-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KAKQ 061536
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
1036 AM EST FRI DEC 6 2013

.SYNOPSIS...
-- Changed Discussion --
A COLD FRONT IN NORTHERN VIRGINIA WILL SLOWLY SAG THROUGH THE
AREA THIS AFTERNOON AND TONIGHT. THE FRONT STALLS NEAR SOUTH
CAROLINA ON SATURDAY...THEN LIFTS NORTH AS A WARM FRONT SATURDAY
NIGHT INTO EARLY MONDAY. THE WARM FRONTAL PASSAGE WILL BRING A
PERIOD OF UNSETTLED AND COMPLEX WEATHER TO THE AREA MAINLY SUNDAY
AND SUNDAY NIGHT.
-- End Changed Discussion --

&&

.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
THE COLD FRONT IS CURRENTLY LOCATED OVER NRN VA AND WILL SLOWLY
SAG THROUGH THE REGION THIS AFTN AND TONIGHT. SHOWERS ALNG AND
BEHIND THE FRONT WILL PUSH ACRS MAINLY NRN THIRD OF THE AREA THIS
AFTN INTO EARLY THIS EVENG. BASED ON LATEST RDR AND LIGHTNING
DATA...HAVE ADDED ISLTD THUNDER TO LIKELY POP AREA...BUT NO SEVERE
WEATHER IS EXPECTED. THE PRESSURE GRADIENT TIGHTENS UP AHEAD OF
THE FRONT AND SW WINDS WILL BECOME BREEZY OVER SERN HALF OF THE
CWA WITH GUSTS TO AROUND 25 MPH THIS AFTN. HAVE ADJUSTED MAX TEMPS
SLIGHTLY FOR THIS AFTN...WITH MAX TEMPS RANGING FM THE LWR TO MID
60S EXTRM NRN CNTIES...TO THE MID TO UPR 70S SE VA AND NE NC.
TEMPS WILL FALL INTO THE 50S ACRS THE NRN THIRD OF THE REGION THIS
AFTN...DUE TO PASSAGE OF COLD FRONT AND PCPN.

THE COLD FRONT SWEEPS THROUGH THE REST OF THE FA TONIGHT AND
MOVES SOUTH OF THE AREA SAT MORNING. PRECIPITATION WILL BECOME
WIDESPREAD AND WITH STEADY RAINFALL AS THE BEST FRONTOGENESIS
OCCURS OVERNIGHT ACROSS THE REGION. LOW TEMPS WILL CONTINUE TO BE
TRICKY TONIGHT...ESPECIALLY SINCE MODELS HAVE SLOWED THE
PENETRATION OF POST-FRONTAL ARCTIC AIR FROM THE NORTHWEST UNTIL
SOMETIME SATURDAY MORNING. HAVE MAINTAINED CONTRASTING LOW TEMPS
WITH READINGS IN THE UPPER 30S TO MID 40S NW...LOW TO MID 50S FAR
SE VA/NE NC.
-- End Changed Discussion --

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
THE AFOREMENTIONED COLD FRONT STALLS OUT ACROSS THE SERN U.S. AS
ARCTIC HIGH PRESSURE EXPANDS EWD FROM THE OHIO VALLEY AND INTO THE
NORTHEAST. N-NE SFC WINDS WILL CONTINUE TO FUNNEL COLDER AIR INTO
THE MID ATLANTIC REGION THROUGH SAT. ALTHOUGH THE TIMING OF COLD
AIR FILTERING INTO THE REGION HAS SLOWED...HIGHS SHOULD STILL HOLD
STEADY AND/OR ONLY RISING A COUPLE OF DEGREES FROM THEIR MORNING
LOWS. EXPECT HIGHS IN THE LOW/MID 40S NW TO THE LOW/MID 50S FAR
SE. 00Z MODEL RUNS KEEP PRECIP LINGERING ALONG THE COAST DURING
THE DAY...THEN GRADUALLY HAVE IT SHIFTING AND TAPERING OFF OVER
FAR SE VA AND ALL OF NE NC SAT EVENING/OVERNIGHT AS THE FRONT LAYS
DOWN (BECOMES MORE WEST TO EAST ORIENTED) ACROSS SC AND THE SE
STATES. AS COLDER AIR FINALLY PUSHES DOWN FROM THE NORTH AND A
COLD WEDGE DEVELOPS...THE FRONT WILL ALSO GET SHUNTED FARTHER
SOUTH.

THE QUESTION THAT REMAINS IS HOW FAR SOUTH WILL THE FRONT GO AND
WHEN WILL IT START TO LIFT NORTH AS A WARM FRONT. MODELS CONTINUE
TO BE IN GENERAL AGREEMENT WITH DRYING OUT THE REGION (WITH THE
EXCEPTION OF NE NC AND AREAS ALONG THE IMMEDIATE VA/NC BORDER FOR
MOST OF SAT NIGHT. THIS DRYING SCENARIO RESULTS IN COLDER AIR
BEING PULLED INTO THE REGION...COOLING ALL BUT FAR SE COASTAL
AREAS OF VA/NC INTO THE UPPER 20S/LOWER 30S. AS THE FRONT MOVES NWD
AS A WARM FRONT LATE SAT NIGHT/SUN...THIS IS WHERE THE OVERALL
PRECIP FORECAST BECOMES VERY DIFFICULT. SHORTWAVE ENERGY MOVING NE
ALONG THE FRONTAL BOUNDARY WILL ACT TO ENHANCE/SPREAD
PRECIPITATION BACK INTO THE REGION FROM THE SOUTH/SOUTHWEST LATE
SAT NIGHT/EARLY SUN MORNING. THE WARMER AIR ASSOCIATED WITH THIS
AIRMASS WILL RIDE OVER THE COLDER AIR IN PLACE AND WILL LIKELY
PRODUCE A WINTRY MIX OF PRECIPITATION EARLY SUN MORNING THROUGH AT
LEAST SUN NIGHT AT TIMES...ESPECIALLY FOR AREAS W/NW OF RICHMOND.
PRECIP PLACEMENT AND TIMING ARE COMING INTO FAIR AGREEMENT AMONGST
MODEL SOLUTIONS IN SPREADING A STEADY SWATH OF PRECIP FROM SOUTH
TO NORTH DURING THE SUN/SUN NIGHT TIMEFRAME. EVEN THOUGH THE
INITIAL ONSET OF PRECIP IS QUESTIONABLE...CONFIDENCE IS INCREASING
REGARDING P-TYPE STARTING AS A SNOW/SLEET/FREEZING RAIN MIX IN THE
PIEDMONT SUN MORNING...WHICH WILL TRANSITION INTO PRIMARILY
FREEZING RAIN THROUGH THE DAY AND CONTINUE INTO SUN NIGHT AS THE
COLD WEDGE PERSISTS. THE REST OF THE AREA SHOULD RECEIVE ALL RAIN
FROM SAT NIGHT THROUGH SUN NIGHT. THE LOWER MD EASTERN SHORE
SHOULD BE PRECIP-FREE UNTIL SUN MORNING. A SNOW/SLEET MIX MAY BE
POSSIBLE IN THE MORNING...WHICH SHOULD TRANSITION TO A RAIN/SLEET
MIX AS THE MARINE BOUNDARY LAYER WARMS THE LOWER LEVELS OF THE
ATMOSPHERE. VERY LITTLE CHANGE IN DIURNAL TEMPERATURES SHOULD BE
ANTICIPATED IN MIXED PRECIP AREAS FROM SAT NIGHT INTO SUN
NIGHT...WHEREAS LOCATIONS IN FAR SE VA/NE NC MAY EXPERIENCE A
10 DEGREE WARM-UP ON SUNDAY AT BEST.

IT IS TOO SOON TO ISSUE WINTER HEADLINES SINCE THE MAIN HAZARDS
ARE EXPECTED TO OCCUR BEYOND 48 HOURS. WILL CONTINUE MIXED PRECIP
WORDING IN THE HAZARDOUS WEATHER OUTLOOK AND EMPHASIZE MORE
ADVERSE CONDITIONS FOR FAR WRN AREAS. POTENTIAL WINTER HIGHLIGHTS
WILL LIKELY BE ADDRESSED WITH THE AFTERNOON FORECAST PACKAGE.
PLEASE REFER TO WWW.ERH.NOAA.GOV/AKQ FOR THE LATEST FORECAST
UPDATES TODAY AND THROUGHOUT THE WEEKEND. YOU CAN ALSO FOLLOW
NWS WAKEFIELD ON FACEBOOK AND ON TWITTER VIA @NWSWAKEFIELDVA.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
FIRST WAVE OF LOW PRESSURE MOVES NE OF FA MON MORNING WITH MODELS
INDICATING A SERIES OF WEAK WAVES MOVING NE AHEAD OF THE NEXT COLD
FRONT THAT WILL CROSS THE REGION LATE MONDAY AFTERNOON AND NIGHT.
ENOUGH MOISTURE PROGGED TO CONTINUE THE RAIN CHCS ACROSS THE AREA
MON. MUCH MILDER AS THE FLOW BECOMES SW BUT THE COLD FRONTAL
PASSAGE RESULTS IN ANOTHER TRICKY TEMP FORECAST. EXPECT A WIDE
RANGE IN TEMPS AS RESIDUAL WEDGING LEADS TO TEMPS HOLDING AROUND
50 NORTHERN MOST COUNTIES...WITH MUCH MILDER AIR (AND MAYBE SOME
PARTIAL SUN) RESULTING IN TEMPS WARMING INTO THE 60S AND POSSIBLY
NEAR 70 INVOF ALBEMARLE SOUND.

SAID COLD FRONT SLOWS ITS SOUTHERLY MOVEMENT MON NITE AND TUESDAY
AS YET ANOTHER IN A SERIES OF SHORTWAVES RIDES NE ALONG THE
BOUNDARY. THIS SCENARIO WILL LIKELY KEEP THE PCPN CHCS GOING
INTO TUESDAY. ONE CAVEAT TO THE FORECAST IS THE COLDER AIR COMING
IN FROM THE NORTH LATE MONDAY NIGHT. AS TEMPS FALL TO NEAR
FREEZING...CRITICAL THICKNESSES SUPPORTS SOME WET SNOW FLAKES
MIXING IN WITH THE RAIN ACROSS NORTHERN MOST COUNTIES...SO HAVE
INTRODUCED A RAIN/SNOW MIX LATE MON NIGHT FROM LKU-SBY. RAIN
ELSEWHERE WITH LOWS IN THE M30S-M40S. FRONT SLOWLY MOVES OFF THE
CAROLINA COAST LATE TUESDAY WITH CAA SETTING IN. STILL A CHC FOR
RAIN WITH HIGHS FROM 40 NORTH TO M50S SOUTH.

NEXT CANADIAN HIGH PRESSURE BUILDS INTO THE AREA WED AND THURS.
THE GFS SHOWS ANOTHER WAVE OF LOW PRESSURE PROGGED TO DEVELOP
ALONG THE STALLED FRONTAL BOUNDARY ACROSS SERN STATES BY MID WEEK
WITH MOISTURE FROM THIS SYSTEM STAYING JUST SOUTH OF AKQ FA. THE
12Z ECMWF PUSHES THE COASTAL SYSTEM FURTHER OFFSHORE WITH HIGH
PRESSURE DOMINATING THE ENTIRE REGION. WILL TREND THE DAY 6 AND
DAY 7 FORECAST AS DRY AND COLDER. HIGHS BOTH DAYS IN THE
M30S-M40S. LOWS 20-30.

&&

.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
EARLY AM CONDITIONS ARE MAINLY VFR IN SSW FLOW AROUND 10 KT.
THROUGH 12Z...EXPECT WINDS TO REMAIN 10-15 KTS SO EVEN WITH VERY
MOIST AIR...DO NOT ANTICIPATE MUCH FOG. HOWEVER...SCATTERED
SHOWERS AND LOW CIGS ARE PRESENT NOT FAR TO THE WEST...AND SHOULD
AFFECT THE TAF SITES AFTER 09Z...ESPECIALLY KRIC/KSBY AND HAVE
TEMPO GROUPS FOR IFR CIGS (< 1 K FT). LESS CONFIDENT ELSEWHERE SO
HAVE JUST INCLUDED MVFR CIGS THERE. LOOKS TO BE MAINLY VFR WITH
4-8 KFT CIGS FOR THE REST OF THE DAY AT KORF/KPHF/KECG. MORE
UNCERTAINTY AT KRIC/KSBY WHERE A WAVE OF LOW PRESSURE ALONG THE
FRONT MAY SHIFT WINDS TO THE E/NE AND BRING LOW CIGS/VSBYS.

FRONT SLATED TO PUSH THROUGH NORTHERN AREAS BY 06Z/SAT...SOUTHERN
AREAS BETWEEN 06-12Z/SAT. EXPECT RAIN AND WIDESPREAD IFR/LIFR
CONDITIONS FOR ABOUT 6-12 HRS BEHIND THE FRONT. BY SATURDAY
AFTN/NIGHT EXPECT SOME CLEARING WITH VFR CONDITIONS RETURNING.
NEXT WAVE OF LOW PRESSURE WILL MOVE THROUGH ON SUNDAY WITH MORE
WIDESPREAD IFR CONDITIONS ALL SITES. P-TYPE SHOULD BE ALL RAIN FOR
KORF/KECG/KPHF...WITH A GOOD PROBABILITY FOR MIXED WINTER PRECIP
AT KRIC AND SOME POTENTIAL AT KSBY BEFORE A CHANGE TO RAIN. LOW
CLOUDS/IFR LIKELY TO PERSIST SUN NIGHT/MON BUT SHOULD BE ALL RAIN
AT TAF SITES AT THAT TIME.

&&

.MARINE...
S/SW FLOW AVERAGING 10-15 KT ACRS THE WATERS EARLY THIS
MORNING...WAVES 1-2 FT ON THE BAY AND SEAS 3-4 FT OVER THE COASTAL
WATERS. A STRONG BUT SLOW MOVING COLD FRONT WILL BEGIN TO AFFECT
NORTHERN MARINE ZONES LATER TODAY AND WITH A WAVE OF LOW PRESSURE
DEVELOPING ALONG THE FRONT...WIND DIRECTION FORECAST WILL BE
CHALLENGING. A MODEL CONSENSUS WOULD KEEP THE BOUNDARY FROM ABOUT
RICHMOND TO THE MELFA THIS AFTN...WITH S/SW WINDS AROUND 15 KT SOUTH
OF THE THIS...AND LIGHT N/NE FLOW TO THE NORTH. NO HEADLINES APPEAR
TO BE NEEDED FOR TODAY...ALTHOUGH GUSTS MAY APPROACH 20 KT OVER THE
SOUTHERN BAY AND CURRITUCK SOUND (AND DID NOT CHANGE PREVIOUS
HEADLINE BRINGING TH SOUND INTO A SCA HEADLINE BY THIS EVENING).

AS THE LOW PRESSURE EJECTS ENE LATER THIS EVENING/OVERNIGHT THE
FRONT WILL THEN DROP SOUTH FAIRLY QUICKLY. MODELS SEEM TO SHOW A
BRIEF SURGE OF 20 KT WINDS WITH THE WIND-SHIFT FOLLOWED BY A BRIEF
LULL BEFORE COLDER AIR ALOFT INCREASES THE MIXING AROUND 12Z/SAT
(GENLY DID NOT GET THAT SPECIFIC AS ANY LULL WILL BE SHORT-LIVED).
BOTTOM LINE IS THAT SCA HEADLINES GO INTO EFFECT FOR ALL REMAINING
MARINE ZONES AT SOME POINT BETWEEN 06-12Z/SAT (HAVE ADDED THE UPPER
JAMES/YORK/RAPPAHANNOCK RIVER TO THE HEADLINES WITH THIS ISSUANCE).
WINDS SAT WILL AVG 20-25 KT G30KT SOUTH AND 15-20KT G25KT NORTH.
BOUNDARY STALLS TO THE SOUTH AS STRONG HIGH PRESSURE BUILDS FROM THE
GREAT LAKES TO NEW ENGLAND ON SUNDAY...WITH SCA CONDITIONS LIKELY TO
PERSIST INTO SUNDAY FOR MUCH OF THE AREA. WINDS SHIFT TO THE SW AND
CONDITIONS IMPROVE SUN NIGHT/MON ALTHOUGH SEAS WILL TEND TO REMAIN
AT OR ABOVE 5 FT ON THE COASTAL WATERS THROUGH MON. ANOTHER COLD
SURGE PUSHES THROUGH THE REGION LATE MON NIGHT/TUE...WITH SCA
CONDITIONS AGAIN LIKELY FOR MOST IF NOT ALL ZONES.

&&

.TIDES/COASTAL FLOODING...
GIVEN THE ASTRONOMICAL TIMING OF THE EVENT...PREDICTED TIDES AND
LEVELS ARE PROGGED TO REMAIN BLO ANY CRITICAL THRESHOLDS THROUGH
THE WEEKEND.

&&

.CLIMATE...
RECORD HIGH TEMPERATURES FRIDAY (12/6)...
RIC 81 IN 1998
ORF 79 IN 1998
SBY 77 IN 1998
ECG 80 IN 1998

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 4 AM SATURDAY TO MIDNIGHT EST
     SATURDAY NIGHT FOR ANZ635>638.
     SMALL CRAFT ADVISORY FROM 1 AM SATURDAY TO 6 AM EST SUNDAY FOR
     ANZ630>632-634-650-652.
     SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 6 AM EST SUNDAY
     FOR ANZ633.
     SMALL CRAFT ADVISORY FROM 4 AM SATURDAY TO 6 AM EST SUNDAY FOR
     ANZ654-656-658.

&&

$$
SYNOPSIS...TMG
NEAR TERM...BMD/TMG
SHORT TERM...BMD/JDM
LONG TERM...MPR
AVIATION...LKB
MARINE...LKB
TIDES/COASTAL FLOODING...LKB
CLIMATE...AKQ