Area Forecast Discussion
Issued by NWS Blacksburg, VA

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000 FXUS61 KRNK 131054 AFDRNK AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BLACKSBURG VA 554 AM EST SAT FEB 13 2016 .SYNOPSIS... A SURGE OF ARCTIC AIR OVERNIGHT WILL RESULT IN VERY WINDY CONDITIONS AND BITTERLY COLD TEMPERATURES...ALONG WITH SOME ADDED SNOW SHOWERS FOR THE FAR WESTERN SLOPES OF THE APPALACHIANS TODAY. COLD HIGH PRESSURE BUILDS IN LATE TONIGHT AND SHIFTS OFF THE MID ATLANTIC COAST BY SUNDAY NIGHT. BY MONDAY ANOTHER WINTER STORM SYSTEM WILL BEGIN TO AFFECT THE REGION WITH THE POTENTIAL FOR SNOW AND MIXED PRECIPITATION SUNDAY NIGHT THROUGH THE FIRST PART OF NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 304 AM EST SATURDAY... LEADING EDGE OF ARCTIC AIR LOCATED OVER THE PIEDMONT EARLY THE MORNING. MAIN SHORTWAVE IS STRETCHED FROM THE GREAT LAKES INTO THE MID ATLANTIC WITH TRAJECTORIES ORIENTED FROM THE LAKES. THIS WILL KEEP SNOW SHOWER STREAMERS INTO THE MTNS THROUGH MIDDAY AS FAR SOUTH AS THE NC MTNS...BUT EXPECT THE ARCTIC AIR TO DRY IT OUT THROUGH THE AFTERNOON WITH LINGERING FLURRIES IN THE SE WV TIL EARLY EVENING. AMOUNTS FOR THE DAYLIGHT HOURS WILL BE AN INCH OR LESS..WITH UP TO 2 INCHES IN THE NW SLOPES OF GREENBRIER COUNTY WV. AS SUCH WILL CONTINUE TO RUN WITH AN ADVISORY FOR THE SNOW WHICH ENTAILS THE WIND SPEEDS. WINDS SHOULD START TO WIND DOWN SOMEWHAT AFTER 10 AM...WHEN BEST PRESSURE RISES AND CORE OF LOW LEVEL JET EXITS EAST. THIS WILL KEEP WIND CHILLS IN THE ADVISORY RANGE...MAINLY AT THE HIGHER ELEVATIONS DURING THE DAYLIGHT HOURS...WITH MOST OF AREAS WEST OF THE BLUE RIDGE HAVING WIND CHILL BELOW ZERO TO -15F TONIGHT. TEMPERATURES TODAY WILL BE VERY COLD AS HIGHLIGHTED BUT THE CLIMATE SECTION BELOW WITH RECORD COLD HIGHS POSSIBLE. EXPECT THE MOUNTAINS TO KEEP MORE CLOUDS TODAY WHILE EAST OF THE BLUE RIDGE CLEARS OUT. HIGHS WILL RANGE FROM THE UPPER 20S DOWN EAST...TO THE LOWER TO MID TEENS WESTERN SLOPES. A 1035 HIGH SHIFTS TO THE OHIO VALLEY BY MIDNIGHT TONIGHT AND INTO THE CENTRAL APPALACHIANS BY DAWN SUNDAY. THIS LESSENS THE WINDS OVERNIGHT SO RADIATIONAL COOLING WILL OCCUR. THE MODELS ARE HOWEVER ADVERTISING SOME MOISTURE IN THE UPPER LEVELS POURING OVERNIGHT...AND THIS SHOULD KEEP TEMPS UP A LITTLE. NONETHELESS SHOULD SEE CLOSE TO OR RECORD COLD LOWS...RANGING FROM AROUND ZERO IN THE WRN SLOPES OF SE WV TO NW NC...TO SINGLE DIGITS IN THE REST OF THE MTNS...AND AROUND 10 TO 12 IN THE EAST. && .SHORT TERM /SUNDAY THROUGH TUESDAY NIGHT/... AS OF 500 AM EST SATURDAY... BITTER COLD ARCTIC HIGH WILL BE RETREATING EAST OF THE REGION SUNDAY...WITH RETURN SOUTHERLY FLOW SETTING UP BY AFTERNOON. A NORTHERN STREAM SHORT WAVE WILL BE RAPIDLY APPROACHING FROM THE MIDWEST BY AFTERNOON. MID/HIGH LEVEL MOISTURE WILL QUICKLY SPREAD OVER THE REGION BY AFTERNOON...GREATLY INHIBITING ANY ATTEMPT TO WARM UP/RECOVER FROM THE BITTER COLD TEMPERATURES EXPECTED DURING THE MORNING. MOISTURE WILL CONTINUE TO INCREASE THROUGH THE EVENING AND THE AIR MASS SHOULD BECOME SATURATED ENOUGH FROM TOP DOWN TO SUPPORT PRECIPITATION COMMENCING IN WESTERN AREAS SHORTLY AFTER SUNSET...THEN INTO EASTERN AREAS AFTER MIDNIGHT. AT THAT TIME...THE ENTIRE COLUMN WILL BE BELOW FREEZING AND SUPPORT ALL SNOW. CONDITIONS SHOULD CONTINUE THIS WAY THROUGH EARLY TO MID-MORNING MONDAY...WITH MOSTLY SNOW ACROSS THE ENTIRE CWA. AT LEAST ADVISORY CRITERIA SNOW SHOULD IMPACT MOST AREAS DURING THIS TIME FRAME...PERHAPS MEETING LOW END WARNING CRITERIA WESTERN AREAS BY EARLY MONDAY. AS THE NORTHERN STREAM SHORT WAVE PASSES...IT WILL LEAVE A WEAK STALLED FRONTAL BOUNDARY TO OUR SOUTH WITH GOOD ISENTROPIC LIFT THROUGH THE DAY MONDAY ALLOWING THE PRECIPITATION TO CONTINUE. DURING THE DAY MONDAY...A STRONGER SOUTHERN STREAM SHORT WAVE WILL MOVE OUT OF THE SOUTHERN PLAINS INTO THE MID-SOUTH...WITH SURFACE LOW PRESSURE DEVELOPING ACROSS THE MID-SOUTH AS A RESULT. THIS WILL ALLOW A WARM FRONT TO BEGIN TO LIFT NORTH INTO THE PIEDMONT. MODEL SOUNDINGS SHOW A SIGNIFICANT WARM NOSE BEGINNING TO DEVELOP AROUND MID-DAY IN THE SOUTH...LIFTING NORTH TOWARD THE I-64 CORRIDOR BY AFTERNOON. MEANWHILE...SURFACE LOW PRESSURE BEGINS TO GRADUALLY INTENSIFY AND LIFT NORTHEAST FROM NORTHERN GEORGIA BY AFTERNOON/EVENING. WINTER PRECIPITATION WILL CONTINUE ACROSS THE REGION MONDAY...MOSTLY ALL SNOW THROUGH THE FIRST HALF OF THE DAY...THEN TRANSITION TO SLEET/SNOW MIX FROM THE SOUTH...LIKELY ALL SLEET IN THE SOUTH BY EVENING. MONDAY NIGHT...A STRONG SOUTHERLY JET BEGINS TO BRING WARM...GULF AIR OVER THE SHALLOW REMAINING COLD AIR MASS. WHILE THE MODELS OFTEN TRY TO WARM UP THE BOUNDARY LAYER TOO QUICKLY IN THIS IN- SITU WEDGE SITUATION...ESPECIALLY CONSIDERING THE STRENGTH OF THE ANTECEDENT ARCTIC AIR MASS...EVENTUALLY IT APPEARS INEVITABLE THAT THE ATMOSPHERE WILL WARM ENOUGH EXCEPT RIGHT NEAR THE SURFACE ACROSS SOUTHERN AREAS FOR PRECIPITATION TO CHANGE TO FREEZING RAIN. AM RELUCTANT TO BUY OFF JUST YET ON THE GFS/ECMWF SCENARIO OF ALL RAIN IN THE PIEDMONT...BUT THIS CANNOT BE ENTIRELY RULED OUT. AGAIN...WILL LEAN TOWARD THE COLDER SOLUTION GIVEN THE INTENSITY OF THE DEPARTING ARCTIC AIR MASS. SLEET WILL LIKELY CONTINUE INTO THE NEW/ROANOKE/AND SOUTHERN SHENANDOAH VALLEYS...WITH SNOW CONTINUING FURTHER NORTH THROUGH TOWARD THE I-64 CORRIDOR. BOTTOM LINE...WINTER STORM LIKELY BEGINNING SUNDAY EVENING AND CONTINUING THROUGH EARLY TUESDAY AT LEAST. FOR NOW AM ADVERTISING SNOW/SLEET/ICE AMOUNTS IN GENERAL AGREEMENT WITH WPC...SHOWING WARNING CRITERIA IN ALL AREAS...6-8 INCHES OF SNOW EASTERN WV...4-6 INCHES NW NC INTO THE NEW RIVER VALLEY AND I-64 CORRIDOR...1-3 INCHES SOUTHSIDE/PIEDMONT...BUT WHERE SLEET ACCUMULATION AND ICE ACCRETION UP TO 1/4 INCH ALSO POSSIBLE. NEEDLESS TO SAY...CONFIDENCE IS GROWING GIVEN INCREASING MODEL CONSENSUS THAT A SIGNIFICANT WINTER STORM IS GOING TO OCCUR SUNDAY NIGHT THROUGH TUESDAY...ALTHOUGH THERE ARE CONSIDERABLE DETAILS TO WORK OUT WITH REGARD MAINLY TO P-TYPE WHICH WILL IN TURN GREATLY DETERMINE AMOUNTS OF SNOW/SLEET/ICE. AS SOON AS THE CURRENT/ONGOING WINTER WEATHER EVENT WINDS DOWN...A WINTER STORM WATCH WILL LIKELY NEED TO BE ISSUED SOON. SIGNIFICANT DISRUPTIONS TO TRAVEL APPEAR LIKELY. FINALLY...AS THE MAIN STORM SYSTEM LIFTS NORTHEAST AWAY FROM THE REGION TUESDAY AND WE SEE A BRIEF DRY SLOT AND DECREASE IN PRECIPITATION EARLY TUESDAY...ANOTHER ALBERTA CLIPPER FOLLOWS QUICKLY. EACH SUCCESSIVE RUN OF THE MODELS HAS TRENDED STRONGER AND STRONGER WITH THIS SYSTEM. AN ADDITIONAL PERIOD OF SNOW APPEARS LIKELY WEST OF THE BLUE RIDGE...WITH ADDITIONAL SNOW ACCUMULATIONS LIKELY ACROSS THE MOUNTAINS OF EASTERN WV. && .LONG TERM /WEDNESDAY THROUGH FRIDAY/... AS OF 530 AM EST SATURDAY... AS NOTED ABOVE...ANOTHER CLIPPER WILL BE IMPACTING THE AREA AT THE BEGINNING OF THE PERIOD BRINGING SNOW SHOWERS...WIND...AND ANOTHER SURGE OF COLD AIR INTO THE REGION. A CANADIAN HIGH WILL BUILD OVER THE REGION FOR THU INTO FRI...THEN SHIFT SOUTHEAST OF THE REGION BY THE WEEKEND. A GENERAL NORTHWEST FLOW ALOFT IS EXPECTED TO CONTINUE THROUGH THE PERIOD...BUT 850MB TEMPS MODERATE TO MORE TYPICAL VALUES FOR THIS TIME OF YEAR. THIS SHOULD ALLOW DAYTIME TEMPERATURES TO BEGIN TO FINALLY RISE ABOVE FREEZING AND ALLOW THE AREA TO RECOVER FROM THE WINTER MESS EXPECTED MON-TUE. OVERALL...TEMPERATURES WILL AVERAGE SLIGHTLY BELOW TO NEAR NORMAL THROUGH THE PERIOD...WITHOUT ANY BITTER COLD SUCH AS IS THE CURRENT CASE. && .AVIATION /12Z SATURDAY THROUGH WEDNESDAY/... AS OF 551 AM EST SATURDAY... SNOW SHOWERS WILL DIMINISH THRU THE MORNING OVER BLF/LWB...SO EXPECT SMALL PERIOD OF MVFR TO IFR CIGS/VSBYS MAINLY BLF. OTHERWISE....SHOULD SEE MVFR CIGS AT BLF THROUGH LATE SAT EVENING THEN VFR. LWB SHOULD GO VFR BY MIDDAY. WINDS WILL STAY UP THROUGH THE MORNING WITH GUSTS FROM THE NW AT 20 TO 30KTS. HIGH PRESSURE BUILDS INTO THE AREA TONIGHT WITH WINDS DIMINISHING AND SKIES CLEARING...THOUGH HIGH CLOUDS ARE COMING IN TOWARD 12Z SUNDAY. EXTENDED DISCUSSION... WINTER STORM IS EXPECTED TO IMPACT THE AREA EARLY NEXT WEEK WITH ONSET OF WINTRY PRECIPITATION BEGINNING SUNDAY NIGHT. CONFIDENCE IS HIGH THAT POOR FLYING CONDITIONS WILL EXIST FROM SUNDAY NIGHT THROUGH TUESDAY. THIS WINTER STORM WILL PRODUCE A VARIETY OF WINTRY PRECIPITATION...STARTING AS SNOW SUNDAY NIGHT...THEN TRANSITIONING TO SLEET AND FREEZING RAIN MONDAY. AFTER THE EARLY WEEK WINTER STORM...THERE IS ANOTHER WEAK CLIPPER SYSTEM THAT MAY IMPACT THE AREA FOR MID WEEK...POSSIBLY RESULTING IN THE CONTINUATION OF POOR FLYING CONDITIONS THROUGH WEDNESDAY. && .CLIMATE... COLDEST AIR OF THE SEASON ARRIVES THIS WEEKEND. SEVERAL RECORD LOW MAX TEMPERATURES AND LOW TEMPERATURES ARE POSSIBLE. BELOW ARE THE CURRENT RECORDS FOR SATURDAY 2/13 AND SUNDAY 2/14. SATURDAY 02/13/2016 SITE MINT YEAR LOMAX YEAR KBLF 4 1988 19 1988 KDAN 11 1955 32 1981 KLYH 5 1979 9 1899 KROA 8 1917 18 1914 KRNK -4 1969 14 1955 SUNDAY 02/14/2016 SITE MINT YEAR LOMAX YEAR KBLF 5 1971 16 1960 KDAN 15 1986 32 1986 KLYH 4 1899 24 1905 KROA 10 1943 26 1986 KRNK -2 1969 24 1986 && .RNK WATCHES/WARNINGS/ADVISORIES... VA...WIND CHILL ADVISORY UNTIL 10 AM EST SUNDAY FOR VAZ007-009>020- 022>024-032>035. WINTER WEATHER ADVISORY UNTIL 7 AM EST THIS MORNING FOR VAZ007- 009-015. NC...WIND CHILL ADVISORY UNTIL 10 AM EST SUNDAY FOR NCZ001-002-018. WINTER WEATHER ADVISORY UNTIL 7 AM EST THIS MORNING FOR NCZ001- 018. WV...WIND CHILL ADVISORY UNTIL 10 AM EST SUNDAY FOR WVZ042>044-507. WINTER WEATHER ADVISORY UNTIL 7 AM EST THIS MORNING FOR WVZ042- 043-508. WIND CHILL WARNING UNTIL 10 AM EST SUNDAY FOR WVZ508. && $$ SYNOPSIS...JH/WP NEAR TERM...WP SHORT TERM...RAB LONG TERM...RAB/RCS AVIATION...PM/WP CLIMATE...CF

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