Area Forecast Discussion
Issued by NWS Blacksburg, VA

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000
FXUS61 KRNK 261109
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
609 AM EST WED NOV 26 2014

.SYNOPSIS...
LOW PRESSURE WILL MOVE NORTHEAST AND DEEPEN ALONG THE CAROLINA
COAST THIS MORNING BEFORE PASSING EAST OF THE VIRGINIA CAPES THIS
AFTERNOON. A CLIPPER TYPE LOW PRESSURE SYSTEM WILL MOVE SOUTHEAST
TOWARD THE REGION LATER TODAY AND WILL CROSS THE MID ATLANTIC
STATES LATER TONIGHT. HIGH PRESSURE WILL COVER THE REGION
THURSDAY NIGHT AND FRIDAY.
&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 220 AM EST WEDNESDAY...

PRECIP CONTINUING TO OVERSPREAD THE REGION EARLY THIS MORNING WITH
SURFACE LOW PRESSURE TRACKING QUICKLY NNE ALONG THE SOUTH CAROLINA
COAST SIMILAR TO THE LATEST GFS/EC INITS. HOWEVER PRECIP GIVEN
SUCH A WARM BOUNDARY LAYER AND LACK OF HIGHER RATES...HAS BEEN
SLOW TO TRANSITION TO SNOW EXCEPT ON THE HIGHER PEAKS FROM BEECH
MTN UP TO MT ROGERS ATTM. LATEST REGIONAL RADAR TRENDS SHOW
HEAVIER PRECIP TO THE SOUTH AND EXPECT THIS AXIS TO PIVOT INTO THE
REGION TOWARD DAYBREAK BEFORE QUICKLY SLIDING EAST BY MIDDAY AS
THE SURFACE LOW TRACKS TO NEAR VA BEACH AROUND 18Z. ALTHOUGH
GUIDANCE IN GENERAL AGREEMENT ON HEAVIER QPF ESPCLY BLUE RIDGE
EAST...STILL LOTS OF UNCERTAINTY IN REGARDS TO PTYPE AS THE NAM
REMAINS QUITE COLD WITH MORE WIDESPREAD SNOW PER LOW PRESSURE
SLIGHTLY FARTHER EAST...WHILE THE GFS/EC STAYING WARMER THROUGH
12Z BEFORE PIVOTING IN COLDER THICKNESS AS THE COASTAL STARTS TO
WIND UP THIS MORNING. THIS TIMING AND HEIGHT OF THE SNOW LEVEL
CRITICAL TO SEEING 3-6 INCHES IN SPOTS ON THE RIDGES AND LITTLE OR
NO ACCUMULATION IN OTHERS AS THE BEST FRONTOGENETIC FORCING LOOKS
TO SET UP ALONG THE BLUE RIDGE THIS MORNING POSSIBLY PRODUCING
HEAVIER TOTALS IN FLOYD/CARROLL CTYS. APPEARS BEST LIFT...DYNAMIC
COOLING AND COLD ADVECTION TO ALL COINCIDE BETWEEN ABOUT 10-15Z
/5A-10A ACROSS THE WESTERN HALF JUST AHEAD OF THE MAIN SHORTWAVE
ALOFT AND WITHIN A BELT OF MORE LOW LEVEL NORTHERLY FLOW BEHIND
THE SURFACE LOW. THIS IS WHEN AN INCH/HOUR TYPE SNOWFALL RATES
POSSIBLE AS GUIDANCE INDICATES SOME CSI BANDING ESPCLY AS BEST
LIFT DEVELOPS WITHIN THE DENDRITIC GROWTH ZONE AND SNOW LEVELS
CHASE DOWN THE RIDGES ABOVE 2500 FEET AND INTO THE VALLEYS.

OTRW WILL CONTINUE TO FOLLOW A MORE BLENDED/CONSENSUS APPROACH AND KEEP
AMOUNTS GENERALLY CLOSE TO GOING VALUES FOR NOW. ONLY EXCEPTIONS TO
LOWER AT THE ONSET SW...AND BY AFTERNOON GIVEN EXITING MOISTURE. FARTHER
EAST...DEGREE OF ACCUMULATION INTO THE NEW RIVER VALLEY AND POINTS
NE DEPENDENT UPON GETTING SNOW ON THE GROUND PRIOR TO THE DAYLIGHT
HOURS AND RATE OF FALL. THUS FEW CHANGES TO GOING HEADLINES FOR
NOW ALTHOUGH SOME ADJUSTS MAY BE NEEDED ONCE THINGS START TO
CHANGEOVER FROM WEST TO EAST PRIOR TO 12Z. SHOULD SEE POPS QUICKLY
TAPER FROM SW TO NE BY 21Z/4PM WITH SOME REDEVELOPMENT OF
RAIN/SNOW SHOWERS OVER THE WEST AS THE FLOW TURNS MORE NW LATE.
HIGH TEMPS IFFY WITH READINGS TO FALL WITH PRECIP EARLY...THEN
PERHAPS REBOUND A BIT MORE THIS AFTERNOON AS MOISTURE EXITS SO
BUMPED UP HIGHS A NOTCH ESPCLY GIVEN CURRENT WARMER READINGS.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
AS OF 400 AM EST WEDNESDAY...

EXPECT A BREAK IN PRECIPITATION BEGINNING EARLY THIS EVENING AS THE
COASTAL LOW MOVES TOWARD NEW ENGLAND. THE BREAK WILL BE SHORT LIVED
HOWEVER AS ANOTHER LOW PRESSURE SYSTEM ENTERS THE CENTRAL
APPALACHIANS AFTER MIDNIGHT. WHILE MOISTURE WILL BE LIMITED AS DRIER
AIR BUILDS INTO THE REGION...THIS LOW WILL BE SUPPORTED ALOFT BY A
VIGOROUS UPPER TROUGH AND...WHEN COMBINED WITH UPSLOPE FLOW AS THE
ENERGY ENCOUNTERS THE MOUNTAINS...SHOULD BE ENOUGH TO SQUEEZE OUT 2
TO 3 INCHES ACROSS THE NORTH CAROLINA HIGHLANDS INTO THE MOUNTAIN
EMPIRE...POSSIBLY AS FAR NORTH AS WESTERN GREENBRIER COUNTY. BECAUSE
OF THE POTENTIAL IMPACT TO HOLIDAY TRAVEL...WILL ISSUE A WINTER
WEATHER ADVISORY FOR THANKSGIVING FOR THESE LOCATIONS RUNNING FROM
MIDNIGHT TO NOON. GREATEST AMOUNTS WILL BE FOUND IN THE HIGHER
TERRAIN/COLDER AIR ALOFT.

ELSEWHERE ACROSS THE MOUNTAINS...MAY SEE UP TO AN INCH OF SNOW IN
SPOTS...BUT MAINLY ON GRASSY SURFACES. EAST OF THE BLUE RIDGE...LOW
LEVEL TEMPERATURES WILL REMAIN SUFFICIENTLY WARM TO KEEP
PRECIPITATION AS LIQUID. THE LOW WILL PASS TOWARD THE COASTAL PLAIN
DURING EARLY AFTERNOON...ENDING PRECIPITATION IN THE EAST AND
LEAVING ONLY DIMINISHING UPSLOPE SNOW SHOWERS ALONG THE RIDGES IN
THE WEST THAT WILL LINGER INTO LATE EVENING.

HIGH PRESSURE WILL PASS ACROSS THE REGION ON FRIDAY...MAKING FOR
MOSTLY CLEAR SKIES AND LIGHT WINDS. AFTERNOON TEMPERATURES WILL BE
ON THE CHILLY SIDE...WITH HIGHS RANGING FROM THE LOW/MID 30S IN THE
WEST TO THE MID 40S IN THE EAST. AS THE HIGH SHIFTS EAST FRIDAY
EVENING...WILL SEE A RETURN OF SOUTHWESTERLY WIND FLOW THAT WILL
CARRY WARMER AIR NORTHWARD ALONG THE APPALACHIAN CHAIN. AS
SUCH...EXPECT WARMER TEMPERATURES FOR SATURDAY...WITH HIGHS IN THE
MID 40S TO LOW 50S. MAY SEE A FEW SHOWERS DEVELOP SATURDAY EVENING
IN THE WEST AS A WARM FRONT LIFTS NORTH ACROSS THE OHIO RIVER VALLEY.

&&

.LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 400 AM EST WEDNESDAY...

THE WARMING TREND THAT STARTED ON SATURDAY WILL CONTINUE ON
SUNDAY AND MONDAY...WITH READINGS SOME 10 TO 15 DEGREES ABOVE
NORMAL FOR THAT TIME. TEMPERATURES WILL COOL TO NEAR NORMAL
READINGS BEHIND THE PASSAGE OF A COLD FRONT ACROSS OUR AREA ON
TUESDAY.

&&

.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
AS OF 600 AM EST WEDNESDAY...

POOR FLYING CONDITIONS CAN BE EXPECTED THIS MORNING INTO EARLY
THIS AFTERNOON AS WIDESPREAD PRECIPITATION ASSOCIATED WITH LOW
PRESSURE ALONG THE COAST KEEPS LOW CIGS AND VSBYS IN PLACE. MOST
OF THIS WILL FALL AS SNOW ACROSS THE WESTERN TERMINALS...ESPCLY
KBCB AND WEST WITH A PERIOD OF HEAVIER SNOW POSSIBLE AT KROA THIS
MORNING...AND AT KLYH BEFORE THINGS START TO TAPER OFF EARLY THIS
AFTERNOON. THUS WILL BE MAINTAINING OVERALL IFR/LIFR OVER THE WEST
UNTIL SNOW/RAIN ENDS WITH A MIX OF MVFR/IFR OVER THE EAST.

THIS STORM SYSTEM IS EXPECTED TO MOVE RAPIDLY NORTHEAST IMPACTING
NUMEROUS FLIGHT TERMINALS EAST OF THE APPALACHIAN MOUNTAINS AND
ALONG THE NEW ENGLAND COAST. FOR THE LOCAL REGION...THIS STORM
SYSTEM SHOULD EXIT THE AREA BY MID/LATE WEDNESDAY AFTERNOON
18-21Z/1-4PM...ONLY TO BE FOLLOWED BY A FAST MOVING CLIPPER TYPE
AREA OF LOW PRESSURE...UPPER LEVEL DISTURBANCE...TONIGHT INTO
EARLY THURSDAY. THIS SECOND WEATHER FEATURE HAS THE POTENTIAL TO
BRING WIDESPREAD SUB-VFR LATER TONIGHT ESPCLY KBLF/KLWB WITH
MVFR/IFR VSBY RESTRICTIONS IN LIGHT SNOW SHOWERS OVERNIGHT. ALSO
POTENTIAL TO SEE SOME FOG FORMATION GIVEN THE WET GROUND WITH MVFR
TO IFR LIKELY FROM KBCB AND POINTS EAST AFTER MIDNIGHT.

EXTENDED DISCUSSION...

LOW CLOUDS AND SNOW SHOWERS/FLURRIES MAY PERSIST AT KBLF/KLWB
INTO THURSDAY NIGHT WITH MVFR CIGS POSSIBLE. OTRW EXPECTING
DOWNSLOPE DRYING TO BRING A RETURN TO VFR FROM THE BLUE RIDGE EAST
AS HIGH PRESSURE STARTS TO BUILD IN AND DRIER AIR WINS OUT. THIS
HIGH PRESSURE SYSTEM SHOULD BUILD ACROSS THE REGION AND TO THE
EAST BY THE WEEKEND RESULTING IN MORE WIDESPREAD VFR TO END THE
WEEK. BY LATE SUNDAY OR MONDAY...A WEAK FRONTAL BOUNDARY COULD
SLIDE DOWN FROM THE NORTH BRINGING THE NEXT CHANCE FOR LIGHT
PRECIP AND SUB-VFR CONDITIONS TO THE REGION...BUT ANY PRECIP LOOKS
TO BE IN THE FORM OF RAIN.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...WINTER WEATHER ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
     VAZ007-009>018.
     WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR VAZ019-
     020-024-035.
     WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO NOON EST
     THURSDAY FOR VAZ007-009-015.
     WINTER STORM WARNING UNTIL 4 PM EST THIS AFTERNOON FOR VAZ015.
     WINTER STORM WARNING UNTIL MIDNIGHT EST TONIGHT FOR VAZ020.
NC...WINTER WEATHER ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
     NCZ001-002-018.
     WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO NOON EST
     THURSDAY FOR NCZ001-018.
     WINTER STORM WARNING UNTIL 4 PM EST THIS AFTERNOON FOR NCZ001-
     018.
WV...WINTER WEATHER ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
     WVZ042>044.
     WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR WVZ507.
     WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO NOON EST
     THURSDAY FOR WVZ508.
     WINTER STORM WARNING UNTIL MIDNIGHT EST TONIGHT FOR WVZ508.

&&

$$
SYNOPSIS...AMS/JH
NEAR TERM...JH
SHORT TERM...AMS/NF
LONG TERM...DS
AVIATION...JH/PM


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