-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KRNK 251949
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
349 PM EDT SAT MAY 25 2013

.SYNOPSIS...
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HIGH PRESSURE WILL BUILD INTO OUR AREA TONIGHT AND SUNDAY...
BRINING MAINLY DRY CONDITIONS FOR THE REST OF THE WEEKEND. EARLY
NEXT WEEK A WARM FRONT LIFTS NORTH ACROSS US...REACHING THE GREAT
LAKES BY MIDWEEK. THIS WILL BRING MUCH WARMER TEMPERATURES AND
SCATTERED AFTERNOON SHOWERS AND STORMS.
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&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
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AS OF 330 PM EDT SATURDAY...

VISIBLE SATELLITE PHOTOS SHOW A VEIL OF HIGH CLOUDS FROM DECAYING
COMPLEX OF STORMS IN THE MISSISSIPPI VALLEY ENTERING THE WESTERN
PORTION OF OUR FORECAST AREA THIS AFTERNOON. WHILE MOST MODELS SHOW
THESE CLOUDS WILL THIN SOME TONIGHT...THE CANADIAN MODEL INDICATES
HIGH CLOUDS WILL INCREASE LATE TONIGHT AS A WEAK UPPER LEVEL SYSTEMS
MOVE OVER SOUTHWEST VA/NW NC.

THESE CLOUDS...AND THE FACT THE FORECAST SFC HIGH CENTER AT 8 AM
SUNDAY MORNING WILL BE WELL TO OUR NORTHWEST...KEEPING LIGHT
NORTHWEST WINDS IN PLACE...MAY INHIBIT THE FORMATION OF FROST. WHERE
SKIES WILL REMAIN MOSTLY CLEAR IN THE EAST AND WIND DIMINISH IN THE
VALLEYS SOME PATCHY FROST MAY BE SEEN ACROSS PARTS OF THE ALLEGHANY
HIGHLANDS AND GREENBRIER VALLEY. AS A RESULT...WILL CONTINUE THE
FROST ADVISORY FOR THIS AREA...BUT WILL REMOVE THE MENTION OF
ISOLATED FROST IN THE HWO ACROSS SOME COUNTIES SURROUNDING
THE ADVISORY.

USED A MIX OF THE GFS/NAM MOS FOR LOWS TONIGHT...LEANING TOWARD THE
COOLER VALUES IN THE EAST WHERE CLOUDS WILL BE LIMITED.

FOR SUNDAY A DEEP...BUT WEAKER...NORTHWEST FLOW WILL PREVAIL. WEAK
UPPER LEVEL DISTURBANCES MOVING THROUGH THE WEST SIDE OF THE
DEPARTING UPPER LEVEL LOW WILL CONTINUE TO BRING HIGH CLOUDS TO THE
AREA. THE GFS CONTINUES TO GENERATE LIGHT PRECIP ACROSS FAR
SOUTHWEST VA/NW NC...BUT THIS WAS DISCOUNTED CONSIDERING THE DEPTH
OF DRY AIR EXPECTED TO PERSIST TOMORROW.

GUIDANCE IS VERY SIMILAR PROJECTING HIGHS A DEGREE OR TWO WARMER
SUNDAY COMPARED TO TODAY...AND WE DID NOT STRAY FAR FROM THESE
VALUES.
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&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
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AS OF 330 PM EDT SATURDAY...

AS A WARM FRONT LIFTS NORTH THROUGH THE OHIO VALLEY...THUNDERSTORM
REMNANTS...WHICH COULD BE JUST SCATTERED SHOWERS ONCE THEY REACH OUR
REGION...MAY HOLD TOGETHER THROUGH SE WEST VA AND SW VA MONDAY. WITH
WAA AND STILL SOME EASTERLY COMPONENT AND CLOUDS...TEMPS MAY RUN A
FEW DEGREES COOLER THAN GUIDANCE SUGGESTS...UNLESS CLOUDS LEAVE
QUICKER DURING THE DAY. BY TUESDAY...THE WARM FRONT IS NORTH...BUT A
SLIGHT UPSLOPE COMPONENT COMBINED WITH INCREASED DEWPOINTS/MAX
T/INSTABILITY CAN SET OFF THUNDERSTORMS ALONG THE RIDGES....YET
STILL SCATTERED. TUESDAY NIGHT WILL BE ONE OF MANY WARM AND HUMID
EVENINGS NEXT WEEK.
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&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
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AS OF 330 PM EDT SATURDAY...

HEAT WAVE POSSIBLE THROUGH THE END OF NEXT WEEK AS A 590DM UPPER
RIDGE CLOSES OFF OVER THE MIDDLE ATLANTIC IN RESPONSE TO A REX BLOCK
AND CLOSED LOW OVER THE CONTINENTIAL DIVIDE. POPS DECREASE THROUGH
THE WEEK WITH SINKING MOTION AND THE PROFILE BECOMING TOO DRY TO
SUPPORT ANYTHING MORE THAN THE MOST ISOLATED THUNDERSTORM ALONG THE
HIGHEST PEAKS BY END WEEK. 90F LOOKS POSSIBLE IN MOST OF THE CITIES
PERHAPS AS EARLY AS THURSDAY. UPPER AIR PATTERN MAY FLATTEN BY THE
END OF NEXT WEEKEND.
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&&

.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
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AS OF 120 PM SATURDAY...

VFR CONDITIONS ARE FORECAST THROUGH THE TAF VALID PERIOD. HIGH
LEVEL CIRRUS CLOUDS WILL INCREASE ACROSS THE WESTERN PORTION OF
THE BLACKSBURG FORECAST AREA...ESPECIALLY AT KBLF. WINDS GUSTING
TO 15-25KTS THIS AFTERNOON WILL DIMINISH AFTER SUNDOWN.

MVFR FOG POSSIBLE IN AT KLWB...BUT A WIDESPREAD FOG EVENT IS NOT
EXPECTED AS WINDS WILL STAY UP JUST ENOUGH.

VFR CONDITIONS WILL PREVAIL SUNDAY...WITH HIGH CLOUDS COVERING THE
WESTERN PORTION OF THE FORECAST AREA. WINDS ON SUNDAY WILL BE
LIGHTER COMPARED TO TODAY.

HIGH CONFIDENCE IN VFR CIGS THROUGH TAF VALID PERIOD.
HIGH CONFIDENCE IN VFR VSBYS THROUGH TAF VALID PERIOD...EXPECT
MEDIUM CONFIDENCE LWB AFT 06Z SUN.
HIGH CONFIDENCE IN WIND SPD/DIR THROUGH TAF VALID PERIOD.

EXTENDED AVIATION DISCUSSION...MOISTURE INCREASES AGAIN NEXT
WEEK AS THE SFC HIGH MOVES EAST AND THE UPPER RIDGE STRENGTHENS
OVER THE MISSISSIPPI VALLEY. WILL BE GETTING TO MORE HUMID WEATHER
AGAIN WITH SCT THUNDERSTORM THREAT BY TUESDAY AND FOG ISSUES AT
NIGHT IN THE VALLEYS AND ESPECIALLY IN ANY AREAS THAT RECEIVE
RAINFALL LATE THE DAY BEFORE.
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&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...FROST ADVISORY FROM 2 AM TO 8 AM EDT SUNDAY FOR VAZ020.
NC...NONE.
WV...FROST ADVISORY FROM 2 AM TO 8 AM EDT SUNDAY FOR WVZ044-045.

&&

$$
SYNOPSIS...PH
NEAR TERM...PH
SHORT TERM...KM
LONG TERM...KM
AVIATION...PH