Area Forecast Discussion
Issued by NWS Wakefield, VA

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000
FXUS61 KAKQ 282011
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
311 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/...
GFS/ECMWF REMAIN IN GOOD AGREEMENT TUESDAY NIGHT THROUGH THE
DAYTIME HOURS ON FRIDAY WITH REGARD TO OVERALL PATTERN. A COLD
ZONAL FLOW WILL PREVAIL ALOFT ACROSS THE REGION
WEDNESDAY/THURSDAY...WITH HIGH PRESSURE BUILDING INTO AND ACROSS
THE AREA. WEATHER IS EXPECTED TO BE DRY WITH TEMPERATURES AT OR
SLIGHTLY BELOW NORMAL FOR LATE DECEMBER. LOW TEMPS TUESDAY NIGHT
AND WEDNESDAY NIGHT AROUND 25-30 DEGREES...A BIT WARMER NEAR THE
COAST. LOWS THURSDAY NIGHT IN THE UPPER 20S NW TO THE LOW-MID
30S SE...WITH MIN TEMPS EXPECTED TO OCCUR BEFORE 06Z...AS CLOUDS
INCREASE OVERNIGHT. HIGH TEMPS TUESDAY THROUGH THURSDAY IN THE
40S...AND IN THE 40S ALL AREAS FRIDAY (EXCEPT SE VA/NE NC WHERE
50S LOOK LIKELY).

GFS/ECMWF CONTINUE TO DIVERGE FROM NEXT FRIDAY NIGHT THROUGH
SATURDAY NIGHT WITH REGARD TO TIMING OF LOW PRESSURE AND ASSOCIATED
COMPLEX FRONTAL SYSTEM. GFS REMAINS 12-18 HOURS FASTER THAN
ECMWF WHICH DEVELOPS A WAVE ALONG THE FRONT SATURDAY
NIGHT...DELAYING THE FRONTAL PASSAGE UNTIL SUNDAY. REGARDLESS...
FRIDAY NIGHT INTO SATURDAY NIGHT NEXT WEEK LOOKS TO BE UNSETTLED
WITH CLOUDS AND SHOWERS. HOWEVER...TEMPERATURES WILL WARM TO
ABOVE NORMAL ON SATURDAY WITH MANY AREAS POTENTIALLY IN THE 60S.

&&

.AVIATION /20Z 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 AVERAGING 10-15 KT THIS MORNING (EVEN A TAD HIGHER THROUGH
15Z)...WILL TEND TO DIMINISH TO 5-10 KT LATER TODAY AS A COLD
FRONT MOVES CLOSER TO THE AREA AND THE PRESSURE GRADIENT WEAKENS.
SEAS AVG 2-3 FT TODAY...WITH BAY WAVES 1-2 FT.

WHILE THIS FRONT IS NOT PARTICULARLY STRONG...EXPECT ENOUGH OF A NNE
SURGE IN IT`S WAKE LATE TONIGHT/EARLY MON TO RAISE SCA HEADLINES FOR
THE LOWER/MIDDLE BAY FOR WINDS TO 20 KT. GRADIENT WEAKENS BY MON
AFTN SO ENDED THE SCA ATTM FOR NOW. DID NOT RAISE HEADLINES FOR THE
COASTAL WATERS BUT EXPECT SEAS TO BUILD TO AROUND 5 FT FOR WATERS S
OF CAPE CHARLES LIGHT IN N/NE 20 KT WINDS DURING THE DAY MON (3RD
PERIOD). NEXT SHIFT MAY NEED TO ADD THESE ADDITIONAL HEADLINES.
FOLLOWING CLOSER TO A GFS/ECMWF/CMC BLEND FOR WINDS (NAM AN OUTLIER
AT DEVELOPING A MUCH STRONGER SFC LOW TUE/TUE NIGHT. THIS CONSENSUS
SOLUTION STILL SUPPORTS WINDS TO INCREASE BACK TO 15-25 KT FOR MOST
OF THE REGION LATE MON NIGHT/TUE WITH SEAS BUILDING TO 5-7 FT ACRS
SOUTHERN COASTAL WATERS...AND 3-4 FT IN THE LOWER BAY. SFC HIGH
PRESSURE SLOWLY BUILDS INTO THE AREA BY MIDWEEK...WITH WINDS/SEAS
DIMINISHING TUE NIGHT/WED.

&&

.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 4 AM TO NOON EST MONDAY FOR ANZ631-
     632-634.

&&

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






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