Area Forecast Discussion
Issued by NWS Blacksburg, VA

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000
FXUS61 KRNK 111509
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
1009 AM EST THU FEB 11 2016

.SYNOPSIS...
HIGH PRESSURE WILL GRADUALLY BUILD EAST INTO THE AREA THIS
AFTERNOON ALLOWING FOR DRIER WEATHER ALONG WITH DIMINISHING WINDS.
A CLIPPER SYSTEM WILL CROSS OUR REGION ON FRIDAY WITH SOME LIGHT
SNOW ACCUMULATIONS...ESPECIALLY IN THE MOUNTAINS. GENERALLY QUIET
WEATHER IS EXPECTED FOR THE WEEKEND WITH MORE SNOW SHOWERS WEST OF
THE BLUE RIDGE ALONG THE FAR WESTERN SLOPES.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 1000 AM EST THURSDAY...

UPDATED TO LET THE GOING HEADLINES EXPIRE WITH ONLY FAR WESTERN
GREENBRIER COUNTY LIKELY TO SEE ADDED SNOWFALL INTO EARLY
AFTERNOON...WHILE WIND CHILLS SLOWLY RECOVER AS TEMPS EDGE UP AND
WINDS DIMINISH WITH HIGH PRESSURE BUILDING IN. HOWEVER WILL STILL
BE COLD WITH CHILLS OVER THE MOUNTAINS STAYING IN THE SINGLE
DIGITS AND TEENS...WITH SOME OF THE HIGHER ELEVATIONS PERSISTING
BELOW ZERO ALTHOUGH TOO ISOLATED TO KEEP A HEADLINE GOING. WILL
ALSO LIKELY COVER THE LINGERING SNOW WITH A SPS UNTIL DRIER AIR
FINALLY WINS OUT AS SEEN OFF LATEST SHORT RANGE GUIDANCE AND
LATEST VISIBLE PICS. OTHERWISE LOWERED HIGHS SLIGHTLY OVER THE
WEST BASED ON CURRENT OBS AND ONLY SLOW RECOVERY AT 85H THIS
AFTERNOON DESPITE INCREASING INSOLATION. EXPECT AREAS EAST OF THE
BLUE RIDGE TO SEE A LITTLE BUMP GIVEN DOWNSLOPE BUT MOSTLY LOW/MID
30S OUT TO THE PIEDMONT. GUSTY WINDS SHOULD PERSIST INTO EARLY
AFTERNOON BEFORE THE SURFACE HIGH FINALLY NOSES EAST AND THE LOW
LEVEL JET FADES AS DEEP COLD ADVECTION STARTS TO BRIEFLY WANE.


PREVIOUS DISCUSSION AS OF 430 AM EST THURSDAY...

COLD NORTHWEST WINDS WILL CONTINUE TO BRING SNOW SHOWERS TO LOCATIONS
WEST OF THE BLUE RIDGE...ESPECIALLY THE FAR WESTERN SLOPES OF THE
APPALACHIANS...THROUGH THIS MORNING. THANKFULLY SYNOPTIC MOISTURE WILL
START TO WANE AS THE UPPER TROF FINALLY PULLS THROUGH THE REGION AND
ALLOWS HIGH PRESSURE TO BUILD IN FROM THE MIDWEST. THIS WILL ALLOW THE
SNOW SHOWERS TO TAPER OFF TO LINGERING FLURRIES BY THIS AFTERNOON. THE
CURRENT WATCH/WARNING SITUATION IS COMPLICATED AS THERE LOOKS TO BE ONE
LAST BURST OF SNOW RIGHT AROUND 12Z THAT MAY BRING AN ADDITIONAL INCH
OR SO TO THE WARNING AREAS AND POSSIBLY A LOCALIZED LIGHT ACCUMULATION
IN A SNOWBANK EAST TO THE BLUE RIDGE. WITH THIS IN MIND IT APPEARS THE
BEST COURSE OF ACTION WILL BE TO CONTINUE THE WARNINGS UNTIL THEY
EXPIRE AT 7AM AND FOLLOW THEM WITH AN ADVISORY THROUGH 10AM. IT WILL BE
A LAST MINUTE DECISION AS TO WHETHER THE CURRENT ADVISORY AREA WILL BE
EXTENDED BEYOND THE CURRENT EXPIRATION TIME OF 7AM. THE JOSTLING OF THE
PRODUCTS ASIDE...THE MAIN POINT IS THAT AN ADDITIONAL LIGHT
ACCUMULATIONS OF SNOW IS POSSIBLE THROUGH THE MORNING RUSH HOUR.

TEMPERATURES THIS MORNING REMAIN COLD AND COMBINED WITH THE GUSTY
NORTHWEST WINDS...THE CURRENT WIND CHILL ADVISORY WILL REMAIN IN TACT
UNTIL 10AM. THEREAFTER...EXPECT ANOTHER COLD DAY WITH HIGHS WEST OF THE
RIDGE GENERALLY IN THE LOW/MID 20S AND MID/UPPER 30S TO THE EAST.
TEMPERATURES TONIGHT WILL DROP EARLY...THEN BEGIN TO RISE AS CLOUDS
MOVE IN FROM THE WEST AHEAD OF THE NEXT SYSTEM BRINGING SOME UPPER
SHORT WAVE ENERGY AND ISENTROPIC LIFT TO THE REGION. CURRENT
INDICATIONS ARE THAT PRECIPITATION WILL HOLD OFF UNTIL FRIDAY SO WILL
RUN WITH A DRY FORECAST THURSDAY NIGHT WITH JUST SOME LOW CHANCE POPS
FAR WEST TOWARD DAYBREAK FRIDAY.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY NIGHT/...
AS OF 445 AM EST THURSDAY...

MULTIPLE WINTER CONCERNS TO CONTINUE THROUGH THE PERIOD.

FRIDAY...ALBERTA CLIPPER SYSTEM RACES THROUGH THE FORECAST
AREA...REACHING THE WESTERN DOORSTEP AROUND DAYBREAK...THEN
TRANSLATING TO THE COAST BY EVENING. TRACK OF BEST LIFT AND
MOISTURE SEEMS TO BE JUST SOUTH OF THE CWA ACROSS NE TN INTO NW
NC...THEN RELOCATING TO THE COAST PLAIN AS LOW PRESSURE IS INDUCED
OFF THE SC/NC COAST IN RESPONSE TO THE UPPER SHORT WAVE. QPF STILL
IN THE 0.1 TO 0.2 RANGE WITHIN THIS BAND...WITH AMOUNTS MOSTLY
LESS THAN 0.10 ACROSS THE BULK OF THE RNK CWA...EXCEPT FOR THE FAR
SOUTHWEST SECTIONS. WITH A VERY COLD AIR MASS AND HIGH SNOW TO
LIQUID RATIO...THESE COULD EQUATE TO 1 TO 3 INCHES OF SNOW. THIS
EVENT ALONE WILL NOT MEET ADVISORY CRITERIA EXCEPT IN A FEW
ISOLATED SPOTS...PERHAPS HIGHER ELEVATIONS OF WATAUGA AND ASHE.
HOWEVER...AS THE ALBERTA CLIPPER PASSES...WE MOVE BACK INTO A
PERIOD OF ENHANCED UPSLOPE SNOW SHOWERS ALONG THE WESTERN SLOPES
OF THE MOUNTAINS FRIDAY NIGHT INTO SATURDAY MORNING. THIS COULD
PUSH SNOW AMOUNTS ACROSS SOME OF THE SOUTHWESTERN AND WESTERN
AREAS INTO THE LOW END OF ADVISORY CRITERIA. WITH ONGOING
HEADLINES...ISSUING SOMETHING FOR THIRD/FOURTH PERIOD...ESPECIALLY
CONSIDERING THE LOW END NATURE OF THE EVENT AT THIS POINT...WOULD
JUST ADD CONFUSION AT THIS POINT. UPSLOPE SNOW SHOULD WIND DOWN A
LITTLE MORE QUICKLY THAN WITH THE CURRENT EVENT...GENERALLY
TAPERING OFF TO FLURRIES BY SATURDAY EVENING.

THE ALBERTA CLIPPER WILL INITIATE ANOTHER STRONG AND EVEN MORE
SIGNIFICANT SURGE OF ARCTIC AIR INTO THE REGION. WHILE THE CORE OF
THE ARCTIC AIR MASS...-40C...WILL TRACK FROM THE CENTRAL GREAT
LAKES TOWARD NEW ENGLAND AND THE NORTHERN MID- ATLANTIC...WE WILL
CERTAINLY SEE OUR SHARE OF BITTER COLD AIR HERE AS WELL. 850MB
TEMPS WILL FALL BELOW -20C BY LATE SATURDAY MORNING IN THE
NORTHERN PART OF THE CWA AND REMAIN THERE UNTIL EARLY SUNDAY
AFTERNOON...WITH SOUTHERN AREAS BOTTOMING OUT AROUND -18C AND
NORTHERN AREAS AROUND -22C. IN 2014 AND 2015...OUR COLDEST
MORNINGS...BELOW ZERO IN MANY AREAS WEST OF THE BLUE RIDGE...CAME
WHEN THE 850MB TEMPS WERE AROUND -25C. IT APPEARS WE WILL FALL
JUST SHORT OF THAT. HOWEVER...STRONG NORTHWEST WINDS WILL COMBINE
WITH THE BITTER COLD TEMPERATURES TO PRODUCE WIND CHILLS BELOW
ZERO JUST ABOUT EVERYWHERE WEST OF THE BLUE RIDGE...WITH -20 TO
-25C WIND CHILLS IN WESTERN GREENBRIER...AND OTHER HIGHER
ELEVATIONS OF BATH DOWN TOWARD WATAUGA. WIND CHILL ADVISORIES AND
EVEN A WIND CHILL WARNING...WILL BE NEEDED IN MANY AREAS WEST OF
THE BLUE RIDGE FOR FRIDAY NIGHT/SATURDAY. AGAIN...THIS WILL NEED
TO BE ISSUED ONCE THE CURRENT SET OF ADVISORIES/WARNINGS EXPIRES.

MAX TEMPS SATURDAY WILL BE HARD PRESSED TO RISE ABOVE 10 IN THE
WESTERN MOUNTAINS AND REMAIN IN THE 20S ACROSS THE PIEDMONT.
SUNDAY WILL BE DRY AND VERY COLD...WITH ONLY A SLIGHT RECOVERY IN
THE AFTERNOON FROM BITTER COLD TEMPS SUNDAY MORNING...AS LOW AS
-5F ACROSS THE WESTERN MOUNTAINS.

&&

.LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 515 AM EST THURSDAY...

SUNDAY THE VERY DEEP POLAR LONG WAVE TROUGH LIFTS NORTHEAST AS THE
ARCTIC SURFACE HIGH SETTLES SQUARELY OVER THE REGION. AT THIS
POINT...THE ATTENTION THEN TURNS TO A COMBINATION OF VIGOROUS
SHORT WAVES DESTINED TO MERGE INTO A SINGLE STRONGER SYSTEM ALONG
THE SOUTHEAST U.S. COAST. THE LATEST GFS HAS TRENDED TOWARD THE
ECMWF...MEANING A FURTHER NORTHWARD TRACK...WHILE THE ECMWF HAS
GENERALLY REMAINED CONSISTENT WITH THE TRACK...BUT HAS TRENDED
COLDER. GIVEN THE ANTECEDENT AIR MASS IN PLACE WILL BE BITTER COLD
AND DRY...THE COLDER TEMPERATURE SOLUTION OF THE GFS SEEMS
PLAUSIBLE. THE MODELS HAVE ALSO TRENDED STRONGER WITH THIS SYSTEM
AS THE ENERGY FROM TWO SHORT WAVES MERGES IN THE GA/SC AREA...NOW
DEPICTING A DEEPER COASTAL LOW AND POTENTIAL MILLER A TYPE
SCENARIO. AS WPC HAS NOTED...THE THREAT IS THERE FOR A SIGNIFICANT
WINTER STORM IN THE EAST...AND THIS DOES INDEED APPEAR TO BE THE
CASE. SIGNIFICANT SNOW AMOUNTS ARE INDICATED VIA BOTH THE GFS AND
ECMWF ACROSS THE RNK CWA...WEST OF THE BLUE RIDGE...WITH STRONG
POTENTIAL FOR MIXED PRECIPITATION...SNOW/SLEET/FREEZING RAIN
ACROSS THE PIEDMONT AS THE WARM NOSE INVADES THAT REGION MONDAY
NIGHT. HAVE ADVERTISED LIKELY POPS FOR THE ENTIRE CWA MON-MON
NIGHT AND CONFINED TO ALL SNOW WEST OR A RAIN/SNOW MIX PIEDMONT GIVEN
UNCERTAINTY WITH COLD AIR DEPTH ACROSS THE PIEDMONT. ALL INTERESTS
ACROSS THE REGION SHOULD MONITOR FUTURE FORECASTS CLOSELY
REGARDING THIS POSSIBLE WINTER STORM EARLY NEXT WEEK.

THERE ARE SOME INDICATIONS THAT TEMPERATURES MAY MODERATE TOWARD
THE MID-WEEK PERIOD...BUT SNOWFALL MON-TUE MAY DETERMINE THAT TO A
GREAT DEGREE. WITH NORTHWEST FLOW ALOFT...WOULD BE VERY CAUTIOUS
ABOUT JUMPING ON ANY SIGNIFICANT WARMING TRENDS AT THIS POINT.

&&

.AVIATION /15Z THURSDAY THROUGH MONDAY/...
AS OF 615 AM EST THURSDAY...

COLD NORTHWEST FLOW WILL CONTINUE TO BRING DOWNSLOPING VFR CONDITIONS
EAST OF THE BLUE RIDGE WITH UPSLOPE SNOW SHOWERS AND GENERALLY MVFR
CONDITIONS THROUGH THIS MORNING. SUPPORT FOR THE SNOW SHOWERS WILL BE
WANING AS HIGH PRESSURE BUILDS IN FROM THE MIDWEST AND THE UPPER TROF
PULLS THROUGH...SO EXPECT A TREND TO VFR ALL SITES BY LATE
MORNING/EARLY AFTERNOON. VFR CONDITIONS WILL THEN PREVAIL THROUGH THE
END OF THE TAF PERIOD.

WINDS WILL REMAIN GUSTY BEFORE SUBSIDING LATER IN THE AFTERNOON...THEN
BECOME LIGHT/VARIABLE OVERNIGHT.

EXTENDED DISCUSSION...

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...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...JH/MBS
NEAR TERM...JH/MBS
SHORT TERM...AMS/RAB
LONG TERM...AMS/RAB
AVIATION...MBS/WP


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