Area Forecast Discussion
Issued by NWS Wakefield, VA

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000
FXUS61 KAKQ 090309
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
1009 PM EST MON FEB 8 2016

.SYNOPSIS...
AN AREA OF LOW PRESSURE DEVELOPS DIRECTLY OVER THE MID ATLANTIC
REGION TONIGHT AND TRACKS EAST-NORTHEAST AND DEEPENS WELL OFF THE
DELMARVA COAST ON TUESDAY AS AS AN UPPER LEVEL TROUGH SWINGS
THROUGH THE REGION TUESDAY AFTERNOON AND EVENING. HIGH PRESSURE
SLOWLY RETURNS WEDNESDAY THROUGH FRIDAY.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
UPDATE...LATEST MODEL GUIDANCE INDICATES THAT COLDER AIR WILL BE
SLOW TO MOVE INTO THE REGION OVERNIGHT...ESPECIALLY FALLING
DEWPOINTS. HAVE ADJUSTED TEMPS/DEWPOINTS ACCORDINGLY. WITH
MINIMAL LIFT THROUGH THE DENDRITIC GROWTH ZONE...WET BULB ZERO
HEIGHTS STAYING ABOVE THE SFC...AND ALL TEMPS (T/TD/TW) STAYING
ABOVE FREEZING OVERNIGHT (EXCEPT FOR ERN PIEDMONT UNTIL A FEW
HOURS BEFORE SUNRISE)...EXPECT PRECIP TYPE TO REMAIN ALL RAIN THIS
EVENING. RAIN MAY MIX WITH SLEET AT TIMES ALONG THE BACK EDGE OF
MAIN PRECIP SWATH...FROM THE ERN PIEDMONT TO CAROLINE COUNTY TO
THE MD LOWER EASTERN SHORE...HOWEVER LITTLE TO NO ACCUMULATIONS
ARE EXPECTED AND IMPACTS TO TRAVEL ARE NOT ANTICIPATED.

PREVIOUS DISCUSSION (356 PM)...CLOUDS HAVE BEEN ON THE INCREASE
ACROSS THE REGION THIS AFTERNOON AS A POTENT UPPER LOW DIGS SOUTH
APPROACHING THE AREA. THE FIRST ROUND OF MOSTLY LIGHT RAIN WAS
PUSHING INTO FAR SW AREA OF FA...SLOWLY MOVING NORTHEAST TOWARD
CENTRAL VA. EXPECT PRECIP COVERAGE TO INCREASE THROUGH 03Z AS
FORCING INCREASES FROM A PASSING COLD FRONT. MODELS ARE IN GOOD
AGREEMENT PUSHING THE PRECIP ACROSS THE CWA THROUGH 09Z. THE
SYSTEM WILL BE SOMEWHAT MOISTURE-STARVED SO QPF AMOUNTS WILL AVG
0.10" OR LESS. LOWS AROUND 32-35 INLAND WITH MID-UPPER 30S CLOSER
TO THE COAST.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY/...
FIRST SHORTWAVE EXITS TO THE NE TUE MORNING WITH PRIMARILY WITH A
MIX OF RAIN AT MD/VA ERN SHORE AND NRN NECK...AND A RAIN/SLEET MIX
WEST OF RICHMOND (LIGHT SNOW SHOWERS FAR WRN FLUVANNA/LOUISA
COUNTIES). THERE WILL STILL BE A LULL IN PRECIP TUESDAY AFTER
DAYBREAK FOR MOST OF THE REGION BEFORE THE NEXT SHORTWAVE DIVES SE
ACROSS THE AREA TUE AFTN/EVENING. THIS MIGHT ALLOW FOR SOME
PARTIAL SUNSHINE THROUGH THE DAY (MIX OF CLOUDS/SUN)...ALLOWING
TEMPS TO RISE TO BETWEEN 40-45 DEGREES. POPS RETURN TO LIKELY
ONCE AGAIN ACROSS THE THE NORTHERN HALF OF THE FA TUE AFTN/EVENING...
THIS TIME COLDER AIR IS PROGGED TO OVERSPREAD THE CWA...ESPECIALLY
BY 21Z. NOT A LONG-LIVED EVENT...BUT POTENTIAL FOR 1-2" OF SNOW
EXISTS ACRS MAINLY AREAS TO THE NE OF METRO RICHMOND WHERE BETTER
LIFT IS EXPECTED...ESPECIALLY THE NORTHERN NECK AND ERN SHORE.
LESSER ACCUMULATIONS <1" POSSIBLE ELSEWHERE (GENERALLY LITTLE TO
NO ACCUMULATION FOR SOUTHERN VA AND NE NC). PARTIAL CLEARING AFTER
MIDNIGHT WITH DIMINISHING CHANCES FOR PRECIP. LOWS M20S WEST TO
LOWER 30S ALONG THE COAST. IF A WINTER WEATHER ADVISORY IS NEEDED...
IT WOULD MOST LIKELY BE FOR THE MD LOWER EASTERN SHORE AND PERHAPS
THE NORTHERN NECK. HAVE HELD OFF ON ISSUING A WINTER WX ADVISORY
FOR NOW DUE TO LACK OF CONFIDENCE IN ONE INCH OF SNOW...BUT IF IT
DOES OCCUR IT WOULD BE DURING TIMES OF THE TUE AFTERNOON AND
EVENING COMMUTE.

A DEEP UPPER LEVEL TROUGH PREVAILS ACROSS THE ERN CONUS ON WED AS
A STRONG RIDGE PERSISTS ALONG THE WEST COAST. OVERALL...SHOULD
HAVE DRIER AIR IN PLACE ACROSS THE REGION WITH DECENT SUBSIDENCE
PRESENT IN THE WAKE OF THE EXITING SHORTWAVE LOCATED WELL TO THE
NORTHEAST. STEEP LAPSE RATES STILL PRESENT DUE TO THE COLD POOL
ALOFT SO EXPECT PARTLY SUNNY/VARIABLY CLOUDY CONDITIONS. KEPT
20 PERCENT POPS FOR SNOW SHOWERS ACROSS NERN AREAS THRU THE
MORNING HRS. OTW...PT SUNNY AND COLD. HIGHS U30S NORTH TO L40S
SOUTH.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
AN UPPER LEVEL LOW PRESSURE SYSTEM WILL HEAD NORTHEAST AND AWAY
FROM THE EASTERN CONUS WEDNESDAY INTO THURSDAY...ONLY TO BE
REPLACED BY A STRONG UPPER LEVEL TROUGH LATE FRIDAY INTO THE
COMING WEEKEND. PCPN CHANCES WILL BE LIMITED THROUGH THE PERIOD...
ALTHOUGH A ROUND OF SNOW SHOWERS IS POSSIBLE ON FRIDAY WITH AN
ARCTIC FRONTAL PASSAGE. BAY/OCEAN EFFECT SNOW SHOWERS ALONG THE
COAST WILL BE POSSIBLE SATURDAY AND SUNDAY AS VERY COLD AIR ALOFT
(-20 TO -25 H85 TEMPS) SETTLE IN. ALTHOUGH A LOW CONFIDENCE
FORECAST ATTM...THERE ARE SOME INDICATIONS THAT LOW PRESSURE
DEVELOPS ALONG THE CAROLINA COAST FRI/FRI NIGHT WHICH COULD
PROVIDE ADDITIONAL MOISTURE FOR THE ARCTIC FRONT TO WORK WITH. IF
THIS ENDS UP BEING THE CASE...THEN ACCUMULATING SNOW WOULD BE
POSSIBLE ACROSS A PORTION OF THE AREA LATE IN THE WEEK. OF MORE
SIGNIFICANCE ATTM IS THE VERY COLD AIR SETTLING OVER THE REGION BY
THE WEEKEND. HIGHS IN THE 30S THU- SAT...BUT THEN ONLY 20S TO
MAYBE LOW 30S SUNDAY. LOWS TEMPS IN THE TEENS AND 20S...WITH
SINGLE DIGITS SATURDAY NIGHT.

&&

.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
COLD FRONT ASSOCIATED WITH LOW PRESSURE OVER THE GREAT LAKES
REGION WILL SWING ACROSS THE MID-ATLANTIC STATES TONIGHT AND IS
EXPECTED TO PRODUCE SOME RAIN SHOWERS AS IT MOVES THROUGH THE
AREA. CEILINGS SHOULD DROP TO MVFR LEVELS WITH THE FRONT. THE
BOUNDARY LAYER WILL BE WARM ENOUGH THAT SNOW WILL NOT BE AN
ISSUE. THE FRONT SHOULD CLEAR THE COAST BETWEEN 6Z AND 9Z.
INITIALLY BEHIND THE FRONT...THERE SHOULD BE A BRIEF PERIOD OF
CLEARING BEFORE THE COLDER AIR ALOFT MOVES INTO THE AREA TUESDAY
MORNING. WHEN THE COLDER AIR ARRIVES...EXPECT SOME LOW TO MID
LEVEL CU TO FORM. MOST AREAS SHOULD REMAIN VFR. HOWEVER...SBY
COULD SEE THE LOWER CLOUDS LINGER ESPECIALLY IF THE LOW LEVEL FLOW
REMAINS MORE EASTERLY AND KEEPS THE LOW LEVEL MOISTURE IN PLACE
LONGER.

OUTLOOK...TUESDAY NIGHT THROUGH THURSDAY...A STRONG SHORTWAVE
TROUGH ROTATING ACROSS THE MID-ATLANTIC STATES ON TUESDAY EVENING
COULD PRODUCE SOME MVFR TO IFR CONDITIONS WITH SNOW SHOWERS.
RIC/SBY HAVE THE BEST CHANCE TO SEE IMPACTS. THE CHANCES FOR
IMPACTS FROM THIS WAVE ARE LESS FROM THE VA TIDEWATER AND AREAS TO
THE SOUTH. VFR CONDITIONS SHOULD PREVAIL WEDNESDAY INTO THURSDAY
AS STRONG HIGH PRESSURE BUILDS INTO THE MID-ATLANTIC REGION.

&&

.MARINE...
LOW PRESSURE CONTINUES TO MOVE WELL OUT TO SEA. SEAS WILL BE SLOW
TO SUBSIDE UNTIL LATER TONIGHT AND TUESDAY. STILL SEEING 4-6 FT
WAVES AT THE MOUTH OF THE CHES BAY EARLY THIS EVENING DUE TO HIGH
SEAS OFFSHORE...SO HAVE SCA THRU 4 AM THERE. SCA`S FOR ALL
COASTAL WATERS REMAIN IN EFFECT THRU AT LEAST WED MORNING AS IT
WILL TAKE UNTIL THEN TO DROP BELOW 5 FT. ANOTHER ROUND OF SCA
CONDITIONS APPEAR LIKELY LATE WED AND THU...AS STRONG NW WINDS ARE
EXPECTED. GALE CONDITIONS MAY BE POSSIBLE BY THE WEEKEND AS SOME
VERY COLD AIR SETTLES OVER THE MARINE AREA.

&&

.HYDROLOGY...
RIVER FLOOD WARNINGS REMAIN IN EFFECT FOR THE BLACKWATER ABOVE
FRANKLIN AND NOTTOWAY AT SEBRELL. SEE FLSAKQ FOR DETAILS.

&&

.TIDES/COASTAL FLOODING...
A HIGH SURF ADVISORY REMAINS IN EFFECT ALONG THE ENTIRE ATL COAST
THRU 6 AM TUESDAY MORNING AS NEARSHORE WAVES REMAIN HIGH (8-12FT).
HAVE EXTENDED THE COASTAL FLOOD ADVISORY FOR THE ENTIRE ATL COAST
AND THE BAY SIDE OF THE VA EASTERN SHORE THRU TUESDAY MORNING`S
HIGH TIDE CYCLE AS WATERS LEVELS ARE EXPECTED TO REACH MINOR
FLOODING THRESHOLDS. A COASTAL FLOOD STATEMENT IS IN EFFECT ACROSS
THE WEST SIDE OF LOWER CHES BAY AND THE LOWER JAMES RIVER FOR THIS
EVENING`S HIGH TIDE CYCLE AS WATER LEVELS ARE EXPECTED TO COME
CLOSE TO MINOR FLOODING THRESHOLDS. THIS MAY ALSO BE THE CASE
AGAIN TUESDAY MORNING FOR THE SAME LOCATIONS...BUT WILL LET NEXT
SHIFT EVALUATE THE NEED FOR ANOTHER STATEMENT OR ADVISORY. FARTHER
NORTH...MINOR FLOODING IS POSSIBLE ALONG THE BAY SIDE OF THE LOWER
MD EASTERN SHORE ON TUESDAY...ESPECIALLY AT BISHOPS HEAD.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...HIGH SURF ADVISORY UNTIL 6 AM EST TUESDAY FOR MDZ025.
     COASTAL FLOOD ADVISORY UNTIL 10 AM EST TUESDAY FOR MDZ025.
NC...HIGH SURF ADVISORY UNTIL 6 AM EST TUESDAY FOR NCZ102.
     COASTAL FLOOD ADVISORY UNTIL 10 AM EST TUESDAY FOR NCZ102.
VA...HIGH SURF ADVISORY UNTIL 6 AM EST TUESDAY FOR VAZ098>100.
     COASTAL FLOOD ADVISORY UNTIL 10 AM EST TUESDAY FOR VAZ098>100.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EST TUESDAY FOR ANZ634.
     SMALL CRAFT ADVISORY UNTIL 10 AM EST WEDNESDAY FOR ANZ650-652-
     654-656-658.

&&

$$
SYNOPSIS...BMD/LKB
NEAR TERM...BMD/JAO
SHORT TERM...JAO
LONG TERM...JDM
AVIATION...ESS/DAP
MARINE...JDM
HYDROLOGY...
TIDES/COASTAL FLOODING...


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