National Weather Service United States Department of Commerce

 


000
FXUS62 KILM 251528
AFDILM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
1128 AM EDT SAT OCT 25 2014

.SYNOPSIS...
THE CENTER OF HIGH PRESSURE WILL REMAIN TO OUR WEST THROUGH SUNDAY.
THE HIGH WILL MOVE OVERHEAD SUNDAY NIGHT INTO MONDAY AND THEN
SHIFT OFFSHORE. THIS WILL RESULT IN PROGRESSIVELY WARMER
TEMPERATURES THROUGH THE MIDDLE OF NEXT WEEK. THE PASSAGE OF A
COLD FRONT LATE IN THE UPCOMING WEEK WILL BRING TEMPERATURES BACK
TO SEASONABLE LEVELS IF NOT BELOW NORMAL. THE ONLY CHANCE FOR
MEASURABLE RAINFALL WILL BE THURSDAY INTO FRIDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 1130 AM SATURDAY...ALOFT VERY DRY AIR HAS MOVED IN THE
REGION WITH PRECIPITABLE WATERS BETWEEN 0.3 TO 0.4 INCH RANGE
WHICH IS WELL BELOW THE CLIMATOLOGICAL 25TH PERCENTILE VALUE AT
CHS AND GSO.

AT THE SURFACE A WEAK SEA BREEZE IS PROJECTED BY THE 13 UTC RUN OF
THE HRRR MAINLY SOUTH OF WRIGHTSVILLE BEACH AND EXTENDING TO THE
SOUTH SANTEE RIVER. THE SEA BREEZE IS ONLY EXPECTED TO MOVE INLAND
10 TO 15 MILES BEFORE SUNSET.

WITH THE DRY AIR IN PLACE EXPECT THE HIGHS TODAY TO REBOUND
QUICKLY WITH MAXIMUM TEMPERATURES IN THE MIDDLE 70S EXCEPT FOR LOW
70S AT THE BEACHES WHICH ARE IMPACTED BY THE SEA BREEZE.

NOCTURNAL JETTING IS EXPECTED TO DEVELOP OVERNIGHT AS WINDS ABOVE
THE BOUNDARY LAYER INCREASE TO 20 TO 25 KT AND THIS WILL PREVENT THE
DEVELOPMENT OF FOG. THE PASSAGE OF A WEAK SURFACE TROUGH...
COINCIDENT WITH THE AFOREMENTIONED UPSTREAM UPPER LEVEL FEATURE...
WILL ALLOW WINDS TO VEER FROM WSW TO W AND NW LATE TONIGHT.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 300 AM SATURDAY...BEAUTIFUL WEATHER IS ANTICIPATED DURING
THIS PERIOD. MID- LEVEL FLOW WILL GRADUALLY FLATTEN DURING
SUNDAY...THEN EVOLVE TO A LONGWAVE RIDGE MONDAY WITH THE MID-LEVEL
HIGH CENTER MOVING TO JUST OFF THE EAST COAST OF FLORIDA. MOST OF
THE PERIOD WILL FEATURE WESTERLY FLOW ALOFT...WHICH IS TYPICALLY
DRYING...AND WHICH WILL COMBINE WITH A SURFACE HIGH MOVING
OVERHEAD TO CREATE DRY AND PRETTY MUCH CLOUDLESS CONDITIONS. IN
ADDITION...AS THICKNESSES RISE AND HIGH PRESSURE SCOOTS
OFFSHORE...HIGH TEMPS WILL CLIMB TOWARDS 80 BOTH DAYS...WHICH IS
5-10 DEGREES ABOVE NORMAL. THE DRY COLUMN AND WEAK GRADIENT WILL
ALLOW FOR GOOD RADIATIONAL COOLING AT NIGHT HOWEVER...SO LOWS
SUNDAY NIGHT WILL DROP TO CLIMATOLOGICAL NORMS AROUND 50...WITH
MONDAY NIGHT EXPECTED TO BE SEVERAL DEGREES WARMER THANKS TO
DEVELOPING RETURN FLOW.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 300 AM SATURDAY...VERY WARM AND SUNNY THE FIRST HALF OF THE
EXTENDED...BUT A BIG AIR MASS CHANGE WILL ACCOMPANY A COLD FRONT
LATE IN THE WEEK. THIS FRONT MAY CAUSE SOME SHOWERS FOR HALLOWEEN.

500MB RIDGE ANCHORED OFF THE ATLANTIC FLORIDA COAST WILL EXTEND
NORTH THROUGH THE FULL LATITUDE OF THE CONUS...PRODUCING SW FLOW
ALOFT THROUGH WEDNESDAY...AND DRIVING HIGH THICKNESSES INTO THE
CAROLINAS. AT THE SURFACE...HIGH PRESSURE WILL DRIFT SLOWLY EAST
THROUGH MID-WEEK AS WELL...AS A COLD FRONT DISPLACES IT FROM THE
WEST. TUE/WED WILL BOTH BE QUITE WARM...WITH HIGHS LIKELY REACHING
THE LOW 80S BOTH AFTNS...AND LOWS FALLING ONLY TO THE MID 50S/NEAR
60. ALTHOUGH MOIST ADVECTION WILL INCREASE TUE/WED...MID-LEVELS
REMAIN TOO DRY FOR ANY PRECIP.

STRONG COLD FRONT APPROACHES THURSDAY...AND MAY LINGER ACROSS THE
AREA ON FRIDAY THANKS TO AN AMPLIFYING LONGWAVE TROUGH DIVING
THROUGH THE MS VLY. THERE IS STILL SOME UNCERTAINTY INTO THE TIMING
OF THIS FEATURE...AS WELL AS ITS INTENSITY...BUT LATE THURSDAY INTO
EARLY FRIDAY DOES APPEAR TO SUPPORT A GOOD CHANCE FOR SHOWERS AND
WILL RAISE POP TO LOW-CHC AS FORECAST PROFILES CONTINUE TO BECOME
MORE SATURATED...MATCHING THE EXTENDED MOS P-NUMBERS. AS THE
LONGWAVE TROUGH DRIFTS EAST ON FRIDAY...IT WILL CAUSE THE FRONT TO
STALL...OR MOVE VERY SLOWLY...SUCH THAT IT WILL BE A RACE TO SEE
IF THE DRY AIR CAN WORK BACK IN BEFORE HALLOWEEN EVENING
FESTIVITIES. ATTM IT LOOKS GOOD FOR HALLOWEEN...BUT THIS WILL HAVE
TO BE MONITORED SINCE THE TROUGH AXIS HANGING BACK TO THE WEST
COULD KEEP THE FRONT OVERHEAD THROUGH THE END OF THE PERIOD.
REGARDLESS OF WHERE THE FRONT IS ON FRIDAY...TEMPS WILL BE MUCH
COOLER...LIKELY FALLING TO BELOW CLIMO BY THE END OF NEXT WEEK.

&&

.AVIATION /16Z SATURDAY THROUGH WEDNESDAY/...
AS OF 12Z...DUE TO THE RATHER SHALLOW NATURE OF THE PATCHY GROUND
FOG THAT IS OCCURRING...FULL SUNSHINE SHOULD ALLOW FOR A RAPID
BURN-OFF AND VFR CONDITIONS BY 13Z. VFR IS THEN EXPECTED FOR THE
REMAINDER OF THE TAF VALID PERIOD.

LIGHT N-NW WINDS THIS MORNING WILL BECOME MORE WESTERLY AFTER
MIDDAY...AOB 8 KT. KCRE/KMYR MAY SEE S-SW WINDS BY 17Z. JUST SCT
CIRRUS EXPECTED THIS AFTERNOON. TOWARDS THIS EVENING SOME SCT MID-
LEVEL CLOUDS WILL DEVELOP AHEAD OF THE NEXT COLD FRONT. THE FRONT
WILL MOVE THROUGH OVERNIGHT...WITH ONLY SCT LOW/MID CLOUDS AND A
WIND-SHIFT TO THE NW.

EXTENDED OUTLOOK...VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD.

&&

.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1130 AM SATURDAY...NORTHWEST WINDS AT 10 KNOTS ARE OCCURRING
LATE THIS MORNING OVER THE COAST WATERS. THESE WINDS ARE EXPECTED
TO BACK TO THE WEST EARLY THIS AFTERNOON AND THEN TO THE
SOUTHWEST AS A SEA- BREEZE DEVELOPS THIS AFTERNOON. PASSAGE OF A
SURFACE TROUGH WILL VEER WINDS BACK TO THE NW LATE TONIGHT.
NOCTURNAL JETTING WILL INCREASE WIND SPEEDS FROM 10 KT OR LESS
TODAY TO 10 TO 15 KT OVERNIGHT. ACROSS PORTIONS OF THE OUTERMOST
WATERS...SUSTAINED WIND SPEEDS MAY REACH 20 KT FOR A TIME
OVERNIGHT. SEAS WILL BE 2 FT OR LESS INTO THIS EVE...BUILDING UP
TO 3 TO 4 FT OVERNIGHT.

SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 300 AM SATURDAY...AFTER A BRIEF PERIOD OF GUSTY W/NW WINDS
EARLY SUNDAY...HIGH PRESSURE BUILDING ACROSS THE WATERS WILL PRODUCE
PRIMARILY LIGHT SPEEDS WITH DIRECTIONS VARYING THROUGH NEARLY THE
ENTIRE COMPASS. W/NW WINDS THE FIRST FEW HOURS OF SUNDAY WILL REACH
15 KTS BEHIND A WEAK FRONT MOVING AWAY FROM THE WATERS...BUT
THEREAFTER THE GRADIENT WILL EASE DUE TO THE HIGH PRESSURE MOVING
OVERHEAD. WINDS SPEEDS DROP TO 5-10 KTS THROUGH THE REST OF THE
SHORT TERM...AND THE DIRECTION WILL VEER FROM NW SUNDAY AFTN...TO NE
BY MONDAY MORNING...AND THEN FINALLY SW BY MONDAY NIGHT. HIGHEST
WAVE AMPLITUDES OCCUR EARLY SUNDAY WITH THE STRONGER WINDS...BUT
WILL STILL BE ONLY 2-3 FT THANKS TO THE OFFSHORE COMPONENT OF THE
WIND. SUNDAY EVE THROUGH MONDAY NIGHT EXPECT 1-2 FT SEAS...WITH
SEVERAL LOW-AMPLITUDE WAVE GROUPS COMPRISING THE SPECTRUM.

LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 300 AM SATURDAY...HIGH PRESSURE MOVING OFFSHORE AND AWAY FROM
THE COAST THROUGH MID-WEEK WILL DOMINATE THE WEATHER THIS PERIOD.
RETURN FLOW AROUND THIS HIGH KEEPS WINDS FROM THE SW TUE AND
WED...WITH THE RELATIVELY WEAK GRADIENT DRIVING WINDS ONLY TO AROUND
10 KTS. VERY LATE WEDNESDAY A COLD FRONT WILL APPROACH AND A WIND
SHIFT TO THE NE MAY OCCUR BEFORE DAYBREAK THURSDAY...BUT SOME
UNCERTAINTY STILL EXISTS. ALTHOUGH THE FLOW WILL BE PERSISTENT FROM
THE SW...THE LIGHT SPEEDS WILL KEEP SEAS AT 1-3 FT BOTH DAYS EVEN AS
A SE GROUND SWELL AMPLIFIES.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.

&&

$$

NEAR TERM...HAWKINS/RJD
SHORT TERM...JDW
LONG TERM...JDW
AVIATION...MRR