-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KRNK 292059
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
359 PM EST THU JAN 29 2015

.SYNOPSIS...
LOW PRESSURE WILL MOVE RAPIDLY EAST ACROSS THE OHIO VALLEY THIS
EVENING AND INTO NEW ENGLAND BY FRIDAY MORNING. A SURFACE COLD
FRONT WILL TRAIL SOUTH FROM THE LOW...AND WILL SWEEP SOUTHEAST
ACROSS THE OHIO VALLEY TONIGHT...THEN THROUGH THE MID ATLANTIC
REGION FRIDAY MORNING. HIGH PRESSURE WILL THEN BUILD ACROSS THE
REGION FOR FRIDAY NIGHT AND SATURDAY...FOLLOWED BY AN AREA OF LOW
PRESSURE WHICH WILL MOVE FROM TEXAS SUNDAY...TO THE MID ATLANTIC
COAST BY MONDAY.

&&

.NEAR TERM /THROUGH FRIDAY/...
AS OF 320 PM EST THURSDAY...

AREA OF LIGHT MIXED WINTRY PRECIPITATION CURRENTLY WEAKENING AND
EXITING THE REGION TO THE EAST. A BIT OF A CLEAR SLOT IS MAKING
ITS WAY INTO THE REGION IN ADVANCE OF THE APPROACHING COLD FRONT.
THIS FRONT IS EXPECTED TO MOVE INTO AND THEN THROUGH THE AREA THIS
EVENING. BEHIND IT...NORTHWEST WINDS WILL BEGIN TO INCREASE AN THE
UPSLOPE RAIN/SNOW MACHINE WILL INITIATE OVER SOUTHEAST WEST
VIRGINIA...SOUTH INTO THE NORTHERN MOUNTAINS OF NORTH CAROLINA.
THE PRECIPITATION SHOULD TRANSITION TO ALL SNOW BY LATE THIS
EVENING. OUR LATEST SNOWFALL TOTALS DO NOT DIFFER GREATLY FROM OUR
PRIOR FORECAST. ADVISORY LEVEL SNOWS STILL LOOK PROMISING ACROSS
WESTERN GREENBRIER COUNTY IN THE TWO TO FOUR RANGE. HAVE INCREASED
WESTERN PARTS OF GRAYSON...ASHE...AND WATAUGA COUNTIES INTO THE
ONE TO TWO INCH RANGE. LOW TEMPERATURES TONIGHT WILL RANGE FROM
THE LOW TO MID 20S ACROSS THE MOUNTAINS WITH READINGS AROUND 30 TO
THE LOWER 30S ACROSS THE PIEDMONT.

WIND GUSTS ARE EXPECTED TO REACH ADVISORY LEVEL TONIGHT...FIRST
ACROSS THE NORTHERN MOUNTAINS NORTH CAROLINA AND THE GRAYSON
HIGHLANDS A LITTLE AFTER MIDNIGHT. AS THE NIGHT
PROGRESSES...ADVISORY LEVEL GUSTS WILL SPREAD NORTH ACROSS THE
HIGHER RIDGES OF SOUTHWEST VIRGINIA...AND THE WESTERN PORTIONS OF
WESTERN GREENBRIER COUNTY. THE HIGHER TERRAIN OF
GRAYSON...ASHE...AND WATAUGA MAY BE APPROACH GUSTS WITH SPEEDS AT
HIGH WIND WARNING CRITERIA FRIDAY MORNING. THE GUSTS WILL WEAKEN
JUST SLIGHTLY DURING FRIDAY AFTERNOON...PRIOR TO AN EXPECTED BRIEF
INCREASE FRIDAY EVENING. SNOW WILL GRADUALLY COME TO AN END DURING
THE DAY...BUT LINGER THE LONGEST ACROSS SOUTHEAST WEST VIRGINIA.
HIGH TEMPERATURES WILL RANGE FROM THE MID 20 TO LOWER 30S ACROSS
THE MOUNTAINS...WITH MANY OF THESE READINGS OCCURRING EARLY IN THE
DAY WITH FALLING TEMPERATURES THEREAFTER. THE PIEDMONT WILL
EXPERIENCE HIGHS IN THE UPPER 30S TO LOWER 40S.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
AS OF 240 PM EST THURSDAY...

LOW PRESSURE OFF THE NEW ENGLAND COAST AND HIGH PRESSURE SLIDING
ACROSS THE OHIO VALLEY WILL KEEP A PRESSURE GRADIENT AND WINDY/GUSTY
CONDITIONS ACROSS THE REGION INTO MONDAY EVENING. THROUGH THE NIGHT
HIGH PRESSURE EDGES INTO THE AREA WITH SOME LOCATIONS BEING ABLE TO
DECOUPLE WHILE BREEZY/GUSTY CONDITIONS REMAIN ACROSS THE MOUNTAINS.
MORNING LOWS WITHOUT THE WIND WILL RANGE FROM 5F TO 15F ACROSS THE
MOUNTAINS TO AROUND 20F EAST OF THE BLUE RIDGE. IF MIXING CONTINUES
INTO SATURDAY MORNING...WIND CHILLS NEAR ZERO ACROSS THE HIGHER
ELEVATIONS TO AROUND 10F ABOVE IN THE LOWER ELEVATIONS. IN THE
EAST...UPPER TEEN WIND CHILLS LIKELY. HIGH PRESSURE BUILDS OVER THE
REGION SATURDAY...THEN SLIDES TO THE SOUTHEAST SATURDAY NIGHT.
MOSTLY SUNNY SKIES SATURDAY WITH TEMPERATURES WARMING INTO THE UPPER
30S WEST TO MID 40S EAST. THE NEXT PRECIPITATION MAKER WILL PUSH
CLOUDS OVER THE AREA SATURDAY NIGHT WITH LOWS DROPPING JUST BELOW
FREEZING.

COMPLICATED WEATHER PATTERN WILL BRING PRECIPITATION INTO THE AREA
SUNDAY. AN UPPER LEVEL LOW OVER THE SOUTHWEST UNITED STATES WILL
THROW ENERGY AND MOISTURE INTO THE PLAINS. AN UPPER LEVEL NORTHERN
STREAM TROUGH WILL SWING OUT OF THE ROCKIES SATURDAY NIGHT. A SERIES
OF SHORT WAVES WILL TRACK ACROSS THE MID WEST AND EVENTUALLY SPIN UP
A SURFACE WAVE OVER THE TENNESSEE VALLEY. ALL THIS ENERGY/MOISTURE
WILL TRACK IN ZONAL FLOW AND INTO THE DEPARTING SURFACE RIDGE. THE
FIRST SIGNS OF MEASURABLE PRECIPITATION MAY HOLD OFF UNTIL THE
AFTERNOON. THE SURFACE LOW AND UPPER LEVEL DYNAMICS COMES ACROSS THE
AREA SUNDAY NIGHT AND HAVE RAISED POPS INTO THE HIGH LIKELY CATEGORY.

THE TOUGH QUESTION NOW DEALS WITH P-TYPE. TEMPERATURES AND
THICKNESSES START COLD ACROSS THE MOUNTAINS FOR PRECIPITATION TO
FALL AS SNOW. IF DRY AIR IS LEFT-OVER FROM DEPARTING
HIGH...PRECIPITATION FALLING COULD SEND WET BULB TEMPERATURES DOWN
BELOW FREEZING (NAM)...KEEPING MOUNTAIN PRECIPITATION AS SNOW AND A
COLD RAIN IN THE EAST. IF THE SURFACE LOW BECOMES STRONGER...MORE
WARM AIR WILL SURGE INTO THE AREA (GFS) CHANGING SNOW OVER TO RAIN
THROUGH THE DAY SUNDAY...THEN COLD AIR ENTERS LATE SUNDAY NIGHT TO
CHANGE RAIN BACK TO SNOW. BEING RIGHT IN THE TRACK OF THE LOW AND
LIMITED DENDRITE GROWTH NOT SUPPORTING STAYING ALL SNOW...WE WILL
LEAN TO A MOSTLY RAIN EVENT SUNDAY...CHANGING OVER TO SNOW WHEN THE
COLD FRONT PASSES SUNDAY NIGHT. ALSO...WE ARE NOT LOOKING AT A WEDGE
LINGERING IN THE REGION...THEREFORE HIGHLY CONFIDENT PRECIPITATION
WILL BE RAIN OR SNOW...NOT A MIXTURE OR CHANGE OVER TO FREEZING
RAIN/SLEET.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 330 PM EST THURSDAY...

TEMPERATURES BELOW NORMAL THROUGH THE EXTENDED...TRENDING TO MUCH
BELOW NORMAL TOWARD THE END OF NEXT WEEK.

MODELS KEEP THINGS PROGRESSIVE AND ARE CONSISTENT IN PHASING THE
UPPER LEVEL SPLIT FLOW PATTERN INTO A LONG WAVE WESTERN
TROF/EASTERN RIDGE PATTERN. THIS WILL OPEN THE DOOR FOR A SHOT OF
ARCTIC AIR AS WE GET TOWARD THE END OF THE PERIOD.

WE START THE PERIOD WITH A COASTAL LOW OFF THE MIDDLE ATLANTIC
COAST PULLING AWAY FROM THE REGION...LEAVING US WITH COLDER AIR
MOVING IN AND RESIDUAL NORTHWEST UPSLOPE FLOW SNOW SHOWERS WEST OF
THE BLUE RIDGE. THE SNOW SHOWERS COME TO AN END MONDAY NIGHT AS
HIGH PRESSURE BUILDS IN FROM THE OHIO VALLEY AND BRINGS US QUIET
AND COLD WEATHER FOR TUESDAY AND TUESDAY NIGHT.

THE NEXT CHANCE FOR PRECIPITATION COMES ON WEDNESDAY AS DEEPENING
LOW PRESSURE SYSTEM IS DRIVEN BY A VIGOROUS SHOT WAVE THROUGH THE
GREAT LAKES REGION AND INTO CANADA. THIS WILL SWING A COLD FRONT
THROUGH THE REGION...OPENS THE DOOR TO ARCTIC HIGH PRESSURE
BUILDING IN FROM THE MIDWEST. MODEL RUN TO RUN VARIABILITY IN THE
EXTENDED HAS BEEN QUITE HIGH RECENTLY AND WHILE EVOLUTION OF THE
OVERALL SYNOPTIC PATTERN SEEMS SOLID...DO NOT HAVE A LOT OF
CONFIDENCE IN SPECIFICS FROM ANY OF THE INDIVIDUAL SOLUTIONS. THE
EURO IS QUITE AGGRESSIVE IN DIGGING THE EASTERN TROF AND DEVELOPS
A COASTAL LOW MOVING OUT OF THE GULF WITH A CHANCE OF WINTRY
PRECIPITATION FOR OUR NORTH AND WEST AREAS...WHILE THE GFS/NAEFS
IS LESS AMPLIFIED AND DOES NOT ADVERTISE A COASTAL LOW AND KEEPS
US MOSTLY DRY. WILL HAVE TO WAIT AND SEE HOW THIS ALL PLAYS OUT IN
LATER MODEL RUNS BUT FOR NOW WILL SHADE THE FORECAST TOWARD THE
DRIER GFS/NAEFS.

&&

.AVIATION /21Z THURSDAY THROUGH TUESDAY/...
AS OF 1235 PM EST THURSDAY...

MAINLY VFR CONDITIONS WILL CONTINUE THROUGH THE REMAINDER OF THE
AFTERNOON ACROSS THE AREA. THE EXCEPTION WILL BE ALONG A BAND OF
PRECIPITATION MOVING ACROSS THE REGION CURRENTLY THAT IS A MIXTURE
OF RAIN AND SLEET. SOME ISOLATED...AND TEMPORARY...MVFR CIGS/VSBYS
ARE POSSIBLE WITHIN THIS BAND.

A COLD FRONT WILL CROSS THE REGION THIS EVENING. EXPECT WINDS TO
SHIFT NORTHWEST AND INCREASE SIGNIFICANTLY. RESIDUAL LOW LEVEL
MOISTURE ALONG WITH THE UPSLOPE WINDS WILL GENERATE SNOW SHOWERS
ACROSS THE MOUNTAINS AND IFR/MVFR CIGS THAT WILL CARRY OVER INTO
FRIDAY MORNING. LITTLE OR NO SNOW IS EXPECTED TO PROGRESS EAST OF
THE CREST OF THE BLUE RIDGE.

DURING THE DAY FRIDAY...SURFACE WILL WILL INCREASE EVEN MORE AS
50KTS AT 850 MB IS EXPECTED TO CROSS THE REGION. ANTICIPATE GUSTS
IN THE MOUNTAINS TO BE AROUND 40 KTS AT SOME OF THE HIGHER
ELEVATIONS.

EXTENDED DISCUSSION...

MVFR CIGS MAY LINGER OVER THE MOUNTAINS INTO FRIDAY NIGHT WITH
STRONG NW WINDS...AFTER WHICH LOOK FOR IMPROVING CONDITIONS WITH
VFR EXPECTED SATURDAY AND SATURDAY NIGHT COURTESY OF HIGH PRESSURE
PASSING OVERHEAD THE FIRST HALF OF THE WEEKEND.

THE NEXT LOW PRESSURE SYSTEM HEADING OUT OF THE SW STATES WILL
BRING A RETURN OF CLOUDS AND SOME PRECIPITATION ON SUNDAY AND
MONDAY WITH WIDESPREAD MVFR TO IFR LIKELY.

BY TUESDAY...HIGH PRESSURE AND VFR CONDITIONS RETURN TO THE AREA.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...WIND ADVISORY FROM 3 AM TO 9 PM EST FRIDAY FOR VAZ009>014-
     016>020-022>024-032>035.
     WIND ADVISORY FROM MIDNIGHT TONIGHT TO MIDNIGHT EST FRIDAY
     NIGHT FOR VAZ015.
NC...WIND ADVISORY FROM 3 AM TO 9 PM EST FRIDAY FOR NCZ002.
     WIND ADVISORY FROM MIDNIGHT TONIGHT TO MIDNIGHT EST FRIDAY
     NIGHT FOR NCZ001-018.
WV...WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO NOON EST
     FRIDAY FOR WVZ508.

&&

$$
SYNOPSIS...DS
NEAR TERM...DS
SHORT TERM...RCS
LONG TERM...MBS
AVIATION...DS