IS
ENOUGH DOWNSLOPING IN THE NNW FLOW ACROSS MY SOUTHEAST COUNTIES TO
KEEP P/C CONDS IN PLACE THROUGH TONIGHT.

AS THE COLD AIR DEPARTS TONIGHT...NAM FORECAST SOUNDINGS INDICATE
THE INVERSION WEAKENS...ALTHOUGH WILL HAVE TO DEAL WITH THE
TYPICAL DIURNAL SFC COOLING AND SHALLOW OVERNIGHT INVERSIONS EARLY
ON SUNDAY BEFORE BETTER MIXING AND BRIGHTER SKIES PREVAIL FOR
MOST.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
MORNING PATCHY FOG WILL DISSIPATE BY MID TO LATE MORNING...AND
WITH CONTINUED RIDGING SFC AND ALOFT...EXPECT SKIES TO BECOME
PARTLY TO MOSTLY SUNNY EVERYWHERE WITH A MILDER AFTERNOON.
NAEFS GIVES HIGHER MAV MOS TEMPS...RANGING IN THE L/M50S MOST
SPOTS.

EXPECT INCREASING LLVL MOISTURE FROM DEEP EAST/SOUTHEAST FLOW
SUNDAY NIGHT AS SFC RIDGE TRACKS TOWARDS NEWFOUNDLAND BRINGING A
LARGE OVER WATER FETCH INTO THE MID ATLANTIC STATES. AT THE SAME
TIME...A DECAYING UPPER WAVE IMPINGING UPON THE UPPER RIDGE FROM
THE WEST OVER THE OHIO VALLEY WILL SPREAD DEEPER LAYER MOISTURE
ACROSS THE REGION BY LATE MONDAY. THE RESULT WILL BE A SLIGHT
CHANCE OF LIGHT RAIN BY DAWN MONDAY...WITH MUCH BETTER CHANCES
LATER MONDAY AS THE CAD IS WELL ESTABLISHED BELOW WAA ALOFT.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
MODELS HAVE WEAK SYSTEM LIFTING NE FROM THE GULF AREA LATER ON
MONDAY INTO TUE. DID SLOW THINGS DOWN SOME AND THINK BULK OF
ANY RAIN WOULD HOLD OFF TO AFT. DID CUT POPS BACK SOME. EXPECT
AMTS TO BE ON THE LIGHT SIDE.

SOME CLDS AND LIGHT RAIN...DRIZZLE FOR THE MOST PART...COULD
LINGER INTO TUE.

QUITE A BIT OF VARIATION IN MODEL SOLUTIONS. COULD SEE NORTHERN
AND WESTERN AREAS STAYING DRY.

FOR WED...CENTRAL PA IS BETWEEN SYSTEMS. GFS LOOKS FAST...
HPC NOT AS FAST... WEIGHTED FCST TO SLOWER SPEED.

OVERALL...ONLY MADE A FEW MINOR CHANGES TO THE PACKAGE.

FOR THU INTO SAT...TEMPS COOLING OFF CLOSER TO NORMAL...AS
RIDGE BUILDS ACROSS THE WESTERN STATES...AND MORE OF A TROUGH
PATTERN PREVAILS ACROSS THE EASTERN STATES. SOME RAIN AND
SNOW SHOWERS WILL BE POSSIBLE ACROSS THE MTS THU INTO FRIDAY.

ENOUGH RIDGING MAY TAKE PLACE ON SATURDAY...TO KEEP MOST OF THE
AREA DRY.


&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
IR IMAGERY INDICATING CONSIDERABLE STRATUS HOLDING ONTO THE ATMOS
OVER PA...EXPECT FOR THE SUSQ-VALLEY WHERE IT REMAINS FEW/SKC.
GUIDANCE SUGGESTS AS FLOW TURNS N/NE BNDRY LYR WILL DRY AND ERODE
STRATUS DECK BTWN 09-12Z. A FEW LOCATIONS COULD SEE PATCHY FG
DEV...HOWEVER EXPECT THIS TO BE LCL. ELSEWHERE ANTICIPATE SKIES TO
BOUNCE TO VFR CONDS AND PERSIST THRU 00Z MON.

OUTLOOK...
MON...MVFR LCL IFR. PSBL SHRA IN THE AFTN.
TUE...MVFR/IFR CIGS. SHRA IN THE AM.
WED...MVFR TO VFR.
THU...MVFR WITH CHC -SHRASN.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...DEVOIR
NEAR TERM...DEVOIR
SHORT TERM...DEVOIR
LONG TERM...MARTIN
AVIATION...BEACHLER

000
FXUS61 KPHI 212333
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
633 PM EST SAT NOV 21 2009

.SYNOPSIS...
HIGH PRESSURE WILL BUILD ACROSS THE NORTHEASTERN STATES TONIGHT
AND SUNDAY. THE HIGH SHOULD BECOME CENTERED OVER CANADA`S MARITIME
PROVINCES ON SUNDAY NIGHT, BEFORE DRIFTING OFF THE COAST. WEAK LOW
PRESSURE IS FORECAST TO DEVELOP OFF THE SOUTHEAST COAST ON SUNDAY
NIGHT AND MONDAY. THE LOW IS EXPECTED TO TRACK TO THE NORTHEAST
AND IT SHOULD PASS WELL TO THE EAST OF DELAWARE AND NEW JERSEY ON
TUESDAY. A COLD FRONT FROM THE WEST EXPECTED TO ARRIVE ON THURSDAY.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AT 3:00 PM, TEMPERATURES IN OUR REGION WERE MAINLY IN THE 50S.
THERE WERE SOME READINGS IN THE 40S UP IN THE POCONOS. THE SKY WAS
MOSTLY SUNNY EXCEPT FOR THICK CIRRUS OVER PARTS OF THE DELMARVA
AND SOUTHERN NEW JERSEY. THERE WAS ALSO A LITTLE STRATOCUMULUS
POKING DOWN OVER THE POCONO REGION.

THE CIRRUS SHOULD CONTINUE TO DRIFT TO THE EAST AND OFF THE
COAST. MEANWHILE, SOME OF THE STRATOCUMULUS FROM THE NORTHWEST MAY
CONTINUE TO OVERSPREAD PARTS OF THE POCONO REGION INTO TONIGHT.

HIGH PRESSURE WILL CONTINUE TO BUILD INTO OUR REGION TONIGHT.
TEMPERATURES SHOULD DROP INTO THE 35 TO 45 DEGREE RANGE.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
A STRENGTHENING HIGH IS FORECAST TO BE CENTERED UP IN THE SAINT
LAWRENCE RIVER VALLEY ON SUNDAY MORNING. IT SHOULD MOVE TO THE
CANADIAN MARITIMES FOR SUNDAY NIGHT.

WITH THE HIGH INFLUENCING OUR REGION, WE ARE ANTICIPATING A
MOSTLY SUNNY SKY FOR SUNDAY. AS THE CENTER OF THE HIGH MOVES TO
OUR NORTHEAST AND A SURFACE RIDGE BUILDS SOUTHWESTWARD ALONG THE
EAST COAST, AN ONSHORE FLOW WILL DEVELOP.

THE 12 UTC NAM AND THE 12 UTC GFS BOTH INDICATE AN INCREASE IN
LOW LEVEL MOISTURE FROM THE SOUTH ON SUNDAY NIGHT.

AS A COASTAL LOW MOVES UP FROM THE SOUTH ON MONDAY, THE PRESSURE
GRADIENT IS EXPECTED TO TIGHTEN. THE 12 UTC NAM IS A LITTLE
STRONGER AND CLOSER TO THE COAST WITH THE LOW THAN THE 12 UTC GFS
AND THE 12 UTC ECMWF. WE WILL FAVOR A COMPROMISE FOR THE TIME
BEING.

AS THE LOW APPROACHES, RAIN IS EXPECTED TO SPREAD INTO OUR REGION
FROM SOUTH TO NORTH ON MONDAY. THE RAIN SHOULD CONTINUE INTO
MONDAY NIGHT.

IT APPEARS AS THOUGH LOW LEVEL MOISTURE WILL LINGER IN OUR REGION
FOR TUESDAY. AS A RESULT, WE WILL MAINTAIN CHANCE POPS.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
ALL MODELS AGREE THAT A SIGNIFICANT CHANGE IN THE PATTERN OCCURS
DURING THE END OF THE WEEK. WE START OFF WITH A BROAD SW FLOW ON
THE EASTERN PORTION OF A MIDWEST TROUGH ON TUESDAY
NIGHT...EVENTUALLY THE MIDWEST TROUGH MOVES EAST, BUT DEEPENS AS
IT HEADS EAST. THE UPPER TROUGH THEN BECOMES CLOSED OFF AS IT
MOVES THROUGH THE REGION.

THIS MEANS THAT WE HAVE QUITE A BIT OF CLOUDS AND POSSIBLE
SHOWERS LATE TUESDAY NIGHT AND WEDNESDAY DUE TO MOISTURE SPREADING
OVER THE REGION WITHIN THE SW FLOW ALOFT. WEDNESDAY NIGHT THROUGH
THANKSGIVING AND INTO THURSDAY NIGHT, WE COULD SEE RAIN AS A
FRONTAL SYSTEM ASSOCIATED WITH THE UPPER TROUGH MOVES THROUGH FROM
THE WEST. THEN ON FRIDAY, COOLER DRIER AIR ARRIVES, BUT WE STILL
COULD HAVE RAIN SHOWERS WITH THE CYCLONIC FLOW ALOFT. FRIDAY NIGHT
AND SATURDAY, IT GETS COLD ENOUGH THAT SOME SNOW SHOWERS ARE
POSSIBLE NORTH, BUT THE REST OF THE AREA SHOULD BE DRY WITH
DOWNSLOPE NW FLOW. ALSO ON SATURDAY, IT SHOULD BE BREEZY/WINDY
WITH THE NW FLOW.

HPC PROGS HAVE THE SITUATION WELL IN HAND AND IN GENERAL THEIR
GUIDANCE HAS BEEN FOLLOWED.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.

SOME OF THE STRATOCU FROM THE POCONOS WAS SHOWING IT WAS SPREADING
INTO AREAS NEAR ABE. THEREFORE, SCATTERED CLOUDS AROUND 25 HND FT
WILL BE FCST THERE WITH A TEMPO BKN GROUP UNTIL MIDNIGHT. THERE IS
THE POSSIBILITY OF SOME OF THESE CLOUDS GETTING INTO RDG, BUT
CONFIDENCE IS TOO LOW TO INCLUDE. OTHERWISE, SKIES HAVE CLEAR
THROUGHOUT THE REST OF THE AREA AND SHOULD REMAIN CLEAR OVERNIGHT.

THE STRATOCU NORTH SHOULD BE GONE BY MORNING, SO MOSTLY CLEAR
SKIES ARE EXPECTED FOR SUNDAY.

OUTLOOK...
CLOUDS WILL BEGIN TO LOWER AND PRECIPITATION IS EXPECTED TO MOVE
INTO THE AREA LATE SUNDAY NIGHT AND COULD LAST THROUGH LATE
TUESDAY OR WEDNESDAY. THIS COULD BRING LOWER CEILINGS AND/OR
VISIBILITIES FOR THE SHORT TERM.

&&

.MARINE...
HIGH PRESSURE WILL MOVE TO OUR NORTHEAST TONIGHT INTO SUNDAY,
WHILE AN AREA OF LOW PRESSURE DEVELOPS NEAR THE GULF STATES. THIS
LOW IS EXPECTED TO STRENGTHEN SUNDAY INTO MONDAY, THEN MOVE UP THE
EAST COAST ON MONDAY AND INTO TUESDAY. BETWEEN THE HIGH TO OUR
NORTH AND THE LOW TO OUR SOUTH, THE GRADIENT WILL TIGHTEN AND
NORTHEAST WINDS WILL STRENGTHEN FOR SUNDAY, MONDAY, THEN BEGIN
SLACKING ON TUESDAY. A PERSISTENT NORTHEAST FETCH WILL DEVELOP,
WHICH IS EXPECTED TO INCREASE THE SEAS OVER THE NEXT SEVERAL DAYS.
THEREFORE WE HAVE ISSUED A SMALL CRAFT ADVISORY STARTING LATE
SUNDAY AND CONTINUING THROUGH MONDAY AFTERNOON. FUTURE FORECASTS
WILL LIKELY NEED TO EXTEND THE ADVISORY. IN FACT, AN ADVISORY MAY
BE POSSIBLE FOR BASICALLY THE ENTIRE FORECAST PERIOD AS THERE ARE
SEVERAL STORM SYSTEMS CURRENTLY EXPECTED TO IMPACT THE AREA
THROUGH MUCH OF NEXT WEEK. WE WILL CONTINUE TO MONITOR THE
SITUATION IN CASE THIS COMES TO FRUITION.

&&

.TIDES/COASTAL FLOODING...
A PERSISTENT NORTHEAST FLOW OVER THE NEXT SEVERAL DAYS COULD HELP
TO INCREASE TIDE LEVELS FOR SUNDAY, MONDAY, AND TUESDAY. TIDE
LEVELS WILL HAVE TO BE MORE THAN 1.5 TO 2.0 FEET ABOVE THE
PREDICTED ASTRONOMICAL TIDE IN ORDER FOR MINOR TIDAL FLOODING TO
OCCUR. CURRENTLY, THE MODELS ARE FORECASTING AROUND 1.0 TO 1.5
FEET IN TIDAL ANOMALIES, SO MINOR TIDAL FLOODING IS NOT EXPECTED
AT THIS TIME. HOWEVER, IF THE LOW PRESSURE SYSTEM STRENGTHENS, THE
POSSIBILITY OF FLOODING COULD INCREASE. WE WILL CONTINUE TO
MONITOR THE FORECAST FOR ANY CHANGES.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 1 PM SUNDAY TO 6 PM EST MONDAY FOR
     ANZ452>455.
     SMALL CRAFT ADVISORY FROM 6 PM SUNDAY TO 6 PM EST MONDAY FOR
     ANZ450-451.

&&

$$
SYNOPSIS...IOVINO
NEAR TERM...IOVINO
SHORT TERM...IOVINO
LONG TERM...STAUBER
AVIATION...ROBERTSON/STAUBER
MARINE...ROBERTSON
TIDES/COASTAL FLOODING...ROBERTSON

000
FXUS61 KPBZ 212041
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
341 PM EST SAT NOV 21 2009

.SYNOPSIS...
HIGH PRESSURE WILL PROVIDE A DRY WEEKEND AS IT MOVES ACROSS THE
UPPER OHIO VALLEY. A LOW PRESSURE SYSTEM MOVING NORTHEASTWARD
ALONG THE ATLANTIC COAST MAY SPREAD SHOWERS AS FAR WEST AS
COMMUNITIES NEAR THE APPALACHIAN MOUNTAINS MONDAY INTO TUESDAY. A
LOW PRESSURE SYSTEM COMING EASTWARD FROM THE CANADIAN ROCKIES WILL
BRING SHOWERS STARTING TUESDAY NIGHT FOLLOWED BY COLDER TEMPERATURES
BY THANKSGIVING NIGHT.

&&

.NEAR TERM /THROUGH SUNDAY/...
ALTHOUGH RECENT SATELLITE IMAGES CONTINUE TO SHOW A FAIRLY
EXTENSIVE DECK OF STRATOCUMULUS CLOUDS ACROSS THE UPPER OHIO
VALLEY. THE CLOUDS REMAIN TRAPPED BENEATH A STRONG SUBSIDENCE
INVERSION. RECENT NAM MODEL PROFILES SHOW THE CLOUDS ERODING
OVERNIGHT. WITH THE LOW LEVEL HYDROLAPSE /VERTICAL HUMIDITY
PROFILE/ SHOWING MOISTURE INCREASING WITH HEIGHT...SUBSEQUENT
NOCTURNAL RADIATIONAL COOLING MAY LEAD TO FOG PATCHES BY EARLY
MORNING.

DURING DAYTIME SUNDAY...EXPECT JUST SCATTERED CLOUDS AND HENCE
CONSIDERABLE SUNSHINE.

FORECASTED TEMPERATURES TO BE MILDER THAN NORMALS USING CLOSE TO
RECENT BLEND OF GFS AND NAM MOS VALUES ALONG WITH SREF MODEL
OUTPUT.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
CONTINUE TO FORECAST A CHANCE OF SHOWERS EARLY MONDAY INTO TUESDAY NEAR
THE APPALACHIAN MOUNTAINS AS RECENT SREF MODEL OUTPUT CONTINUES TO
HAVE A FEW MEMBERS SHOWING RAIN SHOWERS FROM A COASTAL LOW
PRESSURE SYSTEM SPREADING INTO THE APPALACHIAN MOUNTAINS.

EXPECT THE REMAINDER OF THE UPPER OHIO VALLEY TO REMAIN DRY MONDAY
AND MONDAY NIGHT...BUT THERE IS A CHANCE THAT THE INITIAL SHOWERS
WITH THE LOW PRESSURE SYSTEM COMING EASTWARD FROM THE CANADIAN
ROCKIES CAN BEGIN SPREADING ACROSS THE UPPER OHIO VALLEY TUESDAY AFTERNOON.

FORECASTED TEMPERATURES TO CONTINUE WARMER THAN NORMAL AS
SUGGESTED BY RECENT GFS AND NAM MOS VALUES.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
LARGE UPPER LEVEL TROUGH WILL BE THE MAIN PLAYER IN THE EXTENDED
PORTION OF THE FORECAST. AS THE TROUGH DEVELOPS AND MOVES OVER THE
EAST COAST...THE DRY WEATHER AND ABOVE NORMAL TEMPERATURES THAT HAVE
PERSISTED FOR MUCH OF THE MONTH WILL COME TO AN END.

EVEN THOUGH MODELS ARE IN VERY GOOD AGREEMENT ABOUT THE DEVELOPMENT
OF THE UPPER LEVEL SYSTEM...THE ASSOCIATED SURFACE LOW PRESSURE
SOLUTIONS ARE QUITE VARIED IN THE MODELS. NEVERTHELESS...OVERCAST
CONDITIONS AND A CHANCE OF PRECIPITATION CAN BE EXPECTED FROM
WEDNESDAY ALL THE WAY INTO SATURDAY MORNING BEFORE HIGH PRESSURE
BUILDS IN.

TEMPERATURES SHOULD BE COLD ENOUGH THAT EACH NIGHT RAIN
MAY MIX WITH SNOW...BUT WARM GROUND TEMPERATURES WOULD LIKELY
PREVENT ANY ACCUMULATION. THE ONE EXCEPTION TO THIS COULD BE FRIDAY
NIGHT...WHEN FAVORABLE FLOW OFF LAKE ERIE WILL ALLOW FOR LAKE
ENHANCEMENT. AFTER SEASONABLE TEMPERATURES WEDNESDAY...EXPECT HIGHS
TO DROP TO 5-10 DEGREES BELOW NORMAL...WITH SEASONABLE LOW
TEMPERATURES.


&&

.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
CEILINGS CONTINUE TO HOVER RIGHT AROUND THE 3KFT MARK AT ALL TAF
SITES. THESE CLOUDS SHOULD EVENTUALLY BEGIN TO SCATTER OUT BY
SUNSET...WITH ADVANCING HIGH PRESSURE EXPECTED TO BRING IN DRIER
AIR. MVFR CIGS MAY STILL BE POSSIBLE SUNDAY MORNING AT FAVORED
LOCATIONS TO THE NORTH. PATCHY FOG IS POSSIBLE MAINLY IN THE RIVER
VALLEYS. HIGH PRESSURE SHOULD THEN ALLOW FOR VFR CONDITIONS TO
CONTINUE FOR THE REST OF SUNDAY.

A LOW PRESSURE SYSTEM MOVING UP THE EAST COAST SUNDAY NIGHT WILL
BRING THE NEXT CHANCE FOR SHOWERS WITH REDUCED CEILINGS
EXPECTED...ESPECIALLY SOUTHEAST OF A KMGW-KLBE LINE. REDUCED
CEILINGS WILL BE POSSIBLE ACROSS THE AREA ON TUESDAY THROUGH
THURSDAY WITH AN UPPER LEVEL SYSTEM DOMINATING THE WEATHER ACROSS
THE GREAT LAKES.


&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.

&&

$$

000
FXUS61 KCTP 212038
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
338 PM EST SAT NOV 21 2009

.SYNOPSIS...
HIGH PRESSURE WILL PROVIDE FAIR WEATHER THROUGH SUNDAY NIGHT.
STUBBORN CLOUDINESS WILL FINALLY GIVE WAY TO SUNSHINE OVER MOST
SECTIONS ON SUNDAY AHEAD OF A WEATHER SYSTEM THAT PROMISES TO
BRING RAIN STATEWIDE ON MONDAY. THIS SYSTEM WILL BE FOLLOWED BY A
SERIES OF DISTURBANCES WHICH ARE EXPECTED TO BRING COOLER WEATHER
TO THE REGION FOR THE HOLIDAY AND THROUGH THE HOLIDAY WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
NAM BUFKIT PROFILES CONTINUE TO SHOW A CLASSIC BOUNDARY LAYER
INVERSION AROUND THE 296K TO 298K LEVELS ACROSS CENTRAL AND
WESTERN PA BETWEEN 3K AND 5K FEET THIS AFTERNOON. AT THE SAME TIME...
AS CENTER OF 1023 MB SFC HIGH MOVES ONLY SLOWLY EASTWARD ACROSS THE
OHIO VALLEY...CORE OF THE COLDEST AIR AT 850 MB ASSOCIATED WITH 5H TROF
ALOFT IS SINKING SOUTHWARD TOWARDS THE LAURELS. ANY BREAKS IN THE
OVERCAST THAT DO FORM FROM THE CENTRAL AND SOUTH CENTRAL MOUNTAINS...
LAURELS...EXTENDING NWD ACROSS THE NORTHERN TIER QUICKLY FILL IN
AS A RESULT OF THE LOW LEVEL INSTABILITY. HOWEVER...THERE IS
ENOUGH DOWNSLOPING IN THE NNW FLOW ACROSS MY SOUTHEAST COUNTIES TO
KEEP P/C CONDS IN PLACE THROUGH TONIGHT.

AS THE COLD AIR DEPARTS TONIGHT...NAM FORECAST SOUNDINGS INDICATE
THE INVERSION WEAKENS...ALTHOUGH WILL HAVE TO DEAL WITH THE
TYPICAL DIURNAL SFC COOLING AND SHALLOW OVERNIGHT INVERSIONS EARLY
ON SUNDAY BEFORE BETTER MIXING AND BRIGHTER SKIES PREVAIL FOR
MOST.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
MORNING PATCHY FOG WILL DISSIPATE BY MID TO LATE MORNING...AND
WITH CONTINUED RIDGING SFC AND ALOFT...EXPECT SKIES TO BECOME
PARTLY TO MOSTLY SUNNY EVERYWHERE WITH A MILDER AFTERNOON.
NAEFS GIVES HIGHER MAV MOS TEMPS...RANGING IN THE L/M50S MOST
SPOTS.

EXPECT INCREASING LLVL MOISTURE FROM DEEP EAST/SOUTHEAST FLOW
SUNDAY NIGHT AS SFC RIDGE TRACKS TOWARDS NEWFOUNDLAND BRINGING A
LARGE OVER WATER FETCH INTO THE MID ATLANTIC STATES. AT THE SAME
TIME...A DECAYING UPPER WAVE IMPINGING UPON THE UPPER RIDGE FROM
THE WEST OVER THE OHIO VALLEY WILL SPREAD DEEPER LAYER MOISTURE
ACROSS THE REGION BY LATE MONDAY. THE RESULT WILL BE A SLIGHT
CHANCE OF LIGHT RAIN BY DAWN MONDAY...WITH MUCH BETTER CHANCES
LATER MONDAY AS THE CAD IS WELL ESTABLISHED BELOW WAA ALOFT.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
MODELS HAVE WEAK SYSTEM LIFTING NE FROM THE GULF AREA LATER ON
MONDAY INTO TUE. DID SLOW THINGS DOWN SOME AND THINK BULK OF
ANY RAIN WOULD HOLD OFF TO AFT. DID CUT POPS BACK SOME. EXPECT
AMTS TO BE ON THE LIGHT SIDE.

SOME CLDS AND LIGHT RAIN...DRIZZLE FOR THE MOST PART...COULD
LINGER INTO TUE.

QUITE A BIT OF VARIATION IN MODEL SOLUTIONS. COULD SEE NORTHERN
AND WESTERN AREAS STAYING DRY.

FOR WED...CENTRAL PA IS BETWEEN SYSTEMS. GFS LOOKS FAST...
HPC NOT AS FAST... WEIGHTED FCST TO SLOWER SPEED.

OVERALL...ONLY MADE A FEW MINOR CHANGES TO THE PACKAGE.

FOR THU INTO SAT...TEMPS COOLING OFF CLOSER TO NORMAL...AS
RIDGE BUILDS ACROSS THE WESTERN STATES...AND MORE OF A TROUGH
PATTERN PREVAILS ACROSS THE EASTERN STATES. SOME RAIN AND
SNOW SHOWERS WILL BE POSSIBLE ACROSS THE MTS THU INTO FRIDAY.

ENOUGH RIDGING MAY TAKE PLACE ON SATURDAY...TO KEEP MOST OF THE
AREA DRY.

OUTLOOK...
MON...MVFR LCL IFR. PSBL SHRA IN THE AFTN.
TUE...MVFR/IFR CIGS. SHRA IN THE AM.
WED...MVFR TO VFR.
THU...MVFR WITH CHC -SHRASN.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...DEVOIR
NEAR TERM...DEVOIR
SHORT TERM...DEVOIR
LONG TERM...MARTIN
AVIATION...DEVOIR/RXR

000
FXUS61 KPHI 212030
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
330 PM EST SAT NOV 21 2009

.SYNOPSIS...
HIGH PRESSURE WILL BUILD ACROSS THE NORTHEASTERN STATES TONIGHT
AND SUNDAY. THE HIGH SHOULD BECOME CENTERED OVER CANADA`S MARITIME
PROVINCES ON SUNDAY NIGHT, BEFORE DRIFTING OFF THE COAST. WEAK LOW
PRESSURE IS FORECAST TO DEVELOP OFF THE SOUTHEAST COAST ON SUNDAY
NIGHT AND MONDAY. THE LOW IS EXPECTED TO TRACK TO THE NORTHEAST
AND IT SHOULD PASS WELL TO THE EAST OF DELAWARE AND NEW JERSEY ON
TUESDAY. A COLD FRONT FROM THE WEST EXPECTED TO ARRIVE ON THURSDAY.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AT 3:00 PM, TEMPERATURES IN OUR REGION WERE MAINLY IN THE 50S.
THERE WERE SOME READINGS IN THE 40S UP IN THE POCONOS. THE SKY WAS
MOSTLY SUNNY EXCEPT FOR THICK CIRRUS OVER PARTS OF THE DELMARVA
AND SOUTHERN NEW JERSEY. THERE WAS ALSO A LITTLE STRATOCUMULUS
POKING DOWN OVER THE POCONO REGION.

THE CIRRUS SHOULD CONTINUE TO DRIFT TO THE EAST AND OFF THE
COAST. MEANWHILE, SOME OF THE STRATOCUMULUS FROM THE NORTHWEST MAY
CONTINUE TO OVERSPREAD PARTS OF THE POCONO REGION INTO TONIGHT.

HIGH PRESSURE WILL CONTINUE TO BUILD INTO OUR REGION TONIGHT.
TEMPERATURES SHOULD DROP INTO THE 35 TO 45 DEGREE RANGE.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
A STRENGTHENING HIGH IS FORECAST TO BE CENTERED UP IN THE SAINT
LAWRENCE RIVER VALLEY ON SUNDAY MORNING. IT SHOULD MOVE TO THE
CANADIAN MARITIMES FOR SUNDAY NIGHT.

WITH THE HIGH INFLUENCING OUR REGION, WE ARE ANTICIPATING A
MOSTLY SUNNY SKY FOR SUNDAY. AS THE CENTER OF THE HIGH MOVES TO
OUR NORTHEAST AND A SURFACE RIDGE BUILDS SOUTHWESTWARD ALONG THE
EAST COAST, AN ONSHORE FLOW WILL DEVELOP.

THE 12 UTC NAM AND THE 12 UTC GFS BOTH INDICATE AN INCREASE IN
LOW LEVEL MOISTURE FROM THE SOUTH ON SUNDAY NIGHT.

AS A COASTAL LOW MOVES UP FROM THE SOUTH ON MONDAY, THE PRESSURE
GRADIENT IS EXPECTED TO TIGHTEN. THE 12 UTC NAM IS A LITTLE
STRONGER AND CLOSER TO THE COAST WITH THE LOW THAN THE 12 UTC GFS
AND THE 12 UTC ECMWF. WE WILL FAVOR A COMPROMISE FOR THE TIME
BEING.

AS THE LOW APPROACHES, RAIN IS EXPECTED TO SPREAD INTO OUR REGION
FROM SOUTH TO NORTH ON MONDAY. THE RAIN SHOULD CONTINUE INTO
MONDAY NIGHT.

IT APPEARS AS THOUGH LOW LEVEL MOISTURE WILL LINGER IN OUR REGION
FOR TUESDAY. AS A RESULT, WE WILL MAINTAIN CHANCE POPS.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
ALL MODELS AGREE THAT A SIGNIFICANT CHANGE IN THE PATTERN OCCURS
DURING THE END OF THE WEEK. WE START OFF WITH A BROAD SW FLOW ON
THE EASTERN PORTION OF A MIDWEST TROUGH ON TUESDAY
NIGHT...EVENTUALLY THE MIDWEST TROUGH MOVES EAST, BUT DEEPENS AS
IT HEADS EAST. THE UPPER TROUGH THEN BECOMES CLOSED OFF AS IT
MOVES THROUGH THE REGION.

THIS MEANS THAT WE HAVE QUITE A BIT OF CLOUDS AND POSSIBLE
SHOWERS LATE TUESDAY NIGHT AND WEDNESDAY DUE TO MOISTURE SPREADING
OVER THE REGION WITHIN THE SW FLOW ALOFT. WEDNESDAY NIGHT THROUGH
THANKSGIVING AND INTO THURSDAY NIGHT, WE COULD SEE RAIN AS A
FRONTAL SYSTEM ASSOCIATED WITH THE UPPER TROUGH MOVES THROUGH FROM
THE WEST. THEN ON FRIDAY, COOLER DRIER AIR ARRIVES, BUT WE STILL
COULD HAVE RAIN SHOWERS WITH THE CYCLONIC FLOW ALOFT. FRIDAY NIGHT
AND SATURDAY, IT GETS COLD ENOUGH THAT SOME SNOW SHOWERS ARE
POSSIBLE NORTH, BUT THE REST OF THE AREA SHOULD BE DRY WITH
DOWNSLOPE NW FLOW. ALSO ON SATURDAY, IT SHOULD BE BREEZY/WINDY
WITH THE NW FLOW.

HPC PROGS HAVE THE SITUATION WELL IN HAND AND IN GENERAL THEIR
GUIDANCE HAS BEEN FOLLOWED.

&&

.AVIATION /21Z SATURDAY THROUGH THURSDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.

VFR CONDITIONS WILL CONTINUE THROUGH THE ENTIRE FORECAST PERIOD.
THERE WAS A FAIR AMOUNT OF CIRRUS TODAY ACROSS MUCH OF THE AREA,
BUT THIS SHOULD MOVE OUT OF THE AREA LATER TONIGHT, AND PROVIDE A
MOSTLY CLEAR FORECAST THROUGH TOMORROW. THE STRATOCUMULUS CLOUDS
TO OUR NORTH AND WEST NEVER MADE IT TO OUR ARA, AND WE ARE NOT
EXPECTING MUCH AT THIS TIME EITHER. WINDS ARE GENERALLY OUT OF THE
NORTHWEST TONIGHT, AND WILL GRADUALLY SWITCH TO THE NORTH, THEN
NORTHEAST TOMORROW. THE WINDS MAY ACTUALLY BEGIN TO INCREASE IN
THE AFTERNOON SUNDAY, AND POSSIBLY A LITTLE GUSTY IN SOME AREAS.
HOWEVER, WINDS SHOULD REMAIN BELOW 15 KT. THERE MAY BE A BRIEF
PERIOD OF LOWER VISIBILITY IN FOG TOWARD MORNING IN SOME ISOLATED
AREAS, BUT WE ONLY HAVE IT IN THE RDG TAF AT THIS TIME.

OUTLOOK...
CLOUDS WILL BEGIN TO LOWER AND PRECIPITATION IS EXPECTED TO MOVE
INTO THE AREA LATE SUNDAY NIGHT AND COULD LAST THROUGH LATE
TUESDAY OR WEDNESDAY. THIS COULD BRING LOWER CEILINGS AND/OR
VISIBILITIES FOR THE SHORT TERM.

&&

.MARINE...
HIGH PRESSURE WILL MOVE TO OUR NORTHEAST TONIGHT INTO SUNDAY,
WHILE AN AREA OF LOW PRESSURE DEVELOPS NEAR THE GULF STATES. THIS
LOW IS EXPECTED TO STRENGTHEN SUNDAY INTO MONDAY, THEN MOVE UP THE
EAST COAST ON MONDAY AND INTO TUESDAY. BETWEEN THE HIGH TO OUR
NORTH AND THE LOW TO OUR SOUTH, THE GRADIENT WILL TIGHTEN AND
NORTHEAST WINDS WILL STRENGTHEN FOR SUNDAY, MONDAY, THEN BEGIN
SLACKING ON TUESDAY. A PERSISTENT NORTHEAST FETCH WILL DEVELOP,
WHICH IS EXPECTED TO INCREASE THE SEAS OVER THE NEXT SEVERAL DAYS.
THEREFORE WE HAVE ISSUED A SMALL CRAFT ADVISORY STARTING LATE
SUNDAY AND CONTINUING THROUGH MONDAY AFTERNOON. FUTURE FORECASTS
WILL LIKELY NEED TO EXTEND THE ADVISORY. IN FACT, AN ADVISORY MAY
BE POSSIBLE FOR BASICALLY THE ENTIRE FORECAST PERIOD AS THERE ARE
SEVERAL STORM SYSTEMS CURRENTLY EXPECTED TO IMPACT THE AREA
THROUGH MUCH OF NEXT WEEK. WE WILL CONTINUE TO MONITOR THE
SITUATION IN CASE THIS COMES TO FRUITION.

&&

.TIDES/COASTAL FLOODING...
A PERSISTENT NORTHEAST FLOW OVER THE NEXT SEVERAL DAYS COULD HELP
TO INCREASE TIDE LEVELS FOR SUNDAY, MONDAY, AND TUESDAY. TIDE
LEVELS WILL HAVE TO BE MORE THAN 1.5 TO 2.0 FEET ABOVE THE
PREDICTED ASTRONOMICAL TIDE IN ORDER FOR MINOR TIDAL FLOODING TO
OCCUR. CURRENTLY, THE MODELS ARE FORECASTING AROUND 1.0 TO 1.5
FEET IN TIDAL ANOMALIES, SO MINOR TIDAL FLOODING IS NOT EXPECTED
AT THIS TIME. HOWEVER, IF THE LOW PRESSURE SYSTEM STRENGTHENS, THE
POSSIBILITY OF FLOODING COULD INCREASE. WE WILL CONTINUE TO
MONITOR THE FORECAST FOR ANY CHANGES.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 1 PM SUNDAY TO 6 PM EST MONDAY FOR
     ANZ452>455.
     SMALL CRAFT ADVISORY FROM 6 PM SUNDAY TO 6 PM EST MONDAY FOR
     ANZ450-451.

&&

$$

SYNOPSIS/NEAR TERM/SHORT TERM...IOVINO
LONG TERM...STAUBER
AVIATION/MARINE...ROBERTSON
TIDES/COASTAL FLOODING...ROBERTSON

000
FXUS61 KCTP 211929
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
229 PM EST SAT NOV 21 2009

.SYNOPSIS...
HIGH PRESSURE WILL PROVIDE FAIR WEATHER THROUGH SUNDAY NIGHT.
STUBBORN CLOUDINESS WILL FINALLY GIVE WAY TO SUNSHINE OVER MOST
SECTIONS ON SUNDAY AHEAD OF A WEATHER SYSTEM THAT PROMISES TO
BRING RAIN STATEWIDE ON MONDAY. THIS SYSTEM WILL BE FOLLOWED BY A
SERIES OF DISTURBANCES WHICH ARE EXPECTED TO BRING COOLER WEATHER
TO THE REGION FOR THE HOLIDAY AND THROUGH THE HOLIDAY WEEKEND.


&&

.NEAR TERM /THROUGH TONIGHT/...
NAM BUFKIT PROFILES CONTINUE TO SHOW A CLASSIC BOUNDARY LAYER
INVERSION AROUND THE 296K TO 298K LEVELS ACROSS CENTRAL AND
WESTERN PA BETWEEN 3K AND 5K FEET THIS AFTERNOON. AT THE SAME TIME...
AS CENTER OF 1023 MB SFC HIGH MOVES ONLY SLOWLY EASTWARD ACROSS THE
OHIO VALLEY...CORE OF THE COLDEST AIR AT 850 MB ASSOCIATED WITH 5H TROF
ALOFT IS SINKING SOUTHWARD TOWARDS THE LAURELS. ANY BREAKS IN THE
OVERCAST THAT DO FORM FROM THE CENTRAL AND SOUTH CENTRAL MOUNTAINS...
LAURELS...EXTENDING NWD ACROSS THE NORTHERN TIER QUICKLY FILL IN
AS A RESULT OF THE LOW LEVEL INSTABILITY. HOWEVER...THERE IS
ENOUGH DOWNSLOPING IN THE NNW FLOW ACROSS MY SOUTHEAST COUNTIES TO
KEEP P/C CONDS IN PLACE THROUGH TONIGHT.

AS THE COLD AIR DEPARTS TONIGHT...NAM FORECAST SOUNDINGS INDICATE
THE INVERSION WEAKENS...ALTHOUGH WILL HAVE TO DEAL WITH THE
TYPICAL DIURNAL SFC COOLING AND SHALLOW OVERNIGHT INVERSIONS EARLY
ON SUNDAY BEFORE BETTER MIXING AND BRIGHTER SKIES PREVAIL FOR
MOST.

&&

.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
MORNING PATCHY FOG WILL DISSIPATE BY MID TO LATE MORNING...AND
WITH CONTINUED RIDGING SFC AND ALOFT...EXPECT SKIES TO BECOME
PARTLY TO MOSTLY SUNNY EVERYWHERE WITH A MILDER AFTERNOON.
NAEFS GIVES HIGHER MAV MOS TEMPS...RANGING IN THE L/M50S MOST
SPOTS.

EXPECT INCREASING LLVL MOISTURE FROM DEEP EAST/SOUTHEAST FLOW
SUNDAY NIGHT AS SFC RIDGE TRACKS TOWARDS NEWFOUNDLAND BRINGING A
LARGE OVER WATER FETCH INTO THE MID ATLANTIC STATES. AT THE SAME
TIME...A DECAYING UPPER WAVE IMPINGING UPON THE UPPER RIDGE FROM
THE WEST OVER THE OHIO VALLEY WILL SPREAD DEEPER LAYER MOISTURE
ACROSS THE REGION BY LATE MONDAY. THE RESULT WILL BE A SLIGHT
CHANCE OF LIGHT RAIN BY DAWN MONDAY...WITH MUCH BETTER CHANCES
LATER MONDAY AS THE CAD IS WELL ESTABLISHED BELOW WAA ALOFT.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
AN ACTIVE SPLIT FLOW PATTERN IS FCST TO CONTINUE THROUGH MUCH OF THE
PD BY LONG TERM GUIDANCE. SEVERAL UPR LEVEL TROFS ARE FORECAST TO
TRAVERSE THE CONUS IN BOTH THE NRN AND SRN STREAM FLOW WITH
VARYING LEVELS OF INFLUENCE ON PA. OVERALL HOWEVER...MOST OF THE
NEXT WEEK LOOKS TO BE DRY WITH CONTINUED ABOVE NORMAL TEMPERATURES.

THE FIRST TROF...IN THE SRN STREAM...IS FCST TO MOVE ACROSS THE GULF
COAST TDY...THEN LIFT NE ALONG THE MID ATLC COAST LATE SUNDAY.
THE WAVE WILL BE LIFTING INTO THE NRN STREAM MEAN UPR RIDGE WITH
HIGH PRESSURE IN PLACE AT THE SFC. MODEL TRENDS ARE FOR A
SMALLER...FARTHER EAST SOLUTION OF THE SFC LOW ASSCD WITH THE SRN
TROF AND FORECASTS DRIER THAN PVS RUNS. GFS APPEARS AN OUTLIER
WITH A SIG WET FORECAST FOR MONDAY ACROSS MUCH OF PA...AND SUCH
HAVE LOWERED POPS FOR THIS TIME PD FOLLOWING THE MULTITUDE OF
OTHER LONG TERM GUIDANCE.

HIGHEST ENSEMBLE POPS ARE MONDAY DURING THE DAY INTO MONDAY
NIGHT. SOME TIMING ISSUES. LOWERED THE POPS INTO THE 30-50 PERCENT
RANGE MONDAY DURING THE DAY AND UPPED THEM MONDAY NIGHT INTO
TUESDAY DUE TO THE UNCERTAINTY IN THE TIMING. PRETTY WEAK SYSTEM
AND THE RAIN SHOULD BE VERY LIGHT.

AMPLIFICATION IN THE NRN STREAM IS FCST TO OCCUR OVER THE GREAT
LAKES BY TUE...WITH A WEAKENING SFC FRONT REACHING WRN ON WED AS
SUPPORTING CLOSED UPPER TROF LIFTS INTO SERN CANADA. A STRONGER UPR
TROF/COLD FRONT IS FCST TO MOVE THROUGH PA THANKSGIVING NIGHT...IF
CURRENT TIMING HOLDS...WITH A NOTICEABLE COOL DOWN IN STORE FOR
SHOPPERS NEXT FRIDAY. ANY SHOWER ACTIVITY OVER NW PA COULD BE IN
THE FORM OF SNOW THUR-FRI AS 850 TEMPERATURES FALL BELOW 0C.

&&

.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
MOISTURE TRAPPED UNDER SUBSIDENCE INVERSION WILL KEEP SOME MVFR
CIGS FOR SEVERAL HOURS INTO THIS EVENING AND OVERNIGHT ACROSS
CENTRAL AND WESTERN SECTIONS. VFR WILL BE THE RULE IN THE EAST
WITH SLIGHT DOWNSLOPE COMPONENT IN LIGHT WESTERLY WINDS. CLOUDS
WILL INCREASE LATER SUNDAY AND SUNDAY NIGHT AS DEEP EASTERLY FLOW
COMBINED WITH OVERRUNNING MOISTURE FROM THE OHIO VALLEY BRING MVFR CIGS
LATE SUNDAY INTO MONDAY MORNING...FOLLOWED BY WIDESPREAD MVFR/IFR
CIGS AND CHC OF R- THROUGH MONDAY NIGHT.

OUTLOOK...
MON...MVFR LCL IFR. PSBL SHRA IN THE AFTN.
TUE...MVFR/IFR CIGS. SHRA IN THE AM.
WED...MVFR TO VFR.
THU...MVFR WITH CHC -SHRASN.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...DEVOIR
NEAR TERM...DEVOIR
SHORT TERM...DEVOIR
LONG TERM...GRUMM/GARTNER
AVIATION...DEVOIR/RXR

000
FXUS61 KPHI 211505
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1005 AM EST SAT NOV 21 2009

.SYNOPSIS...
HIGH PRESSURE OVER THE OHIO RIVER VALLEY THIS MORNING WILL
STRENGTHEN AND BUILD TOWARD NEW ENGLAND THROUGH THE WEEKEND, THEN
RECEDE EAST SLOWLY. LOW PRESSURE WILL DEVELOP OFF THE SOUTHEAST
COAST ON MONDAY AND MOVE NORTH SLOWLY, PASSING BY TO THE EAST ON
TUESDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HIGH PRESSURE, LOCATED OVER THE OHIO RIVER VALLEY THIS MORNING,
WILL CONTINUE TO BUILD SLOWLY TO THE EAST AND NORTHEAST THIS
AFTERNOON.

AT 10:00 AM, HIGH CLOUDS COVERED OUR FORECAST AREA. THE CIRRUS
OVERHEAD IS EXPECTED TO THIN A BIT FOR THIS AFTERNOON AS THE
ENTIRE CLOUD SHIELD DRIFTS TO THE EAST. MEANWHILE, SOME
STRATOCUMULUS MAY NUDGE DOWN FROM THE NORTHWEST AND OVER SOME OF
OUR COUNTIES IN EASTERN PENNSYLVANIA AND NORTHERN NEW JERSEY. ALL
IN ALL, A PARTLY SUNNY FORECAST SHOULD COVER THE SITUATION.

IT CONTINUES TO APPEAR AS THOUGH AFTERNOON TEMPERATURES IN OUR
REGION WILL BE MAINLY IN THE 50S.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
THE WEAK MID LEVEL LOW DRIFTS TOWARDS US TONIGHT, AND AGAIN THE
MODEL SOUNDINGS HOLD ONTO SOME LOW LEVEL MOISTURE, ESPECIALLY BUT
NOT EXCLUSIVELY NORTHWEST, WHILE SOME HIGH LEVEL MOISTURE
APPROACHES AHEAD OF THE NEXT SYSTEM THAT IS ADVANCING IN THE
SOUTHERN STREAM. WE GO WITH SOMEWHAT MORE CLOUDINESS NORTHWEST AND
SOUTH THAN ELSEWHERE, BUT WE ALLOW FOR THE POSSIBILITY OF SOME
DECOUPLING AND RADIATING OVER THE NORMAL RADIATING SPOTS ON THE
MIN TEMPERATURES. ELSEWHERE, WE STAY WITH THE CONTINUITY/GUIDANCE
COMBINATION. WINDS ARE EXPECTED TO BE LIGHT.

ON SUNDAY, THE MID LEVEL LOW OVER US AND A MID LEVEL HIGH TO ITS NORTH
VERY MUCH RESEMBLE A REX BLOCK, AND THIS ACTUALLY SEEMS TO ALLOW A
LITTLE RIDGING UPSTREAM OF US THAT SLOWS DOWN ADVANCING ENERGY
FROM THE SOUTHERN STREAM. WE HAVE BACKED DOWN A BIT ON OUR SUNDAY
POPS IN RESPONSE, AND NOW WE ONLY CARRY A SLIGHT CHANCE FAR SOUTH.
WE DO INCREASE THE CLOUDS SOME DOWN SOUTH, BUT WE BACK OFF ON THAT
TREND NORTH. THE GRADIENT LOOKS TO BEGIN TO TIGHTEN A BIT,
ESPECIALLY SOUTH, BETWEEN THE STRENGTHENING SURFACE HIGH TO THE
NORTH AND NASCENT SURFACE TROUGHING OFF THE SOUTHEAST COAST. THE
COOLER H925 TEMPS OFF THE NAM HAVE GOOD SUPPORT FROM THE 00Z
ECMWF, AND SO WE HAVE LEANED TOWARD THE COOLER MET STAT GUIDANCE
WITH REGARD TO MAXES.

ON SUNDAY NIGHT, THE MODELS START TO DIFFER ON WHETHER THE REX
BLOCK CONTINUES TO SLOW THE PROGRESS OF SOUTHERN STREAM ENERGY OR
THE ENERGY GETS PULLED TOWARD THE LOW PRESSURE PART OF SAID BLOCK.
EVEN THE MODELS THAT FAVOR THE LATTER SOLUTION HAVE SLOWED DOWN
THE PROGRESS OF MOISTURE, I295 ISENTROPIC LIFT AND LOWER LEVEL
FRONTOGENESIS, SO WE CONTINUED THE TREND OF BACKING OFF SOME ON
THE POPS. WE DO BRING IN MORE CLOUDINESS. WE LEANED TOWARD THE
COOLER MET STAT GUIDANCE AGAIN ON THE MINS, BASICALLY FOR THE SAME
REASON THAT WE SITED FOR SUNDAY.

ON MONDAY INTO MONDAY NIGHT, THERE IS SOME AGREEMENT THAT
ISENTROPIC LIFT MOVES ACROSS THE AREA, FRONTOGENESIS STRENGTHENS
/ESPECIALLY OFF THE COAST/ AND Q-VECTOR CONVERGENCE DEVELOPS
/AGAIN, ESPECIALLY OFF THE COAST/. THE MID LEVEL BLOCK IS PROGGED
TO LIFT NORTHEAST AND OPEN, AND SURFACE LOW PRESSURE IS PROGGED TO
DEVELOP AND LIFT FROM THE SOUTHEAST COAST ON MONDAY TO SOMEWHERE
OFF THE MID ATLANTIC COAST LATE MONDAY NIGHT. HOW ORGANIZED THAT
LOW GETS IS UP IN THE AIR, BUT EVEN THE WEAKER ECMWF HAS A DECENT
PRESSURE GRADIENT BETWEEN THE LOW AND THE HIGH TO THE NORTH. WE
HAVE GONE WITH POPS THAT RANGE FROM LIKELY SOUTHEAST TO CHANCE
ELSEWHERE AS THE INDICATION SEEMS TO BE THAT THE BULK OF THE
PRECIPITATION WILL FALL OFF THE COAST. WE DO CARRY A FAIRLY STRONG
NORTHEAST FLOW IN THIS REGIME, BUT HOPEFULLY NOTHING LIKE WE DEALT
WITH AROUND VETERAN`S DAY. WE GENERALLY CONTINUE TO LEAN TOWARD
THE COOLER GUIDANCE.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
FOLLOWING TRENDS FROM HPC WHICH GENERALLY WENT WITH THE ECMWF SHOWED
LOW PRESSURE MOVING AWAY FROM THE AREA LATE MONDAY NIGHT WITH HIGH
PRESSURE IN EASTERN CANADA EXTENDING SOUTH OVER THE REGION. THIS
SHOULD MEAN DRYING TRENDS LATE MONDAY NIGHT WITH A DRY DAY ON
TUESDAY. TUESDAY NIGHT AND WEDNESDAY WILL SEE ANOTHER FRONT FROM THE
WEST MOVE EAST. THIS FRONT SHOULD CROSS THE REGION WEDNESDAY AFTN.
WITH THE WARM ADVECTION AHEAD OF THE FRONT LATE TUESDAY NIGHT COULD
SEE SOME RAIN AND SHOWERS ARE POSSIBLE DURING THE DAY WEDNESDAY.

FOR THANKSGIVING, AN UPPER TROUGH DIGS INTO THE WESTERN GREAT LAKES.
WE HAVE WARM ADVECTION OVER THE AREA AND DUE TO THIS COMBINATION THE
FORECAST WILL INCLUDE A CHANCE OF SHOWERS.

THURSDAY NIGHT, A STRONG COLD FRONT MOVES THROUGH FROM THE NW AND WE
GET INTO A COLD ADVECTION PATTERN FOR FRIDAY WITH CYCLONIC FLOW
ALOFT AND VERY COOL TEMPERATURES ON FRIDAY. OVER THE FAR NORTHERN
ZONES, THERE IS A CHANCE OF RAIN OR SNOW SHOWERS ON FRIDAY.

HPC TEMPS ARE GENLY REASONABLE.

&&

.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.

VFR FLYING CONDITIONS WILL SUPPORT AVIATION INTERESTS TODAY AND
TONIGHT, AND PROBABLY SUNDAY MORNING AS WELL.

SURFACE HIGH PRESSURE OVER THE EASTERN OHIO VALLEY THIS MORNING
WILL STRENGTHEN SLIGHTLY THIS AFTERNOON AND TONIGHT AS IT DRIFTS
NORTHEASTWARD. THIS HIGH WILL INITIALLY BE UNDERNEATH AN UPPER
TROUGH OVER THE GREAT LAKES AND OHIO VALLEY. THE SOUTHWEST FLOW
AHEAD OF THIS TROUGH WAS KICKING SOME JET STREAM CIRRUS
NORTHEASTWARD INTO OUR AREA EARLY THIS MORNING. HOWEVER, PROBABLY
A GOOD BIT OF THIS WILL BE THIN TODAY. SO, OTHER THAN SOME
CIRRUS, A FEW CUMULUS MAY FORM TOWARD MIDDAY AND LINGER INTO THE
AFTERNOON. A DRY ATMOSPHERE WILL MEAN NO TENDENCY FOR FOG
FORMATION EARLY THIS MORNING. WEST WINDS EARLY THIS MORNING WILL
BECOME NORTHWEST LATER THIS MORNING AND CONTINUE THIS AFTERNOON,
VEERING TO NORTH BY DARK. SUSTAINED WIND SPEEDS SHOULD BE MOSTLY
UNDER 10 KNOTS TODAY.

OUTLOOK...
DRY WEATHER IS FORECAST TO CONTINUE SUNDAY. A CHANCE OF RAIN IS
EXPECTED SUNDAY NIGHT AS LOW PRESSURE WILL MOVE OFF THE SOUTHEAST
U.S. COAST SUNDAY NIGHT AND DEVELOP NORTHWARD MONDAY...AND PERHAPS
REMAIN JUST OFF THE MID ATLANTIC COAST MONDAY NIGHT AND TUESDAY TO
PLAGUE OUR AREA WITH AN OCEANIC FLOW.

&&

.MARINE...
WIND GUSTS AND SEAS WERE UNDER SMALL CRAFT ADVISORY CRITERIA THIS
MORNING AND SHOULD LESSEN SOMEWHAT DURING TODAY AS HIGH PRESSURE
CENTERED JUST TO OUR WEST EARLY THIS MORNING IS FORECAST TO BUILD
NORTHEASTWARD TONIGHT AND SUNDAY. LOW PRESSURE IS THEN EXPECTED TO
MOVE NORTHWARD ALONG OR NEAR THE COAST LATER SUNDAY AND MONDAY AND
REMAIN INTO TUESDAY. RIGHT NOW THIS LOW LOOKS LIKE IT WILL NOT
BECOME TOO STRONG, BUT AT LEAST STRONG ENOUGH FOR ADVISORY LEVEL
WINDS AND SEAS, WITH THE SUNDAY NIGHT INTO TUESDAY TIME FRAME
BEING THE PRIME TIME. HOWEVER, THE GRADIENT MAY BE TIGHT ENOUGH
OVER OUR SOUTHERN WATERS LATER SUNDAY TO WARRANT A SMALL CRAFT
ADVISORY. WAVEWATCH HAS BEEN CONSISTENT IN BUILDING SEAS TO 5 FEET
SUNDAY AFTERNOON, SO A SMALL CRAFT ADVISORY WILL BE ISSUED WITH
THIS MORNING/S PACKAGE FROM LITTLE EGG INLET SOUTH FOR SUNDAY
AFTERNOON (OUR THIRD PERIOD) AND CONTINUED THROUGH SUNDAY NIGHT
FOR NOW (OUR FOURTH PERIOD). THIS WILL LIKELY HAVE TO BE EXTENDED
IN TIME AS WELL AS GEOGRAPHICALLY. OUR NORTHERN WATERS DON/T LOOK
TO START BEFORE SUNDAY NIGHT (WHICH IS OUR FOURTH PERIOD AND TOO
FAR IN ADVANCE TO START AN ADVISORY); LOWER (OR MAYBE EVEN ALL OF)
DELAWARE BAY COULD NEED AN ADVISORY AS WELL. ONCE IT STARTS,
WAVEWATCH HAS ADVISORY LEVEL SEAS THROUGH THIS COMING WEEK.
OBVIOUSLY, CONFIDENCE IS PRETTY LOW AFTER MONDAY AND TUESDAY.

&&

.TIDES/COASTAL FLOODING...
TIDAL ANOMALIES ARE LIKELY TO INCREASE AGAIN IN RESPONSE TO AN
EXPECTED DEVELOPING ONSHORE FLOW SUNDAY AND PARTICULARLY SUNDAY
NIGHT THROUGH MONDAY NIGHT. LOW PRESSURE FORECAST TO DEVELOP TO OUR
SOUTHEAST WILL CONTRAST WITH HIGH PRESSURE OVER NORTHERN NEW ENGLAND
AND THE CANADIAN MARITIMES. AVIATION STORM SURGE GUIDANCE IS
PROBABLY UNDERDONE AT THIS EARLY STAGE, AND ANOMALIES MAY RISE TO
AROUND 1 FOOT ABOVE NORMAL. THE TIME PERIOD OF CONCERN WILL BE
SUNDAY NIGHT INTO TUESDAY; THIS PERIOD IS BETWEEN NEW MOON AND FULL
MOON, SO THE ASTRONOMICAL TIDES ARE NOT AS HIGH AS THEY WERE LAST
WEEK. UNDER NORMAL CIRCUMSTANCES, THIS WOULDN`T POSE ANY PROBLEMS,
BUT WITH THE SEVERE BEACH EROSION THAT OCCURRED WITH LAST WEEK`S
STORM, IT MAY BE THAT LOWER TIDAL ANOMALIES WILL HAVE AN EFFECT WHEN
THEY ORDINARILY WOULD NOT. IT IS STILL TO BE DETERMINED WHETHER THIS
MIGHT CAUSE ANY LEVEL OF TIDAL FLOODING, SO THE SITUATION WILL BE
CLOSELY MONITORED DURING THIS WEEKEND.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 1 PM SUNDAY TO 6 AM EST MONDAY FOR
     ANZ452>455.

&&

$$

SYNOPSIS...DELISI
NEAR TERM...IOVINO
SHORT TERM...DELISI
LONG TERM...STAUBER

000
FXUS61 KCTP 211356
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
856 AM EST SAT NOV 21 2009

.SYNOPSIS...
HIGH PRESSURE SHOULD PROVIDE RELATIVELY DRY WEATHER OVER THE
REGION THROUGH SUNDAY. EASTERLY FLOW AND A WAVE COMING OUT OF THE
GULF SHOULD INCREASE THE CHANCE OF RAIN LATE SUNDAY INTO MONDAY.
THE PATTERN OVER NORTH AMERICA IS CHANGING...THE ENSEMBLES SHOW A
TROUGH ATTEMPTING TO ESTABLISH ITSELF OVER EASTERN NORTH AMERICA
WITH A RIDGE OVER NORTHWESTERN CANADA. A SERIES OF WAVES WILL CARVE
OUT THE TROUGH BRINGING UNSETTLED WEATHER TO THE REGION NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
NAM BUFKIT PROFILES SHOW A CLASSIC BOUNDARY LAYER INVERSION AROUND
THE 296K TO 298K LEVELS ACROSS CENTRAL AND WESTERN PA BETWEEN 3K
AND 5K FEET. WITH CENTER OF 1023 MB SFC HIGH MOVING ONLY SLOWLY
EASTWARD ACROSS THE OHIO VALLEY TODAY...DO NOT EXPECT SUBSTANTIAL
ENOUGH MIXING TO CLEAR THE STRATUS FROM THE CENTRAL AND SOUTH
CENTRAL MOUNTAINS WESTWARD ACROSS THE ALLEGHENIES...BUT THERE
SHOULD BE ENOUGH DOWNSLOPING THROUGH THE MID AFTERNOON HOURS TO
PRODUCE NUMEROUS BREAKS IN THE STRATUS OVER THE SOUTHEAST... ONCE
THE HIGH CLOUD SHIELD STREAMS EAST OF THE AREA BY EARLY AFTERNOON.
OVERALL...A TYPICAL NOVEMBER SKY ACROSS CENTRAL PA.

CORE OF THE COLD AIR AT 850 MB ASSOCIATED WITH 5H TROF ALOFT
SINKING SOUTHWARD VEROM THE CENTRAL AND EASTERN GLAKS WILL DROP
SOUTH OF THE REGION BY LATE THIS AFTERNOON AND EVENING...EASING
THE LOW LEVEL LAPSE RATES AND HELPING TO WEAKEN THE BOUNDARY LAYER
INVERSION. STILL EXPECTING MAXES TO RANGE FROM THE UPPER 40S OVR
THE ALLEGHENIES...TO THE MID 50S AIDED BY SUNBREAKS ACROSS THE
SUSQ RIVER VALLEY.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
LG SCALE SUBSIDENCE IN WAKE OF DEPARTING SHORTWAVE SHOULD RESULT
IN CLEARING SKIES TONIGHT. HOWEVER...LGT WINDS ASSOCIATED WITH SFC
HIGH SHOULD RESULT IN PATCHY RADIATION FOG TOWARD DAWN. ALTHOUGH
THE CLEARING SKIES WILL ALLOW TEMPS TO BECOME COOLER THAN THIS
MORNING...MINS STILL LIKELY TO BE 5-10F ABV NORMAL WITH READINGS
GENERALLY IN THE M/U30S.

AFTER PATCHY AM FOG...RIDGING AT SFC AND ALOFT SHOULD PRODUCE A MSUNNY
AND MILD SUNDAY. NAEFS SUPPORTS THE HIGHER MAV MOS TEMPS...RANGING
IN THE L/M50S MOST SPOTS.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
AN ACTIVE SPLIT FLOW PATTERN IS FCST TO CONTINUE THROUGH MUCH OF THE
PD BY LONG TERM GUIDANCE. SEVERAL UPR LEVEL TROFS ARE FORECAST TO
TRAVERSE THE CONUS IN BOTH THE NRN AND SRN STREAM FLOW WITH
VARYING LEVELS OF INFLUENCE ON PA. OVERALL HOWEVER...MOST OF THE
NEXT WEEK LOOKS TO BE DRY WITH CONTINUED ABOVE NORMAL TEMPERATURES.

THE FIRST TROF...IN THE SRN STREAM...IS FCST TO MOVE ACROSS THE GULF
COAST TDY...THEN LIFT NE ALONG THE MID ATLC COAST LATE SUNDAY.
THE WAVE WILL BE LIFTING INTO THE NRN STREAM MEAN UPR RIDGE WITH
HIGH PRESSURE IN PLACE AT THE SFC. MODEL TRENDS ARE FOR A
SMALLER...FARTHER EAST SOLUTION OF THE SFC LOW ASSCD WITH THE SRN
TROF AND FORECASTS DRIER THAN PVS RUNS. GFS APPEARS AN OUTLIER
WITH A SIG WET FORECAST FOR MONDAY ACROSS MUCH OF PA...AND SUCH
HAVE LOWERED POPS FOR THIS TIME PD FOLLOWING THE MULTITUDE OF
OTHER LONG TERM GUIDANCE.

HIGHEST ENSEMBLE POPS ARE MONDAY DURING THE DAY INTO MONDAY
NIGHT. SOME TIMING ISSUES. LOWERED THE POPS INTO THE 30-50 PERCENT
RANGE MONDAY DURING THE DAY AND UPPED THEM MONDAY NIGHT INTO
TUESDAY DUE TO THE UNCERTAINTY IN THE TIMING. PRETTY WEAK SYSTEM
AND THE RAIN SHOULD BE VERY LIGHT.

AMPLIFICATION IN THE NRN STREAM IS FCST TO OCCUR OVER THE GREAT
LAKES BY TUE...WITH A WEAKENING SFC FRONT REACHING WRN ON WED AS
SUPPORTING CLOSED UPPER TROF LIFTS INTO SERN CANADA. A STRONGER UPR
TROF/COLD FRONT IS FCST TO MOVE THROUGH PA THANKSGIVING NIGHT...IF
CURRENT TIMING HOLDS...WITH A NOTICEABLE COOL DOWN IN STORE FOR
SHOPPERS NEXT FRIDAY. ANY SHOWER ACTIVITY OVER NW PA COULD BE IN
THE FORM OF SNOW THUR-FRI AS 850 TEMPERATURES FALL BELOW 0C.

&&

.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
HIGH PRESSURE BUILDING INTO THE REGION TODAY. MOISTURE LAYER
TRAPPED UNDER SUBSIDENCE INVERSION WILL BRING IFR/MVFR CIGS FOR
SEVERAL HOURS THIS MORNING IN HIGHER TERRAIN TAFS...BUT THESE
SHOULD MIX OUT TO VFR BY EARLY AFTERNOON. VFR WILL BE THE RULE IN
THE EAST WITH SLIGHT DOWNSLOPE COMPONENT IN LIGHT WESTERLY WINDS.

OUTLOOK...
SUN...AREAS OF MVFR/IFR CIGS EARLY IN HIGHER TERRAIN...OTHERWISE VFR.
MON...MVFR LCL IFR. PSBL SHRA IN THE AFTN.
TUE...MVFR/IFR CIGS. SHRA IN THE AM.
WED...MVFR TO VFR EARLY.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...GRUMM
NEAR TERM...FITZGERALD
SHORT TERM...DEVOIR/FITZGERALD
LONG TERM...GRUMM/GARTNER
AVIATION...RXR

000
FXUS61 KCTP 211211
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
711 AM EST SAT NOV 21 2009

.SYNOPSIS...
HIGH PRESSURE SHOULD PROVIDE RELATIVELY DRY WEATHER OVER THE
REGION THROUGH SUNDAY. EASTERLY FLOW AND A WAVE COMING OUT OF THE
GULF SHOULD INCREASE THE CHANCE OF RAIN LATE SUNDAY INTO MONDAY.
THE PATTERN OVER NORTH AMERICA IS CHANGING...THE ENSEMBLES SHOW A
TROUGH ATTEMPTING TO ESTABLISH ITSELF OVER EASTERN NORTH AMERICA
WITH A RIDGE OVER NORTHWESTERN CANADA. A SERIES OF WAVES WILL CARVE
OUT THE TROUGH BRINGING UNSETTLED WEATHER TO THE REGION NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HIGH PRESSURE TO OUR WEST CONTINUES TO PUSH INTO THE REGION.
DESPITE THE HIGH...MOISTURE IN THE WEAK COLD ADVECTION IS KEEPING
A BROAD REGION OF LOW CLOUDS IN PLACE ACROSS WESTERN/CENTRAL PA
THIS MORNING...WHILE DOWNSLOPING FLOW RESULTING IN PTCLDY SKIES
ACROSS THE LOWER SUSQ VALLEY. WESTERLY FLOW SHOULD ENSURE MOST
SOLID CLOUD COVER OVR THE ALLEGHENIES AND MOST BRKS ACROSS THE
SUSQ VALLEY.

UPPER LVL SHORTWAVE PUSHING EAST FROM MICHIGAN CURRENTLY PRODUCING
NO PRECIP TO OUR WEST AND SHOWS LITTLE SIGN OF DOING SO AS IT
MOVES INTO DRIER AIR MASS OVR PA. WSW FLOW ABOVE 700 MB WILL KEEP
PA IN A RELATIVELY MILD AIR MASS FOR NOVEMBER. NAEFS DATA CONTINUES
TO POINT TWD HIGHS SEVERAL DEG ABV NORMAL TDY...WITH MAXES RANGING
FROM U40S OVR THE ALLEGHENIES...TO M50S SUSQ VALLEY.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
LG SCALE SUBSIDENCE IN WAKE OF DEPARTING SHORTWAVE SHOULD RESULT
IN CLEARING SKIES TONIGHT. HOWEVER...LGT WINDS ASSOCIATED WITH SFC
HIGH SHOULD RESULT IN PATCHY RADIATION FOG TOWARD DAWN. ALTHOUGH
THE CLEARING SKIES WILL ALLOW TEMPS TO BECOME COOLER THAN THIS
MORNING...MINS STILL LIKELY TO BE 5-10F ABV NORMAL WITH READINGS
GENERALLY IN THE M/U30S.

AFTER PATCHY AM FOG...RIDGING AT SFC AND ALOFT SHOULD PRODUCE A MSUNNY
AND MILD SUNDAY. NAEFS SUPPORTS THE HIGHER MAV MOS TEMPS...RANGING
IN THE L/M50S MOST SPOTS.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
AN ACTIVE SPLIT FLOW PATTERN IS FCST TO CONTINUE THROUGH MUCH OF THE
PD BY LONG TERM GUIDANCE. SEVERAL UPR LEVEL TROFS ARE FORECAST TO
TRAVERSE THE CONUS IN BOTH THE NRN AND SRN STREAM FLOW WITH
VARYING LEVELS OF INFLUENCE ON PA. OVERALL HOWEVER...MOST OF THE
NEXT WEEK LOOKS TO BE DRY WITH CONTINUED ABOVE NORMAL TEMPERATURES.

THE FIRST TROF...IN THE SRN STREAM...IS FCST TO MOVE ACROSS THE GULF
COAST TDY...THEN LIFT NE ALONG THE MID ATLC COAST LATE SUNDAY.
THE WAVE WILL BE LIFTING INTO THE NRN STREAM MEAN UPR RIDGE WITH
HIGH PRESSURE IN PLACE AT THE SFC. MODEL TRENDS ARE FOR A
SMALLER...FARTHER EAST SOLUTION OF THE SFC LOW ASSCD WITH THE SRN
TROF AND FORECASTS DRIER THAN PVS RUNS. GFS APPEARS AN OUTLIER
WITH A SIG WET FORECAST FOR MONDAY ACROSS MUCH OF PA...AND SUCH
HAVE LOWERED POPS FOR THIS TIME PD FOLLOWING THE MULTITUDE OF
OTHER LONG TERM GUIDANCE.

HIGHEST ENSEMBLE POPS ARE MONDAY DURING THE DAY INTO MONDAY
NIGHT. SOME TIMING ISSUES. LOWERED THE POPS INTO THE 30-50 PERCENT
RANGE MONDAY DURING THE DAY AND UPPED THEM MONDAY NIGHT INTO
TUESDAY DUE TO THE UNCERTAINTY IN THE TIMING. PRETTY WEAK SYSTEM
AND THE RAIN SHOULD BE VERY LIGHT.

AMPLIFICATION IN THE NRN STREAM IS FCST TO OCCUR OVER THE GREAT
LAKES BY TUE...WITH A WEAKENING SFC FRONT REACHING WRN ON WED AS
SUPPORTING CLOSED UPPER TROF LIFTS INTO SERN CANADA. A STRONGER UPR
TROF/COLD FRONT IS FCST TO MOVE THROUGH PA THANKSGIVING NIGHT...IF
CURRENT TIMING HOLDS...WITH A NOTICEABLE COOL DOWN IN STORE FOR
SHOPPERS NEXT FRIDAY. ANY SHOWER ACTIVITY OVER NW PA COULD BE IN
THE FORM OF SNOW THUR-FRI AS 850 TEMPERATURES FALL BELOW 0C.

&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
HIGH PRESSURE BUILDING INTO THE REGION TODAY. MOISTURE LAYER
TRAPPED UNDER SUBSIDENCE INVERSION WILL BRING IFR/MVFR CIGS FOR
SEVERAL HOURS THIS MORNING IN HIGHER TERRAIN TAFS...BUT THESE
SHOULD MIX OUT TO VFR BY EARLY AFTERNOON. VFR WILL BE THE RULE IN
THE EAST WITH SLIGHT DOWNSLOPE COMPONENT IN LIGHT WESTERLY WINDS.

OUTLOOK...
SUN...AREAS OF MVFR/IFR CIGS EARLY IN HIGHER TERRAIN...OTHERWISE VFR.
MON...MVFR LCL IFR. PSBL SHRA IN THE AFTN.
TUE...MVFR/IFR CIGS. SHRA IN THE AM.
WED...MVFR TO VFR EARLY.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...GRUMM
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...GRUMM/GARTNER
AVIATION...RXR

000
FXUS61 KPBZ 211132
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
632 AM EST SAT NOV 21 2009

.SYNOPSIS...
HIGH PRESSURE WILL PROVIDE A DRY WEEKEND. A LOW PRESSURE SYSTEM
MOVING INTO THE MID ATLANTIC STATES WILL BRING A CHANCE OF SHOWERS
MONDAY NIGHT AND TUESDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
STRATOCUMULUS CLOUD DECK TRAPPED UNDER SURFACE HIGH HANGING OVER
THE UPPER OHIO VALLEY LOOKS TO PERSIST THROUGH MUCH OF TODAY
ALTHOUGH SOME BREAKS WILL OPEN AT TIMES. PREVIOUS FORECAST HIGHS IN
THE 50S LOOK GOOD. CLOUDS WILL REMAIN EARLY THEN THEN BEGIN TO
BREAK ALLOWING FOR COLDER READINGS AND DROP MIN TEMPS TOWARD NEW
MAV GUIDANCE.

&&

.SHORT TERM /SUNDAY THROUGH TUESDAY/...
SURFACE HIGH SHIFTS NORTHEAST AND SHOULD ALLOW FOR SOME SUNSHINE
SUNDAY WITH MILD TEMPERATURES. LOW PRESSURE SYSTEM DEVELOPING
OVER THE EASTERN GULF OF MEXICO WILL MOVE TO THE VIRGINIA COAST
MONDAY. GFS AND NEW ECMWF SHOW MOISTURE FROM SYSTEM WORKING NORTH
SUNDAY NIGHT INTO MONDAY WITH A CHANCE FOR SHOWERS AS WELL.
TEMPERATURES WILL REMAIN ABOVE NORMAL. TUESDAY WILL BE IN BETWEEN
SYSTEMS WITH LOW LEVEL MOISTURE SLOW TO CLEAR AND SKIES SHOULD
REMAIN CLOUDY WITH ABOVE NORMAL TEMPERATURES CONTINUING.

&&

.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
UPPER TROUGH  BEGINS TO DOMINATE THIS PERIOD WHICH WILL LEAD TO
MUCH COOLER TEMPERATURES.

WITH MODEL DIFFERENCES IN TIMING...WILL KEEP POPS CHANCE FROM
WEDNESDAY INTO FRIDAY MODELS ALSO COMING INTO LINE FOR A BIT OF A
COLDER SOLUTION FOR THURSDAY AND FRIDAY AS CLOSED UPPER LOW MOVES
ACROSS THE OHIO VALLEY. SINCE TIME RANGE IS SO FAR OUT DID NOT
LOWER TEMPERATURES DRAMATICALLY FROM PREVIOUS FORECAST. SNOW
SHOWERS MIXING NOW LOOKS TO BE MORE DEFINITE AT NIGHT AND MAY
NEED TO ADD SNOW TO THANKSGIVING DAY AS WELL.

&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
CEILING RESTRICTIONS WILL BE THE PRIMARY FLIGHT CONCERN TODAY AS
LOW-LEVEL MOISTURE CONTINUES TO HOLD ACROSS THE AREA. MVFR CIGS
AT KPIT...KBVI...AND KHLG WILL LIFT TO VFR WITH IFR-LIFR CIGS AT
KDUJ AND KFKL LIFTING TO MVFR BY MID-MORNING. HIGH PRESSURE WILL
CONTINUE TO BUILD IN FROM THE SOUTHWEST WITH CIGS BREAKING AT
KMGW/KZZV THIS AFTN. FURTHER NORTHWARD...CIGS WILL PREVAIL AT
3-4KFT ACROSS THE TERMINALS WITH MVFR CIGS EXPECTED AT KDUJ AND
KFKL THIS AFTN.

VFR CONDITIONS WILL PREVAIL SATURDAY NIGHT...EXCEPT AT KDUJ AND
KFKL WHERE MVFR CIGS WILL FINALLY ERODE BY SUNDAY MORNING. A LOW
PRESSURE SYSTEM MOVING UP THE EAST COAST SUNDAY NIGHT WILL BRING
THE NEXT CHANCE FOR SHOWERS WITH REDUCED CEILINGS
EXPECTED...ESPECIALLY SOUTHEAST OF A KMGW-KLBE LINE. REDUCED
CEILINGS WILL BE POSSIBLE ACROSS THE AREA ON TUESDAY AS A COLD
FRONT APPROACHES THE AREA FROM THE WEST AND CONTINUE INTO
WEDNESDAY WITH RAIN SHOWERS WHEN THE FRONT CROSSES THE TERMINALS.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.

&&

$$

000
FXUS61 KCTP 210936
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
436 AM EST SAT NOV 21 2009

.SYNOPSIS...
HIGH PRESSURE SHOULD PROVIDE RELATIVELY DRY WEATHER OVER THE
REGION THROUGH SUNDAY. EASTERLY FLOW AND A WAVE COMING OUT OF THE
GULF SHOULD INCREASE THE CHANCE OF RAIN LATE SUNDAY INTO MONDAY.
THE PATTERN OVER NORTH AMERICA IS CHANGING...THE ENSEMBLES SHOW A
TROUGH ATTEMPTING TO ESTABLISH ITSELF OVER EASTERN NORTH AMERICA
WITH A RIDGE OVER NORTHWESTERN CANADA. A SERIES OF WAVES WILL CARVE
OUT THE TROUGH BRINGING UNSETTLED WEATHER TO THE REGION NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HIGH PRESSURE TO OUR WEST CONTINUES TO PUSH INTO THE REGION.
DESPITE THE HIGH...MOISTURE IN THE WEAK COLD ADVECTION IS KEEPING
A BROAD REGION OF LOW CLOUDS IN PLACE ACROSS WESTERN/CENTRAL PA
THIS MORNING...WHILE DOWNSLOPING FLOW RESULTING IN PTCLDY SKIES
ACROSS THE LOWER SUSQ VALLEY. WESTERLY FLOW SHOULD ENSURE MOST
SOLID CLOUD COVER OVR THE ALLEGHENIES AND MOST BRKS ACROSS THE
SUSQ VALLEY.

UPPER LVL SHORTWAVE PUSHING EAST FROM MICHIGAN CURRENTLY PRODUCING
NO PRECIP TO OUR WEST AND SHOWS LITTLE SIGN OF DOING SO AS IT
MOVES INTO DRIER AIR MASS OVR PA. WSW FLOW ABOVE 700 MB WILL KEEP
PA IN A RELATIVELY MILD AIR MASS FOR NOVEMBER. NAEFS DATA CONTINUES
TO POINT TWD HIGHS SEVERAL DEG ABV NORMAL TDY...WITH MAXES RANGING
FROM U40S OVR THE ALLEGHENIES...TO M50S SUSQ VALLEY.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
LG SCALE SUBSIDENCE IN WAKE OF DEPARTING SHORTWAVE SHOULD RESULT
IN CLEARING SKIES TONIGHT. HOWEVER...LGT WINDS ASSOCIATED WITH SFC
HIGH SHOULD RESULT IN PATCHY RADIATION FOG TOWARD DAWN. ALTHOUGH
THE CLEARING SKIES WILL ALLOW TEMPS TO BECOME COOLER THAN THIS
MORNING...MINS STILL LIKELY TO BE 5-10F ABV NORMAL WITH READINGS
GENERALLY IN THE M/U30S.

AFTER PATCHY AM FOG...RIDGING AT SFC AND ALOFT SHOULD PRODUCE A MSUNNY
AND MILD SUNDAY. NAEFS SUPPORTS THE HIGHER MAV MOS TEMPS...RANGING
IN THE L/M50S MOST SPOTS.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
AN ACTIVE SPLIT FLOW PATTERN IS FCST TO CONTINUE THROUGH MUCH OF THE
PD BY LONG TERM GUIDANCE. SEVERAL UPR LEVEL TROFS ARE FORECAST TO
TRAVERSE THE CONUS IN BOTH THE NRN AND SRN STREAM FLOW WITH
VARYING LEVELS OF INFLUENCE ON PA. OVERALL HOWEVER...MOST OF THE
NEXT WEEK LOOKS TO BE DRY WITH CONTINUED ABOVE NORMAL TEMPERATURES.

THE FIRST TROF...IN THE SRN STREAM...IS FCST TO MOVE ACROSS THE GULF
COAST TDY...THEN LIFT NE ALONG THE MID ATLC COAST LATE SUNDAY.
THE WAVE WILL BE LIFTING INTO THE NRN STREAM MEAN UPR RIDGE WITH
HIGH PRESSURE IN PLACE AT THE SFC. MODEL TRENDS ARE FOR A
SMALLER...FARTHER EAST SOLUTION OF THE SFC LOW ASSCD WITH THE SRN
TROF AND FORECASTS DRIER THAN PVS RUNS. GFS APPEARS AN OUTLIER
WITH A SIG WET FORECAST FOR MONDAY ACROSS MUCH OF PA...AND SUCH
HAVE LOWERED POPS FOR THIS TIME PD FOLLOWING THE MULTITUDE OF
OTHER LONG TERM GUIDANCE.

HIGHEST ENSEMBLE POPS ARE MONDAY DURING THE DAY INTO MONDAY
NIGHT. SOME TIMING ISSUES. LOWERED THE POPS INTO THE 30-50 PERCENT
RANGE MONDAY DURING THE DAY AND UPPED THEM MONDAY NIGHT INTO
TUESDAY DUE TO THE UNCERTAINTY IN THE TIMING. PRETTY WEAK SYSTEM
AND THE RAIN SHOULD BE VERY LIGHT.

AMPLIFICATION IN THE NRN STREAM IS FCST TO OCCUR OVER THE GREAT
LAKES BY TUE...WITH A WEAKENING SFC FRONT REACHING WRN ON WED AS
SUPPORTING CLOSED UPPER TROF LIFTS INTO SERN CANADA. A STRONGER UPR
TROF/COLD FRONT IS FCST TO MOVE THROUGH PA THANKSGIVING NIGHT...IF
CURRENT TIMING HOLDS...WITH A NOTICEABLE COOL DOWN IN STORE FOR
SHOPPERS NEXT FRIDAY. ANY SHOWER ACTIVITY OVER NW PA COULD BE IN
THE FORM OF SNOW THUR-FRI AS 850 TEMPERATURES FALL BELOW 0C.

&&

.AVIATION /09Z SATURDAY THROUGH WEDNESDAY/...
WEAK FRONTAL BNDRY ARRIVING AT BFD ARND 06Z WILL SLOWLY DIMINISH
CIGS TO ARND 1000-1500FT AGL. IFR CIGS ARRIVE AT JST/AOO/UNV/IPT
BTWN 08-12Z...BOUNCING BACK TO VFR CONDS BY 16-18Z WITH BETTER
MIXING. MDT SHUD HOLD AT VFR CONDS FROM WEAK DOWNSLOPING. BY 00Z
SUN LGT NORTHERLY FLOW TURNING NE SHUD KEEP VFR CONDS THRU EARLY
SUN WITH PATCHY MVFR CIGS ACROSS SUSQ-VALLEY AIRFIELDS.

OUTLOOK...
SUN...MVFR/VFR.
MON...MVFR LCL IFR. PSBL SHRA IN THE AFTN.
TUE...MVFR/IFR CIGS. SHRA IN THE AM.
WED...MVFR TO VFR EARLY.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...GRUMM
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...GRUMM/GARTNER
AVIATION...BEACHLER/RXR

000
FXUS61 KPHI 210902 CCA
AFDPHI

AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
402 AM EST SAT NOV 21 2009

.SYNOPSIS...
HIGH PRESSURE OVER THE OHIO RIVER VALLEY THIS MORNING WILL
STRENGTHEN AND BUILD TOWARD NEW ENGLAND THROUGH THE WEEKEND, THEN
RECEDE EAST SLOWLY. LOW PRESSURE WILL DEVELOP OFF THE SOUTHEAST
COAST ON MONDAY AND MOVE NORTH SLOWLY, PASSING BY TO THE EAST ON
TUESDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
GENERALLY SOME HIGH LEVEL CLOUDS AROUND TODAY WITH A WEAK MID
LEVEL DISTURBANCE MEANDERING TO OUR WEST, ALTHOUGH MODEL SOUNDINGS
WANT TO TRAP SOME MOISTURE UNDER THE LOW LEVEL INVERSION UP
NORTHWEST, ESPECIALLY FAR NORTHWEST. WE`VE ACKNOWLEDGED THIS BY
CARRYING SOMEWHAT MORE IN THE WAY OF CLOUDINESS NORTHWEST THAN
ELSEWHERE. CONTINUITY ON TEMPERATURES WAS CONSISTENT WITH MOST
LOCATIONS MIXING TO H925 AND WITH THE FAIRLY AGREEABLE MAV AND MET
STAT GUIDANCE, AND SO WE WENT THAT WAY. EXPECT A FAIRLY MODEST
NORTHWEST WIND.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
THE WEAK MID LEVEL LOW DRIFTS TOWARDS US TONIGHT, AND AGAIN THE
MODEL SOUNDINGS HOLD ONTO SOME LOW LEVEL MOISTURE, ESPECIALLY BUT
NOT EXCLUSIVELY NORTHWEST, WHILE SOME HIGH LEVEL MOISTURE
APPROAHCES AHEAD OF THE NEXT SYSTEM THAT IS ADVANCING IN THE
SOUTHERN STREAM. WE GO WITH SOMEWHAT MORE CLOUDINESS NORTHWEST AND
SOUTH THAN ELSEWHERE, BUT WE ALLOW FOR THE POSSIBILITY OF SOME
DECOUPLING AND RADIATING OVER THE NORMAL RADIATING SPOTS ON THE
MIN TEMPERATURES. ELSEWHERE, WE STAY WITH THE CONTINUITY/GUIDANCE
COMBINATION. WINDS ARE EXPECTED TO BE LIGHT.

ON SUNDAY, THE MID LEVEL LOW OVER US AND A MID LEVEL HIGH TO ITS NORTH
VERY MUCH RESEMBLE A REX BLOCK, AND THIS ACTUALLY SEEMS TO ALLOW A
LITTLE RIDGING UPSTREAM OF US THAT SLOWS DOWN ADVANCING ENERGY
FROM THE SOUTHERN STREAM. WE HAVE BACKED DOWN A BIT ON OUR SUNDAY
POPS IN RESPONSE, AND NOW WE ONLY CARRY A SLIGHT CHANCE FAR SOUTH.
WE DO INCREASE THE CLOUDS SOME DOWN SOUTH, BUT WE BACK OFF ON THAT
TREND NORTH. THE GRADIENT LOOKS TO BEGIN TO TIGHTEN A BIT,
ESPECIALLY SOUTH, BETWEEN THE STRENGTHENING SURFACE HIGH TO THE
NORTH AND NASCENT SURFACE TROUGHING OFF THE SOUTHEAST COAST. THE
COOLER H925 TEMPS OFF THE NAM HAVE GOOD SUPPORT FROM THE 00Z
ECMWF, AND SO WE HAVE LEANED TOWARD THE COOLER MET STAT GUIDANCE
WITH REGARD TO MAXES.

ON SUNDAY NIGHT, THE MODELS START TO DIFFER ON WHETHER THE REX
BLOCK CONTINUES TO SLOW THE PROGRESS OF SOUTHERN STREAM ENERGY OR
THE ENERGY GETS PULLED TOWARD THE LOW PRESSURE PART OF SAID BLOCK.
EVEN THE MODELS THAT FAVOR THE LATTER SOLUTION HAVE SLOWED DOWN
THE PROGRESS OF MOISTURE, I295 ISENTROPIC LIFT AND LOWER LEVEL
FRONTOGENESIS, SO WE CONTINUED THE TREND OF BACKING OFF SOME ON
THE POPS. WE DO BRING IN MORE CLOUDINESS. WE LEANED TOWARD THE
COOLER MET STAT GUIDANCE AGAIN ON THE MINS, BASICALLY FOR THE SAME
REASON THAT WE SITED FOR SUNDAY.

ON MONDAY INTO MONDAY NIGHT, THERE IS SOME AGREEMENT THAT
ISENTROPIC LIFT MOVES ACROSS THE AREA, FRONTOGENESIS STRENGTHENS
/ESPECIALLY OFF THE COAST/ AND Q-VECTOR CONVERGENCE DEVELOPS
/AGAIN, ESPECIALLY OFF THE COAST/. THE MID LEVEL BLOCK IS PROGGED
TO LIFT NORTHEAST AND OPEN, AND SURFACE LOW PRESSURE IS PROGGED TO
DEVELOP AND LIFT FROM THE SOUTHEAST COAST ON MONDAY TO SOMEWHERE
OFF THE MID ATLANTIC COAST LATE MONDAY NIGHT. HOW ORGANIZED THAT
LOW GETS IS UP IN THE AIR, BUT EVEN THE WEAKER ECMWF HAS A DECENT
PRESSURE GRADIENT BETWEEN THE LOW AND THE HIGH TO THE NORTH. WE
HAVE GONE WITH POPS THAT RANGE FROM LIKELY SOUTHEAST TO CHANCE
ELSEWHERE AS THE INDICATION SEEMS TO BE THAT THE BULK OF THE
PRECIPITATION WILL FALL OFF THE COAST. WE DO CARRY A FAIRLY STRONG
NORTHEAST FLOW IN THIS REGIME, BUT HOPEFULLY NOTHING LIKE WE DEALT
WITH AROUND VETERAN`S DAY. WE GENERALLY CONTINUE TO LEAN TOWARD
THE COOLER GUIDANCE.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
FOLLOWING TRENDS FROM HPC WHICH GENERALLY WENT WITH THE ECMWF SHOWED
LOW PRESSURE MOVING AWAY FROM THE AREA LATE MONDAY NIGHT WITH HIGH
PRESSURE IN EASTERN CANADA EXTENDING SOUTH OVER THE REGION. THIS
SHOULD MEAN DRYING TRENDS LATE MONDAY NIGHT WITH A DRY DAY ON
TUESDAY. TUESDAY NIGHT AND WEDNESDAY WILL SEE ANOTHER FRONT FROM THE
WEST MOVE EAST. THIS FRONT SHOULD CROSS THE REGION WEDNESDAY AFTN.
WITH THE WARM ADVECTION AHEAD OF THE FRONT LATE TUESDAY NIGHT COULD
SEE SOME RAIN AND SHOWERS ARE POSSIBLE DURING THE DAY WEDNESDAY.

FOR THANKSGIVING, AN UPPER TROUGH DIGS INTO THE WESTERN GREAT LAKES.
WE HAVE WARM ADVECTION OVER THE AREA AND DUE TO THIS COMBINATION THE
FORECAST WILL INCLUDE A CHANCE OF SHOWERS.

THURSDAY NIGHT, A STRONG COLD FRONT MOVES THROUGH FROM THE NW AND WE
GET INTO A COLD ADVECTION PATTERN FOR FRIDAY WITH CYCLONIC FLOW
ALOFT AND VERY COOL TEMPERATURES ON FRIDAY. OVER THE FAR NORTHERN
ZONES, THERE IS A CHANCE OF RAIN OR SNOW SHOWERS ON FRIDAY.

HPC TEMPS ARE GENLY REASONABLE.

&&

.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.

VFR FLYING CONDITIONS WILL SUPPORT AVIATION INTERESTS TODAY AND
TONIGHT, AND PROBABLY SUNDAY MORNING AS WELL.

SURFACE HIGH PRESSURE OVER THE CENTRAL AND NORTHERN APPALACHIANS AND
EASTERN OHIO VALLEY EARLY THIS MORNING WILL STRENGTHEN SLIGHTLY THIS
AFTERNOON AND TONIGHT AS IT DRIFTS NORTHEASTWARD. THIS HIGH WILL
INITIALLY BE UNDERNEATH AN UPPER TROUGH OVER THE GREAT LAKES AND
OHIO VALLEY. THE SOUTHWEST FLOW AHEAD OF THIS TROUGH WAS KICKING
SOME JET STREAM CIRRUS NORTHEASTWARD INTO OUR AREA EARLY THIS
MORNING. HOWEVER, PROBABLY A GOOD BIT OF THIS WILL BE THIN TODAY.
OTHERWISE, THE STRATOCUMULUS OVER CENTRAL PENNSYLVANIA WAS FAILING
TO ADVANCE EASTWARD. SO, OTHER THAN SOME CIRRUS, A FEW CUMULUS MAY
FORM TOWARD MIDDAY AND LINGER INTO THE AFTERNOON. A DRY ATMOSPHERE
WILL MEAN NO TENDENCY FOR FOG FORMATION EARLY THIS MORNING. WEST
WINDS EARLY THIS MORNING WILL BECOME NORTHWEST LATER THIS MORNING
AND CONTINUE THIS AFTERNOON, VEERING TO NORTH BY DARK. SUSTAINED
WIND SPEEDS SHOULD BE MOSTLY UNDER 10 KNOTS TODAY.

OUTLOOK...
DRY WEATHER IS FORECAST TO CONTINUE SUNDAY. A CHANCE OF RAIN IS
EXPECTED SUNDAY NIGHT AS LOW PRESSURE WILL MOVE OFF THE SOUTHEAST
U.S. COAST SUNDAY NIGHT AND DEVELOP NORTHWARD MONDAY...AND PERHAPS
REMAIN JUST OFF THE MID ATLANTIC COAST MONDAY NIGHT AND TUESDAY TO
PLAGUE OUR AREA WITH AN OCEANIC FLOW.

&&

.MARINE...
WIND GUSTS AND SEAS WERE JUST UNDER SMALL CRAFT ADVISORY CRITERIA
EARLY THIS MORNING ON OUR EASTERN OCEAN WATERS, AND SHOULD LESSEN
SOMEWHAT DURING TODAY AS HIGH PRESSURE CENTERED JUST TO OUR WEST
EARLY THIS MORNING IS FORECAST TO BUILD NORTHEASTWARD TONIGHT AND
SUNDAY. LOW PRESSURE IS THEN EXPECTED TO MOVE NORTHWARD ALONG OR
NEAR THE COAST LATER SUNDAY AND MONDAY AND REMAIN INTO TUESDAY.
RIGHT NOW THIS LOW LOOKS LIKE IT WILL NOT BECOME TOO STRONG, BUT AT
LEAST STRONG ENOUGH FOR ADVISORY LEVEL WINDS AND SEAS, WITH THE
SUNDAY NIGHT INTO TUESDAY TIME FRAME BEING THE PRIME TIME. HOWEVER,
THE GRADIENT MAY BE TIGHT ENOUGH OVER OUR SOUTHERN WATERS LATER
SUNDAY TO WARRANT A SMALL CRAFT ADVISORY. WAVEWATCH HAS BEEN
CONSISTENT IN BUILDING SEAS TO 5 FEET SUNDAY AFTERNOON, SO A SMALL
CRAFT ADVISORY WILL BE ISSUED WITH THIS MORNING/S PACKAGE FROM
LITTLE EGG INLET SOUTH FOR SUNDAY AFTERNOON (OUR THIRD PERIOD) AND
CONTINUED THROUGH SUNDAY NIGHT FOR NOW (OUR FOURTH PERIOD). THIS
WILL LIKELY HAVE TO BE EXTENDED IN TIME AS WELL AS GEOGRAPHICALLY.
OUR NORTHERN WATERS DON/T LOOK TO START BEFORE SUNDAY NIGHT (WHICH
IS OUR FOURTH PERIOD AND TOO FAR IN ADVANCE TO START AN ADVISORY);
LOWER (OR MAYBE EVEN ALL OF) DELAWARE BAY COULD NEED AN ADVISORY AS
WELL. ONCE IT STARTS, WAVEWATCH HAS ADVISORY LEVEL SEAS THROUGH THIS
COMING WEEK. OBVIOUSLY, CONFIDENCE IS PRETTY LOW AFTER MONDAY AND
TUESDAY.

&&

.TIDES/COASTAL FLOODING...
TIDAL ANOMALIES ARE LIKELY TO INCREASE AGAIN IN RESPONSE TO AN
EXPECTED DEVELOPING ONSHORE FLOW SUNDAY AND PARTICULARLY SUNDAY
NIGHT THROUGH MONDAY NIGHT. LOW PRESSURE FORECAST TO DEVELOP TO OUR
SOUTHEAST WILL CONTRAST WITH HIGH PRESSURE OVER NORTHERN NEW ENGLAND
AND THE CANADIAN MARITIMES. AVIATION STORM SURGE GUIDANCE IS
PROBABLY UNDERDONE AT THIS EARLY STAGE, AND ANOMALIES MAY RISE TO
AROUND 1 FOOT ABOVE NORMAL. THE TIME PERIOD OF CONCERN WILL BE
SUNDAY NIGHT INTO TUESDAY; THIS PERIOD IS BETWEEN NEW MOON AND FULL
MOON, SO THE ASTRONOMICAL TIDES ARE NOT AS HIGH AS THEY WERE LAST
WEEK. UNDER NORMAL CIRCUMSTANCES, THIS WOULDN`T POSE ANY PROBLEMS,
BUT WITH THE SEVERE BEACH EROSION THAT OCCURRED WITH LAST WEEK`S
STORM, IT MAY BE THAT LOWER TIDAL ANOMALIES WILL HAVE AN EFFECT WHEN
THEY ORDINARILY WOULD NOT. IT IS STILL TO BE DETERMINED WHETHER THIS
MIGHT CAUSE ANY LEVEL OF TIDAL FLOODING, SO THE SITUATION WILL BE
CLOSELY MONITORED DURING THIS WEEKEND.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 1 PM SUNDAY TO 6 AM EST MONDAY FOR
     ANZ452>455.

&&

$$
SYNOPSIS...DELISI
NEAR TERM...DELISI
SHORT TERM...DELISI
LONG TERM...STAUBER
AVIATION...
MARINE...
TIDES/COASTAL FLOODING...

000
FXUS61 KPHI 210854
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
354 AM EST SAT NOV 21 2009

.SYNOPSIS...
HIGH PRESSURE OVER THE OHIO RIVER VALLEY THIS MORNING WILL
STRENGTHEN AND BUILD TOWARD NEW ENGLAND THROUGH THE WEEKEND. THEN
RECEDE EAST SLOWLY. LOW PRESSURE WILL DEVELOP OFF THE SOUTHEAST
COAST ON MONDAY AND MOVE NORTH SLOWLY, PASSING BY TO THE EAST ON
TUESDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
GENERALLY SOME HIGH LEVEL CLOUDS AROUND TODAY WITH A WEAK MID
LEVEL DISTURBANCE MEANDERING TO OUR WEST, ALTHOUGH MODEL SOUNDINGS
WANT TO TRAP SOME MOISTURE UNDER THE LOW LEVEL INVERSION UP
NORTHWEST, ESPECIALLY FAR NORTHWEST. WE`VE ACKNOWLEDGED THIS BY
CARRYING SOMEWHAT MORE IN THE WAY OF CLOUDINESS NORTHWEST THAN
ELSEWHERE. CONTINUITY ON TEMPERATURES WAS CONSISTENT WITH MOST
LOCATIONS MIXING TO H925 AND WITH THE FAIRLY AGREEABLE MAV AND MET
STAT GUIDANCE, AND SO WE WENT THAT WAY. EXPECT A FAIRLY MODEST
NORTHWEST WIND.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
THE WEAK MID LEVEL LOW DRIFTS TOWARDS US TONIGHT, AND AGAIN THE
MODEL SOUNDINGS HOLD ONTO SOME LOW LEVEL MOISTURE, ESPECIALLY BUT
NOT EXCLUSIVELY NORTHWEST, WHILE SOME HIGH LEVEL MOISTURE
APPROAHCES AHEAD OF THE NEXT SYSTEM THAT IS ADVANCING IN THE
SOUTHERN STREAM. WE GO WITH SOMEWHAT MORE CLOUDINESS NORTHWEST AND
SOUTH THAN ELSEWHERE, BUT WE ALLOW FOR THE POSSIBILITY OF SOME
DECOUPLING AND RADIATING OVER THE NORMAL RADIATING SPOTS ON THE
MIN TEMPERATURES. ELSEWHERE, WE STAY WITH THE CONTINUITY/GUIDANCE
COMBINATION. WINDS ARE EXPECTED TO BE LIGHT.

ON SUNDAY, THE MID LEVEL LOW OVER US AND A MID LEVEL HIGH TO ITS NORTH
VERY MUCH RESEMBLE A REX BLOCK, AND THIS ACTUALLY SEEMS TO ALLOW A
LITTLE RIDGING UPSTREAM OF US THAT SLOWS DOWN ADVANCING ENERGY
FROM THE SOUTHERN STREAM. WE HAVE BACKED DOWN A BIT ON OUR SUNDAY
POPS IN RESPONSE, AND NOW WE ONLY CARRY A SLIGHT CHANCE FAR SOUTH.
WE DO INCREASE THE CLOUDS SOME DOWN SOUTH, BUT WE BACK OFF ON THAT
TREND NORTH. THE GRADIENT LOOKS TO BEGIN TO TIGHTEN A BIT,
ESPECIALLY SOUTH, BETWEEN THE STRENGTHENING SURFACE HIGH TO THE
NORTH AND NASCENT SURFACE TROUGHING OFF THE SOUTHEAST COAST. THE
COOLER H925 TEMPS OFF THE NAM HAVE GOOD SUPPORT FROM THE 00Z
ECMWF, AND SO WE HAVE LEANED TOWARD THE COOLER MET STAT GUIDANCE
WITH REGARD TO MAXES.

ON SUNDAY NIGHT, THE MODELS START TO DIFFER ON WHETHER THE REX
BLOCK CONTINUES TO SLOW THE PROGRESS OF SOUTHERN STREAM ENERGY OR
THE ENERGY GETS PULLED TOWARD THE LOW PRESSURE PART OF SAID BLOCK.
EVEN THE MODELS THAT FAVOR THE LATTER SOLUTION HAVE SLOWED DOWN
THE PROGRESS OF MOISTURE, I295 ISENTROPIC LIFT AND LOWER LEVEL
FRONTOGENESIS, SO WE CONTINUED THE TREND OF BACKING OFF SOME ON
THE POPS. WE DO BRING IN MORE CLOUDINESS. WE LEANED TOWARD THE
COOLER MET STAT GUIDANCE AGAIN ON THE MINS, BASICALLY FOR THE SAME
REASON THAT WE SITED FOR SUNDAY.

ON MONDAY INTO MONDAY NIGHT, THERE IS SOME AGREEMENT THAT
ISENTROPIC LIFT MOVES ACROSS THE AREA, FRONTOGENESIS STRENGTHENS
/ESPECIALLY OFF THE COAST/ AND Q-VECTOR CONVERGENCE DEVELOPS
/AGAIN, ESPECIALLY OFF THE COAST/. THE MID LEVEL BLOCK IS PROGGED
TO LIFT NORTHEAST AND OPEN, AND SURFACE LOW PRESSURE IS PROGGED TO
DEVELOP AND LIFT FROM THE SOUTHEAST COAST ON MONDAY TO SOMEWHERE
OFF THE MID ATLANTIC COAST LATE MONDAY NIGHT. HOW ORGANIZED THAT
LOW GETS IS UP IN THE AIR, BUT EVEN THE WEAKER ECMWF HAS A DECENT
PRESSURE GRADIENT BETWEEN THE LOW AND THE HIGH TO THE NORTH. WE
HAVE GONE WITH POPS THAT RANGE FROM LIKELY SOUTHEAST TO CHANCE
ELSEWHERE AS THE INDICATION SEEMS TO BE THAT THE BULK OF THE
PRECIPITATION WILL FALL OFF THE COAST. WE DO CARRY A FAIRLY STRONG
NORTHEAST FLOW IN THIS REGIME, BUT HOPEFULLY NOTHING LIKE WE DEALT
WITH AROUND VETERAN`S DAY. WE GENERALLY CONTINUE TO LEAN TOWARD
THE COOLER GUIDANCE.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
FOLLOWING TRENDS FROM HPC WHICH GENERALLY WENT WITH THE ECMWF SHOWED
LOW PRESSURE MOVING AWAY FROM THE AREA LATE MONDAY NIGHT WITH HIGH
PRESSURE IN EASTERN CANADA EXTENDING SOUTH OVER THE REGION. THIS
SHOULD MEAN DRYING TRENDS LATE MONDAY NIGHT WITH A DRY DAY ON
TUESDAY. TUESDAY NIGHT AND WEDNESDAY WILL SEE ANOTHER FRONT FROM THE
WEST MOVE EAST. THIS FRONT SHOULD CROSS THE REGION WEDNESDAY AFTN.
WITH THE WARM ADVECTION AHEAD OF THE FRONT LATE TUESDAY NIGHT COULD
SEE SOME RAIN AND SHOWERS ARE POSSIBLE DURING THE DAY WEDNESDAY.

FOR THANKSGIVING, AN UPPER TROUGH DIGS INTO THE WESTERN GREAT LAKES.
WE HAVE WARM ADVECTION OVER THE AREA AND DUE TO THIS COMBINATION THE
FORECAST WILL INCLUDE A CHANCE OF SHOWERS.

THURSDAY NIGHT, A STRONG COLD FRONT MOVES THROUGH FROM THE NW AND WE
GET INTO A COLD ADVECTION PATTERN FOR FRIDAY WITH CYCLONIC FLOW
ALOFT AND VERY COOL TEMPERATURES ON FRIDAY. OVER THE FAR NORTHERN
ZONES, THERE IS A CHANCE OF RAIN OR SNOW SHOWERS ON FRIDAY.

HPC TEMPS ARE GENLY REASONABLE.

&&

.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.

VFR FLYING CONDITIONS WILL SUPPORT AVIATION INTERESTS TODAY AND
TONIGHT, AND PROBABLY SUNDAY MORNING AS WELL.

SURFACE HIGH PRESSURE OVER THE CENTRAL AND NORTHERN APPALACHIANS AND
EASTERN OHIO VALLEY EARLY THIS MORNING WILL STRENGTHEN SLIGHTLY THIS
AFTERNOON AND TONIGHT AS IT DRIFTS NORTHEASTWARD. THIS HIGH WILL
INITIALLY BE UNDERNEATH AN UPPER TROUGH OVER THE GREAT LAKES AND
OHIO VALLEY. THE SOUTHWEST FLOW AHEAD OF THIS TROUGH WAS KICKING
SOME JET STREAM CIRRUS NORTHEASTWARD INTO OUR AREA EARLY THIS
MORNING. HOWEVER, PROBABLY A GOOD BIT OF THIS WILL BE THIN TODAY.
OTHERWISE, THE STRATOCUMULUS OVER CENTRAL PENNSYLVANIA WAS FAILING
TO ADVANCE EASTWARD. SO, OTHER THAN SOME CIRRUS, A FEW CUMULUS MAY
FORM TOWARD MIDDAY AND LINGER INTO THE AFTERNOON. A DRY ATMOSPHERE
WILL MEAN NO TENDENCY FOR FOG FORMATION EARLY THIS MORNING. WEST
WINDS EARLY THIS MORNING WILL BECOME NORTHWEST LATER THIS MORNING
AND CONTINUE THIS AFTERNOON, VEERING TO NORTH BY DARK. SUSTAINED
WIND SPEEDS SHOULD BE MOSTLY UNDER 10 KNOTS TODAY.

OUTLOOK...
DRY WEATHER IS FORECAST TO CONTINUE SUNDAY. A CHANCE OF RAIN IS
EXPECTED SUNDAY NIGHT AS LOW PRESSURE WILL MOVE OFF THE SOUTHEAST
U.S. COAST SUNDAY NIGHT AND DEVELOP NORTHWARD MONDAY...AND PERHAPS
REMAIN JUST OFF THE MID ATLANTIC COAST MONDAY NIGHT AND TUESDAY TO
PLAGUE OUR AREA WITH AN OCEANIC FLOW.

&&

.MARINE...
WIND GUSTS AND SEAS WERE JUST UNDER SMALL CRAFT ADVISORY CRITERIA
EARLY THIS MORNING ON OUR EASTERN OCEAN WATERS, AND SHOULD LESSEN
SOMEWHAT DURING TODAY AS HIGH PRESSURE CENTERED JUST TO OUR WEST
EARLY THIS MORNING IS FORECAST TO BUILD NORTHEASTWARD TONIGHT AND
SUNDAY. LOW PRESSURE IS THEN EXPECTED TO MOVE NORTHWARD ALONG OR
NEAR THE COAST LATER SUNDAY AND MONDAY AND REMAIN INTO TUESDAY.
RIGHT NOW THIS LOW LOOKS LIKE IT WILL NOT BECOME TOO STRONG, BUT AT
LEAST STRONG ENOUGH FOR ADVISORY LEVEL WINDS AND SEAS, WITH THE
SUNDAY NIGHT INTO TUESDAY TIME FRAME BEING THE PRIME TIME. HOWEVER,
THE GRADIENT MAY BE TIGHT ENOUGH OVER OUR SOUTHERN WATERS LATER
SUNDAY TO WARRANT A SMALL CRAFT ADVISORY. WAVEWATCH HAS BEEN
CONSISTENT IN BUILDING SEAS TO 5 FEET SUNDAY AFTERNOON, SO A SMALL
CRAFT ADVISORY WILL BE ISSUED WITH THIS MORNING/S PACKAGE FROM
LITTLE EGG INLET SOUTH FOR SUNDAY AFTERNOON (OUR THIRD PERIOD) AND
CONTINUED THROUGH SUNDAY NIGHT FOR NOW (OUR FOURTH PERIOD). THIS
WILL LIKELY HAVE TO BE EXTENDED IN TIME AS WELL AS GEOGRAPHICALLY.
OUR NORTHERN WATERS DON/T LOOK TO START BEFORE SUNDAY NIGHT (WHICH
IS OUR FOURTH PERIOD AND TOO FAR IN ADVANCE TO START AN ADVISORY);
LOWER (OR MAYBE EVEN ALL OF) DELAWARE BAY COULD NEED AN ADVISORY AS
WELL. ONCE IT STARTS, WAVEWATCH HAS ADVISORY LEVEL SEAS THROUGH THIS
COMING WEEK. OBVIOUSLY, CONFIDENCE IS PRETTY LOW AFTER MONDAY AND
TUESDAY.

&&

.TIDES/COASTAL FLOODING...
TIDAL ANOMALIES ARE LIKELY TO INCREASE AGAIN IN RESPONSE TO AN
EXPECTED DEVELOPING ONSHORE FLOW SUNDAY AND PARTICULARLY SUNDAY
NIGHT THROUGH MONDAY NIGHT. LOW PRESSURE FORECAST TO DEVELOP TO OUR
SOUTHEAST WILL CONTRAST WITH HIGH PRESSURE OVER NORTHERN NEW ENGLAND
AND THE CANADIAN MARITIMES. AVIATION STORM SURGE GUIDANCE IS
PROBABLY UNDERDONE AT THIS EARLY STAGE, AND ANOMALIES MAY RISE TO
AROUND 1 FOOT ABOVE NORMAL. THE TIME PERIOD OF CONCERN WILL BE
SUNDAY NIGHT INTO TUESDAY; THIS PERIOD IS BETWEEN NEW MOON AND FULL
MOON, SO THE ASTRONOMICAL TIDES ARE NOT AS HIGH AS THEY WERE LAST
WEEK. UNDER NORMAL CIRCUMSTANCES, THIS WOULDN`T POSE ANY PROBLEMS,
BUT WITH THE SEVERE BEACH EROSION THAT OCCURRED WITH LAST WEEK`S
STORM, IT MAY BE THAT LOWER TIDAL ANOMALIES WILL HAVE AN EFFECT WHEN
THEY ORDINARILY WOULD NOT. IT IS STILL TO BE DETERMINED WHETHER THIS
MIGHT CAUSE ANY LEVEL OF TIDAL FLOODING, SO THE SITUATION WILL BE
CLOSELY MONITORED DURING THIS WEEKEND.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 1 PM SUNDAY TO 6 AM EST MONDAY FOR
     ANZ452>455.

&&

$$
SYNOPSIS...DELISI
NEAR TERM...DELISI
SHORT TERM...DELISI
LONG TERM...STAUBER
AVIATION...
MARINE...
TIDES/COASTAL FLOODING...

000
FXUS61 KCTP 210742
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
242 AM EST SAT NOV 21 2009

.SYNOPSIS...
HIGH PRESSURE SHOULD PROVIDE RELATIVELY DRY WEATHER OVER THE
REGION THROUGH SUNDAY. EASTERLY FLOW AND A WAVE COMING OUT OF THE
GULF SHOULD INCREASE THE CHANCE OF RAIN LATE SUNDAY INTO MONDAY.
THE PATTERN OVER NORTH AMERICA IS CHANGING...THE ENSEMBLES SHOW A
TROUGH ATTEMPTING TO ESTABLISH ITSELF OVER EASTERN NORTH AMERICA
WITH A RIDGE OVER NORTHWESTERN CANADA. A SERIES OF WAVES WILL CARVE
OUT THE TROUGH BRINGING UNSETTLED WEATHER TO THE REGION NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
HIGH PRESSURE TO OUR WEST CONTINUES TO PUSH INTO THE REGION.
DESPITE THE HIGH...MOISTURE IN THE WEAK COLD ADVECTION IS KEEPING
A BROAD REGION OF LOW CLOUDS IN PLACE AS VIEWED IN THE 11-3.9
MICRON SATELLITE DATA. THE CLOUDS SHOULD SLOW THE COOLING AND BE
SLOW TO DISSIPATE. UPDATE GRIDS SHOWING MORE CLOUDS THAN PREVIOUS
FORECAST.

DEW POINTS MAINLY IN THE LOW TO MID 30S AND WITH THE CLOUDS STAYED
CLOSE TO GUIDANCE WITH LOWS MAINLY IN THE MID TO UPPER 30S.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SUNDAY/...
LITTLE MORE THAN SOME SPRINKLES OVR THE MTNS WITH PASSAGE OF TROF
ON SAT. WESTERLY FLOW SHOULD ENSURE MOST SOLID CLOUD COVER OVR
THE ALLEGHENIES AND MOST BRKS ACROSS THE SUSQ VALLEY. WSW FLOW
ABOVE 700 MB WILL KEEP PA IN A RELATIVELY MILD AIRMASS FOR
NOVEMBER. NAEFS DATA CONTINUES TO POINT TWD HIGHS SATURDAY SEVERAL
DEG ABV NORMAL...WITH MAXES RANGING FROM U40S ACROSS THE
ALLEGHENIES...TO M50S THROUGHOUT SUSQ VALLEY.

THE MEAN BOUNDARY LAYER WIND WILL GRADUALLY VEER AROUND TO THE
NORTH SATURDAY NIGHT. THIS WILL KEEP 60% CLOUD COVER OR MORE
ACROSS THE NRN MTNS...WITH GENERALLY PARTLY CLOUDY SKIES ACROSS
MUCH OF THE REGION TO THE SOUTH OF INTERSTATE 80.

MIN TEMPS SHOULD BE A FEW DEG COLDER SATURDAY NIGHT ACROSS THE
FAR NORTH (COMPARED TO 24 HOURS PRIOR) WITH LESS CLOUD COVER.
CENTRAL AND SOUTHERN SECTIONS OF PENN WILL ONCE AGAIN SEE LOW
LOW TEMPS IN THE M/U 30S OR ABOUT 3-6F ABOVE NORMAL.

DUE TO GEFS AND SREF INTRODUCED A 20 PERCENT CHANCE OF LIGHT RAIN
IN THE SOUTHERN AND SOUTHEASTERN AREAS LATE SUNDAY AFTERNOON. GEFS
IS FASTER.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
AN ACTIVE SPLIT FLOW PATTERN IS FCST TO CONTINUE THROUGH MUCH OF THE
PD BY LONG TERM GUIDANCE. SEVERAL UPR LEVEL TROFS ARE FORECAST TO
TRAVERSE THE CONUS IN BOTH THE NRN AND SRN STREAM FLOW WITH
VARYING LEVELS OF INFLUENCE ON PA. OVERALL HOWEVER...MOST OF THE
NEXT WEEK LOOKS TO BE DRY WITH CONTINUED ABOVE NORMAL TEMPERATURES.

THE FIRST TROF...IN THE SRN STREAM...IS FCST TO MOVE ACROSS THE GULF
COAST SATURDAY THEN LIFT NE ALONG THE MID ATLC COAST LATE SUNDAY.
THE WAVE WILL BE LIFTING INTO THE NRN STREAM MEAN UPR RIDGE WITH
HIGH PRESSURE IN PLACE AT THE SFC. MODEL TRENDS ARE FOR A
SMALLER...FARTHER EAST SOLUTION OF THE SFC LOW ASSCD WITH THE SRN
TROF AND FORECASTS DRIER THAN PVS RUNS. GFS APPEARS AN OUTLIER WITH
A SIG WET FORECAST FOR SUN NIGHT INTO MONDAY ACROSS MUCH OF
PA...AND SUCH HAVE LOWERED POPS FOR THIS TIME PD FOLLOWING THE
MULTITUDE OF OTHER LONG TERM GUIDANCE.

THE NEW 18Z GEFS IS MORE IN LINE BUT STILL FASTER THAN THE 15Z SREF
SHOWING A CHANCE OF LIGHT RAIN SUNDAY NIGHT INTO MONDAY MORNING.
HIGHEST ENSEMBLE POPS ARE MONDAY DURING THE DAY INTO MONDAY NIGHT.
SOME TIMING ISSUES. LOWERED THE POPS INTO THE 50 PERCENT RANGE
MONDAY DURING THE DAY AND UPPED THEM MONDAY NIGHT INTO TUESDAY DUE
TO THE UNCERTAINTY IN THE TIMING. PRETTY WEAK SYSTEM AND THE RAIN
SHOULD BE VERY LIGHT.

AMPLIFICATION IN THE NRN STREAM IS FCST TO OCCUR OVER THE GREAT
LAKES BY TUE...WITH A WEAKENING SFC FRONT REACHING WRN ON WED AS
SUPPORTING CLOSED UPPER TROF LIFTS INTO SERN CANADA. A STRONGER UPR
TROF/COLD FRONT IS FCST TO MOVE THROUGH PA THANKSGIVING NIGHT...IF
CURRENT TIMING HOLDS...WITH A NOTICEABLE COOL DOWN IN STORE FOR
SHOPPERS NEXT FRIDAY. ANY SHOWER ACTIVITY OVER NW PA COULD BE IN
THE FORM OF SNOW THUR-FRI AS 850 TEMPERATURES FALL BELOW 0C.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
WEAK FRONTAL BNDRY ARRIVING AT BFD ARND 06Z WILL SLOWLY DIMINISH
CIGS TO ARND 1000-1500FT AGL. IFR CIGS ARRIVE AT JST/AOO/UNV/IPT
BTWN 08-12Z...BOUNCING BACK TO VFR CONDS BY 16-18Z WITH BETTER
MIXING. MDT SHUD HOLD AT VFR CONDS FROM WEAK DOWNSLOPING. BY 00Z
SUN LGT NORTHERLY FLOW TURNING NE SHUD KEEP VFR CONDS THRU EARLY
SUN WITH PATCHY MVFR CIGS ACROSS SUSQ-VALLEY AIRFIELDS.

OUTLOOK...
SUN...MVFR/VFR.
MON...MVFR LCL IFR. PSBL SHRA IN THE AFTN.
TUE...MVFR/IFR CIGS. SHRA IN THE AM.
WED...MVFR TO VFR EARLY.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...GRUMM
NEAR TERM...GRUMM
SHORT TERM...LAMBERT
LONG TERM...GRUMM/GARTNER
AVIATION...BEACHLER/RXR

000
FXUS61 KPBZ 210723
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
223 AM EST SAT NOV 21 2009

.SYNOPSIS...
HIGH PRESSURE WILL PROVIDE A DRY WEEKEND. A LOW PRESSURE SYSTEM
MOVING INTO THE MID ATLANTIC STATES WILL BRING A CHANCE OF SHOWERS
MONDAY NIGHT AND TUESDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
STRATOCUMULUS CLOUD DECK TRAPPED UNDER SURFACE HIGH HANGING OVER
THE UPPER OHIO VALLEY LOOKS TO PERSIST THROUGH MUCH OF TODAY
ALTHOUGH SOME BREAKS WILL OPEN AT TIMES. PREVIOUS FORECAST HIGHS IN
THE 50S LOOK GOOD. CLOUDS WILL REMAIN EARLY THEN THEN BEGIN TO
BREAK ALLOWING FOR COLDER READINGS AND DROP MIN TEMPS TOWARD NEW
MAV GUIDANCE.

&&

.SHORT TERM /SUNDAY THROUGH TUESDAY/...
SURFACE HIGH SHIFTS NORTHEAST AND SHOULD ALLOW FOR SOME SUNSHINE
SUNDAY WITH MILD TEMPERATURES. LOW PRESSURE SYSTEM DEVELOPING
OVER THE EASTERN GULF OF MEXICO WILL MOVE TO THE VIRGINIA COAST
MONDAY. GFS AND NEW ECMWF SHOW MOISTURE FROM SYSTEM WORKING NORTH
SUNDAY NIGHT INTO MONDAY WITH A CHANCE FOR SHOWERS AS WELL.
TEMPERATURES WILL REMAIN ABOVE NORMAL. TUESDAY WILL BE IN BETWEEN
SYSTEMS WITH LOW LEVEL MOISTURE SLOW TO CLEAR AND SKIES SHOULD
REMAIN CLOUDY WITH ABOVE NORMAL TEMPERATURES CONTINUING.

&&

.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
UPPER TROUGH  BEGINS TO DOMINATE THIS PERIOD WHICH WILL LEAD TO
MUCH COOLER TEMPERATURES.

WITH MODEL DIFFERENCES IN TIMING...WILL KEEP POPS CHANCE FROM
WEDNESDAY INTO FRIDAY MODELS ALSO COMING INTO LINE FOR A BIT OF A
COLDER SOLUTION FOR THURSDAY AND FRIDAY AS CLOSED UPPER LOW MOVES
ACROSS THE OHIO VALLEY. SINCE TIME RANGE IS SO FAR OUT DID NOT
LOWER TEMPERATURES DRAMATICALLY FROM PREVIOUS FORECAST. SNOW
SHOWERS MIXING NOW LOOKS TO BE MORE DEFINITE AT NIGHT AND MAY
NEED TO ADD SNOW TO THANKSGIVING DAY AS WELL.

&&

.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
LOW-LEVEL MOISTURE WILL CONTINUE TO ALLOW FOR 3-4KFT CEILINGS TO
PREVAIL ACROSS THE TERMINALS OVERNIGHT. CIGS WILL DROP TO MVFR
DURING THE PRE-DAWN HRS ACROSS TAF SITES NORTH OF KPIT. WITH KZZV
ON THE EDGE OF THE LOW-LEVEL MOISTURE...CLEARING MAY ALLOW FOR A
BRIEF PD OF MVFR VSBYS DURING THE PRE-DAWN HRS. HIGH PRESSURE WILL
CONTINUE TO BUILD IN FROM THE SOUTHWEST ON SATURDAY...BREAKING
CIGS ACROSS THE SRN TERMINALS WITH CIGS LIFTING TO VFR EVERYWHERE
EXCEPT KDUJ AND KFKL BY 17Z SAT.

VFR CEILINGS WILL PREVAIL SATURDAY NIGHT...EXCEPT AT KDUJ AND
KFKL WHERE MVFR CIGS WILL FINALLY ERODE BY SUNDAY MORNING. A LOW
PRESSURE SYSTEM MOVING UP THE EAST COAST SUNDAY NIGHT WILL BRING
THE NEXT CHANCE FOR SHOWERS WITH REDUCED CEILINGS
EXPECTED...ESPECIALLY SOUTHEAST OF A KMGW-KLBE LINE. REDUCED
CEILINGS WILL BE POSSIBLE ACROSS THE AREA ON TUESDAY AS A COLD
FRONT APPROACHES THE AREA FROM THE WEST AND CONTINUE INTO
WEDNESDAY WHEN THE FRONT CROSSES THE TERMINALS.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.

&&

$$

000
FXUS61 KPBZ 210544
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
1244 AM EST SAT NOV 21 2009

.SYNOPSIS...
HIGH PRESSURE WILL PROVIDE A DRY WEEKEND. A LOW PRESSURE SYSTEM
MOVING FROM MISSISSIPPI TO THE VIRGINIA COAST MAY SPREAD SHOWERS
TO COMMUNITIES NEAR THE APPALACHIAN MOUNTAINS SUNDAY NIGHT INTO
MONDAY.

&&

.NEAR TERM /THROUGH SATURDAY/...
BLEND OF RECENT SATELLITE IMAGES AND NAM MODEL PROFILES SUGGEST
THE CURRENT STRATOCUMULUS CLOUD DECK HANGING OVER THE UPPER OHIO
VALLEY COULD PERSIST THROUGH SATURDAY AS MOISTURE REMAINS TRAPPED
BELOW THE SUBSIDENCE INVERSION. STILL HOLDING OUT FOR PERHAPS SOME
SUNNY BREAKS LATE SATURDAY AFTERNOON.

LOWERED TEMPS A DEGREE OR TWO ON SAT BASED ON CLOUD COVER.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
RECENT SREF MODEL OUTPUT CONTINUES TO SHOW HIGH PRESSURE COMING
NORTHEAST FROM KENTUCKY MAINTAINING DRY CONDITIONS THIS PERIOD
ACROSS THE UPPER OHIO VALLEY AT LEAST AS FAR EAST AS THE I-79
CORRIDOR.

HOWEVER A LOW PRESSURE SYSTEM DEVELOPING OVER THE EASTERN GULF OF
MEXICO WILL MOVE TO THE VIRGINIA COAST MONDAY. SREF MODEL OUTPUT
CONTINUES TO SHOW THAT SHOWERS FROM THAT SYSTEM COULD SPREAD AS
FAR WEST AS THE APPALACHIAN MOUNTAINS SUNDAY NIGHT AND MONDAY. SO
A CHANCE OF SHOWERS HAS BEEN INCLUDED FOR COMMUNITIES NEAR THE
APPALACHIAN MOUNTAINS FOR THAT PERIOD.

FORECASTED TEMPERATURES THIS PERIOD CLOSE TO BLEND OF RECENT GFS
AND NAM MOS AND SREF VALUES...WHICH MAINTAIN MILD TEMPERATURES...6-10
DEG F WARMER THAN NORMAL.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
MAINLY DRY CONDITIONS WILL PREVAIL MONDAY NIGHT INTO TUESDAY AS
MODELS SHOW UPPER OHIO VALLEY BETWEEN SYSTEMS. THEN UPPER
TROUGHING BEGINS TO DOMINATE THE REMAINDER OF NEXT WEEK WHICH
COULD LEAD TO A COOLING TREND.

WITH MODEL DIFFERENCES IN TIMING...WILL KEEP POPS CHANCE FROM
LATE TUESDAY THROUGH THANKSGIVING DAY AND FRIDAY. MODELS ALSO
DIFFER ON THE AMOUNT OF COLDER AIR THAT IS PROGGED TO FILTER IN
FOR THE LAST HALF OF NEXT WEEK. FOR NOW HAVE WILL CONTINUE TO
FORECAST A COOLING TREND BY THANKSGIVING DAY...WITH DAYTIME
TEMPERATURES 5-10 DEGREES BELOW NORMAL THANKSGIVING DAY AND
FRIDAY. THIS WILL SUPPORT THE PRECIP TYPE TO INCLUDE SOME SNOW BY
FRIDAY.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
LOW-LEVEL MOISTURE WILL CONTINUE TO ALLOW FOR 3-4KFT CEILINGS TO
PREVAIL ACROSS THE TERMINALS OVERNIGHT. CIGS WILL DROP TO MVFR
DURING THE PRE-DAWN HRS ACROSS TAF SITES NORTH OF KPIT. WITH KZZV
ON THE EDGE OF THE LOW-LEVEL MOISTURE...CLEARING MAY ALLOW FOR A
BRIEF PD OF MVFR VSBYS DURING THE PRE-DAWN HRS. HIGH PRESSURE WILL
CONTINUE TO BUILD IN FROM THE SOUTHWEST ON SATURDAY...BREAKING
CIGS ACROSS THE SRN TERMINALS WITH CIGS LIFTING TO VFR EVERYWHERE
EXCEPT KDUJ AND KFKL BY 17Z SAT.

VFR CEILINGS WILL PREVAIL SATURDAY NIGHT...EXCEPT AT KDUJ AND
KFKL WHERE MVFR CIGS WILL FINALLY ERODE BY SUNDAY MORNING. A LOW
PRESSURE SYSTEM MOVING UP THE EAST COAST SUNDAY NIGHT WILL BRING
THE NEXT CHANCE FOR SHOWERS WITH REDUCED CEILINGS
EXPECTED...ESPECIALLY SOUTHEAST OF A KMGW-KLBE LINE. REDUCED
CEILINGS WILL BE POSSIBLE ACROSS THE AREA ON TUESDAY AS A COLD
FRONT APPROACHES THE AREA FROM THE WEST AND CONTINUE INTO
WEDNESDAY WHEN THE FRONT CROSSES THE TERMINALS.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.

&&

$$

000
FXUS61 KPHI 210401
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1101 PM EST FRI NOV 20 2009

.SYNOPSIS...
HIGH PRESSURE WILL BUILD ACROSS THE AREA TONIGHT AND SATURDAY. IT
WILL REMAIN IN CONTROL OF THE WEATHER THROUGH THE WEEKEND. LOW
PRESSURE WILL DEVELOP TO THE SOUTH AND MOVE UP ALONG THE EAST
COAST EARLY NEXT WEEK. IT WILL BRING UNSETTLED WEATHER EARLY NEXT
WEEK.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
CONDITIONS REMAIN FAVORABLE FOR GOOD RADIATIONAL COOLING TO OCCUR
TONIGHT AS MOST OF THE CLOUD COVER AROUND WILL BE HIGH CLOUDS,
ALTHOUGH ALONG THE IMMEDIATE COAST THE WARMER WATER WILL TEMPER
THIS SOME. LOW TEMPS WERE LOWERED A BIT ACROSS THE REGION AS TEMPS
INTO THE 30S SEEM LIKELY TO OCCUR, BUT ALONG THE COASTAL STRIP WE
RAISED THEM A LITTLE. MIN TEMPS ALSO WERE RAISED SLIGHTLY AROUND
PHILADELPHIA AND SHOULD BE CLOSER TO 40 OVERNIGHT.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
FAIR WEATHER WITH SEASONABLE TEMPERATURES WILL CONTINUE SATURDAY
AND SUNDAY AS THE HIGH CRESTS OVER THE AREA. HIGHS BOTH DAYS WILL
BE IN THE 50S FOR THE MOST PART...WITH LOWS IN THE 30S.

FCST MODELS SHOWING DIFFERING SOLUTIONS WITH REGARDS TO WEAK LOW
PRESSURE DEVELOPING ALONG THE SOUTHEAST COAST AND MOVING NORTHEAST
LATER SUNDAY AND MONDAY. THE SYSTEM DOES NOT APPEAR TO BECOME VERY
STRONG, BUT IT DOES SEND ENOUGH MOISTURE ACROSS THE AREA FOR
LIKELY POPS FOR THE REGION ON MONDAY. QPF TOTALS WILL MOST LIKELY
BE 1/2 INCH OR SO.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
FOLLOWING TRENDS FROM HPC WHICH GENERALLY WENT WITH THE ECMWF SHOWED
LOW PRESSURE MOVING AWAY FROM THE AREA LATE MONDAY NIGHT WITH HIGH
PRESSURE IN EASTERN CANADA EXTENDING SOUTH OVER THE REGION. THIS
SHOULD MEAN DRYING TRENDS LATE MONDAY NIGHT WITH A DRY DAY ON
TUESDAY. TUESDAY NIGHT AND WEDNESDAY WILL SEE ANOTHER FRONT FROM THE
WEST MOVE EAST. THIS FRONT SHOULD CROSS THE REGION WEDNESDAY AFTN.
WITH THE WARM ADVECTION AHEAD OF THE FRONT LATE TUESDAY NIGHT COULD
SEE SOME RAIN AND SHOWERS ARE POSSIBLE DURING THE DAY WEDNESDAY.

FOR THANKSGIVING, AN UPPER TROUGH DIGS INTO THE WESTERN GREAT LAKES.
WE HAVE WARM ADVECTION OVER THE AREA AND DUE TO THIS COMBINATION THE
FORECAST WILL INCLUDE A CHANCE OF SHOWERS.

THURSDAY NIGHT, A STRONG COLD FRONT MOVES THROUGH FROM THE NW AND WE
GET INTO A COLD ADVECTION PATTERN FOR FRIDAY WITH CYCLONIC FLOW
ALOFT AND VERY COOL TEMPERATURES ON FRIDAY. OVER THE FAR NORTHERN
ZONES, THERE IS A CHANCE OF RAIN OR SNOW SHOWERS ON FRIDAY.

HPC TEMPS ARE GENLY REASONABLE.

&&

.AVIATION /04Z SATURDAY THROUGH WEDNESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.

NORTHWEST WINDS GUSTING UP TO 25 KT IN A FEW LOCATIONS ARE EXPECTED
TO SUBSIDE TOWARD EVENING, THEN REMAIN IN THE 5 TO 10 KT RANGE
DURING THE OVERNIGHT HOURS AND ON SATURDAY. A HIGH BKN DECK FORMED
OVER THE NORTHERN TAF SITES BEFORE NOON, WITH A SCT DECK IN THE
SOUTH. THESE CLOUDS ARE EXPECTED TO DISSIPATE ONCE THE SUN GOES
DOWN. BASICALLY VFR CONDITIONS EXPECTED THROUGH A GOOD PART OF THE
UPCOMING WEEKEND.


OUTLOOK...
DRY WEATHER IS EXPECTED INTO EARLY SUNDAY. A CHANCE OF RAIN RETURNS
FOR LATE SUNDAY INTO MONDAY AS LOW PRESSURE MOVES NORTH ALONG THE
MID ATLANTIC COAST.

&&

.MARINE...
WITH SEAS AROUND 4.5 FT AND WIND GUSTS IN THE 20 TO 25 KT RANGE, SCA
CONDITIONS ARE BARELY BEING REACHED OVER THE OCEAN WATERS. WITH
CONDITIONS EXPECTED TO IMPROVE TOWARD EVENING, THE SCA IN EFFECT
UNTIL 4PM THIS AFTERNOON WILL BE ALLOWED TO EXPIRE BOTH ON THE OCEAN
AND DELAWARE BAY.

HIGH PRESSURE FROM THE WEST IS FORECAST TO BUILD ACROSS OUR REGION
TONIGHT AND SATURDAY, THEN MOVE OFF TO THE EAST ON SUNDAY. LOW
PRESSURE IS THEN EXPECTED TO MOVE NORTH ALONG OR NEAR THE COAST
SUNDAY AND MONDAY. RIGHT NOW THIS LOW LOOKS RELATIVELY WEAK. THE
STRONGEST ONSHORE WINDS (30KT OR SO) WILL LIKELY OCCUR LATE SUNDAY
NIGHT INTO MONDAY MORNING, THEN SUBSIDE AGAIN MONDAY AFTERNOON AND
EVENING. MORE HIGH PRESSURE IS EXPECTED TUESDAY AND WEDNESDAY.

&&

.TIDES/COASTAL FLOODING...
TIDAL ANOMALIES WITH THE WEAK LOW PRESSURE SYSTEM EXPECTED ON SUNDAY
AND MONDAY LOOK TO BE AROUND 1 FOOT. WE`LL BE BETWEEN NEW MOON AND
FULL MOON, SO THE ASTRONOMICAL TIDES ARE FAIRLY LOW. UNDER NORMAL
CIRCUMSTANCES, THIS WOULDN`T POSE ANY PROBLEMS, BUT WITH ANTECEDENT
CONDITIONS BEING WHAT THEY ARE FROM LAST WEEK`S STORM, WE`LL BE
KEEPING AN EYE ON THE SITUATION.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...O`HARA
NEAR TERM...DELISI/MEOLA/O`HARA
SHORT TERM...O`HARA
LONG TERM...STAUBER
AVIATION...MIKETTA
MARINE...MIKETTA
TIDES/COASTAL FLOODING...MIKETTA