Area Forecast Discussion
Issued by NWS Blacksburg, VA

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000
FXUS61 KRNK 250150
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
950 PM EDT THU APR 24 2014

.SYNOPSIS...
HIGH PRESSURE WILL MOVE OFFSHORE TONIGHT. MEANWHILE...A COLD
FRONT WILL HEAD EASTWARD...AND SHOULD CROSS OVER THE MID ATLANTIC
BY FRIDAY TO BRING SCATTERED SHOWERS. HIGH PRESSURE WILL RETURN TO
PROVIDE A DRY AND MILD WEEKEND...BEFORE AN UPPER LEVEL AREA OF LOW
PRESSURE PROVIDES COOLER AND WETTER CONDITIONS NEXT WEEK.

&&

.NEAR TERM /THROUGH FRIDAY/...
AS OF 950 PM EDT THURSDAY...

MADE SOME MINOR ADJUSTMENTS IN TEMPERATURES AND DEW POINTS FOR
TONIGHT. THIS EVENING RNK 00Z/8PM SOUNDINGS SHOWED MOISTURE
INCREASING AROUND 718MB WITH A PWAT AROUND 0.5 INCHES. THE 18Z NAM
GFS AND HRRR HINT AT MOISTURE SLIDING NORTH ACROSS THE SOUTHERN
BLUE RIDGE MOUNTAINS LATE TONIGHT. AS HIGH PRESSURE SLIDES EAST
INTO THE ATLANTIC OCEAN TONIGHT INTO FRIDAY MORNING...MOISTURE
WILL STREAM NORTHWARD INTO OUR REGION. HIGH AND MID CLOUDS WILL
HINDER RADIATIONAL COOLING OVERNIGHT. LOW TEMPERATURES OVERNIGHT
WILL GENERALLY BE IN THE MID 40S TO THE LOWER 50S WITH CLOUDS AND
WEAK WARM AIR ADVECTION ALOFT. A COLD FRONT TO OUR WEST AND ITS
ASSOCIATED WARM FRONT WILL TRAVEL EAST TONIGHT INTO FRIDAY AND
PUSH OFFSHORE BY FRIDAY NIGHT. AT THIS POINT...MADE NO CHANGES
WITH FRIDAY CONVECTION. HAVE A GOOD NIGHT.


AS OF 635 PM EDT THURSDAY...

RAISED EARLY EVENING TEMPERATURES UP A FEW DEGREES WITH SOLAR
HEATING. HIGH PRESSURE WILL SLIDE EAST INTO THE ATLANTIC THIS EVENING
INTO TONIGHT. A COLD FRONT AND ITS ASSOCIATED WARM FRONT WILL
TRAVEL EAST TONIGHT INTO FRIDAY AND PUSH OFFSHORE BY FRIDAY NIGHT.
LOW TEMPERATURES OVERNIGHT WILL GENERALLY BE IN THE MID 40S TO THE
LOWER 50S WITH CLOUDS AND WEAK WARM AIR ADVECTION ALOFT. LATEST
RNK WRFARW AND HRRR SUPPORT CURRENT ARRIVAL TIME FOR CONVECTION
ALONG AND AHEAD OF COLD FRONT. NO MAJOR CHANGES IN CLOUDS...PRECIPITATION
AND POPS TONIGHT INTO FRIDAY. WILL MAKE ADDITIONAL CHANGES IN ISC
GRIDS LATER THIS EVENING.

AS OF 355 PM EDT THURSDAY...

SKIES HAVE CLEARED DURING THE PAST FEW HOURS TO ALLOW TEMPERATURES
TO REACH THE LOWER 60S TO THE LOWER 70S THIS AFTERNOON. HIGH
PRESSURE SHOULD DRIFT OFFSHORE LATER TONIGHT. MEANWHILE...A COLD
FRONT WILL CROSS OVER THE OHIO RIVER VALLEY. THE 12Z NAM/ECMWF/GFS
MODEL GUIDANCES HAVE SLOWED DOWN THE ARRIVAL OF THIS FRONT BY A
FEW HOURS...SO POPS WERE TAPERED DOWNWARD DURING THURSDAY NIGHT
FROM THE PREVIOUS FORECAST. LOW TEMPERATURES WERE HELD IN THE MID
40S TO THE LOWER 50S DUE TO CLOUD COVER AND WEAK WARM AIR
ADVECTION ALOFT.

POPS WERE INCREASED LATER ON FRIDAY MORNING HOURS DUE TO GOOD
AGREEMENT AND A LITTLE MORE OVERALL COVERAGE PORTRAYED IN THE
MODELS. SHOWERS SHOULD LINGER INTO THE AFTERNOON...BEFORE THE
FRONT HEADS TOWARD THE COAST BY SUNSET. QPF AMOUNTS WERE ALSO
INCREASED SLIGHTLY TO AROUND A QUARTER OF AN INCH. HOWEVER...WINDS
SHOULD TURN TO THE WEST AND BECOME GUSTY AFTER THE FRONTAL
PASSAGE...AND END ANY OF THE REMAINING RAINFALL. CHANCES OF
THUNDER WERE ONLY PLACED IN SOUTHSIDE VIRGINIA WERE BUFKIT MODEL
SOUNDINGS SHOW CAPE EXCEEDING 500 J/KG DURING THE AFTERNOON. SPC
KEEPS ANY SEVERE WEATHER THREAT WELL TO THE EAST OF OUR CWA. HIGHS
ON FRIDAY WERE KEPT ON THE SLIGHTLY COOLER SIDE OF GUIDANCE DUE TO
CLOUDS AND RAIN...WITH LOWER 60S TO LOWER 70S EXPECTED.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
AS OF 315 PM EDT THURSDAY...

MOST PRECIP WILL HAVE EXITED THE REGION AT THE BEGINNING OF THIS
PERIOD...SAVE SOUTHSIDE VA/NC PIEDMONT AND THE GREENBRIER VALLEY.
GOOD BURST OF WIND BEHIND THIS COMPACT YET DECENT SHRTWV...WITH SOME
30 KT GUSTS FRIDAY EVENING AT THE USUAL LOCATIONS. SLIGHTLY COOLER
AIR SLIPS INTO THE GREENBRIER VALLEY AND SOUTHERN SHENANDOAH BEHIND
THIS BOUNDARY...BUT WAA RETURNS QUICKLY ACROSS THE SOUTHERN HALF OF
THE CWA. ANOTHER DISTURBANCE DROPPING THROUGH THE GREAT LAKES LATE
SATURDAY...MAY ALLOW SCATTERED SHOWERS AND A THUNDERSTORMS TO FORM
JUST AHEAD OF A COLD FRONT WHICH STALLS AROUND ELKINS WV...WITH SOME
OF THESE WEAKENING...PERHAPS AS THEY MOVE INTO THE GREENBRIER VALLEY
AND THE SOUTHERN SHENANDOAH. SOMETIMES MODELS STRUGGLE WITH THIS
REGIME...SO FOR NOW AT LEAST WENT WITH SLT CHC POPS IN THESE AREAS.
H85 TEMPS IN THE LOWER TEENS TO NEAR +15C CONTINUE FOR SUNDAY...WITH
SOME SPOTS TOUCHING 80F POSSIBLY SATURDAY AND SUNDAY.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 330 PM EDT THURSDAY...

THE NEXT WORKWEEK IS SHAPING UP TO BE ON THE WET SIDE AS A MASSIVE
UPPER LEVEL LOW PINWHEELS EAST FROM THE CENTRAL AND NORTHERN PLAINS.
WILL START MONDAY OUT WITH COOL HIGH PRESSURE WEDGING SOUTHWARD
AGAINST THE EASTERN FACE OF THE APPALACHIANS...MAINTAINING A COOL
EASTERLY WIND ACROSS OUR AREA. A WARM FRONT WILL NORTH ALONG THE
MISSISSIPPI RIVER VALLEY...BUT WILL GET HUNG UP AGAINST THE
APPALACHIANS. AS SUCH...EXPECT SHOWERY WEATHER MONDAY AND TUESDAY...
WITH AN OUTSIDE CHANCE FOR THUNDERSTORMS ACROSS THE MOUNTAIN EMPIRE
AND PERHAPS THE NORTH CAROLINA FOOTHILLS...WHERE THE STABILIZING
AFFECT OF THE HIGH PRESSURE WEDGE WILL BE WEAKEST. WILL SEE A BETTER
THREAT FOR THUNDERSTORMS ON WEDNESDAY AS THE LOW PRESSURE SYSTEM
NEARS THE REGION...ALLOWING THE WARM FRONT TO LIFT NORTHWARD BEFORE
THE TRAILING COLD FRONT MOVES IN.

EASTERLY FLOW AROUND THE HIGH WILL ALSO RESULT IN COOLER
TEMPERATURES...AND THEREFORE UNDERCUT MODEL GUIDANCE BY A FEW
DEGREES. HOWEVER...TEMPERATURES REMAIN LOW CONFIDENCE...AND BELIEVE
IT IS POSSIBLE THAT DID NOT GO LOW ENOUGH FOR AFTERNOON HIGHS MONDAY
AND PARTICULARLY TUESDAY.

&&

.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
AS OF 735 PM EDT THURSDAY...

VFR CONDITIONS EXPECTED THIS EVENING INTO TONIGHT. AS HIGH
PRESSURE HEADS OFFSHORE TONIGHT...CLOUDS SHOULD GRADUALLY INCREASE
IN COVERAGE AHEAD OF THE APPROACHING COLD FRONT. THIS FRONT IS
PROGGED TO TRACK OVER THE MID ATLANTIC BY FRIDAY. CEILINGS SHOULD
LOWER BY DAYBREAK...WITH A FAIRLY GOOD POSSIBILITY OF MVFR AS
NOTED IN THE LAMP GUIDANCE. PRECIPITATION ASSOCIATED WITH THE
FRONT SHOULD MAINLY BE SHOWERS. THERE IS THE POTENTIAL FOR
THUNDERSTORMS IN THE NORTH CAROLINA AND VIRGINIA PIEDMONT TOWARD
FRIDAY AFTERNOON. ALLOWED FOR THE MENTION OF THUNDERSTORM AT DAN.
ELSEWHERE THE PROBABILITY OF THUNDERSTORM IS NOT HIGH ENOUGH TO
MENTION IN TAFS AT THIS POINT.

HIGH TO MEDIUM CONFIDENCE IN CEILINGS...VISIBILITIES AND WINDS
DURING THE TAF PERIOD.

EXTENDED AVIATION DISCUSSION...

THE COLD FRONT SHOULD DEPART OFFSHORE BY FRIDAY NIGHT. WINDS WILL
TURN TO THE NORTHWEST AND INCREASE DURING FRIDAY NIGHT INTO
SATURDAY. VFR CONDITIONS SHOULD PREVAIL THROUGH THIS WEEKEND...AS
HIGH PRESSURE MOVES OVERHEAD. CLOUD COVER WILL STEADILY INCREASE
BY MONDAY...AS A LOW PRESSURE SYSTEM SLOWLY ARRIVES FROM THE
WEST. CONDITIONS MAY DROP BELOW VFR WHEN SCATTERED SHOWERS MOVE
OVER THE MID ATLANTIC DURING LATE MONDAY...AND CHANCES FOR MVFR
ARE EVEN BETTER ON TUESDAY DUE TO PROLONGED CLOUDS AND RAIN.

&&

.FIRE WEATHER...
AS OF 637 PM EDT THURSDAY...

LOW RH VALUES SHOULD RECOVER AFTER SUNSET THIS EVENING INTO
TONIGHT. BY FRIDAY...A COLD FRONT SHOULD PROVIDE SOME WETTING
SHOWERS FOR FRIDAY...ALTHOUGH AMOUNTS WILL BE AROUND A QUARTER OF
AN INCH.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...PW
NEAR TERM...KK/PW
SHORT TERM...KM
LONG TERM...NF
AVIATION...KK/PW
FIRE WEATHER...KK/PW



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