[top]
000
FXUS61 KPHI 230418
AFDPHI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1118 PM EST SUN NOV 22 2009
.SYNOPSIS...
HIGH PRESSURE, LOCATED OVER NEW ENGLAND 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/...
MID AND HIGH LEVEL CLOUDINESS WAS BEGINNING TO INVADE FROM THE
SOUTH LATE THIS EVENING, AND IT SHOULD MAKE GOOD PROGRESS NORTH
OVERNIGHT. MEANWHILE, AREAS OF STRATOCUMULUS WERE MOVING WEST FROM
OFF THE ATLANTIC.
WE MAINTAIN THE THINKING THAT MADE US BACK OFF ON THE
PRECIPITATION UP NORTH AND DELAY IT DOWN SOUTH FOR A COUPLE OF HOURS.
NEAREST TO US LATE THIS EVENING WAS NEAR THE VIRGINIA-NORTH
CAROLINA BORDER AND WAS MOVING SLOWLY NORTH-NORTHEAST. 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 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 /04Z 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 ABOVE
THE MRPSSE, BUT THE APPROACHING HIGH TIDE EARLY MONDAY MORNING IS
THE LOWER ONE AND WILL NOT PRESENT PROBLEMS. WE WILL CONTINUE TO
WATCH THE DEPARTURES. THEY COULD RISE TO THE LEVEL THAT WOULD
CAUSE MINOR TIDAL FLOODING WITH THE MONDAY AFTERNOON/EVENING HIGH
TIDE, ESPECIALLY IN DE WITH THE EARLY AFTERNOON HIGH TIDE. TIDE
LEVELS THEN COULD REACH SOMEWHERE AROUND 5.5 TO 5.8 FT, WITH THE
NORMAL MINOR THRESHOLD BEING 6.0. HOWEVER, BECAUSE OF THE
VETERAN`S DAY STORM, MINOR TIDAL FLOODING COULD OCCUR WITH HEIGHTS
THAT ARE A BIT LOWER THAN 6.0 FT WHERE THE EROSION OCCURRED.
WE WILL CONTINUE TO MONITOR OVER THE NEXT FEW CYCLES. THE SEA
HEIGHTS AT 44009 ARE ONLY FORECAST TO BE 7 TO 8 FEET, WHICH
TRANSLATES TO ABOUT A 3.5 FT BREAKING WAVE ON THE BEACH. QUITE A
BIT DIFFERENT THAN THE 12 TO 13 FT BREAKERS 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/DELISI
SHORT TERM...IOVINO
LONG TERM...GORSE
AVIATION...GORSE
MARINE...ROBERTSON
TIDES/COASTAL FLOODING...EBERWINE/DELISI
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 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 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 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 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 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 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 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 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 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 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 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...
|
