Area Forecast Discussion
Issued by NWS Wakefield, VA

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000
FXUS61 KAKQ 130951
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
451 AM EST SAT FEB 13 2016

.SYNOPSIS...
ARCTIC HIGH PRESSURE BUILDS ACROSS THE REGION THROUGH TONIGHT...THEN
MOVES OFF THE MID ATLANTIC COAST LATE SUNDAY.  LOW PRESSURE OVER THE
DEEP SOUTH MONDAY...LIFTS NORTHEAST ACROSS THE MID ATLANTIC REGION
TUESDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
COLD FRONT MOVES OFFSHORE EARLY THIS MORNING WITH ARCTIC HIGH
PRESSURE BUILDING INTO THE REGION FROM THE NW. DESPITE PLENTY OF
SUN...A VERY COLD DAY ON TAP AS H85 TEMPS PLUMMET TO ARND MINUS 18
TO MINUS 20C (-2 TO -3 STD DEV). STRNG CAA WILL ADD A WIND CHILL
COMPONENT TO THE MIX WITH NW WINDS AVGG 15 TO 25 MPH WITH GUSTS 30
TO 35 MPH. GUSTS OVER THE EASTERN SHORE AND COASTAL AREAS EXPECTED
TO REACH 40 MPH. EXPECT WIND CHILLS BETWEEN 10-15 DEGREES NORTH TO
15-20 DEGREES SOUTH. BAY INDUCED SC STREAMERS WILL LIKELY DVLP OVR
THE CHES BAY / DELMARVA REGIONS BUT EXPECT THE DRY AIRMASS (DP TMPS
ARND ZERO) TO PREVENT ANY SNOW SHWRS FROM DVLPNG. HIGHS FROM THE
M20S NORTH TO L30S SOUTH.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
1035 MB ARCTIC HIGH MOVES INTO THE OHIO/TN VLLYS THIS EVENING
WITH THE CENTER OF THE HIGH OVER WEST VA BY 12Z SUN. NW WINDS
CONT AS RIDGE AXIS REMAINS WEST OF THE FA. HOWEVER...THE HIGH GETS
CLOSE ENUF FOR WINDS TO DIMINISH ACROSS THE PIEDMONT. THIS ALLOWS
FOR DECENT RADIATIONAL COOLING TO OCCUR UNDER MAINLY CLR SKIES.
LOWS PLUNGE INTO THE SINGLE DIGITS TO LOW TEENS INLAND TO UPPER
TEENS NEAR THE COAST. WIND CHILL VALUES GENERALLY 0 TO 5 ABOVE
INLAND AND AROUND 5 BELOW NRN NECK TO THE ERN SHORE. HAVE ISSUED A
WIND CHILL ADVISORY WHERE READINGS ARE EXPECTED TO DROP BLO ZERO.

CENTER OF ARCTIC HIGH MOVES ACROSS THE FA SUN...THEN OFF THE COAST
SUN EVE. TSCTNS SHOW CLR SKIES TO START BUT HIGH LVL MSTR QUICKLY
OVRSPRDS THE RGN WEST TO EAST DURING THE AFTN HRS AHEAD OF THE
NEXT SYSTM APPRCHG FROM THE WEST. HIGHS ONLY WARM INTO THE M-U20S
(-2 STD DEV)...EXCEPT ARND 30 SWRN MOST CNTYS BUT WITH MUCH LESS
WIND.

SFC HIGH SHIFTS TOWARD NEW ENGLAND SUN NIGHT AS THE NEXT STORM
SYSTEM DEVELOPS OVER THE DEEP SOUTH MONDAY. NRN STREAM ENERGY LIFTS
NORTH OF THE REGION SUN NIGHT/MONDAY AS A MID LEVEL TROUGH TRACKS
ACROSS THE CENTRAL CONUS MON. SWLY FLOW ALOFT WILL RESULT IN
MOISTURE RETURN INTO THE MID-ATLANTIC REGION. POPS INCREASE AFTER
MIDNIGHT (CHC POPS MOST AREAS EXCEPT LIKELY NWR MOST CNTYS) LATE
SUN NIGHT AS THE NRN STREAM SYSTEM WEAKENS AND WEAK ISENTROPIC
LIFT ADVECTS INTO THE REGION. AIR MASS COLD ENOUGH FOR ALL SNOW AS
LOWS SUN NIGHT IN THE UPPER TEENS TO ARND 20. GIVEN LGHT QPF AMTS
(LESS THAN .10) SNOW AMTS BY 12Z MON EXPECTED TO BE LESS THAN ONE
INCH.

PRECIP CHANCES QUICKLY INCREASE MON AS A COASTAL TROUGH SHARPENS
ALONG THE COAST AND THE AFOREMENTIONED DEEP SOUTH LOW BEGINS TO LIFT
NEWD TOWARD THE LOCAL AREA. CHC TO LIKELY POPS WILL BE MAINTAINED
DURING THE MORNING INCREASING TO LIKELY TO CATEGORICAL DURING THE
AFTN. THE CHALLENGING PART OF THIS FCST WILL BE PCPN TYPE AS THE
ENTIRE GAMBIT OF PCPN TYPES ARE EXPECTED DUE TO WAA ALOFT AND
CRITICAL THICKNESSES INDICATING A CHANGE OVER FROM SN TO A MIX OF
SN/IP/FZRA LATE MON MORNING ACROSS THE PIEDMONT TO MAINLY RAIN BY
00Z TUE AS TMPS RISE ABOVE FREEZING. LTST DATA SUPPORTS
LOUISA/FLUVANNA CNTYS HOVER ARND FREEZING WELL INTO MON NIGHT.
THIS WOULD LEAD TO FROZEN PCPN TYPES THERE MUCH FOR A LONGER
PERIOD OF TIME. BUFKIT THERMAL PROFILES SUPPORT ANY ICING
(FREEZING RAIN) MAINLY WEST OF THE I95 CORRIDOR. GIVEN MORE ICE
POTENTIAL...SNOW TOTALS WILL BE HELD DOWN TO 1-2 INCHES OVR THE
WRN MOST CNTYS WITH AN INCH OR LESS ELSEWHERE...BUT THE ICING
POTENTIAL WILL INCREASE. ICING AMTS EXPECTED TO RANGE LESS THAN
.05 ALONG THE I95 CORRIDOR UPWARDS TO .10 FROM FVX-LKU. PCPN TYPE
BECOMES MOSTLY LIQUID BTWN 21Z MON AND 00Z TUE EXCEPT NW MOST
CNTYS. TMPS CHALLENGING AS THE MODELS ARE TRYING TO FLOOD WARMER
AIR IN AT THE SFC MUCH QUICKER THAN PREVIOUS FCST HAD. FOR NOW
WILL GO WITH HIGHS NEAR FREEZING ACROSS THE NWRN MOST CNTYS (WHERE
WEDGE ALWAYS HANGS ON THE LONGEST) TO BTWN 45-50 ALONG CSTL AREAS.

DESPITE HOW MESSY MONDAY LOOKS...QPF FCST THRU 00Z TUE BEFORE THE
CHANGEOVER TO LIQUID SUGGESTS THE EVENT WOULD FALL INTO A WINTER
WEATHER ADVSRY HEADLINE VS WARNING HEADLINE. NO HEADLINES WILL BE
ISSUED WITH THIS FCST GIVEN A FOURTH / FIFTH PERIOD EVENT.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
12/12Z NUMERICAL MODELS DEPICT LOW PRESSURE TRACKING NE FROM THE
DEEP SOUTH TO THE SRN APPALACHIANS MONDAY EVENING...THEN RAPIDLY
DEEPENING AS IT LIFTS NE INTO THE MID-ATLANTIC REGION BY MIDDAY
TUESDAY AS A VIGOROUS UPPER TROUGH DIGS ACROSS THE SRN/CENTRAL
APPALACHIANS. THERMAL PROFILES SUGGEST MIXED PCPN COULD CONTINUE
INTO THE EVENING OVER THE PIEDMONT. OVERNIGHT LOWS SHOULD OCCUR IN
THE EVENING...WITH RISING TEMPERATURES OVERNIGHT AS THE LOW-LEVEL
FLOW BECOMES SSE. COLDER TEMPERATURES WILL LIKELY PERSIST THE
LONGEST IN THE FAR NW PIEDMONT COUNTIES WHERE SOME POCKETS OF -FZRA
COULD CONTINUE OVERNIGHT...BUT GENERALLY ALL RAIN IS EXPECTED BY
EARLY TUESDAY MORNING. PERIODS OF MODERATE RAIN ARE POSSIBLE LATE
MONDAY NIGHT INTO TUESDAY AS A BAND OF STRONG VERTICAL ASCENT PASSES
OVER THE REGION. STRONG PRESSURE FALLS COULD PRODUCE A MODESTLY
STRONG SOUTHERLY WIND ACROSS THE ERN THIRD OF THE AREA FOR A 3-6HR
PERIOD TUESDAY. TEMPERATURES WARM TO AT LEAST THE MID/UPPER 50S
ACROSS THE ERN HALF OF THE AREA TUESDAY...WITH LOW 60S POSSIBLE
ALONG THE COAST...WHILE THE PIEDMONT STRUGGLES TO RISE ABOVE THE
UPPER 40S/LOW 50S. GENERALLY EXPECTING DRIER CONDITIONS BY TUESDAY
NIGHT...ALTHOUGH SOME 20-30% POPS WILL LINGER ACROSS THE N AS A
SECONDARY TROUGH SWINGS ACROSS THE NRN MID-ATLANTIC. DRY AND MILD
WEDNESDAY UNDER WNW FLOW WITH HIGHS IN THE UPPER 40S TO MID 50S. A
COLD FRONT TRACKS ACROSS THE AREA WEDNESDAY NIGHT...FOLLOWED BY
CANADIAN HIGH PRESSURE THURSDAY. THIS SHOULD PUSH TEMPERATURES BELOW
NORMAL...BUT WITHIN -1 ST DEV. A MODERATING TREND COMMENCES LATE
WEEK AS HIGH PRESSURE MOVES OFFSHORE AND LOW PRESSURE TRACKS THROUGH
THE GREAT LAKES.

&&

.AVIATION /09Z SATURDAY THROUGH WEDNESDAY/...
PLENTY OF CLOUDINESS ACROSS THE AREA AS LOW PRESSURE MOVES WELL
OFFSHORE AND THE BASE OF AN UPPER TROUGH SWINGS ACROSS THE REGION.
MODIFIED ARCTIC HIGH PRESSURE BUILDS INTO THE MIDWEST THE REST OF
TONIGHT INTO SATURDAY WITH A MUCH COLDER AIRMASS FILTERING INTO
THE MID ATLANTIC REGION DURING THIS TIME. TEMPERATURE AND PRESSURE
GRADIENTS WILL RESULT IN NW WINDS BECOMING BREEZY FROM NW TO SE
THE REST OF TONIGHT...BECOMING GUSTY AFTER 13/1100Z AND CONTINUING
THROUGH THE REST OF SATURDAY. INLAND WINDS AVERAGING 15KT WITH
GUSTS UP TO 20-25KT...ALONG THE COAST WINDS WILL AVERAGE 20-25KT
WITH GUSTS UP TO 30-35KT. SKIES REMAIN MOSTLY CLOUDY AND THEN
START TO BREAK UP AROUND SUNSET. SFC HIGH FINALLY BUILDS INTO THE
REGION BY SUN MORNING...HOWEVER NW WINDS WILL BE SLOW TO DIMINISH
OVERNIGHT (ESPECIALLY ALONG THE IMMEDIATE COAST) DUE TO A VERY
GRADUAL RELAXING OF THE TEMP/PRESSURE GRADIENT.

HIGH PRESSURE DOMINATES ON SUNDAY WITH DRY WX...GENERALLY LIGHT
WINDS...AND VFR CONDITIONS. NEXT COMPLEX WEATHER SYSTEM BEGINS TO
IMPACT THE AREA LATE SUNDAY NIGHT. PLENTY OF COLD AIR IN PLACE FOR
PRECIP TO BEGIN AS ALL SNOW SUNDAY NIGHT INTO MONDAY MORNING.
HOWEVER...A DEEPENING LOW MOVING IN FROM THE SW IS EXPECTED TO
PULL WARMER AIR INTO THE REGION. THIS WILL COMPLICATE PRECIP
FORECAST...ESPECIALLY ACROSS CNTRL VA WHERE COLDER AIR MAY LINGER
AT THE SFC. COULD SEE A WINTRY MIX NORTHWEST HALF OF FA AND A
CHANGEOVER TO ALL RAIN ACROSS THE SOUTHEAST. REGARDLESS OF PRECIP
TYPE...EXPECT CIG/VIS REDUCTIONS ONCE PRECIP BEGINS SUNDAY NIGHT
AND CONTINUING INTO TUESDAY. A BREAK IN PRECIP AND FLIGHT
RESTRICTIONS IS ANTICIPATED TUESDAY NIGHT BUT COULD BE SHORT-
LIVED. ANOTHER WEATHER DISTURBANCE MAY BRUSH ACROSS NRN VA AND THE
MD LOWER EASTERN SHORE WEDNESDAY MORNING BUT IMPACTS ARE NOT
ANTICIPATED AT LOCAL TAF SITES AT THE MOMENT.

&&

.MARINE...
VARIOUS MARINE HEADLINES HAVE BEEN ADJUSTED. PLEASE REFER TO
SPECIFIC MARINE HEADLINE INFO BELOW OR WITHIN WBCMWWAKQ.

NW WINDS PICKING UP RIGHT ON SCHEDULE AS AN ARCTIC AIRMASS BEGINS
TO SURGE INTO THE REGION. INITIAL GUSTS WILL BE 25-30KT BUT WILL
INCREASE RAPIDLY AROUND SUNRISE FROM NORTH TO SOUTH AS THE
TEMP/PRESSURE GRADIENT TIGHTENS SIGNIFICANTLY DURING THE REST OF
TODAY. GALE FORCE GUSTS OF 35-40KT SHOULD BE ANTICIPATED OVER CHES
BAY AND ALL COASTAL WATERS...GRADUALLY ENDING FROM LATE AFTN
THROUGH SUNDAY MORNING. CURRITUCK SOUND AND ERN VA RIVERS WILL
REMAIN WITHIN STRONG SCA CONDITIONS THROUGH TONIGHT...THEN SLOWLY
DIMINISH BELOW THRESHOLDS BY EARLY SUN AFTN. WAVES ON CHES BAY
WILL BUILD QUICKLY TO 4-5FT THIS MORNING WITH THE RAPIDLY
INCREASING WINDS. WAVES MAY EVEN REACH UP TO 6FT FOR BRIEF PERIOD
OF TIME DURING MID MORNING. SEAS ALSO EXPECTED TO BUILD RAPIDLY
ONCE STRONGER NW WINDS AND COLDER AIR/PRESSURE GRADIENT MOVE OVER
THE COASTAL WATERS. SEAS SHOULD AVERAGE 5-8FT AT THEIR PEAK THIS
AFTN. FREEZING SPRAY IS ALSO EXPECTED AS TEMPERATURES PLUMMET
TODAY AND ESPECIALLY TONIGHT/SUN MORNING. A FREEZING SPRAY
ADVISORY REMAINS IN EFFECT FOR TODAY INTO SUNDAY MORNING.

WINDS WILL SLOWLY DIMINISH SUN MORNING AND ARE EXPECTED TO FALL
BELOW 15KT LATE SUN AFTN/EARLY EVENING. ALTHOUGH GALE WARNINGS END
FOR NRN COASTAL WATERS EARLY SUN AFTN...SCA HEADLINES WILL LIKELY
BE NEEDED FOR SEAS LINGERING AROUND 5FT THROUGH LATE AFTN. WINDS
STAY FAIRLY LIGHT THROUGH SUN NIGHT AND EARLY MON FROM THE E-SE AS
ARCTIC HIGH PRESSURE OVER THE WATERS SLIDES OFFSHORE. ANOTHER LOW
PRESSURE SYSTEM APPROACHES FROM THE SW LATE MON NIGHT AND IS
EXPECTED TO TRACK NE ACROSS CNTRL VA ON TUE. THIS WILL ALLOW FOR A
MODESTLY STRONG SSE WIND OF 20-30KT TO DEVELOP WITH BUILDING SEAS
TO 5-9FT AND WAVES TO 3-4FT (UP TO 5FT IN THE MOUTH OF CHES BAY).
SCA WINDS ANTICIPATED MON NIGHT THROUGH TUE...WITH SEAS REMAINING
ELEVATED THROUGH AT LEAST WED NIGHT DUE TO A LESS POTENT SYSTEM
PUSHING ACROSS NRN VA WED MORNING.

&&

.TIDES/COASTAL FLOODING...
STRONG NW FLOW ASSOCIATED WITH AN ARCTIC COLD FRONT WILL PRODUCE
BLOW-OUT TIDES / LOW WATER ADVISORIES FOR SOME AREAS EARLY
SATURDAY MORNING...AND MUCH OF THE COASTLINES SATURDAY AFTERNOON
AND NIGHT. THE MAIN AREAS EARLY SATURDAY MORNING THAT COULD HAVE
LOW WATER ARE ALONG THE ATLANTIC COAST N OF CAPE CHARLES. A LOW
WATER ADVISORY HAS BEEN ISSUED FROM 08-13Z (3 TO 8 AM).

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 10 AM EST SUNDAY
     FOR MDZ021>025.
NC...NONE.
VA...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 10 AM EST SUNDAY
     FOR VAZ075>078-085-099-521-522.
MARINE...LOW WATER ADVISORY UNTIL 8 AM EST THIS MORNING FOR ANZ650-652-
     654.
     FREEZING SPRAY ADVISORY UNTIL NOON EST SUNDAY FOR ANZ630>632-
     634-650-652-654-656.
     GALE WARNING UNTIL 10 AM EST SUNDAY FOR ANZ650-652-654.
     GALE WARNING UNTIL 7 PM EST THIS EVENING FOR ANZ656-658.
     FREEZING SPRAY ADVISORY FROM 7 PM THIS EVENING TO NOON EST
     SUNDAY FOR ANZ658.
     SMALL CRAFT ADVISORY UNTIL NOON EST SUNDAY FOR ANZ633-635>638.
     GALE WARNING UNTIL MIDNIGHT EST TONIGHT FOR ANZ630>632-634.

&&

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


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