Area Forecast Discussion
Issued by NWS Blacksburg, VA

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FXUS61 KRNK 170135
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
935 PM EDT TUE SEP 16 2014

.SYNOPSIS...
A COOL WEDGE OF HIGH PRESSURE SETTLES IN FROM THE NORTH EARLY
WEDNESDAY. THE HIGH WILL STRENGTHEN TO THE NORTH OF THE REGION
THROUGH THE REST OF THE WEEK...KEEPING RATHER COOL BUT OVERALL DRY
WEATHER IN PLACE.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
AS OF 930 PM EDT TUESDAY...

BUMPED UP CLOUD COVER ACROSS THE MOUNTAINS AS SURFACE OBS AND IR
SATELLITE CONTINUE TO SHOW LOW LEVEL CLOUDS ACROSS BLF AND SE WV.
ALSO ADJUSTED POPS DOWN SLIGHTLY FOR THE NEXT FEW HOURS AS
THINKING IS LIGHT RAIN/DRIZZLE WONT OCCUR UNTIL CLOSER TO SUNRISE
IN THE MORNING.

AS OF 715 PM EDT TUESDAY...

SHOWERS AND STORMS HAVE FADED/SHIFTED SOUTH OF THE CWA EARLY THIS
EVENING AND LOWERED POPS TO ACCOUNT FOR THIS. HAD ONE REPORT OF
NICKEL TO QUARTER SIZED HAIL FROM A STORM THAT MOVED OVER BELEWS
LAKE IN ROCKINGHAM COUNTY NC AT 445 PM. DRIER AIR SHIFTING SLOWLY
SWD...BUT STILL LOOKING AT LOW LVL MOISTURE STAYING PUT LATER
TONIGHT...SO KEPT IN CLOUDS MORE EAST OF THE MTNS THOUGH THERE IS
A BATCH OF LOW CLOUDS ACROSS SE KY/WRN WV ATTM...WHICH MAY
INCREASE INTO SE WV...SO MAY HAVE TO UP SKY COVER HERE.

OVERNIGHT...MODELS KEEP JUST ENOUGH MOISTURE IN THE LOW LVLS FOR
PATCHY DRIZZLE OVER THE BLUE RIDGE AND ADJACENT AREAS...WITH THE
NAM MOST AGGRESSIVE WITH THIS SCENARIO.

PREVIOUS VALID DISCUSSION...

HIGH PRESSURE WILL PUSH RAPIDLY EAST ACROSS THE SOUTHERN GREAT
LAKES. AS THE HIGH REACHES NEW ENGLAND... IT WILL THEN BUILD
SOUTHWARD ACROSS THE MID ATLANTIC TO WEDGE AGAINST THE EASTERN
FACE OF THE APPALACHIANS. AS SUCH...EXPECT WINDS TO GRADUALLY
SHIFT FROM NORTHWESTERLY THIS EVENING TO NORTHEASTERLY DURING THE
PREDAWN HOURS OF WEDNESDAY.

THE NORTHEASTERLY WIND FLOW WILL DRAW COOL MOIST AIR FROM THE
ATLANTIC UP THE BLUE RIDGE MOUNTAINS...WHERE IT WILL DEVELOP INTO A
MIXTURE OF FOG...DRIZZLE AND LOW CLOUDS IN THE HIGHER TERRAIN BEFORE
SUNRISE. WITH WINDS HOLDING OUT OF THE EAST THROUGH THE REMAINDER
OF THE DAY...WE CAN EXPECT PATCHES OF FOG AND DRIZZLE TO LINGER
ACROSS THE MOUNTAINS WELL INTO THE AFTERNOON BEFORE WE SEE GRADUAL
IMPROVEMENT.

COOL MARINE AIR COMING AROUND THE HIGH PRESSURE WEDGE...COMBINED
WITH THE CLOUD COVER...WILL KEEP AFTERNOON TEMPERATURES VERY MUCH
ON THE COOL SIDE. WENT A LITTLE ON THE AGGRESSIVE SIDE IN
UNDERCUTTING MODEL GUIDANCE BASED ON THE PROLONGED POTENTIAL FOR
DRIZZLE AND LIGHT RAIN LASTING INTO THE AFTERNOON. WILL BE LOOKING
FOR HIGHS RANGING FROM THE LOW/MID 60S ACROSS THE MOUNTAINS...TO
THE UPPER 60S/LOW 70S ACROSS THE PIEDMONT.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
AS OF 300 PM EDT TUESDAY...

WINDS BECOMING NORTHWEST THROUGH THURSDAY NIGHT WITH ONE SHORTWAVE
CROSSING THE FORECAST AREA OUT OF THE TENNESSEE VALLEY ON WEDNESDAY
NIGHT FOLLOWED QUICKLY BY A WAVE IN THE NORTHERN STREAM. MODELS ALSO
DEPICTING A DECENT JET STREAK AND COOLER 500 MB TEMPERATURES WITH
THE TENNESSEE VALLEY SHORT WAVE WEDNESDAY NIGHT. NOT VERY IMPRESSIVE
HOWEVER WITH THE LIFT OR DEPTH OF THE MOISTURE ON BUFKIT.

HIGH PRESSURE AT THE SURFACE WILL BUILD IN THURSDAY NIGHT AND
FRIDAY. BUFKIT SHOWED ENOUGH OF A SHALLOW LAYER OF MOISTURE AND
SOUTHEAST UPSLOPE WINDS BY FRIDAY MORNING ALONG THE SOUTHERN BLUE
RIDGE THAT STRATUS IS EXPECTED. OCCURRENCE OF DRIZZLE AND FOG IS ALSO
POSSIBLE LATE THURSDAY NIGHT IN TO FRIDAY MORNING.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 300 PM EDT TUESDAY...

AFTER A BRIEF RETURN OF SOME FLAT UPPER RIDGING ON FRIDAY NIGHT...AN
AMPLIFIED EASTERN UNITED STATES TROF DIGS SATURDAY NIGHT THROUGH
TUESDAY...WITH THE ECMWF EVEN HAVING A CUT OFF LOW OVER VIRGINIA BY
LATE TUESDAY. LARGE SURFACE HIGH COVERS THE EAST THOUGH SATURDAY
NIGHT. BACK IN SOUTHWEST FLOW AND WEAK WARM AIR ADVECTION SATURDAY
NIGHT THROUGH SUNDAY...THEN MODELS STILL BRING NEXT FRONT THROUGH
MONDAY. THE SOUTHWEST WINDS ON SATURDAY AND SUNDAY MAY ALSO LIMIT
THE AMOUNT OF LOW LEVEL MOISTURE IN THE REGION.

WILL BE WATCHING FOR DEVELOPMENT OF LOW PRESSURE ALONG THE SOUTHEAST
COAST SATURDAY AND SUNDAY WHICH MAY PUSH DEEPER MOISTURE BACK INTO
THE EASTERN COUNTY WARNING AREA. FOR NOW MODELS HOLD THE HIGHER
MOISTURE EAST OF THE FORECAST AREA.

CONTINUE TO SEE THE POTENTIAL FOR TEMPERATURES TUESDAY MORNING TO BE
BELOW NORMAL. ALSO BEHIND THE COLD FRONT AS UPSLOPE CLOUD COVER WILL
DEVELOP OVER THE MOUNTAINS TUESDAY AND TUESDAY NIGHT.

&&

.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
AS OF 735 PM EDT TUESDAY...

PUTTING MVFR CIGS AT BLF AT ONSET OF TAFS PER LATEST SATELLITE
TRENDS SHOWING MVFR CIGS AND SOME IFR UPSTREAM OVER BKW. THIS
IFR/MVFR WILL ALSO AFFECT LWB AFTER 03Z. NORTH TO NORTHEAST FLOW
WILL MAKE FOR CLOUDIER SKIES ACROSS THE EAST AS WELL AS THE
MTNS...THOUGH HOW LOW CIGS GO IS VARIABLE PER MODEL CHOICE.
LEANING TOWARD MORE IFR/MVFR LATE TONIGHT WITH SOME FOG...THOUGH
THINK FOG WILL BE LESS THAN THE LOWER CIGS.

AS WE HEAD INTO MONDAY...HIGH LOW LVL RH REMAINS ALTHOUGH SOME
IMPROVEMENT TO MVFR THEN VFR EXPECTED AFTER 18Z.



EXTENDED AVIATION DISCUSSION...

BROAD UPPER TROUGH REMAINS IN PLACE ACROSS THE EASTERN STATES FOR
THE REMAINDER OF THE WEEK ALLOWING A LARGE AREA OF HIGH PRESSURE
TO REMAIN WEDGED ACROSS THE MID ATLANTIC THROUGH THE WEEKEND.

THIS SHOULD PUSH THE PESKY DEEP MOISTURE FURTHER SOUTH AWAY FROM
THE REGION. HOWEVER BIGGER CONCERN WILL BE WITH TRAPPED RESIDUAL
LOW LEVEL MOISTURE THAT MAY KEEP SOUTHERN/WESTERN LOCATIONS STUCK
IN PERIODS OF MVFR CIGS INTO FRIDAY AS THE LOW LEVEL EAST/SE FLOW
TAKES SHAPE. HIGH PRESSURE MAY BE STRONG ENOUGH TO PUSH THE LOW
LEVEL MOISTURE TO THE SOUTHWEST SATURDAY AND WITH HEATING/MIXING
COULD SEE THINGS RETURN TO OVERALL VFR FOR EARLY IN THE
WEEKEND...BUT NOT UNTIL SATURDAY AFTERNOON AT THIS POINT.

&&

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

&&

$$
SYNOPSIS...NF/WP
NEAR TERM...CF/NF/WP
SHORT TERM...AMS
LONG TERM...AMS
AVIATION...NF/WP



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