Area Forecast Discussion
Issued by NWS Blacksburg, VA

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FXUS61 KRNK 131439
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
939 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 938 AM EST SATURDAY...

ADJUSTED TEMPERATURES WITH THE LATEST SURFACE OBS AND
LEANED LATE MORNING TEMPERATURES INTO THIS AFTERNOON TOWARDS
LAMP GUIDANCE. MODIFIED SNOW SHOWERS AND SNOW FLURRIES WITH
LATEST WSR-88D IMAGES AND TRENDS. IN GENERAL...ADDED MORE SNOW
SHOWERS AND FLURRIES TO THE MOUNTAINS. RAISED WINDS AND WIND
GUSTY IN THE SOUTHWEST MOUNTAINS. INCREASED CLOUD COVER SHAPING
TOWARDS GFS IN WEST. MORE CHANGES LATER...


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 /15Z 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.
NC...WIND CHILL ADVISORY UNTIL 10 AM EST SUNDAY FOR NCZ001-002-018.
WV...WIND CHILL ADVISORY UNTIL 10 AM EST SUNDAY FOR WVZ042>044-507.
     WIND CHILL WARNING UNTIL 10 AM EST SUNDAY FOR WVZ508.

&&

$$
SYNOPSIS...JH/WP
NEAR TERM...KK/WP
SHORT TERM...RAB
LONG TERM...RAB/RCS
AVIATION...PM/WP
CLIMATE...CF


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