Area Forecast Discussion
Issued by NWS Blacksburg, VA

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FXUS61 KRNK 091007
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
507 AM EST TUE FEB 9 2016

.SYNOPSIS...
A STRONG CYCLONE IN THE UPPER LEVELS OF THE ATMOSPHERE IS CENTERED
OVER THE OHIO VALLEY. THIS FEATURE WILL REMAIN NEARLY STATIONARY
THROUGH WEDNESDAY BEFORE SLOWLY MOVING EAST. WEAK UPPER LEVEL
IMPULSES WILL MOVE ACROSS THE MOUNTAINS THROUGH WEDNESDAY NIGHT
RESULTING IN PERSISTENT SNOW SHOWER AND FLURRY ACTIVITY.
TEMPERATURES WILL REMAIN BELOW NORMAL FOR THE REMAINDER OF THE
WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 500 AM EST TUESDAY...

COLD UPPER LEVEL LOW IS CENTERED OVER OHIO WITH WIDESPREAD SNOW
SHOWER ACTIVITY OCCURRING FROM THE GREAT LAKES TO THE SOUTHERN
APPALACHIANS. THIS UPPER LOW IS PROGGED TO REMAIN NEARLY
STATIONARY OVER THE NEXT 24 HOURS RESULTING IN A PERSISTENT STREAM
OF MOISTURE INTO THE WESTERN SIDE OF THE APPALACHIAN MOUNTAINS.
THIS WILL PROVIDE THE WEST SIDE OF THE MOUNTAINS WITH PERIODS OF
MODERATE ACCUMULATING SNOW. AS THE AIR PASSES OVER THE
MOUNTAINS...THE AIR WILL DRY OUT...RESULTING IN A MORE SCATTERED
NATURE TO THE SNOW SHOWERS WITH LITTLE OR NO ACCUMULATION EAST OF
THE BLUE RIDGE.

MODELS CONTINUE TO FAVOR THE HEAVIEST SNOW ACCUMULATIONS ALONG THE
WEST FACING SLOPES OF THE WEST VIRGINIA HIGHLANDS WITH MULTIDAY
SNOW TOTALS UPWARDS OF 8 TO 12 INCHES IN WESTERN GREENBRIER COUNTY.
LESSER BUT RESPECTABLE AMOUNTS WILL BE OBSERVED FARTHER SOUTHWEST
THROUGH SUMMERS AND MERCER WEST VIRGINIA...TAZEWELL...SMYTH...AND
WESTERN GRAYSON VIRGINIA...AND INTO ASHE AND WATAUGA COUNTIES IN
NORTH CAROLINA. EAST OF THESE COUNTIES...AMOUNTS WILL TAPER TO
JUST AN INCH OR TWO...WITH ONLY TRACE AMOUNTS EAST OF THE BLUE
RIDGE.

WILL NOT MAKE ANY CHANGES TO THE CURRENT WARNING AND ADVISORY
CONFIGURATION...MAINTAINING A WINTER STORM WARNING FROM WESTERN
GREENBRIER COUNTY TO NEAR FLAT TOP WEST VIRGINIA...AND WINTER
WEATHER ADVISORIES FROM THE VA/WV BORDER SOUTHWEST THROUGH THE
WESTERN NEW RIVER VALLEY AND INTO THE MOUNTAINS OF NORTHWEST NORTH
CAROLINA.

TEMPERATURES TODAY WILL STRUGGLE TO CLIMB ABOVE 32 IN THE
MOUNTAINS AND MAY ONLY MAKE IT 5 DEGREES OR SO ABOVE FREEZING FOR
AREAS EAST OF THE BLUE RIDGE. AFTER TODAY...TEMPERATURES WILL
TREND LOWER WITH LOWS TONIGHT HEADED FOR THE TEENS IN THE
MOUNTAINS TO THE LOWER 20S IN THE PIEDMONT.

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 400 AM EST TUESDAY...

BROAD UPPER TROUGH WILL SLOWLY MOVE EAST ALONG THE EAST COAST
WEDNESDAY INTO THURSDAY NIGHT. THERE REMAINS DIFFERENCES IN THE
STRENGTH OF THE UPPER TROUGH...AND IN THE SPEED AND LOCATION OF
SHORTWAVES EMBEDDED IN THE LARGE UPPER TROF. THE NAM AND ECMWF ARE
DEEPER WITH THE UPPER TROUGH COMPARED TO THE GFS. THIS TRANSLATES
TO A FURTHER SOUTH PLACEMENT AND TRACK OF THE ROBUST SHORTWAVE
WEDNESDAY WHICH ROTATES EAST AROUND UPPER TROUGH WEDNESDAY NIGHT
INTO THURSDAY.

SNOW SHOWERS AND SNOW FLURRIES CONTINUE WEDNESDAY INTO WEDNESDAY
NIGHT WITH THE NORTHWEST FLOW AND COLD ADVECTION. THE BEST CHANCES
FOR SNOW WILL OCCUR IN THE MOUNTAINS AND WESTERN SLOPES. HIGH
TEMPERATURES WEDNESDAY WILL RANGE FROM THE LOWER TEENS IN THE
NORTHWEST MOUNTAINS TO THE MID 30S IN THE PIEDMONT.  850 MB
TEMPERATURES WILL DROP TO -18 TO -20 BY 12Z/7AM THURSDAY. THIS WILL
MAKE SNOW SHOWERS IN THE WESTERN MOUNTAINS QUITE EFFICIENT WITH SNOW
TO LIQUID RATIOS OF 25:1 POSSIBLE WEDNESDAY NIGHT. IN
GENERAL...ADDITIONAL SNOW ACCUMULATIONS WEDNESDAY AND WEDNESDAY
NIGHT WILL VARY FROM A COATING TO NEAR 3 INCHES ALONG THE WESTERN
FACING SLOPES ESPECIALLY IN GREENBRIER COUNTY OF SOUTHEAST WEST
VIRGINIA. LOW TEMPERATURES WEDNESDAY NIGHT WILL RANGE FROM AROUND
ZERO IN THE NORTHWEST MOUNTAINS TO NEAR 20 DEGREES IN THE
PIEDMONT. THE COMBINATION OF WIND AND TEMPERATURES WILL MAKE WIND
CHILLS AS COLD AS 5 BELOW TO 20 BELOW ZERO WEDNESDAY NIGHT INTO
THURSDAY MORNING IN THE MOUNTAINS.

THERE IS ENOUGH DRY AIR AND DOWNSLOPING ON THURSDAY TO CREATE SOME
CLEARING EAST OF THE BLUE RIDGE. WHILE IN THE WEST...ISOLATED TO
SCATTERED SNOW SHOWERS WILL CONTINUE ESPECIALLY IN THE NORTHWEST.
AROUND AN INCH OR SO SNOW ACCUMULATION MAY BE POSSIBLE WITH A
HEAVIER SNOW SHOWER THURSDAY. HIGH TEMPERATURES ON THURSDAY WILL
BE IN THE TEENS IN THE MOUNTAINS TO THE LOWER 30S IN THE PIEDMONT.
ON THURSDAY NIGHT...THE UPPER TROUGH AXIS PULLS NORTHEAST AND MOST
OF SNOW SHOWERS AND SNOW FLURRIES SHOULD TAPER OFF. LOW
TEMPERATURES THURSDAY NIGHT WILL RANGE FROM THE SINGLE DIGITS TO
THE TEENS. WIND CHILLS MAY STILL BE NEAR WIND CHILL LEVELS FOR THE
NORTHWEST MOUNTAINS THURSDAY NIGHT INTO FRIDAY MORNING.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 250 PM EST MONDAY...

EASTERN UPPER TROF GETS RE-ENFORCED FRIDAY NIGHT AND
SATURDAY...THEN TROF AXIS MOVES OF THE COAST ON SUNDAY. BOTH THE
ECMWF AND GFS BRING A CLIPPER ACROSS THE CENTRAL UNITED STATES
MONDAY THEN INTO THE MID ATLANTIC REGION BY TUESDAY. WPC SUGGESTED
THE TRACK OFF THE ECMWF MAY BE TOO FAR SOUTH.

SOME 850 MB WARM AIR ADVECTION AND LOW LEVEL CONVERGENCE ALONG
THE LEADING EDGE OF THE NEXT SURGE OF ARCTIC AIR. BEST LIFT LOOKS
TO BE ON FRIDAY WITH SOME UPPER DIFFLUENCE. SNOW SHOULD BE MORE
WIDESPREAD THAN JUST UPSLOPE. THEN GUSTY WINDS AND VERY LOW WIND
CHILL VALUES ON FRIDAY NIGHT THROUGH SATURDAY NIGHT WITH NORTHWEST
850 MB WINDS APPROACHING 50 KNOTS. WIND CHILLS WILL AGAIN BE IN
ADVISORY CRITERIA...BETWEEN -5 TO -19 IN THE MOUNTAINS ON SATURDAY
NIGHT.

A ROUGHLY 1045 MB SURFACE HIGH WILL BUILD INTO THE AREA FRIDAY
NIGHT AND SATURDAY. THIS FEATURE WILL BE CENTERED OVER THE MID
ATLANTIC REGION MONDAY MORNING. WINDS WILL DIMINISH ENOUGH WITH
THE APPROACH OF THIS HIGH...AND WITH THE ASSOCIATED DRY AIR...TO
END UPSLOPE SNOW SHOWERS IN THE MOUNTAINS SUNDAY.

&&

.AVIATION /10Z TUESDAY THROUGH SATURDAY/...
AS OF 1145 PM EST MONDAY...

WILL SEE A PERIOD OF SNOW SHOWERS AFFECT MAINLY BLF AND SOME AT
BCB/LWB EARLY WITH IFR/MVFR VSBYS/CIGS. FURTHER EAST CLEARING
SKIES AND LIGHT WINDS ALLOWED FOR FOG FORMATION AT LYH/DAN THANKS
TO EARLIER RAINFALL. EXPECT THE FOG STAYING AROUND THROUGH 09Z
THEN SOME IMPROVEMENT FROM LIFR/IFR TO MVFR. AS WINDS PICK UP AS
THE SHORTWAVE MOVES ACROSS AFTER 12Z LOOK FOR VFR VSBYS. OVERALL
CIGS FROM ROA EAST SHOULD STAY VFR...POTENTIALLY TOUCH HIGH END
MVFR IF A FLURRY OR LIGHT SNOW SHOWER PASSES BUT SEEMS THAT THE
TIME PERIOD FOR THIS IS SMALL AND NOT ENOUGH TO WARRANT MENTION IN
THE TAF.

A DECENT UPPER DISTURBANCE IS GOING TO MOVE OVER SRN WV/SW VA
10-14Z...WHICH WILL BRING AN AREA OF HEAVIER SNOW SHOWERS TOWARD
BLF/LWB. THIS WILL BRING CIGS/VSBYS BACK TOWARD IFR MAINLY BLF.

ONCE THIS WAVE MOVES BY WINDS WILL BE PICKING UP BUT SNOW
SHOWERS/FLURRIES WILL PERSIST THROUGH THE REST OF THE PERIOD FROM
BCB TO BLF/LWB...WITH MAINLY MVFR CIGS BLF/LWB AND LOW END VFR AT
BCB.

EXTENDED DISCUSSION...

SUB-VFR SHOULD BECOME MORE CONFINED TO THE MOUNTAINS AND WESTERN
SLOPES TUESDAY NIGHT INTO MIDWEEK WITH PROLONGED MVFR/IFR
CONDITIONS AT KBLF/KLWB IN SNOW SHOWERS THROUGH AT LEAST WEDNESDAY
NIGHT AS ARCTIC AIR ARRIVES. POTENTIAL ALSO FOR PERIODS OF MVFR AT
KBCB/KROA AS IMPULSES ROTATE ACROSS THE MOUNTAINS AND BANDS OF
SNOW DEVELOP DURING THE OVERNIGHT HOURS. ACCUMULATING SNOW IS
LIKELY IN THE MOUNTAINS WEST OF THE BLUE RIDGE. FLURRIES MAY ALSO
OCCUR AS FAR EAST AS THE PIEDMONT WHERE INTERVALS OF VFR TO MVFR
CIGS COULD ALSO OCCUR.

CONDITIONS SHOULD BRIEFLY RETURN TO MAINLY VFR THURSDAY/THURSDAY
NIGHT AS WEAK HIGH PRESSURE BUILDS IN AND MOISTURE DECREASES.

ANOTHER SYSTEM MOVING ACROSS THE SOUTH MAY BRING SUB VFR
CONDITIONS WITH WINTRY PRECIP FRIDAY INTO FRIDAY NIGHT. ANOTHER
ARCTIC FRONT CROSSES BY SAT MORNING WITH GUSTY WINDS AND UPSLOPE
SNOW SHOWERS WITH SUB VFR IN THE MTNS.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...WINTER WEATHER ADVISORY UNTIL 7 AM EST THURSDAY FOR VAZ007-
     009>012-015-019-020.
NC...WINTER WEATHER ADVISORY UNTIL 7 AM EST THURSDAY FOR NCZ001-018.
WV...WINTER WEATHER ADVISORY UNTIL 7 AM EST THURSDAY FOR WVZ042>044-
     507.
     WINTER STORM WARNING UNTIL 7 AM EST THURSDAY FOR WVZ043-508.

&&

$$
SYNOPSIS...PM
NEAR TERM...PM
SHORT TERM...KK
LONG TERM...AMS
AVIATION...RCS/WP


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