Area Forecast Discussion
Issued by NWS Wakefield, VA

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000
FXUS61 KAKQ 112102
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
402 PM EST THU FEB 11 2016

.SYNOPSIS...
HIGH PRESSURE BUILDS OVER THE AREA TONIGHT. WEAK LOW
PRESSURE DEVELOPS ALONG THE SOUTHEAST COAST FRIDAY MORNING...LIFTING
NORTHEAST OFF THE NORTH CAROLINA AND VIRGINIA COASTS FRIDAY
AFTERNOON AND EVENING. ARCTIC HIGH PRESSURE BUILDS IN FOR THE
UPCOMING WEEKEND...RESULTING IN THE COLDEST TEMPERATURES SO FAR THIS
YEAR. ANOTHER STORM SYSTEM WILL IMPACT THE REGION EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
LATEST SFC ANALYSIS CENTERS ~1030MB HIGH PRESSURE OVER THE OH
VALLEY. A STATIONARY BOUNDARY REMAINS OVER THE GULF STATES. COLD
THIS AFTERNOON...WITH TEMPS GENERALLY IN THE LOW TO MID 30S. WIND
CHILLS IN THE 20S UNDER A SUNNY SKY.

FOR TONIGHT...HIGH PRESSURE SETTLES OVER THE REGION. WINDS DECOUPLE
ALLOWING FOR EXCEPTIONAL RADIATIONAL COOLING THIS EVENING AS
DEWPOINTS REMAIN IN THE SINGLE DIGITS. MID-LEVEL CLOUDS INCREASE
LATE TONIGHT AS ATTENTION TURNS TO SHORTWAVE ENERGY DIGGING INTO THE
DEEP SOUTH. HEIGHT FALLS WILL INDUCE CYCLOGENESIS OFF THE SC/NC
COAST BY LATE TONIGHT/EARLY FRIDAY MORNING. TEMPS WILL LEVEL OFF
THRU LATE TONIGHT WITH LOWS GENERALLY IN THE MID/UPPER TEENS TO LOW
20S.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
LOW PRESSURE DEEPENS OFF THE NC COAST FRI MORNING AS THE SHORTWAVE
ENERGY PUSHES OVER THE CAROLINAS. SHORTWAVE AND INCREASING WINDS
ALOFT WILL PROVIDE ADEQUATE UVM OVER AN AREA OF 280-285K ISENTROPIC
LIFT ON THE NW PERIPHERY OF THE LOW. MOISTURE ADVECTION WILL BE
MODEST...BUT MIXING RATIOS PROGGED TO REACH 3.0 TO 4.0 G/KG. THERMAL
PROFILES INDICATE HIGH RH/ICE IN THE SNOW GROWTH LAYER ALONG WITH
ABUNDANT LIFT DUE TO AFOREMENTIONED UPPER LEVEL DYNAMICS. THE NET
RESULT WILL BE INCREASING POPS THRU MID TO LATE MORNING FRI AS SNOW
SPREADS INTO THE REGION. PRECIP CONTINUES THRU THE AFTERNOON AS THE
LOW LIFTS OFF THE MID-ATLANTIC COAST. QUESTION BECOMES HOW FAR NW
THE PRECIP SPREADS FRI AFTERNOON. HAVE INCREASED POPS ACROSS THE SE
COUNTIES TO CATEGORICAL...TAPERING OFF THE CHANCE OVER THE NW
COUNTIES. WITH THE LUXURY OF COLD CRITICAL THICKNESS VALUES...SNOW
IS EXPECTED TO BE THE PREDOMINATE PTYPE THRU THE DURATION OF THE
EVENT. THE EXCEPTION MAY BE LATE FRIDAY NEAREST THE ALBEMARLE SOUND
WHERE A LITTLE SLEET MAY MIX WITH THE SNOW TOWARD THE END OF THE
EVENT. HIGHEST AMOUNTS EXPECTED ACROSS NORTHEAST NORTH CAROLINA
WHERE BANDING FROM FRONTOGENETIC FORCING ON THE NW PERIPHERY OF THE
LOW IS INDICATED IN THE MODELS. 2-4 INCHES IS EXPECTED IN THAT
AREA...REQUIRING A WINTER STORM WARNING. FARTHER NORTH AND WEST INTO
HAMPTON ROADS AND THE LOWER PENINSULA AND EASTERN SHORE...SNOWFALL
AMOUNTS WILL TAPER OFF TO 1 TO 3 INCHES...WITH WINTER WEATHER
ADVISORIES IN EFFECT. PLEASE SEE LATEST WSW FOR MORE INFO. SNOWFALL
AMOUNTS TAPER OFF TO 0.5 TO 1.0 INCH TOWARD THE TRI CITIES AND MD
ERN SHORE...THEN A DUSTING TO HALF AN INCH RICHMOND NORTH AND WEST.
SNOW COMES TO AN END FRI EVENING AS THE SFC LOW PUSHES WELL OFF THE
MID-ATLANTIC COAST AND THE ARCTIC BOUNDARY PUSHES THRU THE
REGION.

CLOSED UPPER LOW/ENERGY ASSOCIATED WITH THE POLAR VORTEX DIGS OVER
NEW ENGLAND SATURDAY. ~1040MB ARCTIC HIGH PRESSURE BUILDS OVER THE
MIDWEST...USHERING IN THE COLDEST AIR MASS OF THE SEASON FOR THE
UPCOMING WEEKEND. WINDY SAT WITH NW WINDS GENERALLY 15 TO 25 MPH
WITH GUSTS OF 30 TO 40 MPH (STRONGER NEAR THE COAST AND OVER THE
EASTERN SHORE). HIGHS SAT FORECAST TO WARM ONLY INTO THE MID 20S NW
TO LOW 30S SE (-2 STD DEV) UNDER A SUNNY TO MOSTLY SUNNY SKY. WIND
CHILL VALUES WILL BE IN THE TEENS...RESULTING IN A RAW/COLD/WINDY
DAY. TEMPS PLUMMET INTO THE SINGLE DIGITS TO LOW TEENS SAT NIGHT.
WINDS DECOUPLE INLAND AS THE HIGH BUILDS INTO THE REGION...BUT WIND
CHILLS STILL FORECAST IN THE SINGLE DIGITS INLAND TO 0 TO 8 BELOW
NRN NECK TO THE ERN SHORE. THE HIGH CENTERS OVER THE LOCAL AREA
SUNDAY WITH NLY WINDS 5 TO 10 MPH. SLIGHTLY COLDER SUN WITH
DECREASED MIXING. HIGHS GENERALLY IN THE MID/UPPER 20S (-2 STD DEV)
UNDER A SUNNY TO MOSTLY SUNNY SKY.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
HIGH PRESSURE SHIFTS TOWARD NEW ENGLAND SUNDAY NIGHT WITH ATTENTION
TURNING TO A DEVELOPING SYSTEM OVER THE DEEP SOUTH MONDAY. THERE
REMAINS PLENTY OF UNCERTAINTY WITH RESPECT TO THE DETAILS...ALTHOUGH
THE 11/12Z NUMERICAL GUIDANCE IS TRENDING SLOWER...AND WARMER FOR
MONDAY NIGHT AND ESPECIALLY TUESDAY. THE 11/12Z GFS CONTINUES TO
SHOW SOME LIGHT PCPN MONDAY AS A NRN STREAM TROUGH SWINGS ACROSS THE
AREA. THIS WOULD MAINLY FALL AS SN OR SN/IP...WITH A TRANSITION TO
RA CLOSER TO THE COAST BY AFTERNOON. SUBSTANTIAL WARMING ALOFT WOULD
GENERALLY RESULT IN A TRANSITION TO RA MONDAY NIGHT...ASIDE FROM THE
FAR NW WHERE MIXED PCPN COULD PERSIST INTO TUESDAY MORNING WITH AN
IN-SITU WEDGE IN PLACE. THE LATEST DATA SCOURS OUT THE WEDGE BY
AFTERNOON WITH P-TYPE BECOMING RA EVEN IN THE FAR NW. DRYING OCCURS
MIDWEEK IN THE WAKE OF THE DEPARTING SYSTEM...WITH A NRN STREAM WAVE
CLIPPING THE AREA LATE IN THE PERIOD. THIS WILL BRING ANOTHER SHOT
OF COOLER AIR AS CANADIAN HIGH PRESSURE BUILDS INTO THE AREA
THURSDAY/THURSDAY NIGHT.

HIGHS MONDAY WILL LIKELY STRUGGLE TO GET OUT OF THE LOW 30S ALONG
AND W OF I-95...WHILE COASTAL LOCATIONS WARM INTO THE UPPER 30S TO
LOW 40S. TEMPERATURES REMAIN STEADY MONDAY EVENING AND BEGIN TO RISE
OVERNIGHT EVENTUALLY WARMING INTO THE 40S TO LOW 50S TUESDAY. HIGHS
WEDNESDAY ARE FORECAST TO REACH THE MID 40S TO LOW 50S...FOLLOWED BY
LOW 40S NE...TO UPPER 40S SW THURSDAY. MORNING LOWS ARE FORECAST TO
BE IN THE UPPER 20S TO MID 30S WEDNESDAY MORNING.

&&

.AVIATION /21Z THURSDAY THROUGH TUESDAY/...
GUSTY WNW WNDS TO 25-30 KT CONTG...XPCD TO WANE AFT
22Z/11...BECOMING NW OR VRB 6 KT OR LESS OVRNGT. OTRW...VRF/SKC
CONTG INTO THE OVRNGT HRS.

GRADUALLY LWRG CIGS...ESP ACRS SRN VA/NE NC FRI MRNG. HI
CHC/LIKELY PROB FOR -SN AND MVFR CONDS (PRIMARILY VSBYS)...MNLY
ORF/ECG AREA MIDDAY/AFTN FRI...ENDING IN THE EVE. DRY WX W/ GUSTY
NW WINDS TO 25-35KT RETURN BY SAT. HIGH PRESSURE MOVES OFF THE
COAST BY MONDAY MORNING. THERE WILL BE A CHANCE FOR RAIN OR SNOW
MONDAY AS SOUTHEAST TO SOUTH WINDS BRING A WARM ADVECTION AHEAD OF
THE NEXT WEATHER SYSTEM.

&&

.MARINE...
HIGH PRESSURE BUILDS IN FORM THE NW TONIGHT AND SETTLES
OVER THE MID ATLANTIC COAST FRIDAY MORNING. THE WIND WILL DIMINISH
AND SEAS WILL SUBSIDE THIS EVENING...WITH SCA HEADLINES GRADUALLY
ENDING THROUGH THE EVENING AND EARLY OVERNIGHT HOURS. HIGH PRESSURE
LIFTS TO THE NE FRIDAY WITH A LOW PRESSURE SYSTEM TRACKING OFF THE
SOUTHEAST COAST FRIDAY AFTERNOON AND EVENING. BY AFTERNOON THE WIND
WILL BECOME E/NE S OF CAPE CHARLES WITH GENERALLY A S/SE DIRECTION N
OF CAPE CHARLES. SPEEDS WILL BE AOB 15KT. ADDITIONALLY...THIS LOW
WILL BRING A PERIOD OF SN...WHICH WILL REDUCE VSBY. AS THE LOW LIFTS
TO THE NE FRIDAY NIGHT A STRONG ARCTIC COLD FRONT WILL PASS ACROSS
THE REGION WITH STRONG CAA DEVELOPING LATE FRIDAY NIGHT AND
CONTINUING THROUGH SATURDAY INTO SATURDAY NIGHT AS ARCTIC HIGH
PRESSURE BUILDS IN FROM THE NW. A NW WIND WILL AVERAGE 25-30KT WITH
FREQUENT GUSTS OF 35-40KT OVER THE OCEAN AND BAY. SEAS BUILD TO 5-
8FT WITH 4-5 FT WAVES IN THE BAY. GALE FLAGS HAVE BEEN RAISED FOR
LATE FRIDAY NIGHT INTO SATURDAY (4TH PERIOD). THESE WILL LIKELY NEED
TO BE EXTENDED INTO SATURDAY NIGHT...ESPECIALLY ACROSS THE NRN OCEAN
ZONES. FOR THE RIVERS AND SOUND...WIND SPEEDS HAVE BEEN CAPPED AT
HIGH-END SCA AT THIS TIME. FREEZING SPRAY IS LIKELY AS TEMPERATURES
PLUMMET SATURDAY AND ESPECIALLY SATURDAY NIGHT. THE WIND WILL
DIMINISH SUNDAY INTO SUNDAY NIGHT AS THE HIGH SETTLES ACROSS THE
AREA. LOW PRESSURE APPROACHES FORM THE SW EARLY NEXT WEEK.

&&

.TIDES/COASTAL FLOODING...
THE WNW FLOW WILL ALLOW ANOMALIES TO FURTHER FALL. STRONG NW FLOW
ASSOCIATED WITH AN ARCTIC COLD FRONT COULD PRODUCE BLOW-OUT TIDES
THIS WEEKEND.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...WINTER WEATHER ADVISORY FROM 7 AM FRIDAY TO MIDNIGHT EST
     FRIDAY NIGHT FOR NCZ012>014.
     WINTER STORM WARNING FROM 7 AM FRIDAY TO MIDNIGHT EST FRIDAY
     NIGHT FOR NCZ015>017-030>032-102.
VA...WINTER WEATHER ADVISORY FROM 7 AM FRIDAY TO MIDNIGHT EST
     FRIDAY NIGHT FOR VAZ092-093-095>098-100-523>525.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 AM EST FRIDAY FOR ANZ634-650-652-
     654-656-658.
     GALE WARNING FROM 4 AM TO 7 PM EST SATURDAY FOR ANZ630>632-634-
     650-652-654-656-658.
     SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ633-
     635>638.
     SMALL CRAFT ADVISORY FROM 4 AM TO 7 PM EST SATURDAY FOR ANZ633-
     635>638.
     SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR
     ANZ630>632.

&&

$$
SYNOPSIS...SAM/TMG
NEAR TERM...SAM
SHORT TERM...SAM
LONG TERM...AJZ
AVIATION...ALB/MPR
MARINE...AJZ
TIDES/COASTAL FLOODING...


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