Area Forecast Discussion
Issued by NWS Blacksburg, VA

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499
FXUS61 KRNK 110453
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
1153 PM EST WED FEB 10 2016

.SYNOPSIS...
A STRONG UPPER LOW CENTERED OVER THE OHIO VALLEY WILL MOVE EAST
TONIGHT INTO THURSDAY. WEAK UPPER SHORTWAVES WILL MOVE ACROSS THE
MOUNTAINS THROUGH TONIGHT RESULTING IN SCATTERED SNOW SHOWERS AND
SNOW FLURRIES. A CLIPPER SYSTEM WILL CROSS OUR REGION ON FRIDAY
WITH SOME LIGHT SNOW ACCUMULATIONS...ESPECIALLY IN THE MOUNTAINS.

&&

.NEAR TERM /THROUGH THURSDAY/...
AS OF 1140 PM EST TUESDAY...

ONE MORE STREAMWISE VORT MOVING ACROSS NE TN/WRN NC LATE THIS
EVENING WILL ENHANCE A FEW MORE SNOW SHOWERS AND FLURRIES OVER SW
VA INTO SE WV...BUT EXPECT NO MORE THAN 1-2 INCHES ADDITIONAL IN
THE WRN SLOPES OF SE WV...WITH A DUSTING TO AN INCH IN THE MTNS OF
SW VA...I.E. MOUNTAIN LAKE...BURKES GARDEN.

WINDS HAVE BEEN GUSTY AND STRONG AT LEAST IN THE MTNS OF NC WITH
STRONG CAA ALLOWING GAP WIND FLOW PERFECT FOR THESE WINDS TO
ENHANCE AT GEV. EARLIER THIS EVENING THEY GUSTED TO 59 MPH.
OVERALL...THE LOW LVL WINDS TAKE A WEAKER TURN BUT STILL STAY IN
THE 30 TO 40 MPH RANGE AS THE UPPER VORT PASSES AND A GOOD SHOT OFSUBSIDENCE
KICKS IN. THESE WINDS WERE INCLUDED IN THE WSW AND GRAPHICS.

HEADLINES STILL ACTIVE AND NOT PLANNING ANY CHANGES WITH THIS
UPDATE.

PREVIOUS EARLY EVENING DISCUSSION...

OVERALL...SNOW SHOWER COVERAGE HAS BEEN SCATTERED OVER THE
WEST...BUT WITH ANOTHER STREAMWISE VORT TO PUSH NEWD INTO THE AREA
OVERNIGHT EXPECT ANOTHER WRN SLOPE INCREASE IN COVERAGE. SHOULD
SEE ANOTHER 1-3 INCHES OVER WRN GREENBRIER TO FLATTOP WV...MAYBE
UP TO 4 INCHES IN NW GREENBRIER. FLURRIES WILL BE MAKING IT AS FAR
EAST AS THE NEW RIVER VALLEY AND BLUE RIDGE.

WINDS WILL BE GUSTY AND AT TIMES AT/NEAR ADVISORY LEVELS OVER THE
NC MTNS AS STRONG COLD ADVECTION CONTINUES AND ANOTHER SUBSIDENCE
BAND BEHIND DEPARTING SHORTWAVE MOVES BY 12Z THU.

NO CHANGES TO HEADLINES.

PREVIOUS VALID DISCUSSION...

A BROAD AND COLD UPPER LEVEL LOW WILL TRACK EAST FROM THE OHIO
VALLEY THROUGH THE PERIOD. COLD AIR WILL CONTINUE TO PUSH INTO THE
REGION TONIGHT WITH LOWS BETWEEN 10F-20F.

BLUSTERY CONDITIONS ARE LIKELY EAST OF THE BLUE RIDGE WITH WIND
CHILL VALUES IN THE SINGLE DIGITS THURSDAY MORNING. HIGH PRESSURE
WILL MOVE OVER THE OHIO VALLEY THURSDAY AFTERNOON...SHUTTING DOWN
WINDS AND UPSLOPE SNOW SHOWERS. UNDER MOSTLY SUNNY SKIES THURSDAY
AFTERNOON...TEMPERATURES WILL REBOUND INTO THE 20S WEST TO 30S
EAST.

&&

.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/...
AS OF 230 PM EST WEDNESDAY...

00Z ECMWF IS FARTHER SOUTH WITH THE SHORT WAVE ON FRIDAY...WHILE
THE 12Z NAM AND GFS HAVE THIS FEATURE CROSSING THE INTO SOUTHERN
VIRGINIA FRIDAY AFTERNOON. WINDS BACK TO THE SOUTHWEST AHEAD OF
THE SHORT WAVE ON THURSDAY NIGHT. NAM IS SLOWER THAN THE GFS
BRINGING MOISTURE BACK INTO THE COUNTY WARNING AREA LATE THURSDAY.
BY THE END OF THE DAY FRIDAY...BULK OF MOISTURE WILL HAVE MOVED
EAST AND UPSLOPE SNOW SHOWERS WILL BE BACK IN FULL SWING INTO
EARLY SATURDAY MORNING. DEPTH OF MOISTURE BECOMES TOO
SHALLOW...AND WINDS TOO LIGHT TO SUPPORT UPSLOPE BY SATURDAY
EVENING. LOOKING AT PRECIPITATION AMOUNTS LESS THAN 0.25 INCHES
LIQUID ON FRIDAY...AND EVEN LIGHTER AMOUNTS OF UPSLOPE ON FRIDAY
NIGHT. BUT WITH HIGH SNOW RATIOS...THIS STILL HAS A DECENT
POTENTIAL FOR LIGHT SNOW ACCUMULATIONS. PLAN ON GOING BELOW
GUIDANCE FOR TEMPERATURES THURSDAY NIGHT THROUGH SATURDAY NIGHT
BUT TEMPERATURES MAY BE MARGINALLY TOO WARM ACROSS THE SOUTHERN
COUNTY WARNING AREA FOR MUCH MORE THAN LIGHT SNOW OR A MIX ON
FRIDAY.

FRIDAY NIGHT AND SATURDAY MODELS BRINGING SECOND SURGE OF ARCTIC
AIR INTO THE REGION. 850MB TEMPERATURES LOWER INTO THE -18 TO -22
RANGE BY THE END OF THE DAY SATURDAY. A LOW LEVEL JET OF 40 TO 50
KNOTS WILL MEAN GUSTY SURFACE WINDS AND DANGEROUSLY COLD WIND
CHILLS. GFS PRESSURE RISES LATE FRIDAY NIGHT ALSO SUPPORT GUSTY
WINDS.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 150 PM EST WEDNESDAY...

SUNDAY THE VERY DEEP POLAR LONG WAVE TROF MOVES
NORTHEAST...LEAVING THE MID ATLANTIC REGION IN WEAK 500 MB
RIDGING. THE NEXT SYNOPTIC SCALE SHORT WAVE DIGS INTO THE
TENNESSEE VALLEY ON MONDAY THEN CROSSES THE EASTERN UNITED STATES
ON TUESDAY. HOWEVER...THERE WAS STILL QUITE A LARGE SPREAD IN
MODEL SOLUTIONS...ESPECIALLY ON MONDAY THROUGH WEDNESDAY. WPC WAS
LEANING TOWARD ENSEMBLE SOLUTIONS WHICH FAVOR A SURFACE LOW IN THE
CAROLINAS ON TUESDAY MORNING. MONDAY AND MONDAY NIGHT LOOKING MORE
LIKE A POSSIBLE MIXED PRECIPITATION EVENT BUT CONFIDENCE WAS TOO
LOW TO INCLUDE MORE THAN RAIN OR SNOW AT THIS TIME. TIMING IN THE
MODELS WAS ALSO CHANGING...SLOWER THAN PAST COUPLE OF RUNS.
WHENEVER THE STORM SYSTEM DOES GO THROUGH...LIFT LOOKS IMPRESSIVE
ON ISENTROPIC LEVELS AS DOES THE WARM AIR ADVECTION. HAVE
INCREASED PROBABILITY OF PRECIPITATION IN THE MONDAY AND MONDAY
NIGHT TIME FRAME AND WILL KEEP MENTION OF WINTER STORM THREAT IN
THE HAZARDOUS WEATHER OUTLOOK.

&&

.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 1140 PM EST WEDNESDAY...

MVFR CIGS AT BLF/LWB EARLY ON WILL START TO GET TO VFR BY 12-15Z
WITH SNOW SHOWERS/FLURRIES ENDING. NOT PUTTING ANY VSBY ISSUES AT
THIS TIME..THINKING THE BEST SNOW SHOWERS MAY PUSH ACROSS BLF
BETWEEN 05-06Z.

WINDS WILL STAY GUSTY THROUGH MOST OF THE TAF PERIOD...SUSTAINED
10-15 KTS WITH GUSTS TO 30 KTS POSSIBLE AT BCB/ROA THROUGH 15Z.

HIGH PRESSURE BUILDS IN THIS AFTERNOON/EVENING ALLOWING WINDS TO
RELAX AND SKIES TO CLEAR.

HIGH CONFIDENCE IN ALL PARAMETERS...BUT LOWER EARLY IN BLF/LWB PER
SNOW SHOWER THREAT.


EXTENDED DISCUSSION...

VFR THURSDAY NIGHT AS WEAK HIGH PRESSURE BUILDS IN.

LOW PRESSURE PASSES SOUTH OF US FRIDAY AND MAY THROW SOME MVFR
CIGS TOWARD THE NC/VA BORDER WITH LIGHT SNOW POSSIBLE...THEN NW
FLOW BEHIND THIS IS GOING TO BRING MVFR CIGS TO BLF/LWB INTO SAT
MORNING...BEFORE GOING VFR AGAIN BY LATE SATURDAY. WINDS WILL BE
GUSTY AGAIN WITH ANOTHER SURGE OF ARCTIC AIR POURING IN SATURDAY.
ANOTHER CLIPPER SYSTEM POSES TO MOVE ACROSS THE AREA

SHOULD BE VFR SUNDAY THEN ANOTHER SYSTEM SEEMS POISED TO BRING
WINTRY WX TO THE AREA AS EARLY AS MONDAY WITH SUB-VFR EXPECTED
REGION WIDE. TRACK OF THIS SYSTEM WILL DETERMINE PTYPE AND WHERE
OVER THE MID ATLANTIC AND SOUTHEAST...BUT FOR OUR AREA WINTRY
PRECIP LOOKS FAVORABLE. STAY TUNED.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...WIND CHILL ADVISORY UNTIL 10 AM EST THURSDAY FOR VAZ007-
     009>020-022>024.
     WINTER WEATHER ADVISORY UNTIL 7 AM EST THURSDAY FOR VAZ007-
     009>012-015-019-020.
NC...WIND CHILL ADVISORY UNTIL 10 AM EST THURSDAY FOR NCZ001-002-
     018.
     WINTER WEATHER ADVISORY UNTIL 7 AM EST THURSDAY FOR NCZ001-018.
WV...WIND CHILL ADVISORY UNTIL 10 AM EST THURSDAY FOR WVZ042>044-
     507-508.
     WINTER WEATHER ADVISORY UNTIL 7 AM EST THURSDAY FOR WVZ042>044-
     507.
     WINTER STORM WARNING UNTIL 7 AM EST THURSDAY FOR WVZ043-508.

&&

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



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