Area Forecast Discussion
Issued by NWS Wakefield, VA

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000
FXUS61 KAKQ 282056
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
356 PM EST SUN DEC 28 2014

.SYNOPSIS...
A COLD FRONT MOVES SOUTHWARD THROUGH THE AREA TONIGHT. LOW
PRESSURE OVER THE GULF STATES WILL LIFT NORTHEASTWARD ALONG THE
FRONT...AND INTO THE CAROLINAS TONIGHT INTO MONDAY. HIGH PRESSURE
SLOWLY BUILDS INTO THE REGION FROM THE WEST TUESDAY THROUGH
MIDWEEK.

&&

.NEAR TERM /THROUGH MONDAY/...
BROAD SOUTHWEST FLOW ALOFT PREVAILS OVER THE EASTERN HALF OF THE
U.S. THIS AFTERNOON. SEVERAL SHORTWAVE TROFS EMBEDDED IN THE FLOW
WILL CROSS THE REGION DURING THE NEXT 24-36 HOURS. RIDGING ALOFT
HAS KEPT MUCH OF THE PRECIP AWAY FROM THE AREA SO FAR TODAY...WITH
PRECIP EXPECTED TO REMAIN OVER THE NRN HALF OF THE CWA THROUGH
00Z. AS A RESULT...TEMPERATURES HAVE CLIMBED INTO THE 60S ACROSS
MOST OF THE AREA...WITH A FEW LOCATIONS IN NE NC NEAR 70.

A COLD FRONT IS SLOWLY WORKING ITS WAY SOUTHEASTWARD INTO THE
REGION THIS AFTERNOON...AND WILL DROP THROUGH THE REGION TONIGHT.
A STRONGER SHORTWAVE WILL MOVE ACROSS THE REGION TONIGHT THROUGH
MIDDAY MONDAY...BRINGING MORE WIDESPREAD RAINFALL. PREVIOUS
FORECAST HAD THE SCENARIO COVERED VERY WELL. A GENERAL ONE-THIRD TO
THREE QUARTERS OF AN INCH OF RAINFALL IS EXPECTED ACROSS THE
REGION.

TEMPERATURES ARE EXPECTED TO FALL INTO THE 40S MOST AREAS
TONIGHT...WITH A FEW UPPER 30S FAR NORTH/NORTHEAST...AND AROUND 50
NEAR THE ALBEMARLE SOUND. COLDER N/NNE FLOW ON MONDAY WILL RESULT
IN LITTLE IF ANY TEMPERATURE RISE...WITH MAX TEMPS WITHIN 5
DEGREES OF MONDAY MORNING MIN TEMPS.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
SHORTWAVE EXITS THE REGION BY 00Z TUESDAY...LEAVING CLOUDY AND RAW
CONDITIONS AREA-WIDE. COULD HAVE SOME LIGHT RAIN OR DRIZZLE COULD
OCCUR MONDAY EVENING...BUT MODEL TSECTIONS SUGGEST LOLVLS MAY BE
TOO DRY FOR MUCH DRIZZLE.

YET ANOTHER WEAK SHORTWAVE MOVES ACROSS THE AREA LATE MONDAY
NIGHT/TUESDAY. NAM REMAINS MUCH STRONGER WITH THIS SYSTEM...AND
WOULD SUGGEST A PREIOD OF SNOW FROM THE NRN NECK INTO THE LOWER MD
ERN SHORE. HOWEVER...GFS/ECMWF CONTINUE TO BE MUCH WEAKER WITH
THIS SYSTEM...SUGGESTING ONLY VERY LIGHT PRECIP. WPC PREFERS THE
WEAKER SOLUTION...AS DID PREVIOUS FORECAST...AND HAVE MAINTAINED
ONLY LOW CHC POPS WITH THIS SYSTEM. REGARDLESS...TUESDAY SHOULD
STILL BE A MAINLY CLOUDY DAY...ALTHOUGH SOME CLEARLY POSSIBLE
ACROSS THE NORTH LATE AS SHORTWARVE EXITS. MOST AREAS WILL
STRUGGLE TO GET INTO THE LOW 40S AS A RESULT.

LAST SHORTWAVE EXITS THE REGION TUESDAY
AFTERNOON/EVENING...ALLOWING FOR SKIES TO CLEAR...WITH
TEMPERATURES TUESDAY NIGHT IN THE 20S MOST AREAS. PARTLY TO MOSTLY
SUNNY EXPECTED WEDNESDAY AS HIGH PRESSURE BUILDS INTO THE REGION.
HIGH TEMPERATURES MOSTLY IN THE 40S.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
28/12Z GFS/ECMWF DEMONSTRATE GOOD AGREEMENT THROUGH FRIDAY. DRY AND
MOSTLY CLEAR/SUNNY CONDITIONS SHOULD PREVAIL THROUGH THURSDAY NIGHT
WITH INCREASING CLOUDS FROM THE SW FRIDAY AS LOW PRESSURE TRACKS
ACROSS THE LOWER MISSISSIPPI VALLEY. HIGHS THURSDAY AND FRIDAY
SHOULD RANGE FROM THE LOW/MID 40S NW...TO UPPER 40S/LOW 50S SE. LOWS
THURSDAY MORNING SHOULD BE IN THE LOW/MID 20S...WITH MID/UPPER 20S
FRIDAY MORNING. MODEL SOLUTIONS BEGIN TO DIVERGE FRIDAY NIGHT INTO
SATURDAY AS THE ECMWF MAINTAINS A STRONGER HIGH ACROSS THE GREAT
LAKES...WHICH KEEPS A WARM FRONT FARTHER S...WHILE THE GFS ALLOWS
THE FRONT TO LIFT N THROUGH THE REGION. THE MAIN IMPACT AT THIS TIME
APPEARS TO BE TEMPERATURE...AS OVERALL SURFACE TEMPERATURES APPEAR
WARM ENOUGH TO SUPPORT MOSTLY RAIN (ASIDE FROM A CHC OF SLEET ACROSS
THE N FRIDAY NIGHT). DIFFERENCES CONTINUE THROUGH THE WEEKEND WITH
RESPECT TO THE FRONTAL BOUNDARY. THE ECMWF KEEPS THE BOUNDARY IN
VICINITY OF THE LOCAL AREA THROUGH SUNDAY...WHILE THE GFS BRINGS THE
COLD FRONT IN FROM THE NW BY SATURDAY NIGHT. OVERALL THE FORECAST
DETAILS ARE LOW CONFIDENCE. HOWEVER...THE WEATHER DOES APPEAR TO BE
UNSETTLED NEXT WEEKEND.

&&

.AVIATION /21Z SUNDAY THROUGH FRIDAY/...
AS OF 17Z...THE 18Z TAF ISSUANCE WAS CHALLENGING AS THE TIMING OF
PCPN AND THE BASES OF CLOUDS ARE UNCERTAIN. DESPITE MID LEVEL
SCT-BKN CLOUDS...MVFR CIGS WITH CIGS OF 015-025 WERE DEVELOPING
QUICKLY AHEAD OF THE PCPN ACRS SRN VA AND NC. THERE ARE TWO PERIODS
OF PCPN EXPECTED...ONE FOR MID TO LATE AFTN AND THE OTHER DEVELOPING
IN THE LATE EVENING OR EARLY MORNING. THE COLD FRONT MOVES THROUGH
AROUND 00Z OR AFTER. IFR CIGS ARE LIKELY TO DEVELOP WITH THE LATTER
PCPN EXCEPT AT SBY WHICH WILL BE ON THE EDGE OF THE PCPN BAND.
CONFIDENCE IN ANY IMPROVEMENT OF THE CIGS THROUGH 18Z IS RATHER LOW
WITH THE NE WIND AND A MOIST BOUNDARY LAYER.

OUTLOOK...THE NAM HAS A MUCH DIFFERENT SOLUTION FOR TUESDAY THAN THE
DRIER GFS. LIKEWISE...THE NAM MOS INDICATES PERIODS OF IFR TUESDAY
CONTRARY TO THE GFS. THE REALITY MAY BE SOMEWHERE IN BETWEEN WITH AN
OCCASIONAL IFR IN SRN PORTIONS OF THE AREA AND LOW CHC FOR PCPN.

HIGH PRESSURE BUILDS IN WITH DRY WEATHER AND A CLEAR TO PARTLY
CLOUDY SKY ARE EXPECTED WEDNESDAY AND THURSDAY. PCPN CHANCES RETURN
BY LATE FRIDAY OR SATURDAY WITH THE NEXT LOW PRESSURE SYSTEM
APPROACHING FROM THE WEST.

&&

.MARINE...
SW FLOW WILL GRADUALLY WANE LATE THIS AFTERNOON AS THE SURFACE
PRESSURE GRADIENT SLACKENS AHEAD OF A COLD FRONT. THE COLD FRONT
WILL CROSS THE AREA N-S THIS EVENING FOLLOWED BY A SHALLOW NNE
SURGE. THE SURGE IS NOT PARTICULARLY STRONG BUT STILL ENOUGH WIND
(~20KT) IS EXPECTED FOR THE MIDDLE/LOWER BAY. ADDITIONALLY...ENOUGH
OF A NNE WIND IS EXPECTED TO PUSH SEAS TO ~5FT S OF CAPE CHARLES
LATER MONDAY MORNING. LOW PRESSURE DEVELOPS OFF THE COAST MONDAY
NIGHT AND MOVES FARTHER OFFSHORE TUESDAY. THE 28/12Z NAM IS STILL
CONSIDERED AN OUTLIER SO THE CURRENT FORECAST FOR MONDAY INTO EARLY
TUESDAY LARGELY FOLLOWS CONTINUITY WHICH FEATURED A BLEND OF THE
GFS/ECMWF/CMC. THIS SUPPORTS THE WIND REMAINING NNE WITH SPEEDS
INCREASING TO 15-25KT. SEAS ARE EXPECTED TO BUILD TO 5-7FT MONDAY
NIGHT INTO TUESDAY FOR THE SRN OCEAN ZONES...WITH 3-4FT WAVES IN THE
BAY. SEAS POTENTIALLY COULD BUILD TO 4-6FT ACROSS THE NRN OCEAN
ZONES BY LATE MONDAY NIGHT INTO TUESDAY. THE AFOREMENTIONED SCA FOR
THE SRN OCEAN ZONES WILL BE EXTENDED THROUGH 6PM TUESDAY. THE ONSET
OF SCA CONDITIONS FOR THE NRN OCEAN ZONES WILL NOT LIKELY BEGIN
UNTIL LATER 3RD PERIOD...SO WILL FORGO AN SCA AT THIS TIME. HIGH
PRESSURE GRADUALLY BUILDS INTO THE REGION THROUGH MIDWEEK...WITH
THE WIND DIMINISHING AND SEAS/WAVES SUBSIDING.

&&

.EQUIPMENT...
KDOX 88D RADAR IS EXPECTED TO BE OUT OF SERVICE THROUGH AT LEAST
WED 12/31. SEE FTMDOX (FREE TEXT MESSAGE) FOR DETAILS.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 10 AM MONDAY TO 6 PM EST TUESDAY FOR
     ANZ656-658.
     SMALL CRAFT ADVISORY FROM 4 AM TO NOON EST MONDAY FOR ANZ631-
     632-634.

&&

$$
SYNOPSIS...SAM/WRS
NEAR TERM...WRS
SHORT TERM...SAM/WRS
LONG TERM...AJZ
AVIATION...LSA
MARINE...AJZ
EQUIPMENT...




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