Area Forecast Discussion
Issued by NWS Blacksburg, VA

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000
FXUS61 KRNK 102055
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
355 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 300 PM EST TUESDAY...

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. WITH BREEZY
CONDITIONS...WIND CHILL VALUES WILL BE BELOW ZERO ACROSS THE
MOUNTAINS TO THE SINGLE DIGITS EAST INTO THE PIEDMONT.

AT THE BOTTOM OR SOUTHWESTERN SIDE OF THE UPPER LOW IS A STRONG
AND LENGTHY SHORT WAVE AXIS STRETCHING FROM MINNESOTA TO NORTH
CAROLINA. THIS AXIS HAS PRECIPITATION ASSOCIATED WITH IT COMING
ACROSS IOWA TO EASTERN TENNESSEE. MODELS KEEP THIS PRECIPITATION
SOUTH OF THE AREA...DIRECTING IT INTO THE SOUTH APPALACHIANS
TONIGHT. THIS AREA OF PRECIPITATION IS ALSO TAKING SOME OF THE
MOISTURE THAT IS BRINGING NORTHWEST UPSLOPE SNOWFALL TO THE
MOUNTAINS. SNOWFALL AMOUNTS HAVE BEEN LOWER THAN EXPECTED TODAY
DUE TO MOISTURE STEALING AND POSSIBLY HIGHER SUN ANGLE AS CLOUDS
HAVE ERODED SOME TODAY. WE WILL CONTINUE WITH THE WINTER WEATHER
HEADLINES FOR UPSLOPE SNOW AS LIGHT ACCUMULATIONS OF 1 TO 4 INCHES
ARE STILL POSSIBLE AFTER SUNSET...PARTICULARLY WESTERN GREENBRIER.

BREEZY AND GUSTY CONDITIONS WILL CONTINUE INTO TONIGHT WITH
PRESSURE GRADIENT AND RISES EXPECTED. WINDS TONIGHT WILL NOT MEET
CRITERIA FOR A WIND ADVISORY...BUT IN COMBINATION WITH COLD
TEMPERATURES...A WIND CHILL ADVISORY IS POSTED FOR LOCATIONS ALONG
AND WEST OF THE BLUE RIDGE FOR VALUES BELOW ZERO. 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 /21Z WEDNESDAY THROUGH MONDAY/...
AS OF 1231 PM EST WEDNESDAY...

SNOW SHOWERS...COLD AND WINDS WILL HINDER AVIATION OPERATIONS
TODAY INTO TONIGHT.

BKN/OVC MVFR CLOUDS WITH IFR CONDITIONS POSSIBLE IN SNOW SHOWERS
AND ALONG WESTERN SLOPES THROUGH TONIGHT. KBLF HAS THE BEST
CHANCE OF GOING IFR IN HEAVIER SNOW SHOWERS. SNOW SHOWERS WILL BE
MAINLY CONFINED TO THE WESTERN SLOPES...BUT LIGHT SNOW SHOWERS OR
FLURRIES COULD BREACH THE NEW RIVER VALLEY AND ROANOKE VALLEYS.

WINDS WILL STAY GUSTY WITH SUSTAINED WINDS OUT OF THE WEST
NORTHWEST AT 10 TO 18 KTS WITH GUSTS EXPECTED OVER 25 KTS AT
KBLF/KLWB/KBCB/KROA TODAY. PRESSURE RISES OVERNIGHT WILL
INCREASE GUSTS TO 35 KTS ALONG THE BLUE RIDGE WHILE VALLEYS WINDS
WEAKEN SOME.

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

EXTENDED DISCUSSION...

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

ANOTHER CLIPPER SYSTEM POSES TO MOVE ACROSS THE AREA
FRIDAY...BRINGING THE POTENTIAL FOR SUB-VFR CONDITIONS TO THE WEST.
VFR CONDITIONS SHOULD RETURN FOR MUCH OF THE WEEKEND...PRIOR TO THE
ARRIVAL OF AN ADDITIONAL WEATHER SYSTEM...BRINGING THE THREAT FOR
SUB VFR CONDITIONS AGAIN MONDAY AND TUESDAY.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 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 FROM MIDNIGHT TONIGHT TO 10 AM EST
     THURSDAY FOR NCZ001-002-018.
     WINTER WEATHER ADVISORY UNTIL 7 AM EST THURSDAY FOR NCZ001-018.
WV...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 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
SHORT TERM...AMS
LONG TERM...AMS
AVIATION...RCS


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