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000
FXUS61 KRNK 210926
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
426 AM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE OVER THE OHIO VALLEY WILL MOVE EAST TODAY AND WEDGE
DOWN THE EAST SIDE OF THE APPALACHIANS TONIGHT. LOW PRESSURE WILL
REMAIN ALONG THE CAROLINA COAST TODAY THROUGH MONDAY. A VERY
STRONG COLD FRONT WILL MOVE THROUGH THE REGION ON WEDNESDAY...BRINGING
RAIN AND GUSTY WINDS TO THE AREA.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 330 AM EST SUNDAY...

SURFACE HIGH PRESSURE OVER THE OHIO VALLEY MOVES EAST TODAY THEN
WEDGES DOWN THE EAST SIDE OF THE APPALACHIANS TONIGHT. BY LATE
TONIGHT LOW PRESSURE WILL DEVELOP ALONG THE SOUTHEAST COAST AND HELP
RE-ENFORCE THE WEDGE.

DEEP WESTERLY FLOW ON THE 00Z SOUNDINGS. ONCE WEAK SHORT WAVE
CROSSING OUT OF THE TENNESSEE VALLEY CROSSES THE FORECAST
AREA...WINDS DIMINISH WHICH WILL RESULT IN MOST LOW CLOUDS ERODING
AND LIGHT PRECIPITATION WILL END. BUFKIT SHOWED THERE WILL BE SOME
BREAKS IN THE CLOUD COVER AFTER NOON.

CLOUDS FILL BACK IN FROM THE SOUTH TONIGHT. MODELS SIMILAR WITH
TIMING OF ISENTROPIC LIFT AND UPSLOPE SOUTHEAST WINDS...BRINGING
THE PROBABILITY OF PRECIPITATION INTO THE SOUTHERN COUNTY WARNING
AREA AFTER MIDNIGHT...THEN SPREADING NORTH THROUGH 12Z/7AM MONDAY.

STAYED CLOSE TO MAV GUIDANCE FOR TEMPERATURES THROUGH THE PERIOD.

&&

.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
AS OF 330 AM EST SUNDAY...

FOR MONDAY...AN UPPER LEVEL TROUGH APPROACHING FROM THE WEST WILL
SUPPORT LOW PRESSURE DEEPENING OFF THE CAROLINA COAST...WHILE HIGH
PRESSURE WILL BE WEDGED AGAINST THE EASTERN FACE OF THE
APPALACHIANS. MOISTURE RADIATING INLAND FROM THE LOW WILL ALREADY BE
SPREADING ACROSS OUR AREA BY SUNRISE...AND FORECAST TEMPERATURE
PROFILES SUPPORT A MIXTURE OF SLEET AND FREEZING RAIN ACROSS THE
MOUNTAINS THROUGHOUT THE DAY...AS RAIN FALLING FROM THE WARM AIR
RIDING IN ALOFT FROM THE SOUTH FALLS THROUGH THE COLD AIR BEING
DRAWN IN BY THE HIGH PRESSURE FROM THE NORTHEAST. EAST OF THE
MOUNTAINS...SURFACE TEMPERATURES ARE EXPECTED TO BE WARM ENOUGH THAT
ALL PRECIPITATION WILL REMAIN LIQUID. BEST CHANCES FOR PRECIPITATION
WILL BE EAST OF THE BLUE RIDGE...CLOSER TO THE LOW PASSING ALONG THE
COAST...WITH PRECIPITATION CHANCES DIMINISHING FURTHER WEST AS THE
MOISTURE FIGHTS THE DRY AIR ALREADY IN PLACE. PRECIPITATION WILL BE
MOST WIDESPREAD DURING THE MORNING AND AFTERNOON...AND WILL DECREASE
BY EARLY EVENING AS THE COASTAL LOW BEGINS TO PUSH AWAY FROM THE
AREA. STRONG NORTHEASTERLY FLOW AND WIDESPREAD PRECIPITATION WILL
STRICTLY LIMIT HEATING THROUGH THE DAY...AND HAVE UNDERCUT MODEL
GUIDANCE FOR TEMPERATURES...HOLDING HIGHS IN THE 30S AND LOW 40S
MOST LOCATIONS.

FOR TUESDAY...THE HIGH PRESSURE WEDGE WILL ONLY SLIGHTLY WEAKEN...
BUT WILL DO SO SUFFICIENTLY TO SUPPORT WARMER TEMPERATURES...MAKING
FOR RAIN ACROSS THE REGION...PERHAPS WITH A RESIDUAL AND ISOLATED
POCKET OF LIGHT FREEZING RAIN IN THE MOUNTAINS. RAIN CHANCES WILL
BEGIN TO INCREASE DURING THE EVENING AS A DEEP UPPER LEVEL TROUGH
APPROACHES FROM THE SOUTHERN PLAINS...SUPPORTING DEVELOPMENT OF A
LOW PRESSURE SYSTEM ALONG THE GULF COAST. THE LOW WILL LIFT NORTH
INTO THE TENNESSEE VALLEY OVERNIGHT...RESULTING IN WIDESPREAD RAIN
REACHING THE CENTRAL APPALACHIANS BEFORE SUNRISE WEDNESDAY.

AS THE LOW LIFTS TOWARD THE GREAT LAKES ON CHRISTMAS EVE...IT WILL
CONTINUE TO DEEPEN. WITH IT...THE LOW WILL DRAG A COLD FRONT
EASTWARD...WHICH WILL ENTER OUR WESTERN MOST COUNTIES BY AROUND
SUNSET. STRONG LOW LEVEL WINDS ASSOCIATED WITH THE LOW MAY REACH TO
THE SURFACE AT TIMES...AND MAY RESULT IN SPORADIC TREE DAMAGE AND
POWER OUTAGES. ALSO...WITH PRECIPITABLE WATER VALUES REACHING THE
BALLPARK OF 1.2 INCHES...MAY SEE LOCALLY HEAVY RAIN AS THE COLD
FRONT BEGINS TO PASS ACROSS THE AREA.

THE COLD FRONT WILL PASS RAPIDLY EAST LATE CHRISTMAS EVE EVENING...
AND MAY SEE A BRIEF SHOT OF STRONG WINDS IN THE WAKE OF THE
FRONT...ESPECIALLY ALONG THE HIGHER RIDGES. PRECIPITATION WILL
RAPIDLY DIMINISH HOWEVER AS DRIER AIR WORKS IN FROM THE
WEST...RESULTING IN ONLY RESIDUAL UPSLOPE SHOWERS THAT WILL CHANGE
OVER TO SNOW BY SUNRISE CHRISTMAS DAY.

&&

.LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 300 PM EST SATURDAY...

WEST TO NORTHWEST UPPER FLOW WILL CONTINUE INTO THURSDAY WITH
MOUNTAIN RAIN AND SNOW SHOWERS. HIGHS CHRISTMAS DAY WILL VARY FROM
AROUND 30 DEGREES IN THE NORTHWEST MOUNTAINS TO AROUND 50 DEGREES
IN PIEDMONT. WINDS WILL BE QUITE STRONG ON THURSDAY AS A 50 TO 55
KNOT 850MB JET PIVOTS ACROSS THE REGION. AT THIS TIME...LOOKS LIKE
VALUES SHOULD REMAIN BELOW WIND ADVISORY LEVELS. AS HIGH PRESSURE
SLIDES OFF THE COAST...DRY WEATHER IS EXPECTED CHRISTMAS
NIGHT/THURSDAY NIGHT WITH LOW TEMPERATURES GENERALLY IN THE UPPER
20S AND LOWER 30S.

THE UPPER FLOW SHIFTS TO THE SOUTHWEST FRIDAY INTO FRIDAY NIGHT AS
TROF CURVES OUT IN THE CENTRAL US WITH SFC LOW PRESSURE DEVELOPING
OVER THE MIDWEST WITH A FRONTAL BOUNDARY TRAILING SOUTH. HIGHS ON
FRIDAY WILL VARY FROM THE LOWER 40S IN THE MOUNTAINS TO THE MID 50S
IN THE PIEDMONT. MOISTURE SLOWLY RETURN FRIDAY NIGHT INTO SATURDAY
AS FRONTAL BOUNDARY APPROACHES. LOWS FRIDAY NIGHT DROP INTO THE
LOWER AND MID 30S IN MOST LOCATIONS. A COLD FRONT MOVES ACROSS OUR
REGION SATURDAY INTO SATURDAY NIGHT.

&&

.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
AS OF 1100 PM EST SATURDAY...

LOW LEVEL MOISTURE WILL REMAIN IN PLACE OVER THE MID ATLANTIC
OVERNIGHT. MVFR WILL PERSIST AND POTENTIALLY BECOME IFR VCNTY OF
THE MTNS WHERE RIDGES MAY BE OBCSD ATTMS. RESIDUAL BOUNDARY LAYER
MOISTURE MAY ALSO LEAD TO SOME VERY LIGHT PRECIP...MIXED
DRIZZLE/FLURRIES WITH THE POTENTIAL FOR RIME ICING.

CONFIDENCE IS LOWER FOR THE EVENTUAL CLEARING OF FOG AND LOW
CEILINGS ON SUNDAY...AS HIGH PRESSURE REMAINS WEDGED AGAINST THE
EASTERN SIDE OF THE BLUE RIDGE. SOME OF THE GUIDANCE APPEARS TOO
OPTIMISTIC AND DOES NOT ACCOUNT FOR THE REMAINING LAYER OF
MOISTURE NEAR THE SURFACE...AS THEY PORTRAY SKIES CLEARING BY 18Z
AT ALL TAF SITES. ALTHOUGH CONDITIONS SHOULD EVENTUALLY IMPROVE TO
VFR SUNDAY AFTERNOON AT LYH/ROA/DAN...MVFR CEILINGS WERE LEFT AT
BCB/LWB/BLF FOR THIS UPDATE AS IT MAY TAKE UNTIL MID/LATE
AFTERNOON OR AFTER 18Z/1PM FOR THE LOW CLOUDS TO FINALLY SCATTER.

EXTENDED DISCUSSION...

A LOW PRESSURE SYSTEM ALONG THE GULF COAST WILL TRACK NORTHWARD
ALONG THE EAST COAST DURING SUNDAY NIGHT INTO MONDAY...AND BRING
PRIMARILY RAIN AND MVFR/IFR CONDITIONS OVER THE MID ATLANTIC.
HOWEVER...THERE IS A POTENTIAL FOR PATCHY AREAS OF FREEZING RAIN
ACROSS THE ALLEGHANY HIGHLANDS OF VIRGINIA AND SOUTHEAST WEST
VIRGINIA...WHERE TEMPERATURES MAY STRUGGLE TO GET ABOVE FREEZING
DURING EARLY MONDAY MORNING. LWB MAY BE IMPACTED...BUT THERE IS
LOW CONFIDENCE DUE TO THE UNCERTAINTY OF THE THERMAL PROFILE IN
THE MODEL SOUNDINGS.

WARM AIR ADVECTION DURING MONDAY AND TUESDAY SHOULD END THE
THREAT OF FROZEN PRECIPITATION...BUT PERIODS OF RAIN AND MVFR/IFR
CONDITIONS COULD LINGER THROUGHOUT THIS TIME. A STRONG COLD FRONT
WILL APPROACH FROM THE WEST BY TUESDAY NIGHT INTO WEDNESDAY. POOR
FLYING WEATHER DUE TO MORE RAIN SHOWERS SHOULD ACCOMPANY THE
FRONT...AND A STRONG LOW LEVEL JET MAY POSE A LOW LEVEL WIND SHEAR
THREAT. GUSTY NORTHWEST WINDS AND A CONSIDERABLE TEMPERATURE DROP
ARE EXPECTED BEHIND THE COLD FRONT ON WEDNESDAY NIGHT. UPSLOPE
SNOW SHOWERS ARE POSSIBLE ALONG THE WESTERN SLOPES JUST IN TIME
FOR CHRISTMAS DAY...WHILE VFR CONDITIONS SHOULD RETURN TO MOST
LOCATIONS EAST OF THE BLUE RIDGE.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...AMS
NEAR TERM...AMS
SHORT TERM...NF
LONG TERM...KK
AVIATION...PM/PW




000
FXUS61 KRNK 210926
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
426 AM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE OVER THE OHIO VALLEY WILL MOVE EAST TODAY AND WEDGE
DOWN THE EAST SIDE OF THE APPALACHIANS TONIGHT. LOW PRESSURE WILL
REMAIN ALONG THE CAROLINA COAST TODAY THROUGH MONDAY. A VERY
STRONG COLD FRONT WILL MOVE THROUGH THE REGION ON WEDNESDAY...BRINGING
RAIN AND GUSTY WINDS TO THE AREA.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 330 AM EST SUNDAY...

SURFACE HIGH PRESSURE OVER THE OHIO VALLEY MOVES EAST TODAY THEN
WEDGES DOWN THE EAST SIDE OF THE APPALACHIANS TONIGHT. BY LATE
TONIGHT LOW PRESSURE WILL DEVELOP ALONG THE SOUTHEAST COAST AND HELP
RE-ENFORCE THE WEDGE.

DEEP WESTERLY FLOW ON THE 00Z SOUNDINGS. ONCE WEAK SHORT WAVE
CROSSING OUT OF THE TENNESSEE VALLEY CROSSES THE FORECAST
AREA...WINDS DIMINISH WHICH WILL RESULT IN MOST LOW CLOUDS ERODING
AND LIGHT PRECIPITATION WILL END. BUFKIT SHOWED THERE WILL BE SOME
BREAKS IN THE CLOUD COVER AFTER NOON.

CLOUDS FILL BACK IN FROM THE SOUTH TONIGHT. MODELS SIMILAR WITH
TIMING OF ISENTROPIC LIFT AND UPSLOPE SOUTHEAST WINDS...BRINGING
THE PROBABILITY OF PRECIPITATION INTO THE SOUTHERN COUNTY WARNING
AREA AFTER MIDNIGHT...THEN SPREADING NORTH THROUGH 12Z/7AM MONDAY.

STAYED CLOSE TO MAV GUIDANCE FOR TEMPERATURES THROUGH THE PERIOD.

&&

.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
AS OF 330 AM EST SUNDAY...

FOR MONDAY...AN UPPER LEVEL TROUGH APPROACHING FROM THE WEST WILL
SUPPORT LOW PRESSURE DEEPENING OFF THE CAROLINA COAST...WHILE HIGH
PRESSURE WILL BE WEDGED AGAINST THE EASTERN FACE OF THE
APPALACHIANS. MOISTURE RADIATING INLAND FROM THE LOW WILL ALREADY BE
SPREADING ACROSS OUR AREA BY SUNRISE...AND FORECAST TEMPERATURE
PROFILES SUPPORT A MIXTURE OF SLEET AND FREEZING RAIN ACROSS THE
MOUNTAINS THROUGHOUT THE DAY...AS RAIN FALLING FROM THE WARM AIR
RIDING IN ALOFT FROM THE SOUTH FALLS THROUGH THE COLD AIR BEING
DRAWN IN BY THE HIGH PRESSURE FROM THE NORTHEAST. EAST OF THE
MOUNTAINS...SURFACE TEMPERATURES ARE EXPECTED TO BE WARM ENOUGH THAT
ALL PRECIPITATION WILL REMAIN LIQUID. BEST CHANCES FOR PRECIPITATION
WILL BE EAST OF THE BLUE RIDGE...CLOSER TO THE LOW PASSING ALONG THE
COAST...WITH PRECIPITATION CHANCES DIMINISHING FURTHER WEST AS THE
MOISTURE FIGHTS THE DRY AIR ALREADY IN PLACE. PRECIPITATION WILL BE
MOST WIDESPREAD DURING THE MORNING AND AFTERNOON...AND WILL DECREASE
BY EARLY EVENING AS THE COASTAL LOW BEGINS TO PUSH AWAY FROM THE
AREA. STRONG NORTHEASTERLY FLOW AND WIDESPREAD PRECIPITATION WILL
STRICTLY LIMIT HEATING THROUGH THE DAY...AND HAVE UNDERCUT MODEL
GUIDANCE FOR TEMPERATURES...HOLDING HIGHS IN THE 30S AND LOW 40S
MOST LOCATIONS.

FOR TUESDAY...THE HIGH PRESSURE WEDGE WILL ONLY SLIGHTLY WEAKEN...
BUT WILL DO SO SUFFICIENTLY TO SUPPORT WARMER TEMPERATURES...MAKING
FOR RAIN ACROSS THE REGION...PERHAPS WITH A RESIDUAL AND ISOLATED
POCKET OF LIGHT FREEZING RAIN IN THE MOUNTAINS. RAIN CHANCES WILL
BEGIN TO INCREASE DURING THE EVENING AS A DEEP UPPER LEVEL TROUGH
APPROACHES FROM THE SOUTHERN PLAINS...SUPPORTING DEVELOPMENT OF A
LOW PRESSURE SYSTEM ALONG THE GULF COAST. THE LOW WILL LIFT NORTH
INTO THE TENNESSEE VALLEY OVERNIGHT...RESULTING IN WIDESPREAD RAIN
REACHING THE CENTRAL APPALACHIANS BEFORE SUNRISE WEDNESDAY.

AS THE LOW LIFTS TOWARD THE GREAT LAKES ON CHRISTMAS EVE...IT WILL
CONTINUE TO DEEPEN. WITH IT...THE LOW WILL DRAG A COLD FRONT
EASTWARD...WHICH WILL ENTER OUR WESTERN MOST COUNTIES BY AROUND
SUNSET. STRONG LOW LEVEL WINDS ASSOCIATED WITH THE LOW MAY REACH TO
THE SURFACE AT TIMES...AND MAY RESULT IN SPORADIC TREE DAMAGE AND
POWER OUTAGES. ALSO...WITH PRECIPITABLE WATER VALUES REACHING THE
BALLPARK OF 1.2 INCHES...MAY SEE LOCALLY HEAVY RAIN AS THE COLD
FRONT BEGINS TO PASS ACROSS THE AREA.

THE COLD FRONT WILL PASS RAPIDLY EAST LATE CHRISTMAS EVE EVENING...
AND MAY SEE A BRIEF SHOT OF STRONG WINDS IN THE WAKE OF THE
FRONT...ESPECIALLY ALONG THE HIGHER RIDGES. PRECIPITATION WILL
RAPIDLY DIMINISH HOWEVER AS DRIER AIR WORKS IN FROM THE
WEST...RESULTING IN ONLY RESIDUAL UPSLOPE SHOWERS THAT WILL CHANGE
OVER TO SNOW BY SUNRISE CHRISTMAS DAY.

&&

.LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 300 PM EST SATURDAY...

WEST TO NORTHWEST UPPER FLOW WILL CONTINUE INTO THURSDAY WITH
MOUNTAIN RAIN AND SNOW SHOWERS. HIGHS CHRISTMAS DAY WILL VARY FROM
AROUND 30 DEGREES IN THE NORTHWEST MOUNTAINS TO AROUND 50 DEGREES
IN PIEDMONT. WINDS WILL BE QUITE STRONG ON THURSDAY AS A 50 TO 55
KNOT 850MB JET PIVOTS ACROSS THE REGION. AT THIS TIME...LOOKS LIKE
VALUES SHOULD REMAIN BELOW WIND ADVISORY LEVELS. AS HIGH PRESSURE
SLIDES OFF THE COAST...DRY WEATHER IS EXPECTED CHRISTMAS
NIGHT/THURSDAY NIGHT WITH LOW TEMPERATURES GENERALLY IN THE UPPER
20S AND LOWER 30S.

THE UPPER FLOW SHIFTS TO THE SOUTHWEST FRIDAY INTO FRIDAY NIGHT AS
TROF CURVES OUT IN THE CENTRAL US WITH SFC LOW PRESSURE DEVELOPING
OVER THE MIDWEST WITH A FRONTAL BOUNDARY TRAILING SOUTH. HIGHS ON
FRIDAY WILL VARY FROM THE LOWER 40S IN THE MOUNTAINS TO THE MID 50S
IN THE PIEDMONT. MOISTURE SLOWLY RETURN FRIDAY NIGHT INTO SATURDAY
AS FRONTAL BOUNDARY APPROACHES. LOWS FRIDAY NIGHT DROP INTO THE
LOWER AND MID 30S IN MOST LOCATIONS. A COLD FRONT MOVES ACROSS OUR
REGION SATURDAY INTO SATURDAY NIGHT.

&&

.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
AS OF 1100 PM EST SATURDAY...

LOW LEVEL MOISTURE WILL REMAIN IN PLACE OVER THE MID ATLANTIC
OVERNIGHT. MVFR WILL PERSIST AND POTENTIALLY BECOME IFR VCNTY OF
THE MTNS WHERE RIDGES MAY BE OBCSD ATTMS. RESIDUAL BOUNDARY LAYER
MOISTURE MAY ALSO LEAD TO SOME VERY LIGHT PRECIP...MIXED
DRIZZLE/FLURRIES WITH THE POTENTIAL FOR RIME ICING.

CONFIDENCE IS LOWER FOR THE EVENTUAL CLEARING OF FOG AND LOW
CEILINGS ON SUNDAY...AS HIGH PRESSURE REMAINS WEDGED AGAINST THE
EASTERN SIDE OF THE BLUE RIDGE. SOME OF THE GUIDANCE APPEARS TOO
OPTIMISTIC AND DOES NOT ACCOUNT FOR THE REMAINING LAYER OF
MOISTURE NEAR THE SURFACE...AS THEY PORTRAY SKIES CLEARING BY 18Z
AT ALL TAF SITES. ALTHOUGH CONDITIONS SHOULD EVENTUALLY IMPROVE TO
VFR SUNDAY AFTERNOON AT LYH/ROA/DAN...MVFR CEILINGS WERE LEFT AT
BCB/LWB/BLF FOR THIS UPDATE AS IT MAY TAKE UNTIL MID/LATE
AFTERNOON OR AFTER 18Z/1PM FOR THE LOW CLOUDS TO FINALLY SCATTER.

EXTENDED DISCUSSION...

A LOW PRESSURE SYSTEM ALONG THE GULF COAST WILL TRACK NORTHWARD
ALONG THE EAST COAST DURING SUNDAY NIGHT INTO MONDAY...AND BRING
PRIMARILY RAIN AND MVFR/IFR CONDITIONS OVER THE MID ATLANTIC.
HOWEVER...THERE IS A POTENTIAL FOR PATCHY AREAS OF FREEZING RAIN
ACROSS THE ALLEGHANY HIGHLANDS OF VIRGINIA AND SOUTHEAST WEST
VIRGINIA...WHERE TEMPERATURES MAY STRUGGLE TO GET ABOVE FREEZING
DURING EARLY MONDAY MORNING. LWB MAY BE IMPACTED...BUT THERE IS
LOW CONFIDENCE DUE TO THE UNCERTAINTY OF THE THERMAL PROFILE IN
THE MODEL SOUNDINGS.

WARM AIR ADVECTION DURING MONDAY AND TUESDAY SHOULD END THE
THREAT OF FROZEN PRECIPITATION...BUT PERIODS OF RAIN AND MVFR/IFR
CONDITIONS COULD LINGER THROUGHOUT THIS TIME. A STRONG COLD FRONT
WILL APPROACH FROM THE WEST BY TUESDAY NIGHT INTO WEDNESDAY. POOR
FLYING WEATHER DUE TO MORE RAIN SHOWERS SHOULD ACCOMPANY THE
FRONT...AND A STRONG LOW LEVEL JET MAY POSE A LOW LEVEL WIND SHEAR
THREAT. GUSTY NORTHWEST WINDS AND A CONSIDERABLE TEMPERATURE DROP
ARE EXPECTED BEHIND THE COLD FRONT ON WEDNESDAY NIGHT. UPSLOPE
SNOW SHOWERS ARE POSSIBLE ALONG THE WESTERN SLOPES JUST IN TIME
FOR CHRISTMAS DAY...WHILE VFR CONDITIONS SHOULD RETURN TO MOST
LOCATIONS EAST OF THE BLUE RIDGE.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...AMS
NEAR TERM...AMS
SHORT TERM...NF
LONG TERM...KK
AVIATION...PM/PW





000
FXUS61 KRNK 210414
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
1114 PM EST SAT DEC 20 2014

.SYNOPSIS...
HIGH PRESSURE WILL BRING SOME IMPROVEMENT TO OUR WEATHER ON
SUNDAY...BEFORE A WEAK AREA OF LOW PRESSURE MOVING UP THE COAST
BRINGS PRECIPITATION BACK TO OUR FORECAST FOR SUNDAY NIGHT AND
MONDAY. AFTER A BRIEF BREAK ON TUESDAY...A VERY STRONG COLD FRONT
WILL MOVE THROUGH THE REGION ON WEDNESDAY...BRINGING RAIN AND
GUSTY WINDS TO THE AREA FOR CHRISTMAS EVE.

&&

.NEAR TERM /THROUGH SUNDAY NIGHT/...
AS OF 1100 PM EST SATURDAY...

LOW LEVEL MOISTURE REMAINS OVER THE FORECAST AREA WITH SOLID
OVERCAST BEING REPORTED ACROSS THE FCST AREA. RADAR INDICATES SOME
VERY LIGHT PRECIP FALLING OVER THE NEW RIVER VALLEY. SURFACE
REPORTS INDICATE DRIZZLE OR DRIZZLE MIXED WITH A LITTLE BIT OF
LIGHT SNOW...JUST TRACE AMOUNTS. FOR THE OVERNIGHT...LITTLE CHANGE
EXPECTED WITH MOSTLY CLOUDY SKIES. MOISTURE IN THE SOUNDING
PROFILE IS VERY SHALLOW SO ANY PRECIP SHOULD REMAIN LIGHT.

PROSPECTS FOR ANYTHING MORE THAT A TRACE IS 10 PERCENT OR LESS.
UPPER FLOW IS ESSENTIALLY ZONAL OVER US AND THIS IS KEEPING ANY
DECENT ENERGY LOCKED UP TO OUR NORTH AS A SHORT WAVE MOVES THROUGH
THE FLOW OVERNIGHT. HOWEVER...WEDGE ALONG THE EASTERN SEABOARD
WILL BE SHARPENING THROUGHOUT THE WEEKEND WHICH WILL LEAD TO SOME
UPSLOPE ALONG THE EASTERN SLOPES OF THE BLUE RIDGE WITH LIGHT
SOUTHEASTERLY SURFACE WINDS. THIS WILL HELP SQUEEZE OUT SOME
SNIZZLE...DRIZZLE/FLURRIES...TONIGHT. THERE MAY BE SOME FREEZING
FOG AROUND AS MODEL SOUNDINGS SHOW SATURATED CONDITIONS IN THE
BOUNDARY LAYER IN AREAS WHERE TEMPERATURES WILL BE BELOW FREEZING.
DO NOT BELIEVE ANY HEADLINES ARE CALLED FOR SINCE IT LOOKS TO BE A
FACTOR FOR ONLY A VERY SMALL WINDOW OF TIME JUST BEFORE DAYBREAK
BUT WILL MENTION IN THE HWO. MODEST IMPROVEMENT FOR SUNDAY AS
MOISTURE SLOWLY ERODES...BUT WILL REMAIN POOLED ALONG THE
MOUNTAINS.

WE WILL NOT HAVE TO WAIT LONG FOR OUR NEXT BOUT WITH WINTER AS A
WEAK SHORT WAVE MOVES OVER THE AREA SUNDAY NIGHT AND COMBINES WITH
WEAK ISENTROPIC LIFT TO GENERATE LIGHT PRECIPITATION. PTYPE WILL
BE A STRUGGLE WITH THIS SINCE COLD AIR WEDGE WILL HAVE NEAR
SURFACE TEMPS NEAR FREEZING AS TEMPERATURES ALOFT WARM. TOP DOWN
METHODOLOGY CURRENTLY YIELDS MOSTLY LIQUID WITH SLEET AND FREEZING
RAIN MAINLY FOR THE GREENBRIER VALLEY AND ALLEGHANY
HIGHLANDS...WITH ADDITIONAL POCKETS OF MIXED PRECIPITATION
ELSEWHERE. OVERALL QPF LOOKS TO BE RATHER LIGHT SO THIS DOES NOT
LOOK TO BE A VERY SIGNIFICANT EVENT THOUGH IT DOES NOT TAKE MUCH
FREEZING RAIN TO MAKE TRAVEL HAZARDOUS.

&&

.SHORT TERM /MONDAY/...
AS OF 300 PM EST SATURDAY...

COMPLEX FORECAST FOR THE EARLY TO MID-WEEK WITH TWO SYSTEMS TO DEAL
WITH. FIRST WILL BE EARLY MONDAY EVENT WITH A WEAK LOW ALONG THE NC
COAST AT 12Z AND THE FAMILIAR WEDGE BUILDING DOWN THE EASTERN SLOPES
OF THE APPALACHIANS FROM A PARENT 1030-ISH SURFACE HIGH OVER FAR
NORTHERN NEW ENGLAND. NOT A PARTICULARLY STRONG OR EVEN COLD WEDGE
BUT ENOUGH TO BRING AT LEAST SURFACE TEMPS CLOSE TO FREEZING IN SOME
COLDER LOCATIONS WHILE THE 0C H85 LINE IS GENERALLY ALREADY WELL
NORTH OF THE CWA..DEPENDING OF COURSE ON WHICH MODEL. 12Z GFS AND
NAM ARE BOTH ABOVE FREEZING AT H85 FROM 12Z ONWARD. SURFACE LOW
LIFTS NORTHEAST DURING THE DAY TO A POSITION OFF THE VA CAPES BY 00Z
TUE TAKING WHATEVER PRECIP DOES FALL WITH IT OFF TO THE EAST. QPF
FROM THIS EVENT LIKELY TO BE QUITE MODEST...FROM LESS THAN 0.10
INCHES FAR NORTHWEST TO POSSIBLY 0.25 TO 0.50 INCHES FAR EAST.
ALTHOUGH SEVERAL HOURS OF FREEZING RAIN IS POSSIBLE FOR THE COLDER
WESTERN VALLEYS NOT EXPECTING IT TO LAST VERY LONG AND ALL LIQUID
SHOULD FALL EAST OF THE MOUNTAINS AND THEN ALL AREAS TRANSITION TO
RAIN DURING THE DAY. HIGHS MONDAY WILL REMAINS CHILLY IN THE 30S TO
LOW 40S.

THERE WILL BE A BRIEF BREAK IN THE ACTION OVERNIGHT MONDAY
AS THE WEAK ATLANTIC LOW DEPARTS BUT WITH FLOW REMAINING SOUTHWEST
THERE IS BARELY ANY COLD ADVECTION BEHIND IT WHICH SHOULD LEAVE
TEMPS ACTUALLY FAIRLY MILD...GENERALLY ABOVE FREEZING BY TUESDAY
MORNING.  THE FLOW REMAINS SOUTH TO SOUTHWEST THROUGH THE DAY WITH
PLENTY OF AMBIENT MOISTURE AND SEVERAL WEAK BUT HARD TO TIME
DISTURBANCES SO KEPT MAINLY CHANCE POPS BUT QPF AGAIN QUITE
LOW...BELOW 0.05 INCHES WITH POSSIBLY SOME ENHANCEMENT ALONG THE
BLUE RIDGE. PRECIPITATION SHOULD BE ALL RAIN AS HIGHS IN THE 40S
EXPECTED CWA-WIDE AND WEDGE REMOVED FROM THE EQUATION. SOUTHERLY
FLOW AND WARM ADVECTION BECOMES FAIRLY IMPRESSIVE AHEAD OF THE
MUCH STRONGER LOW DEVELOPING OVER THE LOWER MISSISSIPPI VALLEY
MID- TO LATE DAY TUESDAY. POPS AND QPF WILL INCREASE OVERNIGHT
TUESDAY AS AVAILABLE MODELS SHOW A WIDESPREAD PRECIP EVENT WITH
AMOUNTS APPROACHING A HALF-INCH BY EARLY WEDNESDAY AS THE SURFACE
LOW DEEPENS AND RAPIDLY LIFTS NORTH TOWARD THE GREAT LAKES BY 12Z
WED.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
AS OF 300 PM EST SATURDAY...

UPPER TROUGH OVER THE MISSISSIPPI VALLEY WILL EJECT A NEGATIVELY
TILTED THROUGH THE SOUTHEAST U. S. WEDNESDAY. SFC LOW PRESSURE NEAR
CINCINNATI WITH TRAILING COLD FRONT WILL LIFT NORTHEAST INTO THE
GREAT LAKES BY WEDNESDAY EVENING AND INTO EASTERN CANADA BY
WEDNESDAY NIGHT. A STRONG COLD FRONT WILL MOVE EAST ACROSS OUR
REGION WEDNESDAY INTO WEDNESDAY NIGHT. THERE IS THE POTENTIAL FOR
OUR REGION TO HAVE ACTIVE WEATHER WEDNESDAY WITH PLENTY OF
SHOWERS...PERHAPS VERY GUSTY WINDS AND A FEW THUNDERSTORMS. HOWEVER
THE BEST INSTABILITY AS SEEN IN THE LI FIELDS REMAINS SOUTH AND EAST
OF OUR AREA.  THE DAY 5 CONVECTIVE OUTLOOK FROM SPC HAS PLACED THE
STRONG TO SEVERE THUNDERSTORMS POTENTIAL FURTHER SOUTH ALONG EASTERN
CAROLINA TO FLORIDA. HIGHS ON WEDNESDAY WILL RANGE THE MID 40S IN
THE WEST TO THE MID AND UPPER 50S IN THE EAST. 850MB TEMPERATURES
ARE STILL INDICATING THE COLD AIR PUSHES IN QUICKLY IN WAKE OF THE
COLD FRONT. RAIN AND SNOW SHOWERS WILL CHANGEOVER TO SNOW SHOWERS
AND SNOW FLURRIES IN THE WEST WEDNESDAY NIGHT. SOME LIGHT SNOW
ACCUMULATIONS MAY BE POSSIBLE CHRISTMAS EVE NIGHT IN THE WESTERN
UPSLOPE FAVORED LOCATIONS. BUT A WARM GROUND AND SHARP RICH MOISTURE
CUTOFF MAY HINDER SNOW ACCUMULATIONS. LOW TEMPERATURES WEDNESDAY
NIGHT WILL DROP INTO THE LOWER TO MID 20S IN THE MOUNTAINS TO THE
LOWER 30S IN THE PIEDMONT.

WEST TO NORTHWEST UPPER FLOW WILL CONTINUE INTO THURSDAY WITH
MOUNTAIN RAIN AND SNOW SHOWERS. HIGHS CHRISTMAS DAY WILL VARY FROM
AROUND 30 DEGREES IN THE NORTHWEST MOUNTAINS TO AROUND 50 DEGREES IN
PIEDMONT. WINDS WILL BE QUITE STRONG ON THURSDAY AS A 50 TO 55 KNOT
850MB JET PIVOTS ACROSS THE REGION. AT THIS TIME...LOOKS LIKE VALUES
SHOULD REMAIN BELOW WIND ADVISORY LEVELS. AS HIGH PRESSURE SLIDES
OFF THE COAST...DRY WEATHER IS EXPECTED CHRISTMAS NIGHT/THURSDAY
NIGHT WITH LOW TEMPERATURES GENERALLY IN THE UPPER 20S AND LOWER
30S.

THE UPPER FLOW SHIFTS TO THE SOUTHWEST FRIDAY INTO FRIDAY NIGHT AS
TROF CURVES OUT IN THE CENTRAL US WITH SFC LOW PRESSURE DEVELOPING
OVER THE MIDWEST WITH A FRONTAL BOUNDARY TRAILING SOUTH. HIGHS ON
FRIDAY WILL VARY FROM THE LOWER 40S IN THE MOUNTAINS TO THE MID 50S
IN THE PIEDMONT. MOISTURE SLOWLY RETURN FRIDAY NIGHT INTO SATURDAY
AS FRONTAL BOUNDARY APPROACHES. LOWS FRIDAY NIGHT DROP INTO THE
LOWER AND MID 30S IN MOST LOCATIONS. A COLD FRONT MOVES ACROSS OUR
REGION SATURDAY INTO SATURDAY NIGHT.

&&

.AVIATION /04Z SUNDAY THROUGH THURSDAY/...
AS OF 1100 PM EST SATURDAY...

LOW LEVEL MOISTURE WILL REMAIN IN PLACE OVER THE MID ATLANTIC
OVERNIGHT. MVFR WILL PERSIST AND POTENTIALLY BECOME IFR VCNTY OF
THE MTNS WHERE RIDGES MAY BE OBCSD ATTMS. RESIDUAL BOUNDARY LAYER
MOISTURE MAY ALSO LEAD TO SOME VERY LIGHT PRECIP...MIXED
DRIZZLE/FLURRIES WITH THE POTENTIAL FOR RIME ICING.

CONFIDENCE IS LOWER FOR THE EVENTUAL CLEARING OF FOG AND LOW
CEILINGS ON SUNDAY...AS HIGH PRESSURE REMAINS WEDGED AGAINST THE
EASTERN SIDE OF THE BLUE RIDGE. SOME OF THE GUIDANCE APPEARS TOO
OPTIMISTIC AND DOES NOT ACCOUNT FOR THE REMAINING LAYER OF
MOISTURE NEAR THE SURFACE...AS THEY PORTRAY SKIES CLEARING BY 18Z
AT ALL TAF SITES. ALTHOUGH CONDITIONS SHOULD EVENTUALLY IMPROVE TO
VFR SUNDAY AFTERNOON AT LYH/ROA/DAN...MVFR CEILINGS WERE LEFT AT
BCB/LWB/BLF FOR THIS UPDATE AS IT MAY TAKE UNTIL MID/LATE
AFTERNOON OR AFTER 18Z/1PM FOR THE LOW CLOUDS TO FINALLY SCATTER.

EXTENDED DISCUSSION...

A LOW PRESSURE SYSTEM ALONG THE GULF COAST WILL TRACK NORTHWARD
ALONG THE EAST COAST DURING SUNDAY NIGHT INTO MONDAY...AND BRING
PRIMARILY RAIN AND MVFR/IFR CONDITIONS OVER THE MID ATLANTIC.
HOWEVER...THERE IS A POTENTIAL FOR PATCHY AREAS OF FREEZING RAIN
ACROSS THE ALLEGHANY HIGHLANDS OF VIRGINIA AND SOUTHEAST WEST
VIRGINIA...WHERE TEMPERATURES MAY STRUGGLE TO GET ABOVE FREEZING
DURING EARLY MONDAY MORNING. LWB MAY BE IMPACTED...BUT THERE IS
LOW CONFIDENCE DUE TO THE UNCERTAINTY OF THE THERMAL PROFILE IN
THE MODEL SOUNDINGS.

WARM AIR ADVECTION DURING MONDAY AND TUESDAY SHOULD END THE
THREAT OF FROZEN PRECIPITATION...BUT PERIODS OF RAIN AND MVFR/IFR
CONDITIONS COULD LINGER THROUGHOUT THIS TIME. A STRONG COLD FRONT
WILL APPROACH FROM THE WEST BY TUESDAY NIGHT INTO WEDNESDAY. POOR
FLYING WEATHER DUE TO MORE RAIN SHOWERS SHOULD ACCOMPANY THE
FRONT...AND A STRONG LOW LEVEL JET MAY POSE A LOW LEVEL WIND SHEAR
THREAT. GUSTY NORTHWEST WINDS AND A CONSIDERABLE TEMPERATURE DROP
ARE EXPECTED BEHIND THE COLD FRONT ON WEDNESDAY NIGHT. UPSLOPE
SNOW SHOWERS ARE POSSIBLE ALONG THE WESTERN SLOPES JUST IN TIME
FOR CHRISTMAS DAY...WHILE VFR CONDITIONS SHOULD RETURN TO MOST
LOCATIONS EAST OF THE BLUE RIDGE.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...MBS
NEAR TERM...MBS/PM
SHORT TERM...PC
LONG TERM...KK
AVIATION...PM/PW




000
FXUS61 KRNK 210414
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
1114 PM EST SAT DEC 20 2014

.SYNOPSIS...
HIGH PRESSURE WILL BRING SOME IMPROVEMENT TO OUR WEATHER ON
SUNDAY...BEFORE A WEAK AREA OF LOW PRESSURE MOVING UP THE COAST
BRINGS PRECIPITATION BACK TO OUR FORECAST FOR SUNDAY NIGHT AND
MONDAY. AFTER A BRIEF BREAK ON TUESDAY...A VERY STRONG COLD FRONT
WILL MOVE THROUGH THE REGION ON WEDNESDAY...BRINGING RAIN AND
GUSTY WINDS TO THE AREA FOR CHRISTMAS EVE.

&&

.NEAR TERM /THROUGH SUNDAY NIGHT/...
AS OF 1100 PM EST SATURDAY...

LOW LEVEL MOISTURE REMAINS OVER THE FORECAST AREA WITH SOLID
OVERCAST BEING REPORTED ACROSS THE FCST AREA. RADAR INDICATES SOME
VERY LIGHT PRECIP FALLING OVER THE NEW RIVER VALLEY. SURFACE
REPORTS INDICATE DRIZZLE OR DRIZZLE MIXED WITH A LITTLE BIT OF
LIGHT SNOW...JUST TRACE AMOUNTS. FOR THE OVERNIGHT...LITTLE CHANGE
EXPECTED WITH MOSTLY CLOUDY SKIES. MOISTURE IN THE SOUNDING
PROFILE IS VERY SHALLOW SO ANY PRECIP SHOULD REMAIN LIGHT.

PROSPECTS FOR ANYTHING MORE THAT A TRACE IS 10 PERCENT OR LESS.
UPPER FLOW IS ESSENTIALLY ZONAL OVER US AND THIS IS KEEPING ANY
DECENT ENERGY LOCKED UP TO OUR NORTH AS A SHORT WAVE MOVES THROUGH
THE FLOW OVERNIGHT. HOWEVER...WEDGE ALONG THE EASTERN SEABOARD
WILL BE SHARPENING THROUGHOUT THE WEEKEND WHICH WILL LEAD TO SOME
UPSLOPE ALONG THE EASTERN SLOPES OF THE BLUE RIDGE WITH LIGHT
SOUTHEASTERLY SURFACE WINDS. THIS WILL HELP SQUEEZE OUT SOME
SNIZZLE...DRIZZLE/FLURRIES...TONIGHT. THERE MAY BE SOME FREEZING
FOG AROUND AS MODEL SOUNDINGS SHOW SATURATED CONDITIONS IN THE
BOUNDARY LAYER IN AREAS WHERE TEMPERATURES WILL BE BELOW FREEZING.
DO NOT BELIEVE ANY HEADLINES ARE CALLED FOR SINCE IT LOOKS TO BE A
FACTOR FOR ONLY A VERY SMALL WINDOW OF TIME JUST BEFORE DAYBREAK
BUT WILL MENTION IN THE HWO. MODEST IMPROVEMENT FOR SUNDAY AS
MOISTURE SLOWLY ERODES...BUT WILL REMAIN POOLED ALONG THE
MOUNTAINS.

WE WILL NOT HAVE TO WAIT LONG FOR OUR NEXT BOUT WITH WINTER AS A
WEAK SHORT WAVE MOVES OVER THE AREA SUNDAY NIGHT AND COMBINES WITH
WEAK ISENTROPIC LIFT TO GENERATE LIGHT PRECIPITATION. PTYPE WILL
BE A STRUGGLE WITH THIS SINCE COLD AIR WEDGE WILL HAVE NEAR
SURFACE TEMPS NEAR FREEZING AS TEMPERATURES ALOFT WARM. TOP DOWN
METHODOLOGY CURRENTLY YIELDS MOSTLY LIQUID WITH SLEET AND FREEZING
RAIN MAINLY FOR THE GREENBRIER VALLEY AND ALLEGHANY
HIGHLANDS...WITH ADDITIONAL POCKETS OF MIXED PRECIPITATION
ELSEWHERE. OVERALL QPF LOOKS TO BE RATHER LIGHT SO THIS DOES NOT
LOOK TO BE A VERY SIGNIFICANT EVENT THOUGH IT DOES NOT TAKE MUCH
FREEZING RAIN TO MAKE TRAVEL HAZARDOUS.

&&

.SHORT TERM /MONDAY/...
AS OF 300 PM EST SATURDAY...

COMPLEX FORECAST FOR THE EARLY TO MID-WEEK WITH TWO SYSTEMS TO DEAL
WITH. FIRST WILL BE EARLY MONDAY EVENT WITH A WEAK LOW ALONG THE NC
COAST AT 12Z AND THE FAMILIAR WEDGE BUILDING DOWN THE EASTERN SLOPES
OF THE APPALACHIANS FROM A PARENT 1030-ISH SURFACE HIGH OVER FAR
NORTHERN NEW ENGLAND. NOT A PARTICULARLY STRONG OR EVEN COLD WEDGE
BUT ENOUGH TO BRING AT LEAST SURFACE TEMPS CLOSE TO FREEZING IN SOME
COLDER LOCATIONS WHILE THE 0C H85 LINE IS GENERALLY ALREADY WELL
NORTH OF THE CWA..DEPENDING OF COURSE ON WHICH MODEL. 12Z GFS AND
NAM ARE BOTH ABOVE FREEZING AT H85 FROM 12Z ONWARD. SURFACE LOW
LIFTS NORTHEAST DURING THE DAY TO A POSITION OFF THE VA CAPES BY 00Z
TUE TAKING WHATEVER PRECIP DOES FALL WITH IT OFF TO THE EAST. QPF
FROM THIS EVENT LIKELY TO BE QUITE MODEST...FROM LESS THAN 0.10
INCHES FAR NORTHWEST TO POSSIBLY 0.25 TO 0.50 INCHES FAR EAST.
ALTHOUGH SEVERAL HOURS OF FREEZING RAIN IS POSSIBLE FOR THE COLDER
WESTERN VALLEYS NOT EXPECTING IT TO LAST VERY LONG AND ALL LIQUID
SHOULD FALL EAST OF THE MOUNTAINS AND THEN ALL AREAS TRANSITION TO
RAIN DURING THE DAY. HIGHS MONDAY WILL REMAINS CHILLY IN THE 30S TO
LOW 40S.

THERE WILL BE A BRIEF BREAK IN THE ACTION OVERNIGHT MONDAY
AS THE WEAK ATLANTIC LOW DEPARTS BUT WITH FLOW REMAINING SOUTHWEST
THERE IS BARELY ANY COLD ADVECTION BEHIND IT WHICH SHOULD LEAVE
TEMPS ACTUALLY FAIRLY MILD...GENERALLY ABOVE FREEZING BY TUESDAY
MORNING.  THE FLOW REMAINS SOUTH TO SOUTHWEST THROUGH THE DAY WITH
PLENTY OF AMBIENT MOISTURE AND SEVERAL WEAK BUT HARD TO TIME
DISTURBANCES SO KEPT MAINLY CHANCE POPS BUT QPF AGAIN QUITE
LOW...BELOW 0.05 INCHES WITH POSSIBLY SOME ENHANCEMENT ALONG THE
BLUE RIDGE. PRECIPITATION SHOULD BE ALL RAIN AS HIGHS IN THE 40S
EXPECTED CWA-WIDE AND WEDGE REMOVED FROM THE EQUATION. SOUTHERLY
FLOW AND WARM ADVECTION BECOMES FAIRLY IMPRESSIVE AHEAD OF THE
MUCH STRONGER LOW DEVELOPING OVER THE LOWER MISSISSIPPI VALLEY
MID- TO LATE DAY TUESDAY. POPS AND QPF WILL INCREASE OVERNIGHT
TUESDAY AS AVAILABLE MODELS SHOW A WIDESPREAD PRECIP EVENT WITH
AMOUNTS APPROACHING A HALF-INCH BY EARLY WEDNESDAY AS THE SURFACE
LOW DEEPENS AND RAPIDLY LIFTS NORTH TOWARD THE GREAT LAKES BY 12Z
WED.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
AS OF 300 PM EST SATURDAY...

UPPER TROUGH OVER THE MISSISSIPPI VALLEY WILL EJECT A NEGATIVELY
TILTED THROUGH THE SOUTHEAST U. S. WEDNESDAY. SFC LOW PRESSURE NEAR
CINCINNATI WITH TRAILING COLD FRONT WILL LIFT NORTHEAST INTO THE
GREAT LAKES BY WEDNESDAY EVENING AND INTO EASTERN CANADA BY
WEDNESDAY NIGHT. A STRONG COLD FRONT WILL MOVE EAST ACROSS OUR
REGION WEDNESDAY INTO WEDNESDAY NIGHT. THERE IS THE POTENTIAL FOR
OUR REGION TO HAVE ACTIVE WEATHER WEDNESDAY WITH PLENTY OF
SHOWERS...PERHAPS VERY GUSTY WINDS AND A FEW THUNDERSTORMS. HOWEVER
THE BEST INSTABILITY AS SEEN IN THE LI FIELDS REMAINS SOUTH AND EAST
OF OUR AREA.  THE DAY 5 CONVECTIVE OUTLOOK FROM SPC HAS PLACED THE
STRONG TO SEVERE THUNDERSTORMS POTENTIAL FURTHER SOUTH ALONG EASTERN
CAROLINA TO FLORIDA. HIGHS ON WEDNESDAY WILL RANGE THE MID 40S IN
THE WEST TO THE MID AND UPPER 50S IN THE EAST. 850MB TEMPERATURES
ARE STILL INDICATING THE COLD AIR PUSHES IN QUICKLY IN WAKE OF THE
COLD FRONT. RAIN AND SNOW SHOWERS WILL CHANGEOVER TO SNOW SHOWERS
AND SNOW FLURRIES IN THE WEST WEDNESDAY NIGHT. SOME LIGHT SNOW
ACCUMULATIONS MAY BE POSSIBLE CHRISTMAS EVE NIGHT IN THE WESTERN
UPSLOPE FAVORED LOCATIONS. BUT A WARM GROUND AND SHARP RICH MOISTURE
CUTOFF MAY HINDER SNOW ACCUMULATIONS. LOW TEMPERATURES WEDNESDAY
NIGHT WILL DROP INTO THE LOWER TO MID 20S IN THE MOUNTAINS TO THE
LOWER 30S IN THE PIEDMONT.

WEST TO NORTHWEST UPPER FLOW WILL CONTINUE INTO THURSDAY WITH
MOUNTAIN RAIN AND SNOW SHOWERS. HIGHS CHRISTMAS DAY WILL VARY FROM
AROUND 30 DEGREES IN THE NORTHWEST MOUNTAINS TO AROUND 50 DEGREES IN
PIEDMONT. WINDS WILL BE QUITE STRONG ON THURSDAY AS A 50 TO 55 KNOT
850MB JET PIVOTS ACROSS THE REGION. AT THIS TIME...LOOKS LIKE VALUES
SHOULD REMAIN BELOW WIND ADVISORY LEVELS. AS HIGH PRESSURE SLIDES
OFF THE COAST...DRY WEATHER IS EXPECTED CHRISTMAS NIGHT/THURSDAY
NIGHT WITH LOW TEMPERATURES GENERALLY IN THE UPPER 20S AND LOWER
30S.

THE UPPER FLOW SHIFTS TO THE SOUTHWEST FRIDAY INTO FRIDAY NIGHT AS
TROF CURVES OUT IN THE CENTRAL US WITH SFC LOW PRESSURE DEVELOPING
OVER THE MIDWEST WITH A FRONTAL BOUNDARY TRAILING SOUTH. HIGHS ON
FRIDAY WILL VARY FROM THE LOWER 40S IN THE MOUNTAINS TO THE MID 50S
IN THE PIEDMONT. MOISTURE SLOWLY RETURN FRIDAY NIGHT INTO SATURDAY
AS FRONTAL BOUNDARY APPROACHES. LOWS FRIDAY NIGHT DROP INTO THE
LOWER AND MID 30S IN MOST LOCATIONS. A COLD FRONT MOVES ACROSS OUR
REGION SATURDAY INTO SATURDAY NIGHT.

&&

.AVIATION /04Z SUNDAY THROUGH THURSDAY/...
AS OF 1100 PM EST SATURDAY...

LOW LEVEL MOISTURE WILL REMAIN IN PLACE OVER THE MID ATLANTIC
OVERNIGHT. MVFR WILL PERSIST AND POTENTIALLY BECOME IFR VCNTY OF
THE MTNS WHERE RIDGES MAY BE OBCSD ATTMS. RESIDUAL BOUNDARY LAYER
MOISTURE MAY ALSO LEAD TO SOME VERY LIGHT PRECIP...MIXED
DRIZZLE/FLURRIES WITH THE POTENTIAL FOR RIME ICING.

CONFIDENCE IS LOWER FOR THE EVENTUAL CLEARING OF FOG AND LOW
CEILINGS ON SUNDAY...AS HIGH PRESSURE REMAINS WEDGED AGAINST THE
EASTERN SIDE OF THE BLUE RIDGE. SOME OF THE GUIDANCE APPEARS TOO
OPTIMISTIC AND DOES NOT ACCOUNT FOR THE REMAINING LAYER OF
MOISTURE NEAR THE SURFACE...AS THEY PORTRAY SKIES CLEARING BY 18Z
AT ALL TAF SITES. ALTHOUGH CONDITIONS SHOULD EVENTUALLY IMPROVE TO
VFR SUNDAY AFTERNOON AT LYH/ROA/DAN...MVFR CEILINGS WERE LEFT AT
BCB/LWB/BLF FOR THIS UPDATE AS IT MAY TAKE UNTIL MID/LATE
AFTERNOON OR AFTER 18Z/1PM FOR THE LOW CLOUDS TO FINALLY SCATTER.

EXTENDED DISCUSSION...

A LOW PRESSURE SYSTEM ALONG THE GULF COAST WILL TRACK NORTHWARD
ALONG THE EAST COAST DURING SUNDAY NIGHT INTO MONDAY...AND BRING
PRIMARILY RAIN AND MVFR/IFR CONDITIONS OVER THE MID ATLANTIC.
HOWEVER...THERE IS A POTENTIAL FOR PATCHY AREAS OF FREEZING RAIN
ACROSS THE ALLEGHANY HIGHLANDS OF VIRGINIA AND SOUTHEAST WEST
VIRGINIA...WHERE TEMPERATURES MAY STRUGGLE TO GET ABOVE FREEZING
DURING EARLY MONDAY MORNING. LWB MAY BE IMPACTED...BUT THERE IS
LOW CONFIDENCE DUE TO THE UNCERTAINTY OF THE THERMAL PROFILE IN
THE MODEL SOUNDINGS.

WARM AIR ADVECTION DURING MONDAY AND TUESDAY SHOULD END THE
THREAT OF FROZEN PRECIPITATION...BUT PERIODS OF RAIN AND MVFR/IFR
CONDITIONS COULD LINGER THROUGHOUT THIS TIME. A STRONG COLD FRONT
WILL APPROACH FROM THE WEST BY TUESDAY NIGHT INTO WEDNESDAY. POOR
FLYING WEATHER DUE TO MORE RAIN SHOWERS SHOULD ACCOMPANY THE
FRONT...AND A STRONG LOW LEVEL JET MAY POSE A LOW LEVEL WIND SHEAR
THREAT. GUSTY NORTHWEST WINDS AND A CONSIDERABLE TEMPERATURE DROP
ARE EXPECTED BEHIND THE COLD FRONT ON WEDNESDAY NIGHT. UPSLOPE
SNOW SHOWERS ARE POSSIBLE ALONG THE WESTERN SLOPES JUST IN TIME
FOR CHRISTMAS DAY...WHILE VFR CONDITIONS SHOULD RETURN TO MOST
LOCATIONS EAST OF THE BLUE RIDGE.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...MBS
NEAR TERM...MBS/PM
SHORT TERM...PC
LONG TERM...KK
AVIATION...PM/PW





000
FXUS61 KRNK 210414
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
1114 PM EST SAT DEC 20 2014

.SYNOPSIS...
HIGH PRESSURE WILL BRING SOME IMPROVEMENT TO OUR WEATHER ON
SUNDAY...BEFORE A WEAK AREA OF LOW PRESSURE MOVING UP THE COAST
BRINGS PRECIPITATION BACK TO OUR FORECAST FOR SUNDAY NIGHT AND
MONDAY. AFTER A BRIEF BREAK ON TUESDAY...A VERY STRONG COLD FRONT
WILL MOVE THROUGH THE REGION ON WEDNESDAY...BRINGING RAIN AND
GUSTY WINDS TO THE AREA FOR CHRISTMAS EVE.

&&

.NEAR TERM /THROUGH SUNDAY NIGHT/...
AS OF 1100 PM EST SATURDAY...

LOW LEVEL MOISTURE REMAINS OVER THE FORECAST AREA WITH SOLID
OVERCAST BEING REPORTED ACROSS THE FCST AREA. RADAR INDICATES SOME
VERY LIGHT PRECIP FALLING OVER THE NEW RIVER VALLEY. SURFACE
REPORTS INDICATE DRIZZLE OR DRIZZLE MIXED WITH A LITTLE BIT OF
LIGHT SNOW...JUST TRACE AMOUNTS. FOR THE OVERNIGHT...LITTLE CHANGE
EXPECTED WITH MOSTLY CLOUDY SKIES. MOISTURE IN THE SOUNDING
PROFILE IS VERY SHALLOW SO ANY PRECIP SHOULD REMAIN LIGHT.

PROSPECTS FOR ANYTHING MORE THAT A TRACE IS 10 PERCENT OR LESS.
UPPER FLOW IS ESSENTIALLY ZONAL OVER US AND THIS IS KEEPING ANY
DECENT ENERGY LOCKED UP TO OUR NORTH AS A SHORT WAVE MOVES THROUGH
THE FLOW OVERNIGHT. HOWEVER...WEDGE ALONG THE EASTERN SEABOARD
WILL BE SHARPENING THROUGHOUT THE WEEKEND WHICH WILL LEAD TO SOME
UPSLOPE ALONG THE EASTERN SLOPES OF THE BLUE RIDGE WITH LIGHT
SOUTHEASTERLY SURFACE WINDS. THIS WILL HELP SQUEEZE OUT SOME
SNIZZLE...DRIZZLE/FLURRIES...TONIGHT. THERE MAY BE SOME FREEZING
FOG AROUND AS MODEL SOUNDINGS SHOW SATURATED CONDITIONS IN THE
BOUNDARY LAYER IN AREAS WHERE TEMPERATURES WILL BE BELOW FREEZING.
DO NOT BELIEVE ANY HEADLINES ARE CALLED FOR SINCE IT LOOKS TO BE A
FACTOR FOR ONLY A VERY SMALL WINDOW OF TIME JUST BEFORE DAYBREAK
BUT WILL MENTION IN THE HWO. MODEST IMPROVEMENT FOR SUNDAY AS
MOISTURE SLOWLY ERODES...BUT WILL REMAIN POOLED ALONG THE
MOUNTAINS.

WE WILL NOT HAVE TO WAIT LONG FOR OUR NEXT BOUT WITH WINTER AS A
WEAK SHORT WAVE MOVES OVER THE AREA SUNDAY NIGHT AND COMBINES WITH
WEAK ISENTROPIC LIFT TO GENERATE LIGHT PRECIPITATION. PTYPE WILL
BE A STRUGGLE WITH THIS SINCE COLD AIR WEDGE WILL HAVE NEAR
SURFACE TEMPS NEAR FREEZING AS TEMPERATURES ALOFT WARM. TOP DOWN
METHODOLOGY CURRENTLY YIELDS MOSTLY LIQUID WITH SLEET AND FREEZING
RAIN MAINLY FOR THE GREENBRIER VALLEY AND ALLEGHANY
HIGHLANDS...WITH ADDITIONAL POCKETS OF MIXED PRECIPITATION
ELSEWHERE. OVERALL QPF LOOKS TO BE RATHER LIGHT SO THIS DOES NOT
LOOK TO BE A VERY SIGNIFICANT EVENT THOUGH IT DOES NOT TAKE MUCH
FREEZING RAIN TO MAKE TRAVEL HAZARDOUS.

&&

.SHORT TERM /MONDAY/...
AS OF 300 PM EST SATURDAY...

COMPLEX FORECAST FOR THE EARLY TO MID-WEEK WITH TWO SYSTEMS TO DEAL
WITH. FIRST WILL BE EARLY MONDAY EVENT WITH A WEAK LOW ALONG THE NC
COAST AT 12Z AND THE FAMILIAR WEDGE BUILDING DOWN THE EASTERN SLOPES
OF THE APPALACHIANS FROM A PARENT 1030-ISH SURFACE HIGH OVER FAR
NORTHERN NEW ENGLAND. NOT A PARTICULARLY STRONG OR EVEN COLD WEDGE
BUT ENOUGH TO BRING AT LEAST SURFACE TEMPS CLOSE TO FREEZING IN SOME
COLDER LOCATIONS WHILE THE 0C H85 LINE IS GENERALLY ALREADY WELL
NORTH OF THE CWA..DEPENDING OF COURSE ON WHICH MODEL. 12Z GFS AND
NAM ARE BOTH ABOVE FREEZING AT H85 FROM 12Z ONWARD. SURFACE LOW
LIFTS NORTHEAST DURING THE DAY TO A POSITION OFF THE VA CAPES BY 00Z
TUE TAKING WHATEVER PRECIP DOES FALL WITH IT OFF TO THE EAST. QPF
FROM THIS EVENT LIKELY TO BE QUITE MODEST...FROM LESS THAN 0.10
INCHES FAR NORTHWEST TO POSSIBLY 0.25 TO 0.50 INCHES FAR EAST.
ALTHOUGH SEVERAL HOURS OF FREEZING RAIN IS POSSIBLE FOR THE COLDER
WESTERN VALLEYS NOT EXPECTING IT TO LAST VERY LONG AND ALL LIQUID
SHOULD FALL EAST OF THE MOUNTAINS AND THEN ALL AREAS TRANSITION TO
RAIN DURING THE DAY. HIGHS MONDAY WILL REMAINS CHILLY IN THE 30S TO
LOW 40S.

THERE WILL BE A BRIEF BREAK IN THE ACTION OVERNIGHT MONDAY
AS THE WEAK ATLANTIC LOW DEPARTS BUT WITH FLOW REMAINING SOUTHWEST
THERE IS BARELY ANY COLD ADVECTION BEHIND IT WHICH SHOULD LEAVE
TEMPS ACTUALLY FAIRLY MILD...GENERALLY ABOVE FREEZING BY TUESDAY
MORNING.  THE FLOW REMAINS SOUTH TO SOUTHWEST THROUGH THE DAY WITH
PLENTY OF AMBIENT MOISTURE AND SEVERAL WEAK BUT HARD TO TIME
DISTURBANCES SO KEPT MAINLY CHANCE POPS BUT QPF AGAIN QUITE
LOW...BELOW 0.05 INCHES WITH POSSIBLY SOME ENHANCEMENT ALONG THE
BLUE RIDGE. PRECIPITATION SHOULD BE ALL RAIN AS HIGHS IN THE 40S
EXPECTED CWA-WIDE AND WEDGE REMOVED FROM THE EQUATION. SOUTHERLY
FLOW AND WARM ADVECTION BECOMES FAIRLY IMPRESSIVE AHEAD OF THE
MUCH STRONGER LOW DEVELOPING OVER THE LOWER MISSISSIPPI VALLEY
MID- TO LATE DAY TUESDAY. POPS AND QPF WILL INCREASE OVERNIGHT
TUESDAY AS AVAILABLE MODELS SHOW A WIDESPREAD PRECIP EVENT WITH
AMOUNTS APPROACHING A HALF-INCH BY EARLY WEDNESDAY AS THE SURFACE
LOW DEEPENS AND RAPIDLY LIFTS NORTH TOWARD THE GREAT LAKES BY 12Z
WED.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
AS OF 300 PM EST SATURDAY...

UPPER TROUGH OVER THE MISSISSIPPI VALLEY WILL EJECT A NEGATIVELY
TILTED THROUGH THE SOUTHEAST U. S. WEDNESDAY. SFC LOW PRESSURE NEAR
CINCINNATI WITH TRAILING COLD FRONT WILL LIFT NORTHEAST INTO THE
GREAT LAKES BY WEDNESDAY EVENING AND INTO EASTERN CANADA BY
WEDNESDAY NIGHT. A STRONG COLD FRONT WILL MOVE EAST ACROSS OUR
REGION WEDNESDAY INTO WEDNESDAY NIGHT. THERE IS THE POTENTIAL FOR
OUR REGION TO HAVE ACTIVE WEATHER WEDNESDAY WITH PLENTY OF
SHOWERS...PERHAPS VERY GUSTY WINDS AND A FEW THUNDERSTORMS. HOWEVER
THE BEST INSTABILITY AS SEEN IN THE LI FIELDS REMAINS SOUTH AND EAST
OF OUR AREA.  THE DAY 5 CONVECTIVE OUTLOOK FROM SPC HAS PLACED THE
STRONG TO SEVERE THUNDERSTORMS POTENTIAL FURTHER SOUTH ALONG EASTERN
CAROLINA TO FLORIDA. HIGHS ON WEDNESDAY WILL RANGE THE MID 40S IN
THE WEST TO THE MID AND UPPER 50S IN THE EAST. 850MB TEMPERATURES
ARE STILL INDICATING THE COLD AIR PUSHES IN QUICKLY IN WAKE OF THE
COLD FRONT. RAIN AND SNOW SHOWERS WILL CHANGEOVER TO SNOW SHOWERS
AND SNOW FLURRIES IN THE WEST WEDNESDAY NIGHT. SOME LIGHT SNOW
ACCUMULATIONS MAY BE POSSIBLE CHRISTMAS EVE NIGHT IN THE WESTERN
UPSLOPE FAVORED LOCATIONS. BUT A WARM GROUND AND SHARP RICH MOISTURE
CUTOFF MAY HINDER SNOW ACCUMULATIONS. LOW TEMPERATURES WEDNESDAY
NIGHT WILL DROP INTO THE LOWER TO MID 20S IN THE MOUNTAINS TO THE
LOWER 30S IN THE PIEDMONT.

WEST TO NORTHWEST UPPER FLOW WILL CONTINUE INTO THURSDAY WITH
MOUNTAIN RAIN AND SNOW SHOWERS. HIGHS CHRISTMAS DAY WILL VARY FROM
AROUND 30 DEGREES IN THE NORTHWEST MOUNTAINS TO AROUND 50 DEGREES IN
PIEDMONT. WINDS WILL BE QUITE STRONG ON THURSDAY AS A 50 TO 55 KNOT
850MB JET PIVOTS ACROSS THE REGION. AT THIS TIME...LOOKS LIKE VALUES
SHOULD REMAIN BELOW WIND ADVISORY LEVELS. AS HIGH PRESSURE SLIDES
OFF THE COAST...DRY WEATHER IS EXPECTED CHRISTMAS NIGHT/THURSDAY
NIGHT WITH LOW TEMPERATURES GENERALLY IN THE UPPER 20S AND LOWER
30S.

THE UPPER FLOW SHIFTS TO THE SOUTHWEST FRIDAY INTO FRIDAY NIGHT AS
TROF CURVES OUT IN THE CENTRAL US WITH SFC LOW PRESSURE DEVELOPING
OVER THE MIDWEST WITH A FRONTAL BOUNDARY TRAILING SOUTH. HIGHS ON
FRIDAY WILL VARY FROM THE LOWER 40S IN THE MOUNTAINS TO THE MID 50S
IN THE PIEDMONT. MOISTURE SLOWLY RETURN FRIDAY NIGHT INTO SATURDAY
AS FRONTAL BOUNDARY APPROACHES. LOWS FRIDAY NIGHT DROP INTO THE
LOWER AND MID 30S IN MOST LOCATIONS. A COLD FRONT MOVES ACROSS OUR
REGION SATURDAY INTO SATURDAY NIGHT.

&&

.AVIATION /04Z SUNDAY THROUGH THURSDAY/...
AS OF 1100 PM EST SATURDAY...

LOW LEVEL MOISTURE WILL REMAIN IN PLACE OVER THE MID ATLANTIC
OVERNIGHT. MVFR WILL PERSIST AND POTENTIALLY BECOME IFR VCNTY OF
THE MTNS WHERE RIDGES MAY BE OBCSD ATTMS. RESIDUAL BOUNDARY LAYER
MOISTURE MAY ALSO LEAD TO SOME VERY LIGHT PRECIP...MIXED
DRIZZLE/FLURRIES WITH THE POTENTIAL FOR RIME ICING.

CONFIDENCE IS LOWER FOR THE EVENTUAL CLEARING OF FOG AND LOW
CEILINGS ON SUNDAY...AS HIGH PRESSURE REMAINS WEDGED AGAINST THE
EASTERN SIDE OF THE BLUE RIDGE. SOME OF THE GUIDANCE APPEARS TOO
OPTIMISTIC AND DOES NOT ACCOUNT FOR THE REMAINING LAYER OF
MOISTURE NEAR THE SURFACE...AS THEY PORTRAY SKIES CLEARING BY 18Z
AT ALL TAF SITES. ALTHOUGH CONDITIONS SHOULD EVENTUALLY IMPROVE TO
VFR SUNDAY AFTERNOON AT LYH/ROA/DAN...MVFR CEILINGS WERE LEFT AT
BCB/LWB/BLF FOR THIS UPDATE AS IT MAY TAKE UNTIL MID/LATE
AFTERNOON OR AFTER 18Z/1PM FOR THE LOW CLOUDS TO FINALLY SCATTER.

EXTENDED DISCUSSION...

A LOW PRESSURE SYSTEM ALONG THE GULF COAST WILL TRACK NORTHWARD
ALONG THE EAST COAST DURING SUNDAY NIGHT INTO MONDAY...AND BRING
PRIMARILY RAIN AND MVFR/IFR CONDITIONS OVER THE MID ATLANTIC.
HOWEVER...THERE IS A POTENTIAL FOR PATCHY AREAS OF FREEZING RAIN
ACROSS THE ALLEGHANY HIGHLANDS OF VIRGINIA AND SOUTHEAST WEST
VIRGINIA...WHERE TEMPERATURES MAY STRUGGLE TO GET ABOVE FREEZING
DURING EARLY MONDAY MORNING. LWB MAY BE IMPACTED...BUT THERE IS
LOW CONFIDENCE DUE TO THE UNCERTAINTY OF THE THERMAL PROFILE IN
THE MODEL SOUNDINGS.

WARM AIR ADVECTION DURING MONDAY AND TUESDAY SHOULD END THE
THREAT OF FROZEN PRECIPITATION...BUT PERIODS OF RAIN AND MVFR/IFR
CONDITIONS COULD LINGER THROUGHOUT THIS TIME. A STRONG COLD FRONT
WILL APPROACH FROM THE WEST BY TUESDAY NIGHT INTO WEDNESDAY. POOR
FLYING WEATHER DUE TO MORE RAIN SHOWERS SHOULD ACCOMPANY THE
FRONT...AND A STRONG LOW LEVEL JET MAY POSE A LOW LEVEL WIND SHEAR
THREAT. GUSTY NORTHWEST WINDS AND A CONSIDERABLE TEMPERATURE DROP
ARE EXPECTED BEHIND THE COLD FRONT ON WEDNESDAY NIGHT. UPSLOPE
SNOW SHOWERS ARE POSSIBLE ALONG THE WESTERN SLOPES JUST IN TIME
FOR CHRISTMAS DAY...WHILE VFR CONDITIONS SHOULD RETURN TO MOST
LOCATIONS EAST OF THE BLUE RIDGE.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...MBS
NEAR TERM...MBS/PM
SHORT TERM...PC
LONG TERM...KK
AVIATION...PM/PW




000
FXUS61 KRNK 210414
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
1114 PM EST SAT DEC 20 2014

.SYNOPSIS...
HIGH PRESSURE WILL BRING SOME IMPROVEMENT TO OUR WEATHER ON
SUNDAY...BEFORE A WEAK AREA OF LOW PRESSURE MOVING UP THE COAST
BRINGS PRECIPITATION BACK TO OUR FORECAST FOR SUNDAY NIGHT AND
MONDAY. AFTER A BRIEF BREAK ON TUESDAY...A VERY STRONG COLD FRONT
WILL MOVE THROUGH THE REGION ON WEDNESDAY...BRINGING RAIN AND
GUSTY WINDS TO THE AREA FOR CHRISTMAS EVE.

&&

.NEAR TERM /THROUGH SUNDAY NIGHT/...
AS OF 1100 PM EST SATURDAY...

LOW LEVEL MOISTURE REMAINS OVER THE FORECAST AREA WITH SOLID
OVERCAST BEING REPORTED ACROSS THE FCST AREA. RADAR INDICATES SOME
VERY LIGHT PRECIP FALLING OVER THE NEW RIVER VALLEY. SURFACE
REPORTS INDICATE DRIZZLE OR DRIZZLE MIXED WITH A LITTLE BIT OF
LIGHT SNOW...JUST TRACE AMOUNTS. FOR THE OVERNIGHT...LITTLE CHANGE
EXPECTED WITH MOSTLY CLOUDY SKIES. MOISTURE IN THE SOUNDING
PROFILE IS VERY SHALLOW SO ANY PRECIP SHOULD REMAIN LIGHT.

PROSPECTS FOR ANYTHING MORE THAT A TRACE IS 10 PERCENT OR LESS.
UPPER FLOW IS ESSENTIALLY ZONAL OVER US AND THIS IS KEEPING ANY
DECENT ENERGY LOCKED UP TO OUR NORTH AS A SHORT WAVE MOVES THROUGH
THE FLOW OVERNIGHT. HOWEVER...WEDGE ALONG THE EASTERN SEABOARD
WILL BE SHARPENING THROUGHOUT THE WEEKEND WHICH WILL LEAD TO SOME
UPSLOPE ALONG THE EASTERN SLOPES OF THE BLUE RIDGE WITH LIGHT
SOUTHEASTERLY SURFACE WINDS. THIS WILL HELP SQUEEZE OUT SOME
SNIZZLE...DRIZZLE/FLURRIES...TONIGHT. THERE MAY BE SOME FREEZING
FOG AROUND AS MODEL SOUNDINGS SHOW SATURATED CONDITIONS IN THE
BOUNDARY LAYER IN AREAS WHERE TEMPERATURES WILL BE BELOW FREEZING.
DO NOT BELIEVE ANY HEADLINES ARE CALLED FOR SINCE IT LOOKS TO BE A
FACTOR FOR ONLY A VERY SMALL WINDOW OF TIME JUST BEFORE DAYBREAK
BUT WILL MENTION IN THE HWO. MODEST IMPROVEMENT FOR SUNDAY AS
MOISTURE SLOWLY ERODES...BUT WILL REMAIN POOLED ALONG THE
MOUNTAINS.

WE WILL NOT HAVE TO WAIT LONG FOR OUR NEXT BOUT WITH WINTER AS A
WEAK SHORT WAVE MOVES OVER THE AREA SUNDAY NIGHT AND COMBINES WITH
WEAK ISENTROPIC LIFT TO GENERATE LIGHT PRECIPITATION. PTYPE WILL
BE A STRUGGLE WITH THIS SINCE COLD AIR WEDGE WILL HAVE NEAR
SURFACE TEMPS NEAR FREEZING AS TEMPERATURES ALOFT WARM. TOP DOWN
METHODOLOGY CURRENTLY YIELDS MOSTLY LIQUID WITH SLEET AND FREEZING
RAIN MAINLY FOR THE GREENBRIER VALLEY AND ALLEGHANY
HIGHLANDS...WITH ADDITIONAL POCKETS OF MIXED PRECIPITATION
ELSEWHERE. OVERALL QPF LOOKS TO BE RATHER LIGHT SO THIS DOES NOT
LOOK TO BE A VERY SIGNIFICANT EVENT THOUGH IT DOES NOT TAKE MUCH
FREEZING RAIN TO MAKE TRAVEL HAZARDOUS.

&&

.SHORT TERM /MONDAY/...
AS OF 300 PM EST SATURDAY...

COMPLEX FORECAST FOR THE EARLY TO MID-WEEK WITH TWO SYSTEMS TO DEAL
WITH. FIRST WILL BE EARLY MONDAY EVENT WITH A WEAK LOW ALONG THE NC
COAST AT 12Z AND THE FAMILIAR WEDGE BUILDING DOWN THE EASTERN SLOPES
OF THE APPALACHIANS FROM A PARENT 1030-ISH SURFACE HIGH OVER FAR
NORTHERN NEW ENGLAND. NOT A PARTICULARLY STRONG OR EVEN COLD WEDGE
BUT ENOUGH TO BRING AT LEAST SURFACE TEMPS CLOSE TO FREEZING IN SOME
COLDER LOCATIONS WHILE THE 0C H85 LINE IS GENERALLY ALREADY WELL
NORTH OF THE CWA..DEPENDING OF COURSE ON WHICH MODEL. 12Z GFS AND
NAM ARE BOTH ABOVE FREEZING AT H85 FROM 12Z ONWARD. SURFACE LOW
LIFTS NORTHEAST DURING THE DAY TO A POSITION OFF THE VA CAPES BY 00Z
TUE TAKING WHATEVER PRECIP DOES FALL WITH IT OFF TO THE EAST. QPF
FROM THIS EVENT LIKELY TO BE QUITE MODEST...FROM LESS THAN 0.10
INCHES FAR NORTHWEST TO POSSIBLY 0.25 TO 0.50 INCHES FAR EAST.
ALTHOUGH SEVERAL HOURS OF FREEZING RAIN IS POSSIBLE FOR THE COLDER
WESTERN VALLEYS NOT EXPECTING IT TO LAST VERY LONG AND ALL LIQUID
SHOULD FALL EAST OF THE MOUNTAINS AND THEN ALL AREAS TRANSITION TO
RAIN DURING THE DAY. HIGHS MONDAY WILL REMAINS CHILLY IN THE 30S TO
LOW 40S.

THERE WILL BE A BRIEF BREAK IN THE ACTION OVERNIGHT MONDAY
AS THE WEAK ATLANTIC LOW DEPARTS BUT WITH FLOW REMAINING SOUTHWEST
THERE IS BARELY ANY COLD ADVECTION BEHIND IT WHICH SHOULD LEAVE
TEMPS ACTUALLY FAIRLY MILD...GENERALLY ABOVE FREEZING BY TUESDAY
MORNING.  THE FLOW REMAINS SOUTH TO SOUTHWEST THROUGH THE DAY WITH
PLENTY OF AMBIENT MOISTURE AND SEVERAL WEAK BUT HARD TO TIME
DISTURBANCES SO KEPT MAINLY CHANCE POPS BUT QPF AGAIN QUITE
LOW...BELOW 0.05 INCHES WITH POSSIBLY SOME ENHANCEMENT ALONG THE
BLUE RIDGE. PRECIPITATION SHOULD BE ALL RAIN AS HIGHS IN THE 40S
EXPECTED CWA-WIDE AND WEDGE REMOVED FROM THE EQUATION. SOUTHERLY
FLOW AND WARM ADVECTION BECOMES FAIRLY IMPRESSIVE AHEAD OF THE
MUCH STRONGER LOW DEVELOPING OVER THE LOWER MISSISSIPPI VALLEY
MID- TO LATE DAY TUESDAY. POPS AND QPF WILL INCREASE OVERNIGHT
TUESDAY AS AVAILABLE MODELS SHOW A WIDESPREAD PRECIP EVENT WITH
AMOUNTS APPROACHING A HALF-INCH BY EARLY WEDNESDAY AS THE SURFACE
LOW DEEPENS AND RAPIDLY LIFTS NORTH TOWARD THE GREAT LAKES BY 12Z
WED.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
AS OF 300 PM EST SATURDAY...

UPPER TROUGH OVER THE MISSISSIPPI VALLEY WILL EJECT A NEGATIVELY
TILTED THROUGH THE SOUTHEAST U. S. WEDNESDAY. SFC LOW PRESSURE NEAR
CINCINNATI WITH TRAILING COLD FRONT WILL LIFT NORTHEAST INTO THE
GREAT LAKES BY WEDNESDAY EVENING AND INTO EASTERN CANADA BY
WEDNESDAY NIGHT. A STRONG COLD FRONT WILL MOVE EAST ACROSS OUR
REGION WEDNESDAY INTO WEDNESDAY NIGHT. THERE IS THE POTENTIAL FOR
OUR REGION TO HAVE ACTIVE WEATHER WEDNESDAY WITH PLENTY OF
SHOWERS...PERHAPS VERY GUSTY WINDS AND A FEW THUNDERSTORMS. HOWEVER
THE BEST INSTABILITY AS SEEN IN THE LI FIELDS REMAINS SOUTH AND EAST
OF OUR AREA.  THE DAY 5 CONVECTIVE OUTLOOK FROM SPC HAS PLACED THE
STRONG TO SEVERE THUNDERSTORMS POTENTIAL FURTHER SOUTH ALONG EASTERN
CAROLINA TO FLORIDA. HIGHS ON WEDNESDAY WILL RANGE THE MID 40S IN
THE WEST TO THE MID AND UPPER 50S IN THE EAST. 850MB TEMPERATURES
ARE STILL INDICATING THE COLD AIR PUSHES IN QUICKLY IN WAKE OF THE
COLD FRONT. RAIN AND SNOW SHOWERS WILL CHANGEOVER TO SNOW SHOWERS
AND SNOW FLURRIES IN THE WEST WEDNESDAY NIGHT. SOME LIGHT SNOW
ACCUMULATIONS MAY BE POSSIBLE CHRISTMAS EVE NIGHT IN THE WESTERN
UPSLOPE FAVORED LOCATIONS. BUT A WARM GROUND AND SHARP RICH MOISTURE
CUTOFF MAY HINDER SNOW ACCUMULATIONS. LOW TEMPERATURES WEDNESDAY
NIGHT WILL DROP INTO THE LOWER TO MID 20S IN THE MOUNTAINS TO THE
LOWER 30S IN THE PIEDMONT.

WEST TO NORTHWEST UPPER FLOW WILL CONTINUE INTO THURSDAY WITH
MOUNTAIN RAIN AND SNOW SHOWERS. HIGHS CHRISTMAS DAY WILL VARY FROM
AROUND 30 DEGREES IN THE NORTHWEST MOUNTAINS TO AROUND 50 DEGREES IN
PIEDMONT. WINDS WILL BE QUITE STRONG ON THURSDAY AS A 50 TO 55 KNOT
850MB JET PIVOTS ACROSS THE REGION. AT THIS TIME...LOOKS LIKE VALUES
SHOULD REMAIN BELOW WIND ADVISORY LEVELS. AS HIGH PRESSURE SLIDES
OFF THE COAST...DRY WEATHER IS EXPECTED CHRISTMAS NIGHT/THURSDAY
NIGHT WITH LOW TEMPERATURES GENERALLY IN THE UPPER 20S AND LOWER
30S.

THE UPPER FLOW SHIFTS TO THE SOUTHWEST FRIDAY INTO FRIDAY NIGHT AS
TROF CURVES OUT IN THE CENTRAL US WITH SFC LOW PRESSURE DEVELOPING
OVER THE MIDWEST WITH A FRONTAL BOUNDARY TRAILING SOUTH. HIGHS ON
FRIDAY WILL VARY FROM THE LOWER 40S IN THE MOUNTAINS TO THE MID 50S
IN THE PIEDMONT. MOISTURE SLOWLY RETURN FRIDAY NIGHT INTO SATURDAY
AS FRONTAL BOUNDARY APPROACHES. LOWS FRIDAY NIGHT DROP INTO THE
LOWER AND MID 30S IN MOST LOCATIONS. A COLD FRONT MOVES ACROSS OUR
REGION SATURDAY INTO SATURDAY NIGHT.

&&

.AVIATION /04Z SUNDAY THROUGH THURSDAY/...
AS OF 1100 PM EST SATURDAY...

LOW LEVEL MOISTURE WILL REMAIN IN PLACE OVER THE MID ATLANTIC
OVERNIGHT. MVFR WILL PERSIST AND POTENTIALLY BECOME IFR VCNTY OF
THE MTNS WHERE RIDGES MAY BE OBCSD ATTMS. RESIDUAL BOUNDARY LAYER
MOISTURE MAY ALSO LEAD TO SOME VERY LIGHT PRECIP...MIXED
DRIZZLE/FLURRIES WITH THE POTENTIAL FOR RIME ICING.

CONFIDENCE IS LOWER FOR THE EVENTUAL CLEARING OF FOG AND LOW
CEILINGS ON SUNDAY...AS HIGH PRESSURE REMAINS WEDGED AGAINST THE
EASTERN SIDE OF THE BLUE RIDGE. SOME OF THE GUIDANCE APPEARS TOO
OPTIMISTIC AND DOES NOT ACCOUNT FOR THE REMAINING LAYER OF
MOISTURE NEAR THE SURFACE...AS THEY PORTRAY SKIES CLEARING BY 18Z
AT ALL TAF SITES. ALTHOUGH CONDITIONS SHOULD EVENTUALLY IMPROVE TO
VFR SUNDAY AFTERNOON AT LYH/ROA/DAN...MVFR CEILINGS WERE LEFT AT
BCB/LWB/BLF FOR THIS UPDATE AS IT MAY TAKE UNTIL MID/LATE
AFTERNOON OR AFTER 18Z/1PM FOR THE LOW CLOUDS TO FINALLY SCATTER.

EXTENDED DISCUSSION...

A LOW PRESSURE SYSTEM ALONG THE GULF COAST WILL TRACK NORTHWARD
ALONG THE EAST COAST DURING SUNDAY NIGHT INTO MONDAY...AND BRING
PRIMARILY RAIN AND MVFR/IFR CONDITIONS OVER THE MID ATLANTIC.
HOWEVER...THERE IS A POTENTIAL FOR PATCHY AREAS OF FREEZING RAIN
ACROSS THE ALLEGHANY HIGHLANDS OF VIRGINIA AND SOUTHEAST WEST
VIRGINIA...WHERE TEMPERATURES MAY STRUGGLE TO GET ABOVE FREEZING
DURING EARLY MONDAY MORNING. LWB MAY BE IMPACTED...BUT THERE IS
LOW CONFIDENCE DUE TO THE UNCERTAINTY OF THE THERMAL PROFILE IN
THE MODEL SOUNDINGS.

WARM AIR ADVECTION DURING MONDAY AND TUESDAY SHOULD END THE
THREAT OF FROZEN PRECIPITATION...BUT PERIODS OF RAIN AND MVFR/IFR
CONDITIONS COULD LINGER THROUGHOUT THIS TIME. A STRONG COLD FRONT
WILL APPROACH FROM THE WEST BY TUESDAY NIGHT INTO WEDNESDAY. POOR
FLYING WEATHER DUE TO MORE RAIN SHOWERS SHOULD ACCOMPANY THE
FRONT...AND A STRONG LOW LEVEL JET MAY POSE A LOW LEVEL WIND SHEAR
THREAT. GUSTY NORTHWEST WINDS AND A CONSIDERABLE TEMPERATURE DROP
ARE EXPECTED BEHIND THE COLD FRONT ON WEDNESDAY NIGHT. UPSLOPE
SNOW SHOWERS ARE POSSIBLE ALONG THE WESTERN SLOPES JUST IN TIME
FOR CHRISTMAS DAY...WHILE VFR CONDITIONS SHOULD RETURN TO MOST
LOCATIONS EAST OF THE BLUE RIDGE.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...MBS
NEAR TERM...MBS/PM
SHORT TERM...PC
LONG TERM...KK
AVIATION...PM/PW





000
FXUS61 KRNK 210010
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
710 PM EST SAT DEC 20 2014

.SYNOPSIS...
HIGH PRESSURE WILL BRING SOME IMPROVEMENT TO OUR WEATHER ON
SUNDAY...BEFORE A WEAK AREA OF LOW PRESSURE MOVING UP THE COAST
BRINGS PRECIPITATION BACK TO OUR FORECAST FOR SUNDAY NIGHT AND
MONDAY. AFTER A BRIEF BREAK ON TUESDAY...A VERY STRONG COLD FRONT
WILL MOVE THROUGH THE REGION ON WEDNESDAY...BRINGING RAIN AND
GUSTY WINDS TO THE AREA FOR CHRISTMAS EVE.

&&

.NEAR TERM /THROUGH SUNDAY NIGHT/...
AS OF 300 PM EST SATURDAY...

AFTERNOON SATELLITE IMAGES SHOW SOME BREAKS DEVELOPING THE THE
EXTENSIVE CLOUD COVER OVER THE REGION. MORE BREAKS MAY DEVELOP EAST
OF THE BLUE RIDGE INTO THIS EVENING BUT CLOUDS WILL FILL BACK IN AND
EXPECT CLOUDY SKIES TO PREVAIL THROUGH TONIGHT AND INTO SUNDAY
MORNING. UPPER FLOW IS ESSENTIALLY ZONAL OVER US AND THIS IS KEEPING
ANY DECENT ENERGY LOCKED UP TO OUR NORTH AS A SHORT WAVE MOVES
THROUGH THE FLOW OVERNIGHT. HOWEVER...WEDGE ALONG THE EASTERN
SEABOARD WILL BE SHARPENING THROUGHOUT THE WEEKEND WHICH WILL LEAD
TO SOME UPSLOPE ALONG THE EASTERN SLOPES OF THE BLUE RIDGE WITH
LIGHT SOUTHEASTERLY SURFACE WINDS. THIS WILL HELP SQUEEZE OUT SOME
SPRINKLES/FLURRIES TONIGHT. ALSO BELIEVE THERE WILL BE SOME FREEZING
FOG AROUND AS MODEL SOUNDINGS SHOW SATURATED CONDITIONS IN THE
BOUNDARY LAYER IN AREAS WHERE TEMPERATURES WILL BE BELOW FREEZING.
DO NOT BELIEVE ANY HEADLINES ARE CALLED FOR SINCE IT LOOKS TO BE A
FACTOR FOR ONLY A VERY SMALL WINDOW OF TIME JUST BEFORE DAYBREAK BUT
WILL MENTION IN THE HWO. MODEST IMPROVEMENT FOR SUNDAY AS MOISTURE
SLOWLY ERODES...BUT WILL REMAIN POOLED ALONG THE MOUNTAINS.

WE WILL NOT HAVE TO WAIT LONG FOR OUR NEXT BOUT WITH WINTER AS A
WEAK SHORT WAVE MOVES OVER THE AREA SUNDAY NIGHT AND COMBINES WITH
WEAK ISENTROPIC LIFT TO GENERATE LIGHT PRECIPITATION. PTYPE WILL
BE A STRUGGLE WITH THIS SINCE COLD AIR WEDGE WILL HAVE NEAR
SURFACE TEMPS NEAR FREEZING AS TEMPERATURES ALOFT WARM. TOP DOWN
METHODOLOGY CURRENTLY YIELDS MOSTLY LIQUID WITH SLEET AND FREEZING
RAIN MAINLY FOR THE GREENBRIER VALLEY AND ALLEGHANY
HIGHLANDS...WITH ADDITIONAL POCKETS OF MIXED PRECIPITATION
ELSEWHERE. OVERALL QPF LOOKS TO BE RATHER LIGHT SO THIS DOES NOT
LOOK TO BE A VERY SIGNIFICANT EVENT THOUGH IT DOES NOT TAKE MUCH
FREEZING RAIN TO MAKE TRAVEL HAZARDOUS.

&&

.SHORT TERM /MONDAY/...
AS OF 300 PM EST SATURDAY...

COMPLEX FORECAST FOR THE EARLY TO MID-WEEK WITH TWO SYSTEMS TO DEAL
WITH. FIRST WILL BE EARLY MONDAY EVENT WITH A WEAK LOW ALONG THE NC
COAST AT 12Z AND THE FAMILIAR WEDGE BUILDING DOWN THE EASTERN SLOPES
OF THE APPALACHIANS FROM A PARENT 1030-ISH SURFACE HIGH OVER FAR
NORTHERN NEW ENGLAND. NOT A PARTICULARLY STRONG OR EVEN COLD WEDGE
BUT ENOUGH TO BRING AT LEAST SURFACE TEMPS CLOSE TO FREEZING IN SOME
COLDER LOCATIONS WHILE THE 0C H85 LINE IS GENERALLY ALREADY WELL
NORTH OF THE CWA..DEPENDING OF COURSE ON WHICH MODEL. 12Z GFS AND
NAM ARE BOTH ABOVE FREEZING AT H85 FROM 12Z ONWARD. SURFACE LOW
LIFTS NORTHEAST DURING THE DAY TO A POSITION OFF THE VA CAPES BY 00Z
TUE TAKING WHATEVER PRECIP DOES FALL WITH IT OFF TO THE EAST. QPF
FROM THIS EVENT LIKELY TO BE QUITE MODEST...FROM LESS THAN 0.10
INCHES FAR NORTHWEST TO POSSIBLY 0.25 TO 0.50 INCHES FAR EAST.
ALTHOUGH SEVERAL HOURS OF FREEZING RAIN IS POSSIBLE FOR THE COLDER
WESTERN VALLEYS NOT EXPECTING IT TO LAST VERY LONG AND ALL LIQUID
SHOULD FALL EAST OF THE MOUNTAINS AND THEN ALL AREAS TRANSITION TO
RAIN DURING THE DAY. HIGHS MONDAY WILL REMAINS CHILLY IN THE 30S TO
LOW 40S.

THERE WILL BE A BRIEF BREAK IN THE ACTION OVERNIGHT MONDAY
AS THE WEAK ATLANTIC LOW DEPARTS BUT WITH FLOW REMAINING SOUTHWEST
THERE IS BARELY ANY COLD ADVECTION BEHIND IT WHICH SHOULD LEAVE
TEMPS ACTUALLY FAIRLY MILD...GENERALLY ABOVE FREEZING BY TUESDAY
MORNING.  THE FLOW REMAINS SOUTH TO SOUTHWEST THROUGH THE DAY WITH
PLENTY OF AMBIENT MOISTURE AND SEVERAL WEAK BUT HARD TO TIME
DISTURBANCES SO KEPT MAINLY CHANCE POPS BUT QPF AGAIN QUITE
LOW...BELOW 0.05 INCHES WITH POSSIBLY SOME ENHANCEMENT ALONG THE
BLUE RIDGE. PRECIPITATION SHOULD BE ALL RAIN AS HIGHS IN THE 40S
EXPECTED CWA-WIDE AND WEDGE REMOVED FROM THE EQUATION. SOUTHERLY
FLOW AND WARM ADVECTION BECOMES FAIRLY IMPRESSIVE AHEAD OF THE
MUCH STRONGER LOW DEVELOPING OVER THE LOWER MISSISSIPPI VALLEY
MID- TO LATE DAY TUESDAY. POPS AND QPF WILL INCREASE OVERNIGHT
TUESDAY AS AVAILABLE MODELS SHOW A WIDESPREAD PRECIP EVENT WITH
AMOUNTS APPROACHING A HALF-INCH BY EARLY WEDNESDAY AS THE SURFACE
LOW DEEPENS AND RAPIDLY LIFTS NORTH TOWARD THE GREAT LAKES BY 12Z
WED.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
AS OF 300 PM EST SATURDAY...

UPPER TROUGH OVER THE MISSISSIPPI VALLEY WILL EJECT A NEGATIVELY
TILTED THROUGH THE SOUTHEAST U. S. WEDNESDAY. SFC LOW PRESSURE NEAR
CINCINNATI WITH TRAILING COLD FRONT WILL LIFT NORTHEAST INTO THE
GREAT LAKES BY WEDNESDAY EVENING AND INTO EASTERN CANADA BY
WEDNESDAY NIGHT. A STRONG COLD FRONT WILL MOVE EAST ACROSS OUR
REGION WEDNESDAY INTO WEDNESDAY NIGHT. THERE IS THE POTENTIAL FOR
OUR REGION TO HAVE ACTIVE WEATHER WEDNESDAY WITH PLENTY OF
SHOWERS...PERHAPS VERY GUSTY WINDS AND A FEW THUNDERSTORMS. HOWEVER
THE BEST INSTABILITY AS SEEN IN THE LI FIELDS REMAINS SOUTH AND EAST
OF OUR AREA.  THE DAY 5 CONVECTIVE OUTLOOK FROM SPC HAS PLACED THE
STRONG TO SEVERE THUNDERSTORMS POTENTIAL FURTHER SOUTH ALONG EASTERN
CAROLINA TO FLORIDA. HIGHS ON WEDNESDAY WILL RANGE THE MID 40S IN
THE WEST TO THE MID AND UPPER 50S IN THE EAST. 850MB TEMPERATURES
ARE STILL INDICATING THE COLD AIR PUSHES IN QUICKLY IN WAKE OF THE
COLD FRONT. RAIN AND SNOW SHOWERS WILL CHANGEOVER TO SNOW SHOWERS
AND SNOW FLURRIES IN THE WEST WEDNESDAY NIGHT. SOME LIGHT SNOW
ACCUMULATIONS MAY BE POSSIBLE CHRISTMAS EVE NIGHT IN THE WESTERN
UPSLOPE FAVORED LOCATIONS. BUT A WARM GROUND AND SHARP RICH MOISTURE
CUTOFF MAY HINDER SNOW ACCUMULATIONS. LOW TEMPERATURES WEDNESDAY
NIGHT WILL DROP INTO THE LOWER TO MID 20S IN THE MOUNTAINS TO THE
LOWER 30S IN THE PIEDMONT.

WEST TO NORTHWEST UPPER FLOW WILL CONTINUE INTO THURSDAY WITH
MOUNTAIN RAIN AND SNOW SHOWERS. HIGHS CHRISTMAS DAY WILL VARY FROM
AROUND 30 DEGREES IN THE NORTHWEST MOUNTAINS TO AROUND 50 DEGREES IN
PIEDMONT. WINDS WILL BE QUITE STRONG ON THURSDAY AS A 50 TO 55 KNOT
850MB JET PIVOTS ACROSS THE REGION. AT THIS TIME...LOOKS LIKE VALUES
SHOULD REMAIN BELOW WIND ADVISORY LEVELS. AS HIGH PRESSURE SLIDES
OFF THE COAST...DRY WEATHER IS EXPECTED CHRISTMAS NIGHT/THURSDAY
NIGHT WITH LOW TEMPERATURES GENERALLY IN THE UPPER 20S AND LOWER
30S.

THE UPPER FLOW SHIFTS TO THE SOUTHWEST FRIDAY INTO FRIDAY NIGHT AS
TROF CURVES OUT IN THE CENTRAL US WITH SFC LOW PRESSURE DEVELOPING
OVER THE MIDWEST WITH A FRONTAL BOUNDARY TRAILING SOUTH. HIGHS ON
FRIDAY WILL VARY FROM THE LOWER 40S IN THE MOUNTAINS TO THE MID 50S
IN THE PIEDMONT. MOISTURE SLOWLY RETURN FRIDAY NIGHT INTO SATURDAY
AS FRONTAL BOUNDARY APPROACHES. LOWS FRIDAY NIGHT DROP INTO THE
LOWER AND MID 30S IN MOST LOCATIONS. A COLD FRONT MOVES ACROSS OUR
REGION SATURDAY INTO SATURDAY NIGHT.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
AS OF 700 PM EST SATURDAY...

LOW LEVEL MOISTURE WILL REMAIN IN PLACE OVER THE MID ATLANTIC
OVERNIGHT. MVFR WILL PERSIST AND POTENTIALLY BECOME IFR VCNTY OF
THE MTNS WHERE RIDGES MAY BE OBCSD ATTMS. MODEL GUIDANCE HAS
TURNED MORE CONFIDENT IN FOG FORMATION BY EARLY SUNDAY MORNING DUE
TO LIGHT WINDS AND RESIDUAL BOUNDARY LAYER MOISTURE...WITH
IFR AND POTENTIALLY LIFR VISIBILITIES FOR BCB/LWB/BLF...AND MVFR
VISIBILITIES FOR LYH/ROA/DAN. PATCHY FREEZING FOG OR LIGHT RIME
ICING IS ALSO POSSIBLE ACROSS THE MOUNTAINS WHERE TEMPERATURES
WILL FLIRT WITH FREEZING.

CONFIDENCE IS LOWER FOR THE EVENTUAL CLEARING OF FOG AND LOW
CEILINGS ON SUNDAY...AS HIGH PRESSURE REMAINS WEDGED AGAINST THE
EASTERN SIDE OF THE BLUE RIDGE. SOME OF THE GUIDANCE APPEARS TOO
OPTIMISTIC AND DOES NOT ACCOUNT FOR THE REMAINING LAYER OF
MOISTURE NEAR THE SURFACE...AS THEY PORTRAY SKIES CLEARING BY 18Z
AT ALL TAF SITES. ALTHOUGH CONDITIONS SHOULD EVENTUALLY IMPROVE
TO VFR SUNDAY AFTERNOON AT LYH/ROA/DAN...MVFR CEILINGS WERE LEFT
AT BCB/LWB/BLF FOR THIS UPDATE AS IT MAY TAKE UNTIL MID/LATE
AFTERNOON OR AFTER 18Z/1PM FOR THE LOW CLOUDS TO FINALLY SCATTER.

EXTENDED DISCUSSION...

A LOW PRESSURE SYSTEM ALONG THE GULF COAST WILL TRACK NORTHWARD
ALONG THE EAST COAST DURING SUNDAY NIGHT INTO MONDAY...AND BRING
PRIMARILY RAIN AND MVFR/IFR CONDITIONS OVER THE MID ATLANTIC.
HOWEVER...THERE IS A POTENTIAL FOR PATCHY AREAS OF FREEZING RAIN
ACROSS THE ALLEGHANY HIGHLANDS OF VIRGINIA AND SOUTHEAST WEST
VIRGINIA...WHERE TEMPERATURES MAY STRUGGLE TO GET ABOVE FREEZING
DURING EARLY MONDAY MORNING. LWB MAY BE IMPACTED...BUT THERE IS
LOW CONFIDENCE DUE TO THE UNCERTAINTY OF THE THERMAL PROFILE IN
THE MODEL SOUNDINGS.

WARM AIR ADVECTION DURING MONDAY AND TUESDAY SHOULD END THE
THREAT OF FROZEN PRECIPITATION...BUT PERIODS OF RAIN AND MVFR/IFR
CONDITIONS COULD LINGER THROUGHOUT THIS TIME. A STRONG COLD FRONT
WILL APPROACH FROM THE WEST BY TUESDAY NIGHT INTO WEDNESDAY. POOR
FLYING WEATHER DUE TO MORE RAIN SHOWERS SHOULD ACCOMPANY THE
FRONT...AND A STRONG LOW LEVEL JET MAY POSE A LOW LEVEL WIND SHEAR
THREAT. GUSTY NORTHWEST WINDS AND A CONSIDERABLE TEMPERATURE DROP
ARE EXPECTED BEHIND THE COLD FRONT ON WEDNESDAY NIGHT. UPSLOPE
SNOW SHOWERS ARE POSSIBLE ALONG THE WESTERN SLOPES JUST IN TIME
FOR CHRISTMAS DAY...WHILE VFR CONDITIONS SHOULD RETURN TO MOST
LOCATIONS EAST OF THE BLUE RIDGE.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...MBS
NEAR TERM...MBS
SHORT TERM...PC
LONG TERM...KK
AVIATION...PM/PW




000
FXUS61 KRNK 210010
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
710 PM EST SAT DEC 20 2014

.SYNOPSIS...
HIGH PRESSURE WILL BRING SOME IMPROVEMENT TO OUR WEATHER ON
SUNDAY...BEFORE A WEAK AREA OF LOW PRESSURE MOVING UP THE COAST
BRINGS PRECIPITATION BACK TO OUR FORECAST FOR SUNDAY NIGHT AND
MONDAY. AFTER A BRIEF BREAK ON TUESDAY...A VERY STRONG COLD FRONT
WILL MOVE THROUGH THE REGION ON WEDNESDAY...BRINGING RAIN AND
GUSTY WINDS TO THE AREA FOR CHRISTMAS EVE.

&&

.NEAR TERM /THROUGH SUNDAY NIGHT/...
AS OF 300 PM EST SATURDAY...

AFTERNOON SATELLITE IMAGES SHOW SOME BREAKS DEVELOPING THE THE
EXTENSIVE CLOUD COVER OVER THE REGION. MORE BREAKS MAY DEVELOP EAST
OF THE BLUE RIDGE INTO THIS EVENING BUT CLOUDS WILL FILL BACK IN AND
EXPECT CLOUDY SKIES TO PREVAIL THROUGH TONIGHT AND INTO SUNDAY
MORNING. UPPER FLOW IS ESSENTIALLY ZONAL OVER US AND THIS IS KEEPING
ANY DECENT ENERGY LOCKED UP TO OUR NORTH AS A SHORT WAVE MOVES
THROUGH THE FLOW OVERNIGHT. HOWEVER...WEDGE ALONG THE EASTERN
SEABOARD WILL BE SHARPENING THROUGHOUT THE WEEKEND WHICH WILL LEAD
TO SOME UPSLOPE ALONG THE EASTERN SLOPES OF THE BLUE RIDGE WITH
LIGHT SOUTHEASTERLY SURFACE WINDS. THIS WILL HELP SQUEEZE OUT SOME
SPRINKLES/FLURRIES TONIGHT. ALSO BELIEVE THERE WILL BE SOME FREEZING
FOG AROUND AS MODEL SOUNDINGS SHOW SATURATED CONDITIONS IN THE
BOUNDARY LAYER IN AREAS WHERE TEMPERATURES WILL BE BELOW FREEZING.
DO NOT BELIEVE ANY HEADLINES ARE CALLED FOR SINCE IT LOOKS TO BE A
FACTOR FOR ONLY A VERY SMALL WINDOW OF TIME JUST BEFORE DAYBREAK BUT
WILL MENTION IN THE HWO. MODEST IMPROVEMENT FOR SUNDAY AS MOISTURE
SLOWLY ERODES...BUT WILL REMAIN POOLED ALONG THE MOUNTAINS.

WE WILL NOT HAVE TO WAIT LONG FOR OUR NEXT BOUT WITH WINTER AS A
WEAK SHORT WAVE MOVES OVER THE AREA SUNDAY NIGHT AND COMBINES WITH
WEAK ISENTROPIC LIFT TO GENERATE LIGHT PRECIPITATION. PTYPE WILL
BE A STRUGGLE WITH THIS SINCE COLD AIR WEDGE WILL HAVE NEAR
SURFACE TEMPS NEAR FREEZING AS TEMPERATURES ALOFT WARM. TOP DOWN
METHODOLOGY CURRENTLY YIELDS MOSTLY LIQUID WITH SLEET AND FREEZING
RAIN MAINLY FOR THE GREENBRIER VALLEY AND ALLEGHANY
HIGHLANDS...WITH ADDITIONAL POCKETS OF MIXED PRECIPITATION
ELSEWHERE. OVERALL QPF LOOKS TO BE RATHER LIGHT SO THIS DOES NOT
LOOK TO BE A VERY SIGNIFICANT EVENT THOUGH IT DOES NOT TAKE MUCH
FREEZING RAIN TO MAKE TRAVEL HAZARDOUS.

&&

.SHORT TERM /MONDAY/...
AS OF 300 PM EST SATURDAY...

COMPLEX FORECAST FOR THE EARLY TO MID-WEEK WITH TWO SYSTEMS TO DEAL
WITH. FIRST WILL BE EARLY MONDAY EVENT WITH A WEAK LOW ALONG THE NC
COAST AT 12Z AND THE FAMILIAR WEDGE BUILDING DOWN THE EASTERN SLOPES
OF THE APPALACHIANS FROM A PARENT 1030-ISH SURFACE HIGH OVER FAR
NORTHERN NEW ENGLAND. NOT A PARTICULARLY STRONG OR EVEN COLD WEDGE
BUT ENOUGH TO BRING AT LEAST SURFACE TEMPS CLOSE TO FREEZING IN SOME
COLDER LOCATIONS WHILE THE 0C H85 LINE IS GENERALLY ALREADY WELL
NORTH OF THE CWA..DEPENDING OF COURSE ON WHICH MODEL. 12Z GFS AND
NAM ARE BOTH ABOVE FREEZING AT H85 FROM 12Z ONWARD. SURFACE LOW
LIFTS NORTHEAST DURING THE DAY TO A POSITION OFF THE VA CAPES BY 00Z
TUE TAKING WHATEVER PRECIP DOES FALL WITH IT OFF TO THE EAST. QPF
FROM THIS EVENT LIKELY TO BE QUITE MODEST...FROM LESS THAN 0.10
INCHES FAR NORTHWEST TO POSSIBLY 0.25 TO 0.50 INCHES FAR EAST.
ALTHOUGH SEVERAL HOURS OF FREEZING RAIN IS POSSIBLE FOR THE COLDER
WESTERN VALLEYS NOT EXPECTING IT TO LAST VERY LONG AND ALL LIQUID
SHOULD FALL EAST OF THE MOUNTAINS AND THEN ALL AREAS TRANSITION TO
RAIN DURING THE DAY. HIGHS MONDAY WILL REMAINS CHILLY IN THE 30S TO
LOW 40S.

THERE WILL BE A BRIEF BREAK IN THE ACTION OVERNIGHT MONDAY
AS THE WEAK ATLANTIC LOW DEPARTS BUT WITH FLOW REMAINING SOUTHWEST
THERE IS BARELY ANY COLD ADVECTION BEHIND IT WHICH SHOULD LEAVE
TEMPS ACTUALLY FAIRLY MILD...GENERALLY ABOVE FREEZING BY TUESDAY
MORNING.  THE FLOW REMAINS SOUTH TO SOUTHWEST THROUGH THE DAY WITH
PLENTY OF AMBIENT MOISTURE AND SEVERAL WEAK BUT HARD TO TIME
DISTURBANCES SO KEPT MAINLY CHANCE POPS BUT QPF AGAIN QUITE
LOW...BELOW 0.05 INCHES WITH POSSIBLY SOME ENHANCEMENT ALONG THE
BLUE RIDGE. PRECIPITATION SHOULD BE ALL RAIN AS HIGHS IN THE 40S
EXPECTED CWA-WIDE AND WEDGE REMOVED FROM THE EQUATION. SOUTHERLY
FLOW AND WARM ADVECTION BECOMES FAIRLY IMPRESSIVE AHEAD OF THE
MUCH STRONGER LOW DEVELOPING OVER THE LOWER MISSISSIPPI VALLEY
MID- TO LATE DAY TUESDAY. POPS AND QPF WILL INCREASE OVERNIGHT
TUESDAY AS AVAILABLE MODELS SHOW A WIDESPREAD PRECIP EVENT WITH
AMOUNTS APPROACHING A HALF-INCH BY EARLY WEDNESDAY AS THE SURFACE
LOW DEEPENS AND RAPIDLY LIFTS NORTH TOWARD THE GREAT LAKES BY 12Z
WED.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
AS OF 300 PM EST SATURDAY...

UPPER TROUGH OVER THE MISSISSIPPI VALLEY WILL EJECT A NEGATIVELY
TILTED THROUGH THE SOUTHEAST U. S. WEDNESDAY. SFC LOW PRESSURE NEAR
CINCINNATI WITH TRAILING COLD FRONT WILL LIFT NORTHEAST INTO THE
GREAT LAKES BY WEDNESDAY EVENING AND INTO EASTERN CANADA BY
WEDNESDAY NIGHT. A STRONG COLD FRONT WILL MOVE EAST ACROSS OUR
REGION WEDNESDAY INTO WEDNESDAY NIGHT. THERE IS THE POTENTIAL FOR
OUR REGION TO HAVE ACTIVE WEATHER WEDNESDAY WITH PLENTY OF
SHOWERS...PERHAPS VERY GUSTY WINDS AND A FEW THUNDERSTORMS. HOWEVER
THE BEST INSTABILITY AS SEEN IN THE LI FIELDS REMAINS SOUTH AND EAST
OF OUR AREA.  THE DAY 5 CONVECTIVE OUTLOOK FROM SPC HAS PLACED THE
STRONG TO SEVERE THUNDERSTORMS POTENTIAL FURTHER SOUTH ALONG EASTERN
CAROLINA TO FLORIDA. HIGHS ON WEDNESDAY WILL RANGE THE MID 40S IN
THE WEST TO THE MID AND UPPER 50S IN THE EAST. 850MB TEMPERATURES
ARE STILL INDICATING THE COLD AIR PUSHES IN QUICKLY IN WAKE OF THE
COLD FRONT. RAIN AND SNOW SHOWERS WILL CHANGEOVER TO SNOW SHOWERS
AND SNOW FLURRIES IN THE WEST WEDNESDAY NIGHT. SOME LIGHT SNOW
ACCUMULATIONS MAY BE POSSIBLE CHRISTMAS EVE NIGHT IN THE WESTERN
UPSLOPE FAVORED LOCATIONS. BUT A WARM GROUND AND SHARP RICH MOISTURE
CUTOFF MAY HINDER SNOW ACCUMULATIONS. LOW TEMPERATURES WEDNESDAY
NIGHT WILL DROP INTO THE LOWER TO MID 20S IN THE MOUNTAINS TO THE
LOWER 30S IN THE PIEDMONT.

WEST TO NORTHWEST UPPER FLOW WILL CONTINUE INTO THURSDAY WITH
MOUNTAIN RAIN AND SNOW SHOWERS. HIGHS CHRISTMAS DAY WILL VARY FROM
AROUND 30 DEGREES IN THE NORTHWEST MOUNTAINS TO AROUND 50 DEGREES IN
PIEDMONT. WINDS WILL BE QUITE STRONG ON THURSDAY AS A 50 TO 55 KNOT
850MB JET PIVOTS ACROSS THE REGION. AT THIS TIME...LOOKS LIKE VALUES
SHOULD REMAIN BELOW WIND ADVISORY LEVELS. AS HIGH PRESSURE SLIDES
OFF THE COAST...DRY WEATHER IS EXPECTED CHRISTMAS NIGHT/THURSDAY
NIGHT WITH LOW TEMPERATURES GENERALLY IN THE UPPER 20S AND LOWER
30S.

THE UPPER FLOW SHIFTS TO THE SOUTHWEST FRIDAY INTO FRIDAY NIGHT AS
TROF CURVES OUT IN THE CENTRAL US WITH SFC LOW PRESSURE DEVELOPING
OVER THE MIDWEST WITH A FRONTAL BOUNDARY TRAILING SOUTH. HIGHS ON
FRIDAY WILL VARY FROM THE LOWER 40S IN THE MOUNTAINS TO THE MID 50S
IN THE PIEDMONT. MOISTURE SLOWLY RETURN FRIDAY NIGHT INTO SATURDAY
AS FRONTAL BOUNDARY APPROACHES. LOWS FRIDAY NIGHT DROP INTO THE
LOWER AND MID 30S IN MOST LOCATIONS. A COLD FRONT MOVES ACROSS OUR
REGION SATURDAY INTO SATURDAY NIGHT.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
AS OF 700 PM EST SATURDAY...

LOW LEVEL MOISTURE WILL REMAIN IN PLACE OVER THE MID ATLANTIC
OVERNIGHT. MVFR WILL PERSIST AND POTENTIALLY BECOME IFR VCNTY OF
THE MTNS WHERE RIDGES MAY BE OBCSD ATTMS. MODEL GUIDANCE HAS
TURNED MORE CONFIDENT IN FOG FORMATION BY EARLY SUNDAY MORNING DUE
TO LIGHT WINDS AND RESIDUAL BOUNDARY LAYER MOISTURE...WITH
IFR AND POTENTIALLY LIFR VISIBILITIES FOR BCB/LWB/BLF...AND MVFR
VISIBILITIES FOR LYH/ROA/DAN. PATCHY FREEZING FOG OR LIGHT RIME
ICING IS ALSO POSSIBLE ACROSS THE MOUNTAINS WHERE TEMPERATURES
WILL FLIRT WITH FREEZING.

CONFIDENCE IS LOWER FOR THE EVENTUAL CLEARING OF FOG AND LOW
CEILINGS ON SUNDAY...AS HIGH PRESSURE REMAINS WEDGED AGAINST THE
EASTERN SIDE OF THE BLUE RIDGE. SOME OF THE GUIDANCE APPEARS TOO
OPTIMISTIC AND DOES NOT ACCOUNT FOR THE REMAINING LAYER OF
MOISTURE NEAR THE SURFACE...AS THEY PORTRAY SKIES CLEARING BY 18Z
AT ALL TAF SITES. ALTHOUGH CONDITIONS SHOULD EVENTUALLY IMPROVE
TO VFR SUNDAY AFTERNOON AT LYH/ROA/DAN...MVFR CEILINGS WERE LEFT
AT BCB/LWB/BLF FOR THIS UPDATE AS IT MAY TAKE UNTIL MID/LATE
AFTERNOON OR AFTER 18Z/1PM FOR THE LOW CLOUDS TO FINALLY SCATTER.

EXTENDED DISCUSSION...

A LOW PRESSURE SYSTEM ALONG THE GULF COAST WILL TRACK NORTHWARD
ALONG THE EAST COAST DURING SUNDAY NIGHT INTO MONDAY...AND BRING
PRIMARILY RAIN AND MVFR/IFR CONDITIONS OVER THE MID ATLANTIC.
HOWEVER...THERE IS A POTENTIAL FOR PATCHY AREAS OF FREEZING RAIN
ACROSS THE ALLEGHANY HIGHLANDS OF VIRGINIA AND SOUTHEAST WEST
VIRGINIA...WHERE TEMPERATURES MAY STRUGGLE TO GET ABOVE FREEZING
DURING EARLY MONDAY MORNING. LWB MAY BE IMPACTED...BUT THERE IS
LOW CONFIDENCE DUE TO THE UNCERTAINTY OF THE THERMAL PROFILE IN
THE MODEL SOUNDINGS.

WARM AIR ADVECTION DURING MONDAY AND TUESDAY SHOULD END THE
THREAT OF FROZEN PRECIPITATION...BUT PERIODS OF RAIN AND MVFR/IFR
CONDITIONS COULD LINGER THROUGHOUT THIS TIME. A STRONG COLD FRONT
WILL APPROACH FROM THE WEST BY TUESDAY NIGHT INTO WEDNESDAY. POOR
FLYING WEATHER DUE TO MORE RAIN SHOWERS SHOULD ACCOMPANY THE
FRONT...AND A STRONG LOW LEVEL JET MAY POSE A LOW LEVEL WIND SHEAR
THREAT. GUSTY NORTHWEST WINDS AND A CONSIDERABLE TEMPERATURE DROP
ARE EXPECTED BEHIND THE COLD FRONT ON WEDNESDAY NIGHT. UPSLOPE
SNOW SHOWERS ARE POSSIBLE ALONG THE WESTERN SLOPES JUST IN TIME
FOR CHRISTMAS DAY...WHILE VFR CONDITIONS SHOULD RETURN TO MOST
LOCATIONS EAST OF THE BLUE RIDGE.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...MBS
NEAR TERM...MBS
SHORT TERM...PC
LONG TERM...KK
AVIATION...PM/PW





000
FXUS61 KRNK 202006
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
306 PM EST SAT DEC 20 2014

.SYNOPSIS...
HIGH PRESSURE WILL BRING SOME IMPROVEMENT TO OUR WEATHER ON
SUNDAY...BEFORE A WEAK AREA OF LOW PRESSURE MOVING UP THE COAST
BRINGS PRECIPITATION BACK TO OUR FORECAST FOR SUNDAY NIGHT AND
MONDAY. AFTER A BRIEF BREAK ON TUESDAY...A VERY STRONG COLD FRONT
WILL MOVE THROUGH THE REGION ON WEDNESDAY...BRINGING RAIN AND
GUSTY WINDS TO THE AREA FOR CHRISTMAS EVE.

&&

.NEAR TERM /THROUGH SUNDAY TONIGHT/...
AS OF 300 PM EST SATURDAY...

AFTERNOON SATELLITE IMAGES SHOW SOME BREAKS DEVELOPING THE THE
EXTENSIVE CLOUD COVER OVER THE REGION. MORE BREAKS MAY DEVELOP EAST
OF THE BLUE RIDGE INTO THIS EVENING BUT CLOUDS WILL FILL BACK IN AND
EXPECT CLOUDY SKIES TO PREVAIL THROUGH TONIGHT AND INTO SUNDAY
MORNING. UPPER FLOW IS ESSENTIALLY ZONAL OVER US AND THIS IS KEEPING
ANY DECENT ENERGY LOCKED UP TO OUR NORTH AS A SHORT WAVE MOVES
THROUGH THE FLOW OVERNIGHT. HOWEVER...WEDGE ALONG THE EASTERN
SEABOARD WILL BE SHARPENING THROUGHOUT THE WEEKEND WHICH WILL LEAD
TO SOME UPSLOPE ALONG THE EASTERN SLOPES OF THE BLUE RIDGE WITH
LIGHT SOUTHEASTERLY SURFACE WINDS. THIS WILL HELP SQUEEZE OUT SOME
SPRINKLES/FLURRIES TONIGHT. ALSO BELIEVE THERE WILL BE SOME FREEZING
FOG AROUND AS MODEL SOUNDINGS SHOW SATURATED CONDITIONS IN THE
BOUNDARY LAYER IN AREAS WHERE TEMPERATURES WILL BE BELOW FREEZING.
DO NOT BELIEVE ANY HEADLINES ARE CALLED FOR SINCE IT LOOKS TO BE A
FACTOR FOR ONLY A VERY SMALL WINDOW OF TIME JUST BEFORE DAYBREAK BUT
WILL MENTION IN THE HWO. MODEST IMPROVEMENT FOR SUNDAY AS MOISTURE
SLOWLY ERODES...BUT WILL REMAIN POOLED ALONG THE MOUNTAINS.

WE WILL NOT HAVE TO WAIT LONG FOR OUR NEXT BOUT WITH WINTER AS A
WEAK SHORT WAVE MOVES OVER THE AREA SUNDAY NIGHT AND COMBINES WITH
WEAK ISENTROPIC LIFT TO GENERATE LIGHT PRECIPITATION. PTYPE WILL
BE A STRUGGLE WITH THIS SINCE COLD AIR WEDGE WILL HAVE NEAR
SURFACE TEMPS NEAR FREEZING AS TEMPERATURES ALOFT WARM. TOP DOWN
METHODOLOGY CURRENTLY YIELDS MOSTLY LIQUID WITH SLEET AND FREEZING
RAIN MAINLY FOR THE GREENBRIER VALLEY AND ALLEGHANY
HIGHLANDS...WITH ADDITIONAL POCKETS OF MIXED PRECIPITATION
ELSEWHERE. OVERALL QPF LOOKS TO BE RATHER LIGHT SO THIS DOES NOT
LOOK TO BE A VERY SIGNIFICANT EVENT THOUGH IT DOES NOT TAKE MUCH
FREEZING RAIN TO MAKE TRAVEL HAZARDOUS.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 300 PM EST SATURDAY...

COMPLEX FORECAST FOR THE EARLY TO MID-WEEK WITH TWO SYSTEMS TO DEAL
WITH. FIRST WILL BE EARLY MONDAY EVENT WITH A WEAK LOW ALONG THE NC
COAST AT 12Z AND THE FAMILIAR WEDGE BUILDING DOWN THE EASTERN SLOPES
OF THE APPALACHIANS FROM A PARENT 1030-ISH SURFACE HIGH OVER FAR
NORTHERN NEW ENGLAND. NOT A PARTICULARLY STRONG OR EVEN COLD WEDGE
BUT ENOUGH TO BRING AT LEAST SURFACE TEMPS CLOSE TO FREEZING IN SOME
COLDER LOCATIONS WHILE THE 0C H85 LINE IS GENERALLY ALREADY WELL
NORTH OF THE CWA..DEPENDING OF COURSE ON WHICH MODEL. 12Z GFS AND
NAM ARE BOTH ABOVE FREEZING AT H85 FROM 12Z ONWARD. SURFACE LOW
LIFTS NORTHEAST DURING THE DAY TO A POSITION OFF THE VA CAPES BY 00Z
TUE TAKING WHATEVER PRECIP DOES FALL WITH IT OFF TO THE EAST. QPF
FROM THIS EVENT LIKELY TO BE QUITE MODEST...FROM LESS THAN 0.10
INCHES FAR NORTHWEST TO POSSIBLY 0.25 TO 0.50 INCHES FAR EAST.
ALTHOUGH SEVERAL HOURS OF FREEZING RAIN IS POSSIBLE FOR THE COLDER
WESTERN VALLEYS NOT EXPECTING IT TO LAST VERY LONG AND ALL LIQUID
SHOULD FALL EAST OF THE MOUNTAINS AND THEN ALL AREAS TRANSITION TO
RAIN DURING THE DAY. HIGHS MONDAY WILL REMAINS CHILLY IN THE 30S TO
LOW 40S.

THERE WILL BE A BRIEF BREAK IN THE ACTION OVERNIGHT MONDAY
AS THE WEAK ATLANTIC LOW DEPARTS BUT WITH FLOW REMAINING SOUTHWEST
THERE IS BARELY ANY COLD ADVECTION BEHIND IT WHICH SHOULD LEAVE
TEMPS ACTUALLY FAIRLY MILD...GENERALLY ABOVE FREEZING BY TUESDAY
MORNING.  THE FLOW REMAINS SOUTH TO SOUTHWEST THROUGH THE DAY WITH
PLENTY OF AMBIENT MOISTURE AND SEVERAL WEAK BUT HARD TO TIME
DISTURBANCES SO KEPT MAINLY CHANCE POPS BUT QPF AGAIN QUITE
LOW...BELOW 0.05 INCHES WITH POSSIBLY SOME ENHANCEMENT ALONG THE
BLUE RIDGE. PRECIPITATION SHOULD BE ALL RAIN AS HIGHS IN THE 40S
EXPECTED CWA-WIDE AND WEDGE REMOVED FROM THE EQUATION. SOUTHERLY
FLOW AND WARM ADVECTION BECOMES FAIRLY IMPRESSIVE AHEAD OF THE
MUCH STRONGER LOW DEVELOPING OVER THE LOWER MISSISSIPPI VALLEY
MID- TO LATE DAY TUESDAY. POPS AND QPF WILL INCREASE OVERNIGHT
TUESDAY AS AVAILABLE MODELS SHOW A WIDESPREAD PRECIP EVENT WITH
AMOUNTS APPROACHING A HALF-INCH BY EARLY WEDNESDAY AS THE SURFACE
LOW DEEPENS AND RAPIDLY LIFTS NORTH TOWARD THE GREAT LAKES BY 12Z
WED.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 300 PM EST SATURDAY...

UPPER TROUGH OVER THE MISSISSIPPI VALLEY WILL EJECT A NEGATIVELY
TILTED THROUGH THE SOUTHEAST U. S. WEDNESDAY. SFC LOW PRESSURE NEAR
CINCINNATI WITH TRAILING COLD FRONT WILL LIFT NORTHEAST INTO THE
GREAT LAKES BY WEDNESDAY EVENING AND INTO EASTERN CANADA BY
WEDNESDAY NIGHT. A STRONG COLD FRONT WILL MOVE EAST ACROSS OUR
REGION WEDNESDAY INTO WEDNESDAY NIGHT. THERE IS THE POTENTIAL FOR
OUR REGION TO HAVE ACTIVE WEATHER WEDNESDAY WITH PLENTY OF
SHOWERS...PERHAPS VERY GUSTY WINDS AND A FEW THUNDERSTORMS. HOWEVER
THE BEST INSTABILITY AS SEEN IN THE LI FIELDS REMAINS SOUTH AND EAST
OF OUR AREA.  THE DAY 5 CONVECTIVE OUTLOOK FROM SPC HAS PLACED THE
STRONG TO SEVERE THUNDERSTORMS POTENTIAL FURTHER SOUTH ALONG EASTERN
CAROLINA TO FLORIDA. HIGHS ON WEDNESDAY WILL RANGE THE MID 40S IN
THE WEST TO THE MID AND UPPER 50S IN THE EAST. 850MB TEMPERATURES
ARE STILL INDICATING THE COLD AIR PUSHES IN QUICKLY IN WAKE OF THE
COLD FRONT. RAIN AND SNOW SHOWERS WILL CHANGEOVER TO SNOW SHOWERS
AND SNOW FLURRIES IN THE WEST WEDNESDAY NIGHT. SOME LIGHT SNOW
ACCUMULATIONS MAY BE POSSIBLE CHRISTMAS EVE NIGHT IN THE WESTERN
UPSLOPE FAVORED LOCATIONS. BUT A WARM GROUND AND SHARP RICH MOISTURE
CUTOFF MAY HINDER SNOW ACCUMULATIONS. LOW TEMPERATURES WEDNESDAY
NIGHT WILL DROP INTO THE LOWER TO MID 20S IN THE MOUNTAINS TO THE
LOWER 30S IN THE PIEDMONT.

WEST TO NORTHWEST UPPER FLOW WILL CONTINUE INTO THURSDAY WITH
MOUNTAIN RAIN AND SNOW SHOWERS. HIGHS CHRISTMAS DAY WILL VARY FROM
AROUND 30 DEGREES IN THE NORTHWEST MOUNTAINS TO AROUND 50 DEGREES IN
PIEDMONT. WINDS WILL BE QUITE STRONG ON THURSDAY AS A 50 TO 55 KNOT
850MB JET PIVOTS ACROSS THE REGION. AT THIS TIME...LOOKS LIKE VALUES
SHOULD REMAIN BELOW WIND ADVISORY LEVELS. AS HIGH PRESSURE SLIDES
OFF THE COAST...DRY WEATHER IS EXPECTED CHRISTMAS NIGHT/THURSDAY
NIGHT WITH LOW TEMPERATURES GENERALLY IN THE UPPER 20S AND LOWER
30S.

THE UPPER FLOW SHIFTS TO THE SOUTHWEST FRIDAY INTO FRIDAY NIGHT AS
TROF CURVES OUT IN THE CENTRAL US WITH SFC LOW PRESSURE DEVELOPING
OVER THE MIDWEST WITH A FRONTAL BOUNDARY TRAILING SOUTH. HIGHS ON
FRIDAY WILL VARY FROM THE LOWER 40S IN THE MOUNTAINS TO THE MID 50S
IN THE PIEDMONT. MOISTURE SLOWLY RETURN FRIDAY NIGHT INTO SATURDAY
AS FRONTAL BOUNDARY APPROACHES. LOWS FRIDAY NIGHT DROP INTO THE
LOWER AND MID 30S IN MOST LOCATIONS. A COLD FRONT MOVES ACROSS OUR
REGION SATURDAY INTO SATURDAY NIGHT.

&&

.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
AS OF 1255 PM EST SATURDAY...

A WEAK LOW PRESSURE PASSING TO THE SOUTH WILL DEPART OFF THE EAST
COAST THIS EVENING...BUT LOW LEVEL MOISTURE WILL REMAIN IN PLACE
OVER THE MID ATLANTIC. MVFR CEILINGS SHOULD PERSIST AT BCB/LWB/BLF
BEFORE LIKELY FALLING TO IFR TONIGHT. MEANWHILE...CEILINGS AT
LYH/ROA/DAN SHOULD STAY VFR DURING THE AFTERNOON...BEFORE DIPPING
DOWN TO MVFR TONIGHT. MODEL GUIDANCE HAS TURNED MORE CONFIDENT IN
FOG FORMATION BY EARLY SUNDAY MORNING DUE TO LIGHT WINDS AND
RESIDUAL BOUNDARY LAYER MOISTURE...WITH IFR/LIFR VISIBILITIES FOR
BCB/LWB/BLF...AND MVFR VISIBILITIES FOR LYH/ROA/DAN. PATCHY
FREEZING FOG IS ALSO A POSSIBILITY IN THE MOUNTAINS OVERNIGHT.

CONFIDENCE IS LOWER FOR THE EVENTUAL CLEARING OF FOG AND LOW
CEILINGS ON SUNDAY...AS HIGH PRESSURE REMAINS WEDGED AGAINST THE
EASTERN SIDE OF THE BLUE RIDGE. SOME OF THE GUIDANCE APPEARS TOO
OPTIMISTIC AND DOES NOT ACCOUNT FOR THE REMAINING LAYER OF
MOISTURE NEAR THE SURFACE...AS THEY PORTRAY SKIES CLEARING BY 18Z
AT ALL TAF SITES. ALTHOUGH CONDITIONS SHOULD EVENTUALLY IMPROVE
TO VFR BY MIDDAY SUNDAY AT LYH/ROA/DAN...MVFR CEILINGS WERE LEFT
AT BCB/LWB/BLF FOR THIS UPDATE AS IT MAY TAKE UNTIL AFTER 18Z FOR
THE LOW CLOUDS TO FINALLY SCATTER.

EXTENDED DISCUSSION...

A LOW PRESSURE SYSTEM ALONG THE GULF COAST WILL TRACK NORTHWARD
ALONG THE EAST COAST DURING SUNDAY NIGHT INTO MONDAY...AND BRING
PRIMARILY RAIN AND MVFR/IFR CONDITIONS OVER THE MID ATLANTIC.
HOWEVER...THERE IS A POTENTIAL FOR PATCHY AREAS OF FREEZING RAIN
ACROSS THE ALLEGHANY HIGHLANDS OF VIRGINIA AND SOUTHEAST WEST
VIRGINIA...WHERE TEMPERATURES MAY STRUGGLE TO GET ABOVE FREEZING
DURING EARLY MONDAY MORNING. LWB MAY BE IMPACTED...BUT THERE IS
LOW CONFIDENCE DUE TO THE UNCERTAINTY OF THE THERMAL PROFILE IN
THE MODEL SOUNDINGS.

WARM AIR ADVECTION DURING MONDAY AND TUESDAY SHOULD END THE
THREAT OF FROZEN PRECIPITATION...BUT PERIODS OF RAIN AND MVFR/IFR
CONDITIONS COULD LINGER THROUGHOUT THIS TIME. A STRONG COLD FRONT
WILL APPROACH FROM THE WEST BY TUESDAY NIGHT INTO WEDNESDAY. POOR
FLYING WEATHER DUE TO MORE RAIN SHOWERS SHOULD ACCOMPANY THE
FRONT...AND A STRONG LOW LEVEL JET MAY POSE A LOW LEVEL WIND SHEAR
THREAT. GUSTY NORTHWEST WINDS AND A CONSIDERABLE TEMPERATURE DROP
ARE EXPECTED BEHIND THE COLD FRONT ON WEDNESDAY NIGHT. UPSLOPE
SNOW SHOWERS ARE POSSIBLE ALONG THE WESTERN SLOPES JUST IN TIME
FOR CHRISTMAS DAY...WHILE VFR CONDITIONS SHOULD RETURN TO MOST
LOCATIONS EAST OF THE BLUE RIDGE.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...MBS
NEAR TERM...MBS
SHORT TERM...PC
LONG TERM...KK
AVIATION...PW




000
FXUS61 KRNK 202006
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
306 PM EST SAT DEC 20 2014

.SYNOPSIS...
HIGH PRESSURE WILL BRING SOME IMPROVEMENT TO OUR WEATHER ON
SUNDAY...BEFORE A WEAK AREA OF LOW PRESSURE MOVING UP THE COAST
BRINGS PRECIPITATION BACK TO OUR FORECAST FOR SUNDAY NIGHT AND
MONDAY. AFTER A BRIEF BREAK ON TUESDAY...A VERY STRONG COLD FRONT
WILL MOVE THROUGH THE REGION ON WEDNESDAY...BRINGING RAIN AND
GUSTY WINDS TO THE AREA FOR CHRISTMAS EVE.

&&

.NEAR TERM /THROUGH SUNDAY TONIGHT/...
AS OF 300 PM EST SATURDAY...

AFTERNOON SATELLITE IMAGES SHOW SOME BREAKS DEVELOPING THE THE
EXTENSIVE CLOUD COVER OVER THE REGION. MORE BREAKS MAY DEVELOP EAST
OF THE BLUE RIDGE INTO THIS EVENING BUT CLOUDS WILL FILL BACK IN AND
EXPECT CLOUDY SKIES TO PREVAIL THROUGH TONIGHT AND INTO SUNDAY
MORNING. UPPER FLOW IS ESSENTIALLY ZONAL OVER US AND THIS IS KEEPING
ANY DECENT ENERGY LOCKED UP TO OUR NORTH AS A SHORT WAVE MOVES
THROUGH THE FLOW OVERNIGHT. HOWEVER...WEDGE ALONG THE EASTERN
SEABOARD WILL BE SHARPENING THROUGHOUT THE WEEKEND WHICH WILL LEAD
TO SOME UPSLOPE ALONG THE EASTERN SLOPES OF THE BLUE RIDGE WITH
LIGHT SOUTHEASTERLY SURFACE WINDS. THIS WILL HELP SQUEEZE OUT SOME
SPRINKLES/FLURRIES TONIGHT. ALSO BELIEVE THERE WILL BE SOME FREEZING
FOG AROUND AS MODEL SOUNDINGS SHOW SATURATED CONDITIONS IN THE
BOUNDARY LAYER IN AREAS WHERE TEMPERATURES WILL BE BELOW FREEZING.
DO NOT BELIEVE ANY HEADLINES ARE CALLED FOR SINCE IT LOOKS TO BE A
FACTOR FOR ONLY A VERY SMALL WINDOW OF TIME JUST BEFORE DAYBREAK BUT
WILL MENTION IN THE HWO. MODEST IMPROVEMENT FOR SUNDAY AS MOISTURE
SLOWLY ERODES...BUT WILL REMAIN POOLED ALONG THE MOUNTAINS.

WE WILL NOT HAVE TO WAIT LONG FOR OUR NEXT BOUT WITH WINTER AS A
WEAK SHORT WAVE MOVES OVER THE AREA SUNDAY NIGHT AND COMBINES WITH
WEAK ISENTROPIC LIFT TO GENERATE LIGHT PRECIPITATION. PTYPE WILL
BE A STRUGGLE WITH THIS SINCE COLD AIR WEDGE WILL HAVE NEAR
SURFACE TEMPS NEAR FREEZING AS TEMPERATURES ALOFT WARM. TOP DOWN
METHODOLOGY CURRENTLY YIELDS MOSTLY LIQUID WITH SLEET AND FREEZING
RAIN MAINLY FOR THE GREENBRIER VALLEY AND ALLEGHANY
HIGHLANDS...WITH ADDITIONAL POCKETS OF MIXED PRECIPITATION
ELSEWHERE. OVERALL QPF LOOKS TO BE RATHER LIGHT SO THIS DOES NOT
LOOK TO BE A VERY SIGNIFICANT EVENT THOUGH IT DOES NOT TAKE MUCH
FREEZING RAIN TO MAKE TRAVEL HAZARDOUS.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 300 PM EST SATURDAY...

COMPLEX FORECAST FOR THE EARLY TO MID-WEEK WITH TWO SYSTEMS TO DEAL
WITH. FIRST WILL BE EARLY MONDAY EVENT WITH A WEAK LOW ALONG THE NC
COAST AT 12Z AND THE FAMILIAR WEDGE BUILDING DOWN THE EASTERN SLOPES
OF THE APPALACHIANS FROM A PARENT 1030-ISH SURFACE HIGH OVER FAR
NORTHERN NEW ENGLAND. NOT A PARTICULARLY STRONG OR EVEN COLD WEDGE
BUT ENOUGH TO BRING AT LEAST SURFACE TEMPS CLOSE TO FREEZING IN SOME
COLDER LOCATIONS WHILE THE 0C H85 LINE IS GENERALLY ALREADY WELL
NORTH OF THE CWA..DEPENDING OF COURSE ON WHICH MODEL. 12Z GFS AND
NAM ARE BOTH ABOVE FREEZING AT H85 FROM 12Z ONWARD. SURFACE LOW
LIFTS NORTHEAST DURING THE DAY TO A POSITION OFF THE VA CAPES BY 00Z
TUE TAKING WHATEVER PRECIP DOES FALL WITH IT OFF TO THE EAST. QPF
FROM THIS EVENT LIKELY TO BE QUITE MODEST...FROM LESS THAN 0.10
INCHES FAR NORTHWEST TO POSSIBLY 0.25 TO 0.50 INCHES FAR EAST.
ALTHOUGH SEVERAL HOURS OF FREEZING RAIN IS POSSIBLE FOR THE COLDER
WESTERN VALLEYS NOT EXPECTING IT TO LAST VERY LONG AND ALL LIQUID
SHOULD FALL EAST OF THE MOUNTAINS AND THEN ALL AREAS TRANSITION TO
RAIN DURING THE DAY. HIGHS MONDAY WILL REMAINS CHILLY IN THE 30S TO
LOW 40S.

THERE WILL BE A BRIEF BREAK IN THE ACTION OVERNIGHT MONDAY
AS THE WEAK ATLANTIC LOW DEPARTS BUT WITH FLOW REMAINING SOUTHWEST
THERE IS BARELY ANY COLD ADVECTION BEHIND IT WHICH SHOULD LEAVE
TEMPS ACTUALLY FAIRLY MILD...GENERALLY ABOVE FREEZING BY TUESDAY
MORNING.  THE FLOW REMAINS SOUTH TO SOUTHWEST THROUGH THE DAY WITH
PLENTY OF AMBIENT MOISTURE AND SEVERAL WEAK BUT HARD TO TIME
DISTURBANCES SO KEPT MAINLY CHANCE POPS BUT QPF AGAIN QUITE
LOW...BELOW 0.05 INCHES WITH POSSIBLY SOME ENHANCEMENT ALONG THE
BLUE RIDGE. PRECIPITATION SHOULD BE ALL RAIN AS HIGHS IN THE 40S
EXPECTED CWA-WIDE AND WEDGE REMOVED FROM THE EQUATION. SOUTHERLY
FLOW AND WARM ADVECTION BECOMES FAIRLY IMPRESSIVE AHEAD OF THE
MUCH STRONGER LOW DEVELOPING OVER THE LOWER MISSISSIPPI VALLEY
MID- TO LATE DAY TUESDAY. POPS AND QPF WILL INCREASE OVERNIGHT
TUESDAY AS AVAILABLE MODELS SHOW A WIDESPREAD PRECIP EVENT WITH
AMOUNTS APPROACHING A HALF-INCH BY EARLY WEDNESDAY AS THE SURFACE
LOW DEEPENS AND RAPIDLY LIFTS NORTH TOWARD THE GREAT LAKES BY 12Z
WED.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 300 PM EST SATURDAY...

UPPER TROUGH OVER THE MISSISSIPPI VALLEY WILL EJECT A NEGATIVELY
TILTED THROUGH THE SOUTHEAST U. S. WEDNESDAY. SFC LOW PRESSURE NEAR
CINCINNATI WITH TRAILING COLD FRONT WILL LIFT NORTHEAST INTO THE
GREAT LAKES BY WEDNESDAY EVENING AND INTO EASTERN CANADA BY
WEDNESDAY NIGHT. A STRONG COLD FRONT WILL MOVE EAST ACROSS OUR
REGION WEDNESDAY INTO WEDNESDAY NIGHT. THERE IS THE POTENTIAL FOR
OUR REGION TO HAVE ACTIVE WEATHER WEDNESDAY WITH PLENTY OF
SHOWERS...PERHAPS VERY GUSTY WINDS AND A FEW THUNDERSTORMS. HOWEVER
THE BEST INSTABILITY AS SEEN IN THE LI FIELDS REMAINS SOUTH AND EAST
OF OUR AREA.  THE DAY 5 CONVECTIVE OUTLOOK FROM SPC HAS PLACED THE
STRONG TO SEVERE THUNDERSTORMS POTENTIAL FURTHER SOUTH ALONG EASTERN
CAROLINA TO FLORIDA. HIGHS ON WEDNESDAY WILL RANGE THE MID 40S IN
THE WEST TO THE MID AND UPPER 50S IN THE EAST. 850MB TEMPERATURES
ARE STILL INDICATING THE COLD AIR PUSHES IN QUICKLY IN WAKE OF THE
COLD FRONT. RAIN AND SNOW SHOWERS WILL CHANGEOVER TO SNOW SHOWERS
AND SNOW FLURRIES IN THE WEST WEDNESDAY NIGHT. SOME LIGHT SNOW
ACCUMULATIONS MAY BE POSSIBLE CHRISTMAS EVE NIGHT IN THE WESTERN
UPSLOPE FAVORED LOCATIONS. BUT A WARM GROUND AND SHARP RICH MOISTURE
CUTOFF MAY HINDER SNOW ACCUMULATIONS. LOW TEMPERATURES WEDNESDAY
NIGHT WILL DROP INTO THE LOWER TO MID 20S IN THE MOUNTAINS TO THE
LOWER 30S IN THE PIEDMONT.

WEST TO NORTHWEST UPPER FLOW WILL CONTINUE INTO THURSDAY WITH
MOUNTAIN RAIN AND SNOW SHOWERS. HIGHS CHRISTMAS DAY WILL VARY FROM
AROUND 30 DEGREES IN THE NORTHWEST MOUNTAINS TO AROUND 50 DEGREES IN
PIEDMONT. WINDS WILL BE QUITE STRONG ON THURSDAY AS A 50 TO 55 KNOT
850MB JET PIVOTS ACROSS THE REGION. AT THIS TIME...LOOKS LIKE VALUES
SHOULD REMAIN BELOW WIND ADVISORY LEVELS. AS HIGH PRESSURE SLIDES
OFF THE COAST...DRY WEATHER IS EXPECTED CHRISTMAS NIGHT/THURSDAY
NIGHT WITH LOW TEMPERATURES GENERALLY IN THE UPPER 20S AND LOWER
30S.

THE UPPER FLOW SHIFTS TO THE SOUTHWEST FRIDAY INTO FRIDAY NIGHT AS
TROF CURVES OUT IN THE CENTRAL US WITH SFC LOW PRESSURE DEVELOPING
OVER THE MIDWEST WITH A FRONTAL BOUNDARY TRAILING SOUTH. HIGHS ON
FRIDAY WILL VARY FROM THE LOWER 40S IN THE MOUNTAINS TO THE MID 50S
IN THE PIEDMONT. MOISTURE SLOWLY RETURN FRIDAY NIGHT INTO SATURDAY
AS FRONTAL BOUNDARY APPROACHES. LOWS FRIDAY NIGHT DROP INTO THE
LOWER AND MID 30S IN MOST LOCATIONS. A COLD FRONT MOVES ACROSS OUR
REGION SATURDAY INTO SATURDAY NIGHT.

&&

.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
AS OF 1255 PM EST SATURDAY...

A WEAK LOW PRESSURE PASSING TO THE SOUTH WILL DEPART OFF THE EAST
COAST THIS EVENING...BUT LOW LEVEL MOISTURE WILL REMAIN IN PLACE
OVER THE MID ATLANTIC. MVFR CEILINGS SHOULD PERSIST AT BCB/LWB/BLF
BEFORE LIKELY FALLING TO IFR TONIGHT. MEANWHILE...CEILINGS AT
LYH/ROA/DAN SHOULD STAY VFR DURING THE AFTERNOON...BEFORE DIPPING
DOWN TO MVFR TONIGHT. MODEL GUIDANCE HAS TURNED MORE CONFIDENT IN
FOG FORMATION BY EARLY SUNDAY MORNING DUE TO LIGHT WINDS AND
RESIDUAL BOUNDARY LAYER MOISTURE...WITH IFR/LIFR VISIBILITIES FOR
BCB/LWB/BLF...AND MVFR VISIBILITIES FOR LYH/ROA/DAN. PATCHY
FREEZING FOG IS ALSO A POSSIBILITY IN THE MOUNTAINS OVERNIGHT.

CONFIDENCE IS LOWER FOR THE EVENTUAL CLEARING OF FOG AND LOW
CEILINGS ON SUNDAY...AS HIGH PRESSURE REMAINS WEDGED AGAINST THE
EASTERN SIDE OF THE BLUE RIDGE. SOME OF THE GUIDANCE APPEARS TOO
OPTIMISTIC AND DOES NOT ACCOUNT FOR THE REMAINING LAYER OF
MOISTURE NEAR THE SURFACE...AS THEY PORTRAY SKIES CLEARING BY 18Z
AT ALL TAF SITES. ALTHOUGH CONDITIONS SHOULD EVENTUALLY IMPROVE
TO VFR BY MIDDAY SUNDAY AT LYH/ROA/DAN...MVFR CEILINGS WERE LEFT
AT BCB/LWB/BLF FOR THIS UPDATE AS IT MAY TAKE UNTIL AFTER 18Z FOR
THE LOW CLOUDS TO FINALLY SCATTER.

EXTENDED DISCUSSION...

A LOW PRESSURE SYSTEM ALONG THE GULF COAST WILL TRACK NORTHWARD
ALONG THE EAST COAST DURING SUNDAY NIGHT INTO MONDAY...AND BRING
PRIMARILY RAIN AND MVFR/IFR CONDITIONS OVER THE MID ATLANTIC.
HOWEVER...THERE IS A POTENTIAL FOR PATCHY AREAS OF FREEZING RAIN
ACROSS THE ALLEGHANY HIGHLANDS OF VIRGINIA AND SOUTHEAST WEST
VIRGINIA...WHERE TEMPERATURES MAY STRUGGLE TO GET ABOVE FREEZING
DURING EARLY MONDAY MORNING. LWB MAY BE IMPACTED...BUT THERE IS
LOW CONFIDENCE DUE TO THE UNCERTAINTY OF THE THERMAL PROFILE IN
THE MODEL SOUNDINGS.

WARM AIR ADVECTION DURING MONDAY AND TUESDAY SHOULD END THE
THREAT OF FROZEN PRECIPITATION...BUT PERIODS OF RAIN AND MVFR/IFR
CONDITIONS COULD LINGER THROUGHOUT THIS TIME. A STRONG COLD FRONT
WILL APPROACH FROM THE WEST BY TUESDAY NIGHT INTO WEDNESDAY. POOR
FLYING WEATHER DUE TO MORE RAIN SHOWERS SHOULD ACCOMPANY THE
FRONT...AND A STRONG LOW LEVEL JET MAY POSE A LOW LEVEL WIND SHEAR
THREAT. GUSTY NORTHWEST WINDS AND A CONSIDERABLE TEMPERATURE DROP
ARE EXPECTED BEHIND THE COLD FRONT ON WEDNESDAY NIGHT. UPSLOPE
SNOW SHOWERS ARE POSSIBLE ALONG THE WESTERN SLOPES JUST IN TIME
FOR CHRISTMAS DAY...WHILE VFR CONDITIONS SHOULD RETURN TO MOST
LOCATIONS EAST OF THE BLUE RIDGE.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...MBS
NEAR TERM...MBS
SHORT TERM...PC
LONG TERM...KK
AVIATION...PW





000
FXUS61 KRNK 201756
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
1256 PM EST SAT DEC 20 2014

.SYNOPSIS...
WEAK LOW PRESSURE ACROSS THE SOUTHEAST STATES WILL PASS EAST AND
OFFSHORE THIS AFTERNOON KEEPING MOST SIGNIFICANT PRECIPITATION TO
THE SOUTH OF THE REGION. HIGH PRESSURE WILL SPILL BACK SOUTH INTO
THE AREA TONIGHT THROUGH SUNDAY NIGHT AHEAD OF ANOTHER LOW
PRESSURE SYSTEM THAT WILL SLIDE UP THE COAST ON MONDAY. A STRONG
COLD FRONT APPROACHES FROM THE WEST TUESDAY INTO TUESDAY NIGHT
BEFORE PASSING THROUGH THE REGION ON WEDNESDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 940 AM EST SATURDAY...

FLAVOR OF THE GOING FORECAST IS LOOKING GOOD SO JUST MINOR
ADJUSTMENTS FOR LATEST OBSERVATIONS AND TRENDS. RETURNS ON RADAR
CONTINUE TO RACE EASTWARD THIS MORNING AS AN UNINSPIRED AREA OF
LOW PRESSURE CONTINUES TO SLIDE BY TO OUR SOUTH. WATER VAPOR
IMAGERY SHOWS A LOT OF DRYING MOVING IN ALOFT SO THERE WILL BE NO
DEEP MOISTURE TO WORK WITH ONCE WE GET INTO THIS AFTERNOON...BUT
BUFKIT SOUNDINGS STILL SHOW DECENT MOISTURE IN THE LOW LEVELS FROM
THE BLUE RIDGE WEST SO LIKELY TRANSITIONING INTO A SNIZZLE SCENARIO
FOR THE MTNS. WE SHOULD BE JUST ABOUT DONE WITH MEASURABLE PCPN
FOR TODAY SO NOT EXPECTING ANY ADDITIONAL ACCUMS OF SNOW. BEST
RETURNS ON RADAR ARE CURRENTLY OVER THE PIEDMONT WHERE LOW LEVELS
ARE STILL FAIRLY DRY SO PROBABLY MORE VIRGA THAN ANYTHING REACHING
THE GROUND.

.PREVIOUS AFD...
LIGHT PRECIP EVENT TO UNFOLD THIS MORNING STILL
LOOKS ON TRACK AS SURFACE LOW PRESSURE PASSES WELL TO THE SOUTH
AND EAST OF THE REGION THROUGH THIS EVENING. THIS SHOULD KEEP THE
MAJORITY OF THE BETTER LIFT AND DEEP MOISTURE OFF TO THE SE WITH
ANY PRECIP OVER THE REGION PRIMARILY DRIVEN VIA WEAK UPPER
DIFFLUENCE BETWEEN MID LEVEL WAVES. ONE SUCH SHORTWAVE BEING WITH
THE LEAD SOUTHERNMOST IMPULSE LOOKS TO SLIDE ACROSS NW N CAROLINA
THIS MORNING AND COINCIDE WITH WEAK SE FLOW UNDER THE LEFT FRONT
OF THE PASSING SPEED MAX ALOFT. THIS SHOULD HELP DEVELOP AN AXIS
OF LIGHT SNOW FROM THE NC MOUNTAINS ALONG THE I-77 CORRIDOR EARLY
ON WITH SOME OF THIS SPREADING EAST BUT IN A DIMINISHING STATE
GIVEN DAMPENING SUPPORT AND RESIDUAL DRY AIR.

WITH THE LATEST MODELS ESPCLY SREF PRINTING OUT QPF OF AROUND A
TENTH OF AN INCH OR SO...BUMPED UP POPS TO HIGHER CHANCE SW AND
KEPT EXTENSION OF THE GOING CHANCE POPS ESPCLY SOUTH OF HIGHWAY
460 THIS MORNING. THIS MAY BRING A HALF/ONE INCH OF SNOW AT
ELEVATION FROM I-77 AND POINTS WEST EARLY ON BUT WITHOUT ANY
HEADLINES AS COULD EASILY END UP BEING SNOW SHOWERS/FLURRIES AT
WORSE PER LATEST RADAR TRENDS. ELSW EXPECT LITTLE OR NO
ACCUMULATION GIVEN THE VERY LIGHT PRECIP TYPE SCENARIO IF AT ALL
AS SEEN OFF THE LATEST HRRR. HIGH TEMPS REMAIN TRICKY AFTER SUCH A
COLD START WITH POTENTIAL TO SEE SOME BREAKS DEVELOP BLUE RIDGE
AND ACROSS THE NORTH/WEST LATER ON. THUS TRENDED VALUES UP A
DEGREE OR TWO NORTH WHILE DECREASING A CAT OR SO ESPCLY SE WHERE
SOMEWHAT DEEPER MOISTURE WILL BE LAST TO EXIT.

WEAK RIDGING TO THE NW DIPS BACK INTO THE AREA BEHIND THE DEPARTING
WAVE OVERNIGHT ALLOWING DRYING ALOFT TO TAKE SHAPE UNDER WEAK
SUBSIDENCE. HOWEVER JUST HOW MUCH LOW LEVEL MOISTURE REMAINS TRAPPED IN
QUESTION AND PARTLY DEPENDENT ON THE DEGREE OF MOISTENING TODAY WITH
THE CURRENT EVENT. GFS REMAINS RATHER DRY WITH WEAK NW FLOW THROUGH THE
COLUMN...WHILE THE NAM WETTER UNDER A LIGHT LOW LEVEL EAST/SE
COMPONENT THAT KEEPS QUITE A BIT OF BOUNDARY LAYER MOISTURE ACROSS THE
REGION. THIS COULD POSE A FREEZING DRIZZLE ISSUE ESPCLY BLUE RIDGE WITH
LOTS OF FREEZING FOG/LOW CLOUDS AROUND BUT QUITE IFFY. THUS WILL
GO WITH MORE CLOUDS AND SOME FREEZING FOG OVERNIGHT WHILE LEAVING
OUT ANY -FZDZ MENTION FOR NOW DESPITE DECENT DEPTH TO MOISTURE
UNDER THE INVERSION OFF THE NAM. LOW TEMPS ALSO REFLECT MOISTURE
DIFFERENCES WITH THE MAV MOS WELL INTO THE 20S MOST SPOTS WHILE
THE MET MOS A GOOD 5-10 DEGREES WARMER DUE TO CLOUDS. FOR
NOW...TWEAKED DOWN IN THE VALLEYS AND BLUE RIDGE WHILE LEAVING
THINGS A BIT WARMER WEST-SW WHERE LEFTOVER CLOUDS MORE OF A GOOD
BET IN THE WAKE OF TODAYS POSSIBLE PRECIP.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY/...
AS OF 430 AM EST SATURDAY...

WILL START SUNDAY OFF WITH LOW PRESSURE DEVELOPING ALONG THE
SOUTHEAST COAST. HIGH PRESSURE OVER EASTERN CANADA WILL CONTINUE TO
BUILD SOUTHWARD ACROSS NEW ENGLAND AND THE MID ATLANTIC...BECOMING
INCREASINGLY WEDGED AGAINST THE EASTERN FACE OF THE APPALACHIANS.
WILL SEE WINDS SHIFT MORE EAST NORTHEASTERLY BY EVENING...WITH THE
UPSLOPE FLOW ALONG THE BLUE RIDGE SUPPORTING POCKETS OF LIGHT RAIN
OR DRIZZLE...MAINLY OVER THE NORTH CAROLINA HIGHLANDS BY SUNSET.

THE LOW WILL PASS ALONG THE CAROLINA COAST SUNDAY NIGHT...RESULTING
IN INCREASING PRECIPITATION CHANCES APPROACHING DAWN ON MONDAY. AS
TEMPERATURES COOL THROUGH THE NIGHT...EXPECT TO SEE LIGHT RAIN/
DRIZZLE CHANGE OVER TO A MIXTURE OF RAIN AND FREEZING DRIZZLE OR
SLEET ACROSS THE AREA...WITH MORE MIXED PRECIPITATION NORTH OF
HIGHWAY 460. FORECAST SOUNDINGS INDICATE THAT MOISTURE REMAINS
SHALLOW HOWEVER...SO EXPECT VERY LITTLE ICE ACCUMULATION...IF ANY.
20/00Z MODELS HAVE TRENDED SLIGHTLY WEAKER WITH THIS LOW...WITH SOME
MODELS INDICATING MOISTURE HAVING A HARD TIME MAKING IT INTO
SOUTHEAST WEST VIRGINIA/FAR WESTERN VIRGINIA...REMAINING MORE
CONFINED TO THE PIEDMONT AND BLUE RIDGE. PRECIPITATION AMOUNTS ARE
ALSO LOWER...GENERALLY A FEW HUNDREDTHS OF AN INCH ACROSS THE
WESTERN RIDGES...TO A TENTH OR TWO ACROSS THE PIEDMONT.

MODEST DAYTIME WARMING ON MONDAY WILL CAUSE ANY MIXED PRECIPITATION
TO CHANGE OVER TO LIQUID MOST AREAS...ALTHOUGH A FEW POCKETS OF
SLEET OR LIGHT FREEZING RAIN MAY LINGER IN THE COLDER AIR ALONG AND
NORTH OF THE INTERSTATE 64 CORRIDOR THROUGH THE DAY. THE BRUNT OF
THE ENERGY WILL PASS EAST DURING EARLY AFTERNOON...LEAVING ONLY
SPOTTY PRECIPITATION THROUGH THE REMAINDER OF THE DAY.

BEGINNING MONDAY NIGHT...WILL SEE A GRADUAL WARMING TREND TAKE SHAPE
AS A DEEP LOW PRESSURE SYSTEM DEVELOPS OVER THE SOUTHERN PLAINS. THE
HIGH PRESSURE WEDGE WILL REMAIN IN PLACE THROUGH THE NIGHT...HOWEVER
TEMPERATURES ARE EXPECTED TO REMAIN WARM ENOUGH MOST LOCATIONS FOR
PRECIPITATION TO REMAIN LIQUID.

LOW PRESSURE WILL PUSH NORTH TOWARD THE GREAT LAKES TUESDAY AND
TUESDAY NIGHT...RESULTING IN INCREASING RAIN CHANCES DURING THE
PERIOD. PRECIPITABLE WATER VALUES WILL INCREASE SIGNIFICANTLY...
ESPECIALLY TUESDAY NIGHT...RISING TO THE 1.1 TO 1.4 INCH RANGE...
WHICH IS SIGNIFICANTLY HIGHER THAN NORMAL FOR LATE DECEMBER. AS
SUCH...HAVE WENT WILL HIGHER PRECIPITATION CHANCES FOR TUESDAY
NIGHT...WITH A COLD FRONT APPROACHING FROM THE WEST. MAY ALSO SEE
GUSTY WINDS TUESDAY NIGHT ACROSS THE MOUNTAINS AS A 50KT TO 60KT LOW
LEVEL JET ENTERS THE AREA.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 400 AM EST SATURDAY...

MODEL CONSENSUS OF GFS AND ECMWF IS THAT A SYNOPTIC UPPER TROUGH
OVER THE MISSISSIPPI VALLEY WILL EJECT A NEGATIVELY TILTED
THROUGH THE SOUTHEAST U. S. EARLY WEDNESDAY. WITH THE POSITION OF
THE ASSOCIATED SURFACE OCCLUDED FRONT AND THE TRIPLE POINT PASSING
SOMEWHERE NEAR OR JUST SOUTH OF OUR REGION...THERE IS THE
POTENTIAL FOR OUR REGION TO HAVE ACTIVE WEATHER WEDNESDAY WITH
PLENTY OF SHOWERS...PERHAPS VERY GUSTY WINDS AND A FEW
THUNDERSTORMS. LOOKS LIKE THE AXIS OF BETTER INSTABILITY MAY BE A
LITTLE FURTHER SOUTH ON THE 12Z MODEL RUN.

A COLD FRONT WILL MOVE EAST ACROSS OUR REGION WEDNESDAY INTO
WEDNESDAY NIGHT. HIGHS ON WEDNESDAY WILL WARM INTO THE LOWER 40S
IN THE WEST TO THE LOWER 50S IN THE EAST. RAIN AND SNOW SHOWERS
WILL CHANGEOVER TO SNOW SHOWERS AND SNOW FLURRIES IN THE WEST
WEDNESDAY NIGHT. LOW TEMPERATURES WEDNESDAY NIGHT WILL DROP INTO
THE MID 20S IN THE MOUNTAINS TO THE LOWER 30S IN THE PIEDMONT.
WEST TO NORTHWEST UPPER FLOW WILL CONTINUE INTO THURSDAY WITH
HIGHS FROM THE UPPER 20S IN THE MOUNTAINS TO AROUND 50 IN
PIEDMONT. WINDS WILL BE QUITE STRONG ON THURSDAY AS A 50 TO 55
KNOT 850MB JET PIVOTS ACROSS THE REGION. THE UPPER FLOW SHIFTS TO
THE SOUTHWEST THURSDAY NIGHT INTO FRIDAY AS TROF CURVES OUT IN THE
CENTRAL US WITH SFC INFLECTION OF LOW PRESSURE DEVELOPING OVER THE
TENNESSEE VALLEY BY FRIDAY MORNING. MOISTURE SLOWLY RETURN FRIDAY
NIGHT INTO SATURDAY AS THE HIGH CENTER SLIDE OFF THE COAST.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AS OF 1255 PM EST SATURDAY...

A WEAK LOW PRESSURE PASSING TO THE SOUTH WILL DEPART OFF THE EAST
COAST THIS EVENING...BUT LOW LEVEL MOISTURE WILL REMAIN IN PLACE
OVER THE MID ATLANTIC. MVFR CEILINGS SHOULD PERSIST AT BCB/LWB/BLF
BEFORE LIKELY FALLING TO IFR TONIGHT. MEANWHILE...CEILINGS AT
LYH/ROA/DAN SHOULD STAY VFR DURING THE AFTERNOON...BEFORE DIPPING
DOWN TO MVFR TONIGHT. MODEL GUIDANCE HAS TURNED MORE CONFIDENT IN
FOG FORMATION BY EARLY SUNDAY MORNING DUE TO LIGHT WINDS AND
RESIDUAL BOUNDARY LAYER MOISTURE...WITH IFR/LIFR VISIBILITIES FOR
BCB/LWB/BLF...AND MVFR VISIBILITIES FOR LYH/ROA/DAN. PATCHY
FREEZING FOG IS ALSO A POSSIBILITY IN THE MOUNTAINS OVERNIGHT.

CONFIDENCE IS LOWER FOR THE EVENTUAL CLEARING OF FOG AND LOW
CEILINGS ON SUNDAY...AS HIGH PRESSURE REMAINS WEDGED AGAINST THE
EASTERN SIDE OF THE BLUE RIDGE. SOME OF THE GUIDANCE APPEARS TOO
OPTIMISTIC AND DOES NOT ACCOUNT FOR THE REMAINING LAYER OF
MOISTURE NEAR THE SURFACE...AS THEY PORTRAY SKIES CLEARING BY 18Z
AT ALL TAF SITES. ALTHOUGH CONDITIONS SHOULD EVENTUALLY IMPROVE
TO VFR BY MIDDAY SUNDAY AT LYH/ROA/DAN...MVFR CEILINGS WERE LEFT
AT BCB/LWB/BLF FOR THIS UPDATE AS IT MAY TAKE UNTIL AFTER 18Z FOR
THE LOW CLOUDS TO FINALLY SCATTER.

EXTENDED DISCUSSION...

A LOW PRESSURE SYSTEM ALONG THE GULF COAST WILL TRACK NORTHWARD
ALONG THE EAST COAST DURING SUNDAY NIGHT INTO MONDAY...AND BRING
PRIMARILY RAIN AND MVFR/IFR CONDITIONS OVER THE MID ATLANTIC.
HOWEVER...THERE IS A POTENTIAL FOR PATCHY AREAS OF FREEZING RAIN
ACROSS THE ALLEGHANY HIGHLANDS OF VIRGINIA AND SOUTHEAST WEST
VIRGINIA...WHERE TEMPERATURES MAY STRUGGLE TO GET ABOVE FREEZING
DURING EARLY MONDAY MORNING. LWB MAY BE IMPACTED...BUT THERE IS
LOW CONFIDENCE DUE TO THE UNCERTAINTY OF THE THERMAL PROFILE IN
THE MODEL SOUNDINGS.

WARM AIR ADVECTION DURING MONDAY AND TUESDAY SHOULD END THE
THREAT OF FROZEN PRECIPITATION...BUT PERIODS OF RAIN AND MVFR/IFR
CONDITIONS COULD LINGER THROUGHOUT THIS TIME. A STRONG COLD FRONT
WILL APPROACH FROM THE WEST BY TUESDAY NIGHT INTO WEDNESDAY. POOR
FLYING WEATHER DUE TO MORE RAIN SHOWERS SHOULD ACCOMPANY THE
FRONT...AND A STRONG LOW LEVEL JET MAY POSE A LOW LEVEL WIND SHEAR
THREAT. GUSTY NORTHWEST WINDS AND A CONSIDERABLE TEMPERATURE DROP
ARE EXPECTED BEHIND THE COLD FRONT ON WEDNESDAY NIGHT. UPSLOPE
SNOW SHOWERS ARE POSSIBLE ALONG THE WESTERN SLOPES JUST IN TIME
FOR CHRISTMAS DAY...WHILE VFR CONDITIONS SHOULD RETURN TO MOST
LOCATIONS EAST OF THE BLUE RIDGE.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...JH
NEAR TERM...JH/MBS
SHORT TERM...AMS/NF
LONG TERM...KK
AVIATION...PW





000
FXUS61 KRNK 201446 CCA
AFDRNK

AREA FORECAST DISCUSSION...CORRECTED TIME
NATIONAL WEATHER SERVICE BLACKSBURG VA
943 AM EST SAT DEC 20 2014

.SYNOPSIS...
WEAK LOW PRESSURE ACROSS THE SOUTHEAST STATES WILL PASS EAST AND
OFFSHORE THIS AFTERNOON KEEPING MOST SIGNIFICANT PRECIPITATION TO
THE SOUTH OF THE REGION. HIGH PRESSURE WILL SPILL BACK SOUTH INTO
THE AREA TONIGHT THROUGH SUNDAY NIGHT AHEAD OF ANOTHER LOW
PRESSURE SYSTEM THAT WILL SLIDE UP THE COAST ON MONDAY. A STRONG
COLD FRONT APPROACHES FROM THE WEST TUESDAY INTO TUESDAY NIGHT
BEFORE PASSING THROUGH THE REGION ON WEDNESDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 940 AM EST SATURDAY...

FLAVOR OF THE GOING FORECAST IS LOOKING GOOD SO JUST MINOR
ADJUSTMENTS FOR LATEST OBSERVATIONS AND TRENDS. RETURNS ON RADAR
CONTINUE TO RACE EASTWARD THIS MORNING AS AN UNINSPIRED AREA OF
LOW PRESSURE CONTINUES TO SLIDE BY TO OUR SOUTH. WATER VAPOR
IMAGERY SHOWS A LOT OF DRYING MOVING IN ALOFT SO THERE WILL BE NO
DEEP MOISTURE TO WORK WITH ONCE WE GET INTO THIS AFTERNOON...BUT
BUFKIT SOUNDINGS STILL SHOW DECENT MOISTURE IN THE LOW LEVELS FROM
THE BLUE RIDGE WEST SO LIKELY TRANSITIONING INTO A SNIZZLE SCENARIO
FOR THE MTNS. WE SHOULD BE JUST ABOUT DONE WITH MEASURABLE PCPN
FOR TODAY SO NOT EXPECTING ANY ADDITIONAL ACCUMS OF SNOW. BEST
RETURNS ON RADAR ARE CURRENTLY OVER THE PIEDMONT WHERE LOW LEVELS
ARE STILL FAIRLY DRY SO PROBABLY MORE VIRGA THAN ANYTHING REACHING
THE GROUND.

.PREVIOUS AFD...
LIGHT PRECIP EVENT TO UNFOLD THIS MORNING STILL
LOOKS ON TRACK AS SURFACE LOW PRESSURE PASSES WELL TO THE SOUTH
AND EAST OF THE REGION THROUGH THIS EVENING. THIS SHOULD KEEP THE
MAJORITY OF THE BETTER LIFT AND DEEP MOISTURE OFF TO THE SE WITH
ANY PRECIP OVER THE REGION PRIMARILY DRIVEN VIA WEAK UPPER
DIFFLUENCE BETWEEN MID LEVEL WAVES. ONE SUCH SHORTWAVE BEING WITH
THE LEAD SOUTHERNMOST IMPULSE LOOKS TO SLIDE ACROSS NW N CAROLINA
THIS MORNING AND COINCIDE WITH WEAK SE FLOW UNDER THE LEFT FRONT
OF THE PASSING SPEED MAX ALOFT. THIS SHOULD HELP DEVELOP AN AXIS
OF LIGHT SNOW FROM THE NC MOUNTAINS ALONG THE I-77 CORRIDOR EARLY
ON WITH SOME OF THIS SPREADING EAST BUT IN A DIMINISHING STATE
GIVEN DAMPENING SUPPORT AND RESIDUAL DRY AIR.

WITH THE LATEST MODELS ESPCLY SREF PRINTING OUT QPF OF AROUND A
TENTH OF AN INCH OR SO...BUMPED UP POPS TO HIGHER CHANCE SW AND
KEPT EXTENSION OF THE GOING CHANCE POPS ESPCLY SOUTH OF HIGHWAY
460 THIS MORNING. THIS MAY BRING A HALF/ONE INCH OF SNOW AT
ELEVATION FROM I-77 AND POINTS WEST EARLY ON BUT WITHOUT ANY
HEADLINES AS COULD EASILY END UP BEING SNOW SHOWERS/FLURRIES AT
WORSE PER LATEST RADAR TRENDS. ELSW EXPECT LITTLE OR NO
ACCUMULATION GIVEN THE VERY LIGHT PRECIP TYPE SCENARIO IF AT ALL
AS SEEN OFF THE LATEST HRRR. HIGH TEMPS REMAIN TRICKY AFTER SUCH A
COLD START WITH POTENTIAL TO SEE SOME BREAKS DEVELOP BLUE RIDGE
AND ACROSS THE NORTH/WEST LATER ON. THUS TRENDED VALUES UP A
DEGREE OR TWO NORTH WHILE DECREASING A CAT OR SO ESPCLY SE WHERE
SOMEWHAT DEEPER MOISTURE WILL BE LAST TO EXIT.

WEAK RIDGING TO THE NW DIPS BACK INTO THE AREA BEHIND THE DEPARTING
WAVE OVERNIGHT ALLOWING DRYING ALOFT TO TAKE SHAPE UNDER WEAK
SUBSIDENCE. HOWEVER JUST HOW MUCH LOW LEVEL MOISTURE REMAINS TRAPPED IN
QUESTION AND PARTLY DEPENDENT ON THE DEGREE OF MOISTENING TODAY WITH
THE CURRENT EVENT. GFS REMAINS RATHER DRY WITH WEAK NW FLOW THROUGH THE
COLUMN...WHILE THE NAM WETTER UNDER A LIGHT LOW LEVEL EAST/SE
COMPONENT THAT KEEPS QUITE A BIT OF BOUNDARY LAYER MOISTURE ACROSS THE
REGION. THIS COULD POSE A FREEZING DRIZZLE ISSUE ESPCLY BLUE RIDGE WITH
LOTS OF FREEZING FOG/LOW CLOUDS AROUND BUT QUITE IFFY. THUS WILL
GO WITH MORE CLOUDS AND SOME FREEZING FOG OVERNIGHT WHILE LEAVING
OUT ANY -FZDZ MENTION FOR NOW DESPITE DECENT DEPTH TO MOISTURE
UNDER THE INVERSION OFF THE NAM. LOW TEMPS ALSO REFLECT MOISTURE
DIFFERENCES WITH THE MAV MOS WELL INTO THE 20S MOST SPOTS WHILE
THE MET MOS A GOOD 5-10 DEGREES WARMER DUE TO CLOUDS. FOR
NOW...TWEAKED DOWN IN THE VALLEYS AND BLUE RIDGE WHILE LEAVING
THINGS A BIT WARMER WEST-SW WHERE LEFTOVER CLOUDS MORE OF A GOOD
BET IN THE WAKE OF TODAYS POSSIBLE PRECIP.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY/...
AS OF 430 AM EST SATURDAY...

WILL START SUNDAY OFF WITH LOW PRESSURE DEVELOPING ALONG THE
SOUTHEAST COAST. HIGH PRESSURE OVER EASTERN CANADA WILL CONTINUE TO
BUILD SOUTHWARD ACROSS NEW ENGLAND AND THE MID ATLANTIC...BECOMING
INCREASINGLY WEDGED AGAINST THE EASTERN FACE OF THE APPALACHIANS.
WILL SEE WINDS SHIFT MORE EAST NORTHEASTERLY BY EVENING...WITH THE
UPSLOPE FLOW ALONG THE BLUE RIDGE SUPPORTING POCKETS OF LIGHT RAIN
OR DRIZZLE...MAINLY OVER THE NORTH CAROLINA HIGHLANDS BY SUNSET.

THE LOW WILL PASS ALONG THE CAROLINA COAST SUNDAY NIGHT...RESULTING
IN INCREASING PRECIPITATION CHANCES APPROACHING DAWN ON MONDAY. AS
TEMPERATURES COOL THROUGH THE NIGHT...EXPECT TO SEE LIGHT RAIN/
DRIZZLE CHANGE OVER TO A MIXTURE OF RAIN AND FREEZING DRIZZLE OR
SLEET ACROSS THE AREA...WITH MORE MIXED PRECIPITATION NORTH OF
HIGHWAY 460. FORECAST SOUNDINGS INDICATE THAT MOISTURE REMAINS
SHALLOW HOWEVER...SO EXPECT VERY LITTLE ICE ACCUMULATION...IF ANY.
20/00Z MODELS HAVE TRENDED SLIGHTLY WEAKER WITH THIS LOW...WITH SOME
MODELS INDICATING MOISTURE HAVING A HARD TIME MAKING IT INTO
SOUTHEAST WEST VIRGINIA/FAR WESTERN VIRGINIA...REMAINING MORE
CONFINED TO THE PIEDMONT AND BLUE RIDGE. PRECIPITATION AMOUNTS ARE
ALSO LOWER...GENERALLY A FEW HUNDREDTHS OF AN INCH ACROSS THE
WESTERN RIDGES...TO A TENTH OR TWO ACROSS THE PIEDMONT.

MODEST DAYTIME WARMING ON MONDAY WILL CAUSE ANY MIXED PRECIPITATION
TO CHANGE OVER TO LIQUID MOST AREAS...ALTHOUGH A FEW POCKETS OF
SLEET OR LIGHT FREEZING RAIN MAY LINGER IN THE COLDER AIR ALONG AND
NORTH OF THE INTERSTATE 64 CORRIDOR THROUGH THE DAY. THE BRUNT OF
THE ENERGY WILL PASS EAST DURING EARLY AFTERNOON...LEAVING ONLY
SPOTTY PRECIPITATION THROUGH THE REMAINDER OF THE DAY.

BEGINNING MONDAY NIGHT...WILL SEE A GRADUAL WARMING TREND TAKE SHAPE
AS A DEEP LOW PRESSURE SYSTEM DEVELOPS OVER THE SOUTHERN PLAINS. THE
HIGH PRESSURE WEDGE WILL REMAIN IN PLACE THROUGH THE NIGHT...HOWEVER
TEMPERATURES ARE EXPECTED TO REMAIN WARM ENOUGH MOST LOCATIONS FOR
PRECIPITATION TO REMAIN LIQUID.

LOW PRESSURE WILL PUSH NORTH TOWARD THE GREAT LAKES TUESDAY AND
TUESDAY NIGHT...RESULTING IN INCREASING RAIN CHANCES DURING THE
PERIOD. PRECIPITABLE WATER VALUES WILL INCREASE SIGNIFICANTLY...
ESPECIALLY TUESDAY NIGHT...RISING TO THE 1.1 TO 1.4 INCH RANGE...
WHICH IS SIGNIFICANTLY HIGHER THAN NORMAL FOR LATE DECEMBER. AS
SUCH...HAVE WENT WILL HIGHER PRECIPITATION CHANCES FOR TUESDAY
NIGHT...WITH A COLD FRONT APPROACHING FROM THE WEST. MAY ALSO SEE
GUSTY WINDS TUESDAY NIGHT ACROSS THE MOUNTAINS AS A 50KT TO 60KT LOW
LEVEL JET ENTERS THE AREA.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 400 AM EST SATURDAY...

MODEL CONSENSUS OF GFS AND ECMWF IS THAT A SYNOPTIC UPPER TROUGH
OVER THE MISSISSIPPI VALLEY WILL EJECT A NEGATIVELY TILTED
THROUGH THE SOUTHEAST U. S. EARLY WEDNESDAY. WITH THE POSITION OF
THE ASSOCIATED SURFACE OCCLUDED FRONT AND THE TRIPLE POINT PASSING
SOMEWHERE NEAR OR JUST SOUTH OF OUR REGION...THERE IS THE
POTENTIAL FOR OUR REGION TO HAVE ACTIVE WEATHER WEDNESDAY WITH
PLENTY OF SHOWERS...PERHAPS VERY GUSTY WINDS AND A FEW
THUNDERSTORMS. LOOKS LIKE THE AXIS OF BETTER INSTABILITY MAY BE A
LITTLE FURTHER SOUTH ON THE 12Z MODEL RUN.

A COLD FRONT WILL MOVE EAST ACROSS OUR REGION WEDNESDAY INTO
WEDNESDAY NIGHT. HIGHS ON WEDNESDAY WILL WARM INTO THE LOWER 40S
IN THE WEST TO THE LOWER 50S IN THE EAST. RAIN AND SNOW SHOWERS
WILL CHANGEOVER TO SNOW SHOWERS AND SNOW FLURRIES IN THE WEST
WEDNESDAY NIGHT. LOW TEMPERATURES WEDNESDAY NIGHT WILL DROP INTO
THE MID 20S IN THE MOUNTAINS TO THE LOWER 30S IN THE PIEDMONT.
WEST TO NORTHWEST UPPER FLOW WILL CONTINUE INTO THURSDAY WITH
HIGHS FROM THE UPPER 20S IN THE MOUNTAINS TO AROUND 50 IN
PIEDMONT. WINDS WILL BE QUITE STRONG ON THURSDAY AS A 50 TO 55
KNOT 850MB JET PIVOTS ACROSS THE REGION. THE UPPER FLOW SHIFTS TO
THE SOUTHWEST THURSDAY NIGHT INTO FRIDAY AS TROF CURVES OUT IN THE
CENTRAL US WITH SFC INFLECTION OF LOW PRESSURE DEVELOPING OVER THE
TENNESSEE VALLEY BY FRIDAY MORNING. MOISTURE SLOWLY RETURN FRIDAY
NIGHT INTO SATURDAY AS THE HIGH CENTER SLIDE OFF THE COAST.

&&

.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
AS OF 545 AM EST SATURDAY...

AXIS OF LIGHT SNOW NOW MOVING ACROSS THE FAR WEST/SW AND LIKELY TO
IMPACT KBLF SHORTLY WITH A BRIEF PERIOD OF MVFR CIGS/VSBYS. OTRW
LOOKING AT LOWERING CIGS THIS MORNING FROM WEST TO EAST WITH MVFR
CIGS POSSIBLY SPREADING AS FAR EAST AS KBCB/KROA...AND NORTH AS
KLWB WHERE STILL MAINTAINING VFR VSBYS IN -SN THROUGH LATE
MORNING FOR NOW. THINKING EASTERN SITES SHOULD STAY VFR WITH ONLY
SOME SPOTTY -RA/-SN ARRIVING BY MID MORNING IF THE PRECIP HOLDS
TOGETHER.

THIS SYSTEM MOVES OUT FAIRLY QUICKLY WITH MOST PRECIPITATION
ENDING BY 19-20Z/2-3PM IF NOT SOONER. HOWEVER...A SHALLOW LAYER OF
MOISTURE BANKING UP AGAINST THE WESTERN SLOPES WILL KEEP
CLOUDS...LOWERING TO MVFR LEVELS AT KBLF THIS AFTERNOON. MAY SEE
CIGS ACTUALLY RISE A BIT BEHIND THE DEPARTING SPOTTY PRECIP ELSW BEFORE
SHALLOW MOISTURE BECOMES MORE WIDESPREAD THIS EVENING ESPCLY WHERE
ANY EARLIER SNOW/RAIN OCCURRED. THIS MAY LEAD TO LOW CLOUDS WITH
EVEN IFR CONDITIONS IN SPOTS GIVEN WESTERLY FLOW AROUND KBLF
OVERNIGHT...AND MVFR TO IFR ALONG THE BLUE RIDGE LATE. SOME
PATCHY DRIZZLE/LIGHT SNOW IS ALSO POSSIBLE THIS EVENING THEN
PERHAPS MORE WIDESPREAD ALONG THE BLUE RIDGE INCLUDING PATCHY
DENSE FOG AFTER MIDNIGHT. THIS HOWEVER REMAINS LOW CONFIDENCE
GIVEN DIFFERING MODEL SOLUTIONS BUT DID INCLUDE SOME LOWER
CIGS/VSBYS AT MOST SPOTS WITH POSSIBLE IFR IN STRATUS/FOG.

EXTENDED DISCUSSION...

ONCE THIS FEATURE EXITS WILL SEE THE NEXT WAVE ALONG THE COAST
BRING ANOTHER ROUND OF SUB-VFR CONDITIONS FOR LATER SUNDAY NIGHT
INTO MONDAY. RAIN WILL BE THE PRIMARY PRECIPITATION TYPE WITH
THE POTENTIAL FOR POCKETS OF FREEZING RAIN LATE SUNDAY NIGHT INTO
MONDAY MORNING ACROSS COLDER NORTHERN PORTIONS OF FORECAST AREA WHICH
MIGHT IMPACT LWB IF TEMPERATURES ARE COLD ENOUGH.

RAIN WILL IMPACT AREAS ALONG AND EAST OF THE BLUE RIDGE...WITH
YET ANOTHER SYSTEM SLATED FOR LATE TUESDAY INTO WEDNESDAY AHEAD OF
A STRONG COLD FRONT. THESE SYSTEMS ARE EXPECTED TO BRING A PERIOD
MAINLY RAIN BUT COULD BE SOME WINTRY WX AS WELL ESPECIALLY IN THE
MOUNTAINS WITH THE SUNDAY NIGHT/MONDAY EVENT. EXPECT POTENTIAL LOW
LEVEL WIND SHEAR AS WELL AND POOR FLYING WEATHER FOR EARLY NEXT
WEEK. RAIN AND SNOW SHOWERS WILL CONTINUE INTO WEDNESDAY. GUSTY
NORTHWEST WINDS ARE POSSIBLE WEDNESDAY INTO THURSDAY. MOUNTAIN
SNOW SHOWERS AND SNOW FLURRIES EXPECTED WEDNESDAY NIGHT INTO
CHRISTMAS.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...JH
NEAR TERM...JH/MBS
SHORT TERM...AMS/NF
LONG TERM...KK
AVIATION...JH/PH/WP




000
FXUS61 KRNK 201446 CCA
AFDRNK

AREA FORECAST DISCUSSION...CORRECTED TIME
NATIONAL WEATHER SERVICE BLACKSBURG VA
943 AM EST SAT DEC 20 2014

.SYNOPSIS...
WEAK LOW PRESSURE ACROSS THE SOUTHEAST STATES WILL PASS EAST AND
OFFSHORE THIS AFTERNOON KEEPING MOST SIGNIFICANT PRECIPITATION TO
THE SOUTH OF THE REGION. HIGH PRESSURE WILL SPILL BACK SOUTH INTO
THE AREA TONIGHT THROUGH SUNDAY NIGHT AHEAD OF ANOTHER LOW
PRESSURE SYSTEM THAT WILL SLIDE UP THE COAST ON MONDAY. A STRONG
COLD FRONT APPROACHES FROM THE WEST TUESDAY INTO TUESDAY NIGHT
BEFORE PASSING THROUGH THE REGION ON WEDNESDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 940 AM EST SATURDAY...

FLAVOR OF THE GOING FORECAST IS LOOKING GOOD SO JUST MINOR
ADJUSTMENTS FOR LATEST OBSERVATIONS AND TRENDS. RETURNS ON RADAR
CONTINUE TO RACE EASTWARD THIS MORNING AS AN UNINSPIRED AREA OF
LOW PRESSURE CONTINUES TO SLIDE BY TO OUR SOUTH. WATER VAPOR
IMAGERY SHOWS A LOT OF DRYING MOVING IN ALOFT SO THERE WILL BE NO
DEEP MOISTURE TO WORK WITH ONCE WE GET INTO THIS AFTERNOON...BUT
BUFKIT SOUNDINGS STILL SHOW DECENT MOISTURE IN THE LOW LEVELS FROM
THE BLUE RIDGE WEST SO LIKELY TRANSITIONING INTO A SNIZZLE SCENARIO
FOR THE MTNS. WE SHOULD BE JUST ABOUT DONE WITH MEASURABLE PCPN
FOR TODAY SO NOT EXPECTING ANY ADDITIONAL ACCUMS OF SNOW. BEST
RETURNS ON RADAR ARE CURRENTLY OVER THE PIEDMONT WHERE LOW LEVELS
ARE STILL FAIRLY DRY SO PROBABLY MORE VIRGA THAN ANYTHING REACHING
THE GROUND.

.PREVIOUS AFD...
LIGHT PRECIP EVENT TO UNFOLD THIS MORNING STILL
LOOKS ON TRACK AS SURFACE LOW PRESSURE PASSES WELL TO THE SOUTH
AND EAST OF THE REGION THROUGH THIS EVENING. THIS SHOULD KEEP THE
MAJORITY OF THE BETTER LIFT AND DEEP MOISTURE OFF TO THE SE WITH
ANY PRECIP OVER THE REGION PRIMARILY DRIVEN VIA WEAK UPPER
DIFFLUENCE BETWEEN MID LEVEL WAVES. ONE SUCH SHORTWAVE BEING WITH
THE LEAD SOUTHERNMOST IMPULSE LOOKS TO SLIDE ACROSS NW N CAROLINA
THIS MORNING AND COINCIDE WITH WEAK SE FLOW UNDER THE LEFT FRONT
OF THE PASSING SPEED MAX ALOFT. THIS SHOULD HELP DEVELOP AN AXIS
OF LIGHT SNOW FROM THE NC MOUNTAINS ALONG THE I-77 CORRIDOR EARLY
ON WITH SOME OF THIS SPREADING EAST BUT IN A DIMINISHING STATE
GIVEN DAMPENING SUPPORT AND RESIDUAL DRY AIR.

WITH THE LATEST MODELS ESPCLY SREF PRINTING OUT QPF OF AROUND A
TENTH OF AN INCH OR SO...BUMPED UP POPS TO HIGHER CHANCE SW AND
KEPT EXTENSION OF THE GOING CHANCE POPS ESPCLY SOUTH OF HIGHWAY
460 THIS MORNING. THIS MAY BRING A HALF/ONE INCH OF SNOW AT
ELEVATION FROM I-77 AND POINTS WEST EARLY ON BUT WITHOUT ANY
HEADLINES AS COULD EASILY END UP BEING SNOW SHOWERS/FLURRIES AT
WORSE PER LATEST RADAR TRENDS. ELSW EXPECT LITTLE OR NO
ACCUMULATION GIVEN THE VERY LIGHT PRECIP TYPE SCENARIO IF AT ALL
AS SEEN OFF THE LATEST HRRR. HIGH TEMPS REMAIN TRICKY AFTER SUCH A
COLD START WITH POTENTIAL TO SEE SOME BREAKS DEVELOP BLUE RIDGE
AND ACROSS THE NORTH/WEST LATER ON. THUS TRENDED VALUES UP A
DEGREE OR TWO NORTH WHILE DECREASING A CAT OR SO ESPCLY SE WHERE
SOMEWHAT DEEPER MOISTURE WILL BE LAST TO EXIT.

WEAK RIDGING TO THE NW DIPS BACK INTO THE AREA BEHIND THE DEPARTING
WAVE OVERNIGHT ALLOWING DRYING ALOFT TO TAKE SHAPE UNDER WEAK
SUBSIDENCE. HOWEVER JUST HOW MUCH LOW LEVEL MOISTURE REMAINS TRAPPED IN
QUESTION AND PARTLY DEPENDENT ON THE DEGREE OF MOISTENING TODAY WITH
THE CURRENT EVENT. GFS REMAINS RATHER DRY WITH WEAK NW FLOW THROUGH THE
COLUMN...WHILE THE NAM WETTER UNDER A LIGHT LOW LEVEL EAST/SE
COMPONENT THAT KEEPS QUITE A BIT OF BOUNDARY LAYER MOISTURE ACROSS THE
REGION. THIS COULD POSE A FREEZING DRIZZLE ISSUE ESPCLY BLUE RIDGE WITH
LOTS OF FREEZING FOG/LOW CLOUDS AROUND BUT QUITE IFFY. THUS WILL
GO WITH MORE CLOUDS AND SOME FREEZING FOG OVERNIGHT WHILE LEAVING
OUT ANY -FZDZ MENTION FOR NOW DESPITE DECENT DEPTH TO MOISTURE
UNDER THE INVERSION OFF THE NAM. LOW TEMPS ALSO REFLECT MOISTURE
DIFFERENCES WITH THE MAV MOS WELL INTO THE 20S MOST SPOTS WHILE
THE MET MOS A GOOD 5-10 DEGREES WARMER DUE TO CLOUDS. FOR
NOW...TWEAKED DOWN IN THE VALLEYS AND BLUE RIDGE WHILE LEAVING
THINGS A BIT WARMER WEST-SW WHERE LEFTOVER CLOUDS MORE OF A GOOD
BET IN THE WAKE OF TODAYS POSSIBLE PRECIP.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY/...
AS OF 430 AM EST SATURDAY...

WILL START SUNDAY OFF WITH LOW PRESSURE DEVELOPING ALONG THE
SOUTHEAST COAST. HIGH PRESSURE OVER EASTERN CANADA WILL CONTINUE TO
BUILD SOUTHWARD ACROSS NEW ENGLAND AND THE MID ATLANTIC...BECOMING
INCREASINGLY WEDGED AGAINST THE EASTERN FACE OF THE APPALACHIANS.
WILL SEE WINDS SHIFT MORE EAST NORTHEASTERLY BY EVENING...WITH THE
UPSLOPE FLOW ALONG THE BLUE RIDGE SUPPORTING POCKETS OF LIGHT RAIN
OR DRIZZLE...MAINLY OVER THE NORTH CAROLINA HIGHLANDS BY SUNSET.

THE LOW WILL PASS ALONG THE CAROLINA COAST SUNDAY NIGHT...RESULTING
IN INCREASING PRECIPITATION CHANCES APPROACHING DAWN ON MONDAY. AS
TEMPERATURES COOL THROUGH THE NIGHT...EXPECT TO SEE LIGHT RAIN/
DRIZZLE CHANGE OVER TO A MIXTURE OF RAIN AND FREEZING DRIZZLE OR
SLEET ACROSS THE AREA...WITH MORE MIXED PRECIPITATION NORTH OF
HIGHWAY 460. FORECAST SOUNDINGS INDICATE THAT MOISTURE REMAINS
SHALLOW HOWEVER...SO EXPECT VERY LITTLE ICE ACCUMULATION...IF ANY.
20/00Z MODELS HAVE TRENDED SLIGHTLY WEAKER WITH THIS LOW...WITH SOME
MODELS INDICATING MOISTURE HAVING A HARD TIME MAKING IT INTO
SOUTHEAST WEST VIRGINIA/FAR WESTERN VIRGINIA...REMAINING MORE
CONFINED TO THE PIEDMONT AND BLUE RIDGE. PRECIPITATION AMOUNTS ARE
ALSO LOWER...GENERALLY A FEW HUNDREDTHS OF AN INCH ACROSS THE
WESTERN RIDGES...TO A TENTH OR TWO ACROSS THE PIEDMONT.

MODEST DAYTIME WARMING ON MONDAY WILL CAUSE ANY MIXED PRECIPITATION
TO CHANGE OVER TO LIQUID MOST AREAS...ALTHOUGH A FEW POCKETS OF
SLEET OR LIGHT FREEZING RAIN MAY LINGER IN THE COLDER AIR ALONG AND
NORTH OF THE INTERSTATE 64 CORRIDOR THROUGH THE DAY. THE BRUNT OF
THE ENERGY WILL PASS EAST DURING EARLY AFTERNOON...LEAVING ONLY
SPOTTY PRECIPITATION THROUGH THE REMAINDER OF THE DAY.

BEGINNING MONDAY NIGHT...WILL SEE A GRADUAL WARMING TREND TAKE SHAPE
AS A DEEP LOW PRESSURE SYSTEM DEVELOPS OVER THE SOUTHERN PLAINS. THE
HIGH PRESSURE WEDGE WILL REMAIN IN PLACE THROUGH THE NIGHT...HOWEVER
TEMPERATURES ARE EXPECTED TO REMAIN WARM ENOUGH MOST LOCATIONS FOR
PRECIPITATION TO REMAIN LIQUID.

LOW PRESSURE WILL PUSH NORTH TOWARD THE GREAT LAKES TUESDAY AND
TUESDAY NIGHT...RESULTING IN INCREASING RAIN CHANCES DURING THE
PERIOD. PRECIPITABLE WATER VALUES WILL INCREASE SIGNIFICANTLY...
ESPECIALLY TUESDAY NIGHT...RISING TO THE 1.1 TO 1.4 INCH RANGE...
WHICH IS SIGNIFICANTLY HIGHER THAN NORMAL FOR LATE DECEMBER. AS
SUCH...HAVE WENT WILL HIGHER PRECIPITATION CHANCES FOR TUESDAY
NIGHT...WITH A COLD FRONT APPROACHING FROM THE WEST. MAY ALSO SEE
GUSTY WINDS TUESDAY NIGHT ACROSS THE MOUNTAINS AS A 50KT TO 60KT LOW
LEVEL JET ENTERS THE AREA.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 400 AM EST SATURDAY...

MODEL CONSENSUS OF GFS AND ECMWF IS THAT A SYNOPTIC UPPER TROUGH
OVER THE MISSISSIPPI VALLEY WILL EJECT A NEGATIVELY TILTED
THROUGH THE SOUTHEAST U. S. EARLY WEDNESDAY. WITH THE POSITION OF
THE ASSOCIATED SURFACE OCCLUDED FRONT AND THE TRIPLE POINT PASSING
SOMEWHERE NEAR OR JUST SOUTH OF OUR REGION...THERE IS THE
POTENTIAL FOR OUR REGION TO HAVE ACTIVE WEATHER WEDNESDAY WITH
PLENTY OF SHOWERS...PERHAPS VERY GUSTY WINDS AND A FEW
THUNDERSTORMS. LOOKS LIKE THE AXIS OF BETTER INSTABILITY MAY BE A
LITTLE FURTHER SOUTH ON THE 12Z MODEL RUN.

A COLD FRONT WILL MOVE EAST ACROSS OUR REGION WEDNESDAY INTO
WEDNESDAY NIGHT. HIGHS ON WEDNESDAY WILL WARM INTO THE LOWER 40S
IN THE WEST TO THE LOWER 50S IN THE EAST. RAIN AND SNOW SHOWERS
WILL CHANGEOVER TO SNOW SHOWERS AND SNOW FLURRIES IN THE WEST
WEDNESDAY NIGHT. LOW TEMPERATURES WEDNESDAY NIGHT WILL DROP INTO
THE MID 20S IN THE MOUNTAINS TO THE LOWER 30S IN THE PIEDMONT.
WEST TO NORTHWEST UPPER FLOW WILL CONTINUE INTO THURSDAY WITH
HIGHS FROM THE UPPER 20S IN THE MOUNTAINS TO AROUND 50 IN
PIEDMONT. WINDS WILL BE QUITE STRONG ON THURSDAY AS A 50 TO 55
KNOT 850MB JET PIVOTS ACROSS THE REGION. THE UPPER FLOW SHIFTS TO
THE SOUTHWEST THURSDAY NIGHT INTO FRIDAY AS TROF CURVES OUT IN THE
CENTRAL US WITH SFC INFLECTION OF LOW PRESSURE DEVELOPING OVER THE
TENNESSEE VALLEY BY FRIDAY MORNING. MOISTURE SLOWLY RETURN FRIDAY
NIGHT INTO SATURDAY AS THE HIGH CENTER SLIDE OFF THE COAST.

&&

.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
AS OF 545 AM EST SATURDAY...

AXIS OF LIGHT SNOW NOW MOVING ACROSS THE FAR WEST/SW AND LIKELY TO
IMPACT KBLF SHORTLY WITH A BRIEF PERIOD OF MVFR CIGS/VSBYS. OTRW
LOOKING AT LOWERING CIGS THIS MORNING FROM WEST TO EAST WITH MVFR
CIGS POSSIBLY SPREADING AS FAR EAST AS KBCB/KROA...AND NORTH AS
KLWB WHERE STILL MAINTAINING VFR VSBYS IN -SN THROUGH LATE
MORNING FOR NOW. THINKING EASTERN SITES SHOULD STAY VFR WITH ONLY
SOME SPOTTY -RA/-SN ARRIVING BY MID MORNING IF THE PRECIP HOLDS
TOGETHER.

THIS SYSTEM MOVES OUT FAIRLY QUICKLY WITH MOST PRECIPITATION
ENDING BY 19-20Z/2-3PM IF NOT SOONER. HOWEVER...A SHALLOW LAYER OF
MOISTURE BANKING UP AGAINST THE WESTERN SLOPES WILL KEEP
CLOUDS...LOWERING TO MVFR LEVELS AT KBLF THIS AFTERNOON. MAY SEE
CIGS ACTUALLY RISE A BIT BEHIND THE DEPARTING SPOTTY PRECIP ELSW BEFORE
SHALLOW MOISTURE BECOMES MORE WIDESPREAD THIS EVENING ESPCLY WHERE
ANY EARLIER SNOW/RAIN OCCURRED. THIS MAY LEAD TO LOW CLOUDS WITH
EVEN IFR CONDITIONS IN SPOTS GIVEN WESTERLY FLOW AROUND KBLF
OVERNIGHT...AND MVFR TO IFR ALONG THE BLUE RIDGE LATE. SOME
PATCHY DRIZZLE/LIGHT SNOW IS ALSO POSSIBLE THIS EVENING THEN
PERHAPS MORE WIDESPREAD ALONG THE BLUE RIDGE INCLUDING PATCHY
DENSE FOG AFTER MIDNIGHT. THIS HOWEVER REMAINS LOW CONFIDENCE
GIVEN DIFFERING MODEL SOLUTIONS BUT DID INCLUDE SOME LOWER
CIGS/VSBYS AT MOST SPOTS WITH POSSIBLE IFR IN STRATUS/FOG.

EXTENDED DISCUSSION...

ONCE THIS FEATURE EXITS WILL SEE THE NEXT WAVE ALONG THE COAST
BRING ANOTHER ROUND OF SUB-VFR CONDITIONS FOR LATER SUNDAY NIGHT
INTO MONDAY. RAIN WILL BE THE PRIMARY PRECIPITATION TYPE WITH
THE POTENTIAL FOR POCKETS OF FREEZING RAIN LATE SUNDAY NIGHT INTO
MONDAY MORNING ACROSS COLDER NORTHERN PORTIONS OF FORECAST AREA WHICH
MIGHT IMPACT LWB IF TEMPERATURES ARE COLD ENOUGH.

RAIN WILL IMPACT AREAS ALONG AND EAST OF THE BLUE RIDGE...WITH
YET ANOTHER SYSTEM SLATED FOR LATE TUESDAY INTO WEDNESDAY AHEAD OF
A STRONG COLD FRONT. THESE SYSTEMS ARE EXPECTED TO BRING A PERIOD
MAINLY RAIN BUT COULD BE SOME WINTRY WX AS WELL ESPECIALLY IN THE
MOUNTAINS WITH THE SUNDAY NIGHT/MONDAY EVENT. EXPECT POTENTIAL LOW
LEVEL WIND SHEAR AS WELL AND POOR FLYING WEATHER FOR EARLY NEXT
WEEK. RAIN AND SNOW SHOWERS WILL CONTINUE INTO WEDNESDAY. GUSTY
NORTHWEST WINDS ARE POSSIBLE WEDNESDAY INTO THURSDAY. MOUNTAIN
SNOW SHOWERS AND SNOW FLURRIES EXPECTED WEDNESDAY NIGHT INTO
CHRISTMAS.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...JH
NEAR TERM...JH/MBS
SHORT TERM...AMS/NF
LONG TERM...KK
AVIATION...JH/PH/WP





000
FXUS61 KRNK 201443
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
943 AM EST SAT DEC 20 2014

.SYNOPSIS...
WEAK LOW PRESSURE ACROSS THE SOUTHEAST STATES WILL PASS EAST AND
OFFSHORE THIS AFTERNOON KEEPING MOST SIGNIFICANT PRECIPITATION TO
THE SOUTH OF THE REGION. HIGH PRESSURE WILL SPILL BACK SOUTH INTO
THE AREA TONIGHT THROUGH SUNDAY NIGHT AHEAD OF ANOTHER LOW
PRESSURE SYSTEM THAT WILL SLIDE UP THE COAST ON MONDAY. A STRONG
COLD FRONT APPROACHES FROM THE WEST TUESDAY INTO TUESDAY NIGHT
BEFORE PASSING THROUGH THE REGION ON WEDNESDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 1040 AM EST SATURDAY...

FLAVOR OF THE GOING FORECAST IS LOOKING GOOD SO JUST MINOR
ADJUSTMENTS FOR LATEST OBSERVATIONS AND TRENDS. RETURNS ON RADAR
CONTINUE TO RACE EASTWARD THIS MORNING AS AN UNINSPIRED AREA OF
LOW PRESSURE CONTINUES TO SLIDE BY TO OUR SOUTH. WATER VAPOR
IMAGERY SHOWS A LOT OF DRYING MOVING IN ALOFT SO THERE WILL BE NO
DEEP MOISTURE TO WORK WITH ONCE WE GET INTO THIS AFTERNOON...BUT
BUFKIT SOUNDINGS STILL SHOW DECENT MOISTURE IN THE LOW LEVELS FROM
THE BLUE RIDGE WEST SO LIKELY TRANSITIONING INTO A SNIZZLE SCENARIO
FOR THE MTNS. WE SHOULD BE JUST ABOUT DONE WITH MEASURABLE PCPN
FOR TODAY SO NOT EXPECTING ANY ADDITIONAL ACCUMS OF SNOW. BEST
RETURNS ON RADAR ARE CURRENTLY OVER THE PIEDMONT WHERE LOW LEVELS
ARE STILL FAIRLY DRY SO PROBABLY MORE VIRGA THAN ANYTHING REACHING
THE GROUND.

.PREVIOUS AFD...
LIGHT PRECIP EVENT TO UNFOLD THIS MORNING STILL
LOOKS ON TRACK AS SURFACE LOW PRESSURE PASSES WELL TO THE SOUTH
AND EAST OF THE REGION THROUGH THIS EVENING. THIS SHOULD KEEP THE
MAJORITY OF THE BETTER LIFT AND DEEP MOISTURE OFF TO THE SE WITH
ANY PRECIP OVER THE REGION PRIMARILY DRIVEN VIA WEAK UPPER
DIFFLUENCE BETWEEN MID LEVEL WAVES. ONE SUCH SHORTWAVE BEING WITH
THE LEAD SOUTHERNMOST IMPULSE LOOKS TO SLIDE ACROSS NW N CAROLINA
THIS MORNING AND COINCIDE WITH WEAK SE FLOW UNDER THE LEFT FRONT
OF THE PASSING SPEED MAX ALOFT. THIS SHOULD HELP DEVELOP AN AXIS
OF LIGHT SNOW FROM THE NC MOUNTAINS ALONG THE I-77 CORRIDOR EARLY
ON WITH SOME OF THIS SPREADING EAST BUT IN A DIMINISHING STATE
GIVEN DAMPENING SUPPORT AND RESIDUAL DRY AIR.

WITH THE LATEST MODELS ESPCLY SREF PRINTING OUT QPF OF AROUND A
TENTH OF AN INCH OR SO...BUMPED UP POPS TO HIGHER CHANCE SW AND
KEPT EXTENSION OF THE GOING CHANCE POPS ESPCLY SOUTH OF HIGHWAY
460 THIS MORNING. THIS MAY BRING A HALF/ONE INCH OF SNOW AT
ELEVATION FROM I-77 AND POINTS WEST EARLY ON BUT WITHOUT ANY
HEADLINES AS COULD EASILY END UP BEING SNOW SHOWERS/FLURRIES AT
WORSE PER LATEST RADAR TRENDS. ELSW EXPECT LITTLE OR NO
ACCUMULATION GIVEN THE VERY LIGHT PRECIP TYPE SCENARIO IF AT ALL
AS SEEN OFF THE LATEST HRRR. HIGH TEMPS REMAIN TRICKY AFTER SUCH A
COLD START WITH POTENTIAL TO SEE SOME BREAKS DEVELOP BLUE RIDGE
AND ACROSS THE NORTH/WEST LATER ON. THUS TRENDED VALUES UP A
DEGREE OR TWO NORTH WHILE DECREASING A CAT OR SO ESPCLY SE WHERE
SOMEWHAT DEEPER MOISTURE WILL BE LAST TO EXIT.

WEAK RIDGING TO THE NW DIPS BACK INTO THE AREA BEHIND THE DEPARTING
WAVE OVERNIGHT ALLOWING DRYING ALOFT TO TAKE SHAPE UNDER WEAK
SUBSIDENCE. HOWEVER JUST HOW MUCH LOW LEVEL MOISTURE REMAINS TRAPPED IN
QUESTION AND PARTLY DEPENDENT ON THE DEGREE OF MOISTENING TODAY WITH
THE CURRENT EVENT. GFS REMAINS RATHER DRY WITH WEAK NW FLOW THROUGH THE
COLUMN...WHILE THE NAM WETTER UNDER A LIGHT LOW LEVEL EAST/SE
COMPONENT THAT KEEPS QUITE A BIT OF BOUNDARY LAYER MOISTURE ACROSS THE
REGION. THIS COULD POSE A FREEZING DRIZZLE ISSUE ESPCLY BLUE RIDGE WITH
LOTS OF FREEZING FOG/LOW CLOUDS AROUND BUT QUITE IFFY. THUS WILL
GO WITH MORE CLOUDS AND SOME FREEZING FOG OVERNIGHT WHILE LEAVING
OUT ANY -FZDZ MENTION FOR NOW DESPITE DECENT DEPTH TO MOISTURE
UNDER THE INVERSION OFF THE NAM. LOW TEMPS ALSO REFLECT MOISTURE
DIFFERENCES WITH THE MAV MOS WELL INTO THE 20S MOST SPOTS WHILE
THE MET MOS A GOOD 5-10 DEGREES WARMER DUE TO CLOUDS. FOR
NOW...TWEAKED DOWN IN THE VALLEYS AND BLUE RIDGE WHILE LEAVING
THINGS A BIT WARMER WEST-SW WHERE LEFTOVER CLOUDS MORE OF A GOOD
BET IN THE WAKE OF TODAYS POSSIBLE PRECIP.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY/...
AS OF 430 AM EST SATURDAY...

WILL START SUNDAY OFF WITH LOW PRESSURE DEVELOPING ALONG THE
SOUTHEAST COAST. HIGH PRESSURE OVER EASTERN CANADA WILL CONTINUE TO
BUILD SOUTHWARD ACROSS NEW ENGLAND AND THE MID ATLANTIC...BECOMING
INCREASINGLY WEDGED AGAINST THE EASTERN FACE OF THE APPALACHIANS.
WILL SEE WINDS SHIFT MORE EAST NORTHEASTERLY BY EVENING...WITH THE
UPSLOPE FLOW ALONG THE BLUE RIDGE SUPPORTING POCKETS OF LIGHT RAIN
OR DRIZZLE...MAINLY OVER THE NORTH CAROLINA HIGHLANDS BY SUNSET.

THE LOW WILL PASS ALONG THE CAROLINA COAST SUNDAY NIGHT...RESULTING
IN INCREASING PRECIPITATION CHANCES APPROACHING DAWN ON MONDAY. AS
TEMPERATURES COOL THROUGH THE NIGHT...EXPECT TO SEE LIGHT RAIN/
DRIZZLE CHANGE OVER TO A MIXTURE OF RAIN AND FREEZING DRIZZLE OR
SLEET ACROSS THE AREA...WITH MORE MIXED PRECIPITATION NORTH OF
HIGHWAY 460. FORECAST SOUNDINGS INDICATE THAT MOISTURE REMAINS
SHALLOW HOWEVER...SO EXPECT VERY LITTLE ICE ACCUMULATION...IF ANY.
20/00Z MODELS HAVE TRENDED SLIGHTLY WEAKER WITH THIS LOW...WITH SOME
MODELS INDICATING MOISTURE HAVING A HARD TIME MAKING IT INTO
SOUTHEAST WEST VIRGINIA/FAR WESTERN VIRGINIA...REMAINING MORE
CONFINED TO THE PIEDMONT AND BLUE RIDGE. PRECIPITATION AMOUNTS ARE
ALSO LOWER...GENERALLY A FEW HUNDREDTHS OF AN INCH ACROSS THE
WESTERN RIDGES...TO A TENTH OR TWO ACROSS THE PIEDMONT.

MODEST DAYTIME WARMING ON MONDAY WILL CAUSE ANY MIXED PRECIPITATION
TO CHANGE OVER TO LIQUID MOST AREAS...ALTHOUGH A FEW POCKETS OF
SLEET OR LIGHT FREEZING RAIN MAY LINGER IN THE COLDER AIR ALONG AND
NORTH OF THE INTERSTATE 64 CORRIDOR THROUGH THE DAY. THE BRUNT OF
THE ENERGY WILL PASS EAST DURING EARLY AFTERNOON...LEAVING ONLY
SPOTTY PRECIPITATION THROUGH THE REMAINDER OF THE DAY.

BEGINNING MONDAY NIGHT...WILL SEE A GRADUAL WARMING TREND TAKE SHAPE
AS A DEEP LOW PRESSURE SYSTEM DEVELOPS OVER THE SOUTHERN PLAINS. THE
HIGH PRESSURE WEDGE WILL REMAIN IN PLACE THROUGH THE NIGHT...HOWEVER
TEMPERATURES ARE EXPECTED TO REMAIN WARM ENOUGH MOST LOCATIONS FOR
PRECIPITATION TO REMAIN LIQUID.

LOW PRESSURE WILL PUSH NORTH TOWARD THE GREAT LAKES TUESDAY AND
TUESDAY NIGHT...RESULTING IN INCREASING RAIN CHANCES DURING THE
PERIOD. PRECIPITABLE WATER VALUES WILL INCREASE SIGNIFICANTLY...
ESPECIALLY TUESDAY NIGHT...RISING TO THE 1.1 TO 1.4 INCH RANGE...
WHICH IS SIGNIFICANTLY HIGHER THAN NORMAL FOR LATE DECEMBER. AS
SUCH...HAVE WENT WILL HIGHER PRECIPITATION CHANCES FOR TUESDAY
NIGHT...WITH A COLD FRONT APPROACHING FROM THE WEST. MAY ALSO SEE
GUSTY WINDS TUESDAY NIGHT ACROSS THE MOUNTAINS AS A 50KT TO 60KT LOW
LEVEL JET ENTERS THE AREA.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 400 AM EST SATURDAY...

MODEL CONSENSUS OF GFS AND ECMWF IS THAT A SYNOPTIC UPPER TROUGH
OVER THE MISSISSIPPI VALLEY WILL EJECT A NEGATIVELY TILTED
THROUGH THE SOUTHEAST U. S. EARLY WEDNESDAY. WITH THE POSITION OF
THE ASSOCIATED SURFACE OCCLUDED FRONT AND THE TRIPLE POINT PASSING
SOMEWHERE NEAR OR JUST SOUTH OF OUR REGION...THERE IS THE
POTENTIAL FOR OUR REGION TO HAVE ACTIVE WEATHER WEDNESDAY WITH
PLENTY OF SHOWERS...PERHAPS VERY GUSTY WINDS AND A FEW
THUNDERSTORMS. LOOKS LIKE THE AXIS OF BETTER INSTABILITY MAY BE A
LITTLE FURTHER SOUTH ON THE 12Z MODEL RUN.

A COLD FRONT WILL MOVE EAST ACROSS OUR REGION WEDNESDAY INTO
WEDNESDAY NIGHT. HIGHS ON WEDNESDAY WILL WARM INTO THE LOWER 40S
IN THE WEST TO THE LOWER 50S IN THE EAST. RAIN AND SNOW SHOWERS
WILL CHANGEOVER TO SNOW SHOWERS AND SNOW FLURRIES IN THE WEST
WEDNESDAY NIGHT. LOW TEMPERATURES WEDNESDAY NIGHT WILL DROP INTO
THE MID 20S IN THE MOUNTAINS TO THE LOWER 30S IN THE PIEDMONT.
WEST TO NORTHWEST UPPER FLOW WILL CONTINUE INTO THURSDAY WITH
HIGHS FROM THE UPPER 20S IN THE MOUNTAINS TO AROUND 50 IN
PIEDMONT. WINDS WILL BE QUITE STRONG ON THURSDAY AS A 50 TO 55
KNOT 850MB JET PIVOTS ACROSS THE REGION. THE UPPER FLOW SHIFTS TO
THE SOUTHWEST THURSDAY NIGHT INTO FRIDAY AS TROF CURVES OUT IN THE
CENTRAL US WITH SFC INFLECTION OF LOW PRESSURE DEVELOPING OVER THE
TENNESSEE VALLEY BY FRIDAY MORNING. MOISTURE SLOWLY RETURN FRIDAY
NIGHT INTO SATURDAY AS THE HIGH CENTER SLIDE OFF THE COAST.

&&

.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
AS OF 545 AM EST SATURDAY...

AXIS OF LIGHT SNOW NOW MOVING ACROSS THE FAR WEST/SW AND LIKELY TO
IMPACT KBLF SHORTLY WITH A BRIEF PERIOD OF MVFR CIGS/VSBYS. OTRW
LOOKING AT LOWERING CIGS THIS MORNING FROM WEST TO EAST WITH MVFR
CIGS POSSIBLY SPREADING AS FAR EAST AS KBCB/KROA...AND NORTH AS
KLWB WHERE STILL MAINTAINING VFR VSBYS IN -SN THROUGH LATE
MORNING FOR NOW. THINKING EASTERN SITES SHOULD STAY VFR WITH ONLY
SOME SPOTTY -RA/-SN ARRIVING BY MID MORNING IF THE PRECIP HOLDS
TOGETHER.

THIS SYSTEM MOVES OUT FAIRLY QUICKLY WITH MOST PRECIPITATION
ENDING BY 19-20Z/2-3PM IF NOT SOONER. HOWEVER...A SHALLOW LAYER OF
MOISTURE BANKING UP AGAINST THE WESTERN SLOPES WILL KEEP
CLOUDS...LOWERING TO MVFR LEVELS AT KBLF THIS AFTERNOON. MAY SEE
CIGS ACTUALLY RISE A BIT BEHIND THE DEPARTING SPOTTY PRECIP ELSW BEFORE
SHALLOW MOISTURE BECOMES MORE WIDESPREAD THIS EVENING ESPCLY WHERE
ANY EARLIER SNOW/RAIN OCCURRED. THIS MAY LEAD TO LOW CLOUDS WITH
EVEN IFR CONDITIONS IN SPOTS GIVEN WESTERLY FLOW AROUND KBLF
OVERNIGHT...AND MVFR TO IFR ALONG THE BLUE RIDGE LATE. SOME
PATCHY DRIZZLE/LIGHT SNOW IS ALSO POSSIBLE THIS EVENING THEN
PERHAPS MORE WIDESPREAD ALONG THE BLUE RIDGE INCLUDING PATCHY
DENSE FOG AFTER MIDNIGHT. THIS HOWEVER REMAINS LOW CONFIDENCE
GIVEN DIFFERING MODEL SOLUTIONS BUT DID INCLUDE SOME LOWER
CIGS/VSBYS AT MOST SPOTS WITH POSSIBLE IFR IN STRATUS/FOG.

EXTENDED DISCUSSION...

ONCE THIS FEATURE EXITS WILL SEE THE NEXT WAVE ALONG THE COAST
BRING ANOTHER ROUND OF SUB-VFR CONDITIONS FOR LATER SUNDAY NIGHT
INTO MONDAY. RAIN WILL BE THE PRIMARY PRECIPITATION TYPE WITH
THE POTENTIAL FOR POCKETS OF FREEZING RAIN LATE SUNDAY NIGHT INTO
MONDAY MORNING ACROSS COLDER NORTHERN PORTIONS OF FORECAST AREA WHICH
MIGHT IMPACT LWB IF TEMPERATURES ARE COLD ENOUGH.

RAIN WILL IMPACT AREAS ALONG AND EAST OF THE BLUE RIDGE...WITH
YET ANOTHER SYSTEM SLATED FOR LATE TUESDAY INTO WEDNESDAY AHEAD OF
A STRONG COLD FRONT. THESE SYSTEMS ARE EXPECTED TO BRING A PERIOD
MAINLY RAIN BUT COULD BE SOME WINTRY WX AS WELL ESPECIALLY IN THE
MOUNTAINS WITH THE SUNDAY NIGHT/MONDAY EVENT. EXPECT POTENTIAL LOW
LEVEL WIND SHEAR AS WELL AND POOR FLYING WEATHER FOR EARLY NEXT
WEEK. RAIN AND SNOW SHOWERS WILL CONTINUE INTO WEDNESDAY. GUSTY
NORTHWEST WINDS ARE POSSIBLE WEDNESDAY INTO THURSDAY. MOUNTAIN
SNOW SHOWERS AND SNOW FLURRIES EXPECTED WEDNESDAY NIGHT INTO
CHRISTMAS.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...JH
NEAR TERM...JH/MBS
SHORT TERM...AMS/NF
LONG TERM...KK
AVIATION...JH/PH/WP




000
FXUS61 KRNK 201443
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
943 AM EST SAT DEC 20 2014

.SYNOPSIS...
WEAK LOW PRESSURE ACROSS THE SOUTHEAST STATES WILL PASS EAST AND
OFFSHORE THIS AFTERNOON KEEPING MOST SIGNIFICANT PRECIPITATION TO
THE SOUTH OF THE REGION. HIGH PRESSURE WILL SPILL BACK SOUTH INTO
THE AREA TONIGHT THROUGH SUNDAY NIGHT AHEAD OF ANOTHER LOW
PRESSURE SYSTEM THAT WILL SLIDE UP THE COAST ON MONDAY. A STRONG
COLD FRONT APPROACHES FROM THE WEST TUESDAY INTO TUESDAY NIGHT
BEFORE PASSING THROUGH THE REGION ON WEDNESDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 1040 AM EST SATURDAY...

FLAVOR OF THE GOING FORECAST IS LOOKING GOOD SO JUST MINOR
ADJUSTMENTS FOR LATEST OBSERVATIONS AND TRENDS. RETURNS ON RADAR
CONTINUE TO RACE EASTWARD THIS MORNING AS AN UNINSPIRED AREA OF
LOW PRESSURE CONTINUES TO SLIDE BY TO OUR SOUTH. WATER VAPOR
IMAGERY SHOWS A LOT OF DRYING MOVING IN ALOFT SO THERE WILL BE NO
DEEP MOISTURE TO WORK WITH ONCE WE GET INTO THIS AFTERNOON...BUT
BUFKIT SOUNDINGS STILL SHOW DECENT MOISTURE IN THE LOW LEVELS FROM
THE BLUE RIDGE WEST SO LIKELY TRANSITIONING INTO A SNIZZLE SCENARIO
FOR THE MTNS. WE SHOULD BE JUST ABOUT DONE WITH MEASURABLE PCPN
FOR TODAY SO NOT EXPECTING ANY ADDITIONAL ACCUMS OF SNOW. BEST
RETURNS ON RADAR ARE CURRENTLY OVER THE PIEDMONT WHERE LOW LEVELS
ARE STILL FAIRLY DRY SO PROBABLY MORE VIRGA THAN ANYTHING REACHING
THE GROUND.

.PREVIOUS AFD...
LIGHT PRECIP EVENT TO UNFOLD THIS MORNING STILL
LOOKS ON TRACK AS SURFACE LOW PRESSURE PASSES WELL TO THE SOUTH
AND EAST OF THE REGION THROUGH THIS EVENING. THIS SHOULD KEEP THE
MAJORITY OF THE BETTER LIFT AND DEEP MOISTURE OFF TO THE SE WITH
ANY PRECIP OVER THE REGION PRIMARILY DRIVEN VIA WEAK UPPER
DIFFLUENCE BETWEEN MID LEVEL WAVES. ONE SUCH SHORTWAVE BEING WITH
THE LEAD SOUTHERNMOST IMPULSE LOOKS TO SLIDE ACROSS NW N CAROLINA
THIS MORNING AND COINCIDE WITH WEAK SE FLOW UNDER THE LEFT FRONT
OF THE PASSING SPEED MAX ALOFT. THIS SHOULD HELP DEVELOP AN AXIS
OF LIGHT SNOW FROM THE NC MOUNTAINS ALONG THE I-77 CORRIDOR EARLY
ON WITH SOME OF THIS SPREADING EAST BUT IN A DIMINISHING STATE
GIVEN DAMPENING SUPPORT AND RESIDUAL DRY AIR.

WITH THE LATEST MODELS ESPCLY SREF PRINTING OUT QPF OF AROUND A
TENTH OF AN INCH OR SO...BUMPED UP POPS TO HIGHER CHANCE SW AND
KEPT EXTENSION OF THE GOING CHANCE POPS ESPCLY SOUTH OF HIGHWAY
460 THIS MORNING. THIS MAY BRING A HALF/ONE INCH OF SNOW AT
ELEVATION FROM I-77 AND POINTS WEST EARLY ON BUT WITHOUT ANY
HEADLINES AS COULD EASILY END UP BEING SNOW SHOWERS/FLURRIES AT
WORSE PER LATEST RADAR TRENDS. ELSW EXPECT LITTLE OR NO
ACCUMULATION GIVEN THE VERY LIGHT PRECIP TYPE SCENARIO IF AT ALL
AS SEEN OFF THE LATEST HRRR. HIGH TEMPS REMAIN TRICKY AFTER SUCH A
COLD START WITH POTENTIAL TO SEE SOME BREAKS DEVELOP BLUE RIDGE
AND ACROSS THE NORTH/WEST LATER ON. THUS TRENDED VALUES UP A
DEGREE OR TWO NORTH WHILE DECREASING A CAT OR SO ESPCLY SE WHERE
SOMEWHAT DEEPER MOISTURE WILL BE LAST TO EXIT.

WEAK RIDGING TO THE NW DIPS BACK INTO THE AREA BEHIND THE DEPARTING
WAVE OVERNIGHT ALLOWING DRYING ALOFT TO TAKE SHAPE UNDER WEAK
SUBSIDENCE. HOWEVER JUST HOW MUCH LOW LEVEL MOISTURE REMAINS TRAPPED IN
QUESTION AND PARTLY DEPENDENT ON THE DEGREE OF MOISTENING TODAY WITH
THE CURRENT EVENT. GFS REMAINS RATHER DRY WITH WEAK NW FLOW THROUGH THE
COLUMN...WHILE THE NAM WETTER UNDER A LIGHT LOW LEVEL EAST/SE
COMPONENT THAT KEEPS QUITE A BIT OF BOUNDARY LAYER MOISTURE ACROSS THE
REGION. THIS COULD POSE A FREEZING DRIZZLE ISSUE ESPCLY BLUE RIDGE WITH
LOTS OF FREEZING FOG/LOW CLOUDS AROUND BUT QUITE IFFY. THUS WILL
GO WITH MORE CLOUDS AND SOME FREEZING FOG OVERNIGHT WHILE LEAVING
OUT ANY -FZDZ MENTION FOR NOW DESPITE DECENT DEPTH TO MOISTURE
UNDER THE INVERSION OFF THE NAM. LOW TEMPS ALSO REFLECT MOISTURE
DIFFERENCES WITH THE MAV MOS WELL INTO THE 20S MOST SPOTS WHILE
THE MET MOS A GOOD 5-10 DEGREES WARMER DUE TO CLOUDS. FOR
NOW...TWEAKED DOWN IN THE VALLEYS AND BLUE RIDGE WHILE LEAVING
THINGS A BIT WARMER WEST-SW WHERE LEFTOVER CLOUDS MORE OF A GOOD
BET IN THE WAKE OF TODAYS POSSIBLE PRECIP.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY/...
AS OF 430 AM EST SATURDAY...

WILL START SUNDAY OFF WITH LOW PRESSURE DEVELOPING ALONG THE
SOUTHEAST COAST. HIGH PRESSURE OVER EASTERN CANADA WILL CONTINUE TO
BUILD SOUTHWARD ACROSS NEW ENGLAND AND THE MID ATLANTIC...BECOMING
INCREASINGLY WEDGED AGAINST THE EASTERN FACE OF THE APPALACHIANS.
WILL SEE WINDS SHIFT MORE EAST NORTHEASTERLY BY EVENING...WITH THE
UPSLOPE FLOW ALONG THE BLUE RIDGE SUPPORTING POCKETS OF LIGHT RAIN
OR DRIZZLE...MAINLY OVER THE NORTH CAROLINA HIGHLANDS BY SUNSET.

THE LOW WILL PASS ALONG THE CAROLINA COAST SUNDAY NIGHT...RESULTING
IN INCREASING PRECIPITATION CHANCES APPROACHING DAWN ON MONDAY. AS
TEMPERATURES COOL THROUGH THE NIGHT...EXPECT TO SEE LIGHT RAIN/
DRIZZLE CHANGE OVER TO A MIXTURE OF RAIN AND FREEZING DRIZZLE OR
SLEET ACROSS THE AREA...WITH MORE MIXED PRECIPITATION NORTH OF
HIGHWAY 460. FORECAST SOUNDINGS INDICATE THAT MOISTURE REMAINS
SHALLOW HOWEVER...SO EXPECT VERY LITTLE ICE ACCUMULATION...IF ANY.
20/00Z MODELS HAVE TRENDED SLIGHTLY WEAKER WITH THIS LOW...WITH SOME
MODELS INDICATING MOISTURE HAVING A HARD TIME MAKING IT INTO
SOUTHEAST WEST VIRGINIA/FAR WESTERN VIRGINIA...REMAINING MORE
CONFINED TO THE PIEDMONT AND BLUE RIDGE. PRECIPITATION AMOUNTS ARE
ALSO LOWER...GENERALLY A FEW HUNDREDTHS OF AN INCH ACROSS THE
WESTERN RIDGES...TO A TENTH OR TWO ACROSS THE PIEDMONT.

MODEST DAYTIME WARMING ON MONDAY WILL CAUSE ANY MIXED PRECIPITATION
TO CHANGE OVER TO LIQUID MOST AREAS...ALTHOUGH A FEW POCKETS OF
SLEET OR LIGHT FREEZING RAIN MAY LINGER IN THE COLDER AIR ALONG AND
NORTH OF THE INTERSTATE 64 CORRIDOR THROUGH THE DAY. THE BRUNT OF
THE ENERGY WILL PASS EAST DURING EARLY AFTERNOON...LEAVING ONLY
SPOTTY PRECIPITATION THROUGH THE REMAINDER OF THE DAY.

BEGINNING MONDAY NIGHT...WILL SEE A GRADUAL WARMING TREND TAKE SHAPE
AS A DEEP LOW PRESSURE SYSTEM DEVELOPS OVER THE SOUTHERN PLAINS. THE
HIGH PRESSURE WEDGE WILL REMAIN IN PLACE THROUGH THE NIGHT...HOWEVER
TEMPERATURES ARE EXPECTED TO REMAIN WARM ENOUGH MOST LOCATIONS FOR
PRECIPITATION TO REMAIN LIQUID.

LOW PRESSURE WILL PUSH NORTH TOWARD THE GREAT LAKES TUESDAY AND
TUESDAY NIGHT...RESULTING IN INCREASING RAIN CHANCES DURING THE
PERIOD. PRECIPITABLE WATER VALUES WILL INCREASE SIGNIFICANTLY...
ESPECIALLY TUESDAY NIGHT...RISING TO THE 1.1 TO 1.4 INCH RANGE...
WHICH IS SIGNIFICANTLY HIGHER THAN NORMAL FOR LATE DECEMBER. AS
SUCH...HAVE WENT WILL HIGHER PRECIPITATION CHANCES FOR TUESDAY
NIGHT...WITH A COLD FRONT APPROACHING FROM THE WEST. MAY ALSO SEE
GUSTY WINDS TUESDAY NIGHT ACROSS THE MOUNTAINS AS A 50KT TO 60KT LOW
LEVEL JET ENTERS THE AREA.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 400 AM EST SATURDAY...

MODEL CONSENSUS OF GFS AND ECMWF IS THAT A SYNOPTIC UPPER TROUGH
OVER THE MISSISSIPPI VALLEY WILL EJECT A NEGATIVELY TILTED
THROUGH THE SOUTHEAST U. S. EARLY WEDNESDAY. WITH THE POSITION OF
THE ASSOCIATED SURFACE OCCLUDED FRONT AND THE TRIPLE POINT PASSING
SOMEWHERE NEAR OR JUST SOUTH OF OUR REGION...THERE IS THE
POTENTIAL FOR OUR REGION TO HAVE ACTIVE WEATHER WEDNESDAY WITH
PLENTY OF SHOWERS...PERHAPS VERY GUSTY WINDS AND A FEW
THUNDERSTORMS. LOOKS LIKE THE AXIS OF BETTER INSTABILITY MAY BE A
LITTLE FURTHER SOUTH ON THE 12Z MODEL RUN.

A COLD FRONT WILL MOVE EAST ACROSS OUR REGION WEDNESDAY INTO
WEDNESDAY NIGHT. HIGHS ON WEDNESDAY WILL WARM INTO THE LOWER 40S
IN THE WEST TO THE LOWER 50S IN THE EAST. RAIN AND SNOW SHOWERS
WILL CHANGEOVER TO SNOW SHOWERS AND SNOW FLURRIES IN THE WEST
WEDNESDAY NIGHT. LOW TEMPERATURES WEDNESDAY NIGHT WILL DROP INTO
THE MID 20S IN THE MOUNTAINS TO THE LOWER 30S IN THE PIEDMONT.
WEST TO NORTHWEST UPPER FLOW WILL CONTINUE INTO THURSDAY WITH
HIGHS FROM THE UPPER 20S IN THE MOUNTAINS TO AROUND 50 IN
PIEDMONT. WINDS WILL BE QUITE STRONG ON THURSDAY AS A 50 TO 55
KNOT 850MB JET PIVOTS ACROSS THE REGION. THE UPPER FLOW SHIFTS TO
THE SOUTHWEST THURSDAY NIGHT INTO FRIDAY AS TROF CURVES OUT IN THE
CENTRAL US WITH SFC INFLECTION OF LOW PRESSURE DEVELOPING OVER THE
TENNESSEE VALLEY BY FRIDAY MORNING. MOISTURE SLOWLY RETURN FRIDAY
NIGHT INTO SATURDAY AS THE HIGH CENTER SLIDE OFF THE COAST.

&&

.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
AS OF 545 AM EST SATURDAY...

AXIS OF LIGHT SNOW NOW MOVING ACROSS THE FAR WEST/SW AND LIKELY TO
IMPACT KBLF SHORTLY WITH A BRIEF PERIOD OF MVFR CIGS/VSBYS. OTRW
LOOKING AT LOWERING CIGS THIS MORNING FROM WEST TO EAST WITH MVFR
CIGS POSSIBLY SPREADING AS FAR EAST AS KBCB/KROA...AND NORTH AS
KLWB WHERE STILL MAINTAINING VFR VSBYS IN -SN THROUGH LATE
MORNING FOR NOW. THINKING EASTERN SITES SHOULD STAY VFR WITH ONLY
SOME SPOTTY -RA/-SN ARRIVING BY MID MORNING IF THE PRECIP HOLDS
TOGETHER.

THIS SYSTEM MOVES OUT FAIRLY QUICKLY WITH MOST PRECIPITATION
ENDING BY 19-20Z/2-3PM IF NOT SOONER. HOWEVER...A SHALLOW LAYER OF
MOISTURE BANKING UP AGAINST THE WESTERN SLOPES WILL KEEP
CLOUDS...LOWERING TO MVFR LEVELS AT KBLF THIS AFTERNOON. MAY SEE
CIGS ACTUALLY RISE A BIT BEHIND THE DEPARTING SPOTTY PRECIP ELSW BEFORE
SHALLOW MOISTURE BECOMES MORE WIDESPREAD THIS EVENING ESPCLY WHERE
ANY EARLIER SNOW/RAIN OCCURRED. THIS MAY LEAD TO LOW CLOUDS WITH
EVEN IFR CONDITIONS IN SPOTS GIVEN WESTERLY FLOW AROUND KBLF
OVERNIGHT...AND MVFR TO IFR ALONG THE BLUE RIDGE LATE. SOME
PATCHY DRIZZLE/LIGHT SNOW IS ALSO POSSIBLE THIS EVENING THEN
PERHAPS MORE WIDESPREAD ALONG THE BLUE RIDGE INCLUDING PATCHY
DENSE FOG AFTER MIDNIGHT. THIS HOWEVER REMAINS LOW CONFIDENCE
GIVEN DIFFERING MODEL SOLUTIONS BUT DID INCLUDE SOME LOWER
CIGS/VSBYS AT MOST SPOTS WITH POSSIBLE IFR IN STRATUS/FOG.

EXTENDED DISCUSSION...

ONCE THIS FEATURE EXITS WILL SEE THE NEXT WAVE ALONG THE COAST
BRING ANOTHER ROUND OF SUB-VFR CONDITIONS FOR LATER SUNDAY NIGHT
INTO MONDAY. RAIN WILL BE THE PRIMARY PRECIPITATION TYPE WITH
THE POTENTIAL FOR POCKETS OF FREEZING RAIN LATE SUNDAY NIGHT INTO
MONDAY MORNING ACROSS COLDER NORTHERN PORTIONS OF FORECAST AREA WHICH
MIGHT IMPACT LWB IF TEMPERATURES ARE COLD ENOUGH.

RAIN WILL IMPACT AREAS ALONG AND EAST OF THE BLUE RIDGE...WITH
YET ANOTHER SYSTEM SLATED FOR LATE TUESDAY INTO WEDNESDAY AHEAD OF
A STRONG COLD FRONT. THESE SYSTEMS ARE EXPECTED TO BRING A PERIOD
MAINLY RAIN BUT COULD BE SOME WINTRY WX AS WELL ESPECIALLY IN THE
MOUNTAINS WITH THE SUNDAY NIGHT/MONDAY EVENT. EXPECT POTENTIAL LOW
LEVEL WIND SHEAR AS WELL AND POOR FLYING WEATHER FOR EARLY NEXT
WEEK. RAIN AND SNOW SHOWERS WILL CONTINUE INTO WEDNESDAY. GUSTY
NORTHWEST WINDS ARE POSSIBLE WEDNESDAY INTO THURSDAY. MOUNTAIN
SNOW SHOWERS AND SNOW FLURRIES EXPECTED WEDNESDAY NIGHT INTO
CHRISTMAS.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...JH
NEAR TERM...JH/MBS
SHORT TERM...AMS/NF
LONG TERM...KK
AVIATION...JH/PH/WP





000
FXUS61 KRNK 201102
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
602 AM EST SAT DEC 20 2014

.SYNOPSIS...
WEAK LOW PRESSURE ACROSS THE SOUTHEAST STATES WILL PASS EAST AND
OFFSHORE THIS AFTERNOON KEEPING MOST SIGNIFICANT PRECIPITATION TO
THE SOUTH OF THE REGION. HIGH PRESSURE WILL SPILL BACK SOUTH INTO
THE AREA TONIGHT THROUGH SUNDAY NIGHT AHEAD OF ANOTHER LOW
PRESSURE SYSTEM THAT WILL SLIDE UP THE COAST ON MONDAY. A STRONG
COLD FRONT APPROACHES FROM THE WEST TUESDAY INTO TUESDAY NIGHT
BEFORE PASSING THROUGH THE REGION ON WEDNESDAY.
&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 222 AM EST SATURDAY...

LIGHT PRECIP EVENT TO UNFOLD THIS MORNING STILL LOOKS ON TRACK AS
SURFACE LOW PRESSURE PASSES WELL TO THE SOUTH AND EAST OF THE
REGION THROUGH THIS EVENING. THIS SHOULD KEEP THE MAJORITY OF THE
BETTER LIFT AND DEEP MOISTURE OFF TO THE SE WITH ANY PRECIP OVER THE
REGION PRIMARILY DRIVEN VIA WEAK UPPER DIFFLUENCE BETWEEN MID LEVEL
WAVES. ONE SUCH SHORTWAVE BEING WITH THE LEAD SOUTHERNMOST IMPULSE
LOOKS TO SLIDE ACROSS NW N CAROLINA THIS MORNING AND COINCIDE WITH WEAK
SE FLOW UNDER THE LEFT FRONT OF THE PASSING SPEED MAX ALOFT. THIS
SHOULD HELP DEVELOP AN AXIS OF LIGHT SNOW FROM THE NC MOUNTAINS ALONG
THE I-77 CORRIDOR EARLY ON WITH SOME OF THIS SPREADING EAST BUT IN A
DIMINISHING STATE GIVEN DAMPENING SUPPORT AND RESIDUAL DRY AIR.

WITH THE LATEST MODELS ESPCLY SREF PRINTING OUT QPF OF AROUND A
TENTH OF AN INCH OR SO...BUMPED UP POPS TO HIGHER CHANCE SW AND
KEPT EXTENSION OF THE GOING CHANCE POPS ESPCLY SOUTH OF HIGHWAY
460 THIS MORNING. THIS MAY BRING A HALF/ONE INCH OF SNOW AT
ELEVATION FROM I-77 AND POINTS WEST EARLY ON BUT WITHOUT ANY
HEADLINES AS COULD EASILY END UP BEING SNOW SHOWERS/FLURRIES AT
WORSE PER LATEST RADAR TRENDS. ELSW EXPECT LITTLE OR NO
ACCUMULATION GIVEN THE VERY LIGHT PRECIP TYPE SCENARIO IF AT ALL
AS SEEN OFF THE LATEST HRRR. HIGH TEMPS REMAIN TRICKY AFTER SUCH A
COLD START WITH POTENTIAL TO SEE SOME BREAKS DEVELOP BLUE RIDGE
AND ACROSS THE NORTH/WEST LATER ON. THUS TRENDED VALUES UP A
DEGREE OR TWO NORTH WHILE DECREASING A CAT OR SO ESPCLY SE WHERE
SOMEWHAT DEEPER MOISTURE WILL BE LAST TO EXIT.

WEAK RIDGING TO THE NW DIPS BACK INTO THE AREA BEHIND THE DEPARTING
WAVE OVERNIGHT ALLOWING DRYING ALOFT TO TAKE SHAPE UNDER WEAK
SUBSIDENCE. HOWEVER JUST HOW MUCH LOW LEVEL MOISTURE REMAINS TRAPPED IN
QUESTION AND PARTLY DEPENDENT ON THE DEGREE OF MOISTENING TODAY WITH
THE CURRENT EVENT. GFS REMAINS RATHER DRY WITH WEAK NW FLOW THROUGH THE
COLUMN...WHILE THE NAM WETTER UNDER A LIGHT LOW LEVEL EAST/SE
COMPONENT THAT KEEPS QUITE A BIT OF BOUNDARY LAYER MOISTURE ACROSS THE
REGION. THIS COULD POSE A FREEZING DRIZZLE ISSUE ESPCLY BLUE RIDGE WITH
LOTS OF FREEZING FOG/LOW CLOUDS AROUND BUT QUITE IFFY. THUS WILL
GO WITH MORE CLOUDS AND SOME FREEZING FOG OVERNIGHT WHILE LEAVING
OUT ANY -FZDZ MENTION FOR NOW DESPITE DECENT DEPTH TO MOISTURE
UNDER THE INVERSION OFF THE NAM. LOW TEMPS ALSO REFLECT MOISTURE
DIFFERENCES WITH THE MAV MOS WELL INTO THE 20S MOST SPOTS WHILE
THE MET MOS A GOOD 5-10 DEGREES WARMER DUE TO CLOUDS. FOR
NOW...TWEAKED DOWN IN THE VALLEYS AND BLUE RIDGE WHILE LEAVING
THINGS A BIT WARMER WEST-SW WHERE LEFTOVER CLOUDS MORE OF A GOOD
BET IN THE WAKE OF TODAYS POSSIBLE PRECIP.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY/...
AS OF 430 AM EST SATURDAY...

WILL START SUNDAY OFF WITH LOW PRESSURE DEVELOPING ALONG THE
SOUTHEAST COAST. HIGH PRESSURE OVER EASTERN CANADA WILL CONTINUE TO
BUILD SOUTHWARD ACROSS NEW ENGLAND AND THE MID ATLANTIC...BECOMING
INCREASINGLY WEDGED AGAINST THE EASTERN FACE OF THE APPALACHIANS.
WILL SEE WINDS SHIFT MORE EAST NORTHEASTERLY BY EVENING...WITH THE
UPSLOPE FLOW ALONG THE BLUE RIDGE SUPPORTING POCKETS OF LIGHT RAIN
OR DRIZZLE...MAINLY OVER THE NORTH CAROLINA HIGHLANDS BY SUNSET.

THE LOW WILL PASS ALONG THE CAROLINA COAST SUNDAY NIGHT...RESULTING
IN INCREASING PRECIPITATION CHANCES APPROACHING DAWN ON MONDAY. AS
TEMPERATURES COOL THROUGH THE NIGHT...EXPECT TO SEE LIGHT RAIN/
DRIZZLE CHANGE OVER TO A MIXTURE OF RAIN AND FREEZING DRIZZLE OR
SLEET ACROSS THE AREA...WITH MORE MIXED PRECIPITATION NORTH OF
HIGHWAY 460. FORECAST SOUNDINGS INDICATE THAT MOISTURE REMAINS
SHALLOW HOWEVER...SO EXPECT VERY LITTLE ICE ACCUMULATION...IF ANY.
20/00Z MODELS HAVE TRENDED SLIGHTLY WEAKER WITH THIS LOW...WITH SOME
MODELS INDICATING MOISTURE HAVING A HARD TIME MAKING IT INTO
SOUTHEAST WEST VIRGINIA/FAR WESTERN VIRGINIA...REMAINING MORE
CONFINED TO THE PIEDMONT AND BLUE RIDGE. PRECIPITATION AMOUNTS ARE
ALSO LOWER...GENERALLY A FEW HUNDREDTHS OF AN INCH ACROSS THE
WESTERN RIDGES...TO A TENTH OR TWO ACROSS THE PIEDMONT.

MODEST DAYTIME WARMING ON MONDAY WILL CAUSE ANY MIXED PRECIPITATION
TO CHANGE OVER TO LIQUID MOST AREAS...ALTHOUGH A FEW POCKETS OF
SLEET OR LIGHT FREEZING RAIN MAY LINGER IN THE COLDER AIR ALONG AND
NORTH OF THE INTERSTATE 64 CORRIDOR THROUGH THE DAY. THE BRUNT OF
THE ENERGY WILL PASS EAST DURING EARLY AFTERNOON...LEAVING ONLY
SPOTTY PRECIPITATION THROUGH THE REMAINDER OF THE DAY.

BEGINNING MONDAY NIGHT...WILL SEE A GRADUAL WARMING TREND TAKE SHAPE
AS A DEEP LOW PRESSURE SYSTEM DEVELOPS OVER THE SOUTHERN PLAINS. THE
HIGH PRESSURE WEDGE WILL REMAIN IN PLACE THROUGH THE NIGHT...HOWEVER
TEMPERATURES ARE EXPECTED TO REMAIN WARM ENOUGH MOST LOCATIONS FOR
PRECIPITATION TO REMAIN LIQUID.

LOW PRESSURE WILL PUSH NORTH TOWARD THE GREAT LAKES TUESDAY AND
TUESDAY NIGHT...RESULTING IN INCREASING RAIN CHANCES DURING THE
PERIOD. PRECIPITABLE WATER VALUES WILL INCREASE SIGNIFICANTLY...
ESPECIALLY TUESDAY NIGHT...RISING TO THE 1.1 TO 1.4 INCH RANGE...
WHICH IS SIGNIFICANTLY HIGHER THAN NORMAL FOR LATE DECEMBER. AS
SUCH...HAVE WENT WILL HIGHER PRECIPITATION CHANCES FOR TUESDAY
NIGHT...WITH A COLD FRONT APPROACHING FROM THE WEST. MAY ALSO SEE
GUSTY WINDS TUESDAY NIGHT ACROSS THE MOUNTAINS AS A 50KT TO 60KT LOW
LEVEL JET ENTERS THE AREA.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 400 AM EST SATURDAY...

MODEL CONSENSUS OF GFS AND ECMWF IS THAT A SYNOPTIC UPPER TROUGH
OVER THE MISSISSIPPI VALLEY WILL EJECT A NEGATIVELY TILTED
THROUGH THE SOUTHEAST U. S. EARLY WEDNESDAY. WITH THE POSITION OF
THE ASSOCIATED SURFACE OCCLUDED FRONT AND THE TRIPLE POINT PASSING
SOMEWHERE NEAR OR JUST SOUTH OF OUR REGION...THERE IS THE
POTENTIAL FOR OUR REGION TO HAVE ACTIVE WEATHER WEDNESDAY WITH
PLENTY OF SHOWERS...PERHAPS VERY GUSTY WINDS AND A FEW
THUNDERSTORMS. LOOKS LIKE THE AXIS OF BETTER INSTABILITY MAY BE A
LITTLE FURTHER SOUTH ON THE 12Z MODEL RUN.

A COLD FRONT WILL MOVE EAST ACROSS OUR REGION WEDNESDAY INTO
WEDNESDAY NIGHT. HIGHS ON WEDNESDAY WILL WARM INTO THE LOWER 40S
IN THE WEST TO THE LOWER 50S IN THE EAST. RAIN AND SNOW SHOWERS
WILL CHANGEOVER TO SNOW SHOWERS AND SNOW FLURRIES IN THE WEST
WEDNESDAY NIGHT. LOW TEMPERATURES WEDNESDAY NIGHT WILL DROP INTO
THE MID 20S IN THE MOUNTAINS TO THE LOWER 30S IN THE PIEDMONT.
WEST TO NORTHWEST UPPER FLOW WILL CONTINUE INTO THURSDAY WITH
HIGHS FROM THE UPPER 20S IN THE MOUNTAINS TO AROUND 50 IN
PIEDMONT. WINDS WILL BE QUITE STRONG ON THURSDAY AS A 50 TO 55
KNOT 850MB JET PIVOTS ACROSS THE REGION. THE UPPER FLOW SHIFTS TO
THE SOUTHWEST THURSDAY NIGHT INTO FRIDAY AS TROF CURVES OUT IN THE
CENTRAL US WITH SFC INFLECTION OF LOW PRESSURE DEVELOPING OVER THE
TENNESSEE VALLEY BY FRIDAY MORNING. MOISTURE SLOWLY RETURN FRIDAY
NIGHT INTO SATURDAY AS THE HIGH CENTER SLIDE OFF THE COAST.

&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 545 AM EST SATURDAY...

AXIS OF LIGHT SNOW NOW MOVING ACROSS THE FAR WEST/SW AND LIKELY TO
IMPACT KBLF SHORTLY WITH A BRIEF PERIOD OF MVFR CIGS/VSBYS. OTRW
LOOKING AT LOWERING CIGS THIS MORNING FROM WEST TO EAST WITH MVFR
CIGS POSSIBLY SPREADING AS FAR EAST AS KBCB/KROA...AND NORTH AS
KLWB WHERE STILL MAINTAINING VFR VSBYS IN -SN THROUGH LATE
MORNING FOR NOW. THINKING EASTERN SITES SHOULD STAY VFR WITH ONLY
SOME SPOTTY -RA/-SN ARRIVING BY MID MORNING IF THE PRECIP HOLDS
TOGETHER.

THIS SYSTEM MOVES OUT FAIRLY QUICKLY WITH MOST PRECIPITATION
ENDING BY 19-20Z/2-3PM IF NOT SOONER. HOWEVER...A SHALLOW LAYER OF
MOISTURE BANKING UP AGAINST THE WESTERN SLOPES WILL KEEP
CLOUDS...LOWERING TO MVFR LEVELS AT KBLF THIS AFTERNOON. MAY SEE
CIGS ACTUALLY RISE A BIT BEHIND THE DEPARTING SPOTTY PRECIP ELSW BEFORE
SHALLOW MOISTURE BECOMES MORE WIDESPREAD THIS EVENING ESPCLY WHERE
ANY EARLIER SNOW/RAIN OCCURRED. THIS MAY LEAD TO LOW CLOUDS WITH
EVEN IFR CONDITIONS IN SPOTS GIVEN WESTERLY FLOW AROUND KBLF
OVERNIGHT...AND MVFR TO IFR ALONG THE BLUE RIDGE LATE. SOME
PATCHY DRIZZLE/LIGHT SNOW IS ALSO POSSIBLE THIS EVENING THEN
PERHAPS MORE WIDESPREAD ALONG THE BLUE RIDGE INCLUDING PATCHY
DENSE FOG AFTER MIDNIGHT. THIS HOWEVER REMAINS LOW CONFIDENCE
GIVEN DIFFERING MODEL SOLUTIONS BUT DID INCLUDE SOME LOWER
CIGS/VSBYS AT MOST SPOTS WITH POSSIBLE IFR IN STRATUS/FOG.

EXTENDED DISCUSSION...

ONCE THIS FEATURE EXITS WILL SEE THE NEXT WAVE ALONG THE COAST
BRING ANOTHER ROUND OF SUB-VFR CONDITIONS FOR LATER SUNDAY NIGHT
INTO MONDAY. RAIN WILL BE THE PRIMARY PRECIPITATION TYPE WITH
THE POTENTIAL FOR POCKETS OF FREEZING RAIN LATE SUNDAY NIGHT INTO
MONDAY MORNING ACROSS COLDER NORTHERN PORTIONS OF FORECAST AREA WHICH
MIGHT IMPACT LWB IF TEMPERATURES ARE COLD ENOUGH.

RAIN WILL IMPACT AREAS ALONG AND EAST OF THE BLUE RIDGE...WITH
YET ANOTHER SYSTEM SLATED FOR LATE TUESDAY INTO WEDNESDAY AHEAD OF
A STRONG COLD FRONT. THESE SYSTEMS ARE EXPECTED TO BRING A PERIOD
MAINLY RAIN BUT COULD BE SOME WINTRY WX AS WELL ESPECIALLY IN THE
MOUNTAINS WITH THE SUNDAY NIGHT/MONDAY EVENT. EXPECT POTENTIAL LOW
LEVEL WIND SHEAR AS WELL AND POOR FLYING WEATHER FOR EARLY NEXT
WEEK. RAIN AND SNOW SHOWERS WILL CONTINUE INTO WEDNESDAY. GUSTY
NORTHWEST WINDS ARE POSSIBLE WEDNESDAY INTO THURSDAY. MOUNTAIN
SNOW SHOWERS AND SNOW FLURRIES EXPECTED WEDNESDAY NIGHT INTO
CHRISTMAS.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...JH
NEAR TERM...JH
SHORT TERM...AMS/NF
LONG TERM...KK
AVIATION...JH/PH/WP





000
FXUS61 KRNK 201102
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
602 AM EST SAT DEC 20 2014

.SYNOPSIS...
WEAK LOW PRESSURE ACROSS THE SOUTHEAST STATES WILL PASS EAST AND
OFFSHORE THIS AFTERNOON KEEPING MOST SIGNIFICANT PRECIPITATION TO
THE SOUTH OF THE REGION. HIGH PRESSURE WILL SPILL BACK SOUTH INTO
THE AREA TONIGHT THROUGH SUNDAY NIGHT AHEAD OF ANOTHER LOW
PRESSURE SYSTEM THAT WILL SLIDE UP THE COAST ON MONDAY. A STRONG
COLD FRONT APPROACHES FROM THE WEST TUESDAY INTO TUESDAY NIGHT
BEFORE PASSING THROUGH THE REGION ON WEDNESDAY.
&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 222 AM EST SATURDAY...

LIGHT PRECIP EVENT TO UNFOLD THIS MORNING STILL LOOKS ON TRACK AS
SURFACE LOW PRESSURE PASSES WELL TO THE SOUTH AND EAST OF THE
REGION THROUGH THIS EVENING. THIS SHOULD KEEP THE MAJORITY OF THE
BETTER LIFT AND DEEP MOISTURE OFF TO THE SE WITH ANY PRECIP OVER THE
REGION PRIMARILY DRIVEN VIA WEAK UPPER DIFFLUENCE BETWEEN MID LEVEL
WAVES. ONE SUCH SHORTWAVE BEING WITH THE LEAD SOUTHERNMOST IMPULSE
LOOKS TO SLIDE ACROSS NW N CAROLINA THIS MORNING AND COINCIDE WITH WEAK
SE FLOW UNDER THE LEFT FRONT OF THE PASSING SPEED MAX ALOFT. THIS
SHOULD HELP DEVELOP AN AXIS OF LIGHT SNOW FROM THE NC MOUNTAINS ALONG
THE I-77 CORRIDOR EARLY ON WITH SOME OF THIS SPREADING EAST BUT IN A
DIMINISHING STATE GIVEN DAMPENING SUPPORT AND RESIDUAL DRY AIR.

WITH THE LATEST MODELS ESPCLY SREF PRINTING OUT QPF OF AROUND A
TENTH OF AN INCH OR SO...BUMPED UP POPS TO HIGHER CHANCE SW AND
KEPT EXTENSION OF THE GOING CHANCE POPS ESPCLY SOUTH OF HIGHWAY
460 THIS MORNING. THIS MAY BRING A HALF/ONE INCH OF SNOW AT
ELEVATION FROM I-77 AND POINTS WEST EARLY ON BUT WITHOUT ANY
HEADLINES AS COULD EASILY END UP BEING SNOW SHOWERS/FLURRIES AT
WORSE PER LATEST RADAR TRENDS. ELSW EXPECT LITTLE OR NO
ACCUMULATION GIVEN THE VERY LIGHT PRECIP TYPE SCENARIO IF AT ALL
AS SEEN OFF THE LATEST HRRR. HIGH TEMPS REMAIN TRICKY AFTER SUCH A
COLD START WITH POTENTIAL TO SEE SOME BREAKS DEVELOP BLUE RIDGE
AND ACROSS THE NORTH/WEST LATER ON. THUS TRENDED VALUES UP A
DEGREE OR TWO NORTH WHILE DECREASING A CAT OR SO ESPCLY SE WHERE
SOMEWHAT DEEPER MOISTURE WILL BE LAST TO EXIT.

WEAK RIDGING TO THE NW DIPS BACK INTO THE AREA BEHIND THE DEPARTING
WAVE OVERNIGHT ALLOWING DRYING ALOFT TO TAKE SHAPE UNDER WEAK
SUBSIDENCE. HOWEVER JUST HOW MUCH LOW LEVEL MOISTURE REMAINS TRAPPED IN
QUESTION AND PARTLY DEPENDENT ON THE DEGREE OF MOISTENING TODAY WITH
THE CURRENT EVENT. GFS REMAINS RATHER DRY WITH WEAK NW FLOW THROUGH THE
COLUMN...WHILE THE NAM WETTER UNDER A LIGHT LOW LEVEL EAST/SE
COMPONENT THAT KEEPS QUITE A BIT OF BOUNDARY LAYER MOISTURE ACROSS THE
REGION. THIS COULD POSE A FREEZING DRIZZLE ISSUE ESPCLY BLUE RIDGE WITH
LOTS OF FREEZING FOG/LOW CLOUDS AROUND BUT QUITE IFFY. THUS WILL
GO WITH MORE CLOUDS AND SOME FREEZING FOG OVERNIGHT WHILE LEAVING
OUT ANY -FZDZ MENTION FOR NOW DESPITE DECENT DEPTH TO MOISTURE
UNDER THE INVERSION OFF THE NAM. LOW TEMPS ALSO REFLECT MOISTURE
DIFFERENCES WITH THE MAV MOS WELL INTO THE 20S MOST SPOTS WHILE
THE MET MOS A GOOD 5-10 DEGREES WARMER DUE TO CLOUDS. FOR
NOW...TWEAKED DOWN IN THE VALLEYS AND BLUE RIDGE WHILE LEAVING
THINGS A BIT WARMER WEST-SW WHERE LEFTOVER CLOUDS MORE OF A GOOD
BET IN THE WAKE OF TODAYS POSSIBLE PRECIP.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY/...
AS OF 430 AM EST SATURDAY...

WILL START SUNDAY OFF WITH LOW PRESSURE DEVELOPING ALONG THE
SOUTHEAST COAST. HIGH PRESSURE OVER EASTERN CANADA WILL CONTINUE TO
BUILD SOUTHWARD ACROSS NEW ENGLAND AND THE MID ATLANTIC...BECOMING
INCREASINGLY WEDGED AGAINST THE EASTERN FACE OF THE APPALACHIANS.
WILL SEE WINDS SHIFT MORE EAST NORTHEASTERLY BY EVENING...WITH THE
UPSLOPE FLOW ALONG THE BLUE RIDGE SUPPORTING POCKETS OF LIGHT RAIN
OR DRIZZLE...MAINLY OVER THE NORTH CAROLINA HIGHLANDS BY SUNSET.

THE LOW WILL PASS ALONG THE CAROLINA COAST SUNDAY NIGHT...RESULTING
IN INCREASING PRECIPITATION CHANCES APPROACHING DAWN ON MONDAY. AS
TEMPERATURES COOL THROUGH THE NIGHT...EXPECT TO SEE LIGHT RAIN/
DRIZZLE CHANGE OVER TO A MIXTURE OF RAIN AND FREEZING DRIZZLE OR
SLEET ACROSS THE AREA...WITH MORE MIXED PRECIPITATION NORTH OF
HIGHWAY 460. FORECAST SOUNDINGS INDICATE THAT MOISTURE REMAINS
SHALLOW HOWEVER...SO EXPECT VERY LITTLE ICE ACCUMULATION...IF ANY.
20/00Z MODELS HAVE TRENDED SLIGHTLY WEAKER WITH THIS LOW...WITH SOME
MODELS INDICATING MOISTURE HAVING A HARD TIME MAKING IT INTO
SOUTHEAST WEST VIRGINIA/FAR WESTERN VIRGINIA...REMAINING MORE
CONFINED TO THE PIEDMONT AND BLUE RIDGE. PRECIPITATION AMOUNTS ARE
ALSO LOWER...GENERALLY A FEW HUNDREDTHS OF AN INCH ACROSS THE
WESTERN RIDGES...TO A TENTH OR TWO ACROSS THE PIEDMONT.

MODEST DAYTIME WARMING ON MONDAY WILL CAUSE ANY MIXED PRECIPITATION
TO CHANGE OVER TO LIQUID MOST AREAS...ALTHOUGH A FEW POCKETS OF
SLEET OR LIGHT FREEZING RAIN MAY LINGER IN THE COLDER AIR ALONG AND
NORTH OF THE INTERSTATE 64 CORRIDOR THROUGH THE DAY. THE BRUNT OF
THE ENERGY WILL PASS EAST DURING EARLY AFTERNOON...LEAVING ONLY
SPOTTY PRECIPITATION THROUGH THE REMAINDER OF THE DAY.

BEGINNING MONDAY NIGHT...WILL SEE A GRADUAL WARMING TREND TAKE SHAPE
AS A DEEP LOW PRESSURE SYSTEM DEVELOPS OVER THE SOUTHERN PLAINS. THE
HIGH PRESSURE WEDGE WILL REMAIN IN PLACE THROUGH THE NIGHT...HOWEVER
TEMPERATURES ARE EXPECTED TO REMAIN WARM ENOUGH MOST LOCATIONS FOR
PRECIPITATION TO REMAIN LIQUID.

LOW PRESSURE WILL PUSH NORTH TOWARD THE GREAT LAKES TUESDAY AND
TUESDAY NIGHT...RESULTING IN INCREASING RAIN CHANCES DURING THE
PERIOD. PRECIPITABLE WATER VALUES WILL INCREASE SIGNIFICANTLY...
ESPECIALLY TUESDAY NIGHT...RISING TO THE 1.1 TO 1.4 INCH RANGE...
WHICH IS SIGNIFICANTLY HIGHER THAN NORMAL FOR LATE DECEMBER. AS
SUCH...HAVE WENT WILL HIGHER PRECIPITATION CHANCES FOR TUESDAY
NIGHT...WITH A COLD FRONT APPROACHING FROM THE WEST. MAY ALSO SEE
GUSTY WINDS TUESDAY NIGHT ACROSS THE MOUNTAINS AS A 50KT TO 60KT LOW
LEVEL JET ENTERS THE AREA.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 400 AM EST SATURDAY...

MODEL CONSENSUS OF GFS AND ECMWF IS THAT A SYNOPTIC UPPER TROUGH
OVER THE MISSISSIPPI VALLEY WILL EJECT A NEGATIVELY TILTED
THROUGH THE SOUTHEAST U. S. EARLY WEDNESDAY. WITH THE POSITION OF
THE ASSOCIATED SURFACE OCCLUDED FRONT AND THE TRIPLE POINT PASSING
SOMEWHERE NEAR OR JUST SOUTH OF OUR REGION...THERE IS THE
POTENTIAL FOR OUR REGION TO HAVE ACTIVE WEATHER WEDNESDAY WITH
PLENTY OF SHOWERS...PERHAPS VERY GUSTY WINDS AND A FEW
THUNDERSTORMS. LOOKS LIKE THE AXIS OF BETTER INSTABILITY MAY BE A
LITTLE FURTHER SOUTH ON THE 12Z MODEL RUN.

A COLD FRONT WILL MOVE EAST ACROSS OUR REGION WEDNESDAY INTO
WEDNESDAY NIGHT. HIGHS ON WEDNESDAY WILL WARM INTO THE LOWER 40S
IN THE WEST TO THE LOWER 50S IN THE EAST. RAIN AND SNOW SHOWERS
WILL CHANGEOVER TO SNOW SHOWERS AND SNOW FLURRIES IN THE WEST
WEDNESDAY NIGHT. LOW TEMPERATURES WEDNESDAY NIGHT WILL DROP INTO
THE MID 20S IN THE MOUNTAINS TO THE LOWER 30S IN THE PIEDMONT.
WEST TO NORTHWEST UPPER FLOW WILL CONTINUE INTO THURSDAY WITH
HIGHS FROM THE UPPER 20S IN THE MOUNTAINS TO AROUND 50 IN
PIEDMONT. WINDS WILL BE QUITE STRONG ON THURSDAY AS A 50 TO 55
KNOT 850MB JET PIVOTS ACROSS THE REGION. THE UPPER FLOW SHIFTS TO
THE SOUTHWEST THURSDAY NIGHT INTO FRIDAY AS TROF CURVES OUT IN THE
CENTRAL US WITH SFC INFLECTION OF LOW PRESSURE DEVELOPING OVER THE
TENNESSEE VALLEY BY FRIDAY MORNING. MOISTURE SLOWLY RETURN FRIDAY
NIGHT INTO SATURDAY AS THE HIGH CENTER SLIDE OFF THE COAST.

&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 545 AM EST SATURDAY...

AXIS OF LIGHT SNOW NOW MOVING ACROSS THE FAR WEST/SW AND LIKELY TO
IMPACT KBLF SHORTLY WITH A BRIEF PERIOD OF MVFR CIGS/VSBYS. OTRW
LOOKING AT LOWERING CIGS THIS MORNING FROM WEST TO EAST WITH MVFR
CIGS POSSIBLY SPREADING AS FAR EAST AS KBCB/KROA...AND NORTH AS
KLWB WHERE STILL MAINTAINING VFR VSBYS IN -SN THROUGH LATE
MORNING FOR NOW. THINKING EASTERN SITES SHOULD STAY VFR WITH ONLY
SOME SPOTTY -RA/-SN ARRIVING BY MID MORNING IF THE PRECIP HOLDS
TOGETHER.

THIS SYSTEM MOVES OUT FAIRLY QUICKLY WITH MOST PRECIPITATION
ENDING BY 19-20Z/2-3PM IF NOT SOONER. HOWEVER...A SHALLOW LAYER OF
MOISTURE BANKING UP AGAINST THE WESTERN SLOPES WILL KEEP
CLOUDS...LOWERING TO MVFR LEVELS AT KBLF THIS AFTERNOON. MAY SEE
CIGS ACTUALLY RISE A BIT BEHIND THE DEPARTING SPOTTY PRECIP ELSW BEFORE
SHALLOW MOISTURE BECOMES MORE WIDESPREAD THIS EVENING ESPCLY WHERE
ANY EARLIER SNOW/RAIN OCCURRED. THIS MAY LEAD TO LOW CLOUDS WITH
EVEN IFR CONDITIONS IN SPOTS GIVEN WESTERLY FLOW AROUND KBLF
OVERNIGHT...AND MVFR TO IFR ALONG THE BLUE RIDGE LATE. SOME
PATCHY DRIZZLE/LIGHT SNOW IS ALSO POSSIBLE THIS EVENING THEN
PERHAPS MORE WIDESPREAD ALONG THE BLUE RIDGE INCLUDING PATCHY
DENSE FOG AFTER MIDNIGHT. THIS HOWEVER REMAINS LOW CONFIDENCE
GIVEN DIFFERING MODEL SOLUTIONS BUT DID INCLUDE SOME LOWER
CIGS/VSBYS AT MOST SPOTS WITH POSSIBLE IFR IN STRATUS/FOG.

EXTENDED DISCUSSION...

ONCE THIS FEATURE EXITS WILL SEE THE NEXT WAVE ALONG THE COAST
BRING ANOTHER ROUND OF SUB-VFR CONDITIONS FOR LATER SUNDAY NIGHT
INTO MONDAY. RAIN WILL BE THE PRIMARY PRECIPITATION TYPE WITH
THE POTENTIAL FOR POCKETS OF FREEZING RAIN LATE SUNDAY NIGHT INTO
MONDAY MORNING ACROSS COLDER NORTHERN PORTIONS OF FORECAST AREA WHICH
MIGHT IMPACT LWB IF TEMPERATURES ARE COLD ENOUGH.

RAIN WILL IMPACT AREAS ALONG AND EAST OF THE BLUE RIDGE...WITH
YET ANOTHER SYSTEM SLATED FOR LATE TUESDAY INTO WEDNESDAY AHEAD OF
A STRONG COLD FRONT. THESE SYSTEMS ARE EXPECTED TO BRING A PERIOD
MAINLY RAIN BUT COULD BE SOME WINTRY WX AS WELL ESPECIALLY IN THE
MOUNTAINS WITH THE SUNDAY NIGHT/MONDAY EVENT. EXPECT POTENTIAL LOW
LEVEL WIND SHEAR AS WELL AND POOR FLYING WEATHER FOR EARLY NEXT
WEEK. RAIN AND SNOW SHOWERS WILL CONTINUE INTO WEDNESDAY. GUSTY
NORTHWEST WINDS ARE POSSIBLE WEDNESDAY INTO THURSDAY. MOUNTAIN
SNOW SHOWERS AND SNOW FLURRIES EXPECTED WEDNESDAY NIGHT INTO
CHRISTMAS.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...JH
NEAR TERM...JH
SHORT TERM...AMS/NF
LONG TERM...KK
AVIATION...JH/PH/WP




000
FXUS61 KRNK 201008
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
508 AM EST SAT DEC 20 2014

.SYNOPSIS...
WEAK LOW PRESSURE ACROSS THE SOUTHEAST STATES WILL PASS EAST AND
OFFSHORE THIS AFTERNOON KEEPING MOST SIGNIFICANT PRECIPITATION TO
THE SOUTH OF THE REGION. HIGH PRESSURE WILL SPILL BACK SOUTH INTO
THE AREA TONIGHT THROUGH SUNDAY NIGHT AHEAD OF ANOTHER LOW
PRESSURE SYSTEM THAT WILL SLIDE UP THE COAST ON MONDAY. A STRONG
COLD FRONT APPROACHES FROM THE WEST TUESDAY INTO TUESDAY NIGHT
BEFORE PASSING THROUGH THE REGION ON WEDNESDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 222 AM EST SATURDAY...

LIGHT PRECIP EVENT TO UNFOLD THIS MORNING STILL LOOKS ON TRACK AS
SURFACE LOW PRESSURE PASSES WELL TO THE SOUTH AND EAST OF THE
REGION THROUGH THIS EVENING. THIS SHOULD KEEP THE MAJORITY OF THE
BETTER LIFT AND DEEP MOISTURE OFF TO THE SE WITH ANY PRECIP OVER THE
REGION PRIMARILY DRIVEN VIA WEAK UPPER DIFFLUENCE BETWEEN MID LEVEL
WAVES. ONE SUCH SHORTWAVE BEING WITH THE LEAD SOUTHERNMOST IMPULSE
LOOKS TO SLIDE ACROSS NW N CAROLINA THIS MORNING AND COINCIDE WITH WEAK
SE FLOW UNDER THE LEFT FRONT OF THE PASSING SPEED MAX ALOFT. THIS
SHOULD HELP DEVELOP AN AXIS OF LIGHT SNOW FROM THE NC MOUNTAINS ALONG
THE I-77 CORRIDOR EARLY ON WITH SOME OF THIS SPREADING EAST BUT IN A
DIMINISHING STATE GIVEN DAMPENING SUPPORT AND RESIDUAL DRY AIR.

WITH THE LATEST MODELS ESPCLY SREF PRINTING OUT QPF OF AROUND A
TENTH OF AN INCH OR SO...BUMPED UP POPS TO HIGHER CHANCE SW AND
KEPT EXTENSION OF THE GOING CHANCE POPS ESPCLY SOUTH OF HIGHWAY
460 THIS MORNING. THIS MAY BRING A HALF INCH OF SNOW AT ELEVATION
FROM I-77 AND POINTS WEST EARLY ON BUT WITHOUT ANY HEADLINES AS
COULD EASILY END UP BEING SNOW SHOWERS/FLURRIES AT WORSE PER
LATEST RADAR TRENDS. ELSW EXPECT LITTLE OR NO ACCUMULATION GIVEN THE
VERY LIGHT PRECIP TYPE SCENARIO IF AT ALL AS SEEN OFF THE LATEST
HRRR. HIGH TEMPS REMAIN TRICKY AFTER SUCH A COLD START WITH
POTENTIAL TO SEE SOME BREAKS DEVELOP BLUE RIDGE AND ACROSS THE
NORTH/WEST LATER ON. THUS TRENDED VALUES UP A DEGREE OR TWO NORTH
WHILE DECREASING A CAT OR SO ESPCLY SE WHERE SOMEWHAT DEEPER
MOISTURE WILL BE LAST TO EXIT.

WEAK RIDGING TO THE NW DIPS BACK INTO THE AREA BEHIND THE DEPARTING
WAVE OVERNIGHT ALLOWING DRYING ALOFT TO TAKE SHAPE UNDER WEAK
SUBSIDENCE. HOWEVER JUST HOW MUCH LOW LEVEL MOISTURE REMAINS TRAPPED IN
QUESTION AND PARTLY DEPENDENT ON THE DEGREE OF MOISTENING TODAY WITH
THE CURRENT EVENT. GFS REMAINS RATHER DRY WITH WEAK NW FLOW THROUGH THE
COLUMN...WHILE THE NAM WETTER UNDER A LIGHT LOW LEVEL EAST/SE
COMPONENT THAT KEEPS QUITE A BIT OF BOUNDARY LAYER MOISTURE ACROSS THE
REGION. THIS COULD POSE A FREEZING DRIZZLE ISSUE ESPCLY BLUE RIDGE WITH
LOTS OF FREEZING FOG/LOW CLOUDS AROUND BUT QUITE IFFY. THUS WILL
GO WITH MORE CLOUDS AND SOME FREEZING FOG OVERNIGHT WHILE LEAVING
OUT ANY -FZDZ MENTION FOR NOW DESPITE DECENT DEPTH TO MOISTURE
UNDER THE INVERSION OFF THE NAM. LOW TEMPS ALSO REFLECT MOISTURE
DIFFERENCES WITH THE MAV MOS WELL INTO THE 20S MOST SPOTS WHILE
THE MET MOS A GOOD 5-10 DEGREES WARMER DUE TO CLOUDS. FOR
NOW...TWEAKED DOWN IN THE VALLEYS AND BLUE RIDGE WHILE LEAVING
THINGS A BIT WARMER WEST-SW WHERE LEFTOVER CLOUDS MORE OF A GOOD
BET IN THE WAKE OF TODAYS POSSIBLE PRECIP.

&&

.SHORT TERM /SUNDAY THROUGH TUESDAY NIGHT/...
AS OF 430 AM EST SATURDAY...

WILL START SUNDAY OFF WITH LOW PRESSURE DEVELOPING ALONG THE
SOUTHEAST COAST. HIGH PRESSURE OVER EASTERN CANADA WILL CONTINUE TO
BUILD SOUTHWARD ACROSS NEW ENGLAND AND THE MID ATLANTIC...BECOMING
INCREASINGLY WEDGED AGAINST THE EASTERN FACE OF THE APPALACHIANS.
WILL SEE WINDS SHIFT MORE EAST NORTHEASTERLY BY EVENING...WITH THE
UPSLOPE FLOW ALONG THE BLUE RIDGE SUPPORTING POCKETS OF LIGHT RAIN
OR DRIZZLE...MAINLY OVER THE NORTH CAROLINA HIGHLANDS BY SUNSET.

THE LOW WILL PASS ALONG THE CAROLINA COAST SUNDAY NIGHT...RESULTING
IN INCREASING PRECIPITATION CHANCES APPROACHING DAWN ON MONDAY. AS
TEMPERATURES COOL THROUGH THE NIGHT...EXPECT TO SEE LIGHT RAIN/
DRIZZLE CHANGE OVER TO A MIXTURE OF RAIN AND FREEZING DRIZZLE OR
SLEET ACROSS THE AREA...WITH MORE MIXED PRECIPITATION NORTH OF
HIGHWAY 460. FORECAST SOUNDINGS INDICATE THAT MOISTURE REMAINS
SHALLOW HOWEVER...SO EXPECT VERY LITTLE ICE ACCUMULATION...IF ANY.
20/00Z MODELS HAVE TRENDED SLIGHTLY WEAKER WITH THIS LOW...WITH SOME
MODELS INDICATING MOISTURE HAVING A HARD TIME MAKING IT INTO
SOUTHEAST WEST VIRGINIA/FAR WESTERN VIRGINIA...REMAINING MORE
CONFINED TO THE PIEDMONT AND BLUE RIDGE. PRECIPITATION AMOUNTS ARE
ALSO LOWER...GENERALLY A FEW HUNDREDTHS OF AN INCH ACROSS THE
WESTERN RIDGES...TO A TENTH OR TWO ACROSS THE PIEDMONT.

MODEST DAYTIME WARMING ON MONDAY WILL CAUSE ANY MIXED PRECIPITATION
TO CHANGE OVER TO LIQUID MOST AREAS...ALTHOUGH A FEW POCKETS OF
SLEET OR LIGHT FREEZING RAIN MAY LINGER IN THE COLDER AIR ALONG AND
NORTH OF THE INTERSTATE 64 CORRIDOR THROUGH THE DAY. THE BRUNT OF
THE ENERGY WILL PASS EAST DURING EARLY AFTERNOON...LEAVING ONLY
SPOTTY PRECIPITATION THROUGH THE REMAINDER OF THE DAY.

BEGINNING MONDAY NIGHT...WILL SEE A GRADUAL WARMING TREND TAKE SHAPE
AS A DEEP LOW PRESSURE SYSTEM DEVELOPS OVER THE SOUTHERN PLAINS. THE
HIGH PRESSURE WEDGE WILL REMAIN IN PLACE THROUGH THE NIGHT...HOWEVER
TEMPERATURES ARE EXPECTED TO REMAIN WARM ENOUGH MOST LOCATIONS FOR
PRECIPITATION TO REMAIN LIQUID.

LOW PRESSURE WILL PUSH NORTH TOWARD THE GREAT LAKES TUESDAY AND
TUESDAY NIGHT...RESULTING IN INCREASING RAIN CHANCES DURING THE
PERIOD. PRECIPITABLE WATER VALUES WILL INCREASE SIGNIFICANTLY...
ESPECIALLY TUESDAY NIGHT...RISING TO THE 1.1 TO 1.4 INCH RANGE...
WHICH IS SIGNIFICANTLY HIGHER THAN NORMAL FOR LATE DECEMBER. AS
SUCH...HAVE WENT WILL HIGHER PRECIPITATION CHANCES FOR TUESDAY
NIGHT...WITH A COLD FRONT APPROACHING FROM THE WEST. MAY ALSO SEE
GUSTY WINDS TUESDAY NIGHT ACROSS THE MOUNTAINS AS A 50KT TO 60KT LOW
LEVEL JET ENTERS THE AREA.
&&

.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 400 AM EST SATURDAY...

MODEL CONSENSUS OF GFS AND ECMWF IS THAT A SYNOPTIC UPPER TROUGH
OVER THE MISSISSIPPI VALLEY WILL EJECT A NEGATIVELY TILTED
THROUGH THE SOUTHEAST U. S. EARLY WEDNESDAY. WITH THE POSITION OF
THE ASSOCIATED SURFACE OCCLUDED FRONT AND THE TRIPLE POINT PASSING
SOMEWHERE NEAR OR JUST SOUTH OF OUR REGION...THERE IS THE
POTENTIAL FOR OUR REGION TO HAVE ACTIVE WEATHER WEDNESDAY WITH
PLENTY OF SHOWERS...PERHAPS VERY GUSTY WINDS AND A FEW
THUNDERSTORMS. LOOKS LIKE THE AXIS OF BETTER INSTABILITY MAY BE A
LITTLE FURTHER SOUTH ON THE 12Z MODEL RUN.

A COLD FRONT WILL MOVE EAST ACROSS OUR REGION WEDNESDAY INTO
WEDNESDAY NIGHT. HIGHS ON WEDNESDAY WILL WARM INTO THE LOWER 40S
IN THE WEST TO THE LOWER 50S IN THE EAST. RAIN AND SNOW SHOWERS
WILL CHANGEOVER TO SNOW SHOWERS AND SNOW FLURRIES IN THE WEST
WEDNESDAY NIGHT. LOW TEMPERATURES WEDNESDAY NIGHT WILL DROP INTO
THE MID 20S IN THE MOUNTAINS TO THE LOWER 30S IN THE PIEDMONT.
WEST TO NORTHWEST UPPER FLOW WILL CONTINUE INTO THURSDAY WITH
HIGHS FROM THE UPPER 20S IN THE MOUNTAINS TO AROUND 50 IN
PIEDMONT. WINDS WILL BE QUITE STRONG ON THURSDAY AS A 50 TO 55
KNOT 850MB JET PIVOTS ACROSS THE REGION. THE UPPER FLOW SHIFTS TO
THE SOUTHWEST THURSDAY NIGHT INTO FRIDAY AS TROF CURVES OUT IN THE
CENTRAL US WITH SFC INFLECTION OF LOW PRESSURE DEVELOPING OVER THE
TENNESSEE VALLEY BY FRIDAY MORNING. MOISTURE SLOWLY RETURN FRIDAY
NIGHT INTO SATURDAY AS THE HIGH CENTER SLIDE OFF THE COAST.

&&

.AVIATION /10Z SATURDAY THROUGH WEDNESDAY/...
AS OF 1125 PM EST FRIDAY...

HIGH CLOUDINESS COVERED THE REGION THIS MORNING...WITH MOSTLY VFR
CONDITIONS OBSERVED. LOW CLOUDS WITH IFR CIGS IN SOUTHEAST WV
NORTH OF KLWB AND KBLF ARE FORECAST REMAIN NORTH THESE LOCATIONS
TONIGHT.

THE TIMING FOR THE ARRIVAL OF LIGHT SNOW CONTINUES TO BE DELAYED
AS A DEEP LAYER OF DRY AIR OVER OUR AREA WILL TAKE TIME TO
SATURATE. THE LIGHT SNOW IS EXPECTED BEGIN ALONG THE SOUTHERN
BLUE RIDGE BETWEEN 10Z-13Z AND SPREAD NORTHWARD IN OUR AREA. CIGS
WILL FALL...BUT NOT EXPECTED TO DROP INTO THE MVFR RANGE. LIGHT
SNOW/FLURRIES WITH LITTLE RESTRICTIONS TO VISIBILITY SHOULD ARRIVE
AT MOST SITES BETWEEN 12Z-15Z

THIS SYSTEM MOVES OUT FAIRLY QUICK WITH MOST PRECIPITATION ENDING
BY SATURDAY AFTERNOON. HOWEVER...A SHALLOW LAYER OF MOISTURE
BANKING UP AGAINST THE WESTERN SLOPES WILL KEEP CLOUDS...LOWERING
TO MVFR LEVELS...AT KBLF AND KLWB AND POSSIBILITY KBCB LATE
SATURDAY AFTERNOON THROUGH THE NIGHT. SOME PATCHY DRIZZLE/LIGHT
SNOW IS ALSO POSSIBLE SATURDAY EVENING.

MEDIUM CONFIDENCE ON VISIBILITIES...WINDS AND CEILINGS DURING THE
TAF PERIOD.

EXTENDED DISCUSSION...

ONCE THIS FEATURE EXITS WILL SEE THE NEXT WAVE ALONG THE COAST
BRING ANOTHER ROUND OF SUB-VFR CONDITIONS FOR LATER SUNDAY NIGHT
INTO MONDAY. RAIN WILL BE THE PRIMARY PRECIPITATION TYPE WITH
THE POTENTIAL FOR POCKETS OF FREEZING RAIN LATE SUNDAY NIGHT INTO
MONDAY MORNING ACROSS COLDER NORTHERN PORTIONS OF FORECAST AREA WHICH
MIGHT IMPACT LWB IF TEMPERATURES ARE COLD ENOUGH.

RAIN WILL IMPACT AREAS ALONG AND EAST OF THE BLUE RIDGE...WITH
YET ANOTHER SYSTEM SLATED FOR LATE TUESDAY INTO WEDNESDAY AHEAD OF
A STRONG COLD FRONT. THESE SYSTEMS ARE EXPECTED TO BRING A PERIOD
MAINLY RAIN BUT COULD BE SOME WINTRY WX AS WELL ESPECIALLY IN THE
MOUNTAINS WITH THE SUNDAY NIGHT/MONDAY EVENT. EXPECT POTENTIAL LOW
LEVEL WIND SHEAR AS WELL AND POOR FLYING WEATHER FOR EARLY NEXT
WEEK. RAIN AND SNOW SHOWERS WILL CONTINUE INTO WEDNESDAY. GUSTY
NORTHWEST WINDS ARE POSSIBLE WEDNESDAY INTO THURSDAY. MOUNTAIN
SNOW SHOWERS AND SNOW FLURRIES EXPECTED WEDNESDAY NIGHT INTO
CHRISTMAS.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...JH/WP
NEAR TERM...JH
SHORT TERM...AMS/NF
LONG TERM...KK
AVIATION...PH/WP




000
FXUS61 KRNK 201008
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
508 AM EST SAT DEC 20 2014

.SYNOPSIS...
WEAK LOW PRESSURE ACROSS THE SOUTHEAST STATES WILL PASS EAST AND
OFFSHORE THIS AFTERNOON KEEPING MOST SIGNIFICANT PRECIPITATION TO
THE SOUTH OF THE REGION. HIGH PRESSURE WILL SPILL BACK SOUTH INTO
THE AREA TONIGHT THROUGH SUNDAY NIGHT AHEAD OF ANOTHER LOW
PRESSURE SYSTEM THAT WILL SLIDE UP THE COAST ON MONDAY. A STRONG
COLD FRONT APPROACHES FROM THE WEST TUESDAY INTO TUESDAY NIGHT
BEFORE PASSING THROUGH THE REGION ON WEDNESDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 222 AM EST SATURDAY...

LIGHT PRECIP EVENT TO UNFOLD THIS MORNING STILL LOOKS ON TRACK AS
SURFACE LOW PRESSURE PASSES WELL TO THE SOUTH AND EAST OF THE
REGION THROUGH THIS EVENING. THIS SHOULD KEEP THE MAJORITY OF THE
BETTER LIFT AND DEEP MOISTURE OFF TO THE SE WITH ANY PRECIP OVER THE
REGION PRIMARILY DRIVEN VIA WEAK UPPER DIFFLUENCE BETWEEN MID LEVEL
WAVES. ONE SUCH SHORTWAVE BEING WITH THE LEAD SOUTHERNMOST IMPULSE
LOOKS TO SLIDE ACROSS NW N CAROLINA THIS MORNING AND COINCIDE WITH WEAK
SE FLOW UNDER THE LEFT FRONT OF THE PASSING SPEED MAX ALOFT. THIS
SHOULD HELP DEVELOP AN AXIS OF LIGHT SNOW FROM THE NC MOUNTAINS ALONG
THE I-77 CORRIDOR EARLY ON WITH SOME OF THIS SPREADING EAST BUT IN A
DIMINISHING STATE GIVEN DAMPENING SUPPORT AND RESIDUAL DRY AIR.

WITH THE LATEST MODELS ESPCLY SREF PRINTING OUT QPF OF AROUND A
TENTH OF AN INCH OR SO...BUMPED UP POPS TO HIGHER CHANCE SW AND
KEPT EXTENSION OF THE GOING CHANCE POPS ESPCLY SOUTH OF HIGHWAY
460 THIS MORNING. THIS MAY BRING A HALF INCH OF SNOW AT ELEVATION
FROM I-77 AND POINTS WEST EARLY ON BUT WITHOUT ANY HEADLINES AS
COULD EASILY END UP BEING SNOW SHOWERS/FLURRIES AT WORSE PER
LATEST RADAR TRENDS. ELSW EXPECT LITTLE OR NO ACCUMULATION GIVEN THE
VERY LIGHT PRECIP TYPE SCENARIO IF AT ALL AS SEEN OFF THE LATEST
HRRR. HIGH TEMPS REMAIN TRICKY AFTER SUCH A COLD START WITH
POTENTIAL TO SEE SOME BREAKS DEVELOP BLUE RIDGE AND ACROSS THE
NORTH/WEST LATER ON. THUS TRENDED VALUES UP A DEGREE OR TWO NORTH
WHILE DECREASING A CAT OR SO ESPCLY SE WHERE SOMEWHAT DEEPER
MOISTURE WILL BE LAST TO EXIT.

WEAK RIDGING TO THE NW DIPS BACK INTO THE AREA BEHIND THE DEPARTING
WAVE OVERNIGHT ALLOWING DRYING ALOFT TO TAKE SHAPE UNDER WEAK
SUBSIDENCE. HOWEVER JUST HOW MUCH LOW LEVEL MOISTURE REMAINS TRAPPED IN
QUESTION AND PARTLY DEPENDENT ON THE DEGREE OF MOISTENING TODAY WITH
THE CURRENT EVENT. GFS REMAINS RATHER DRY WITH WEAK NW FLOW THROUGH THE
COLUMN...WHILE THE NAM WETTER UNDER A LIGHT LOW LEVEL EAST/SE
COMPONENT THAT KEEPS QUITE A BIT OF BOUNDARY LAYER MOISTURE ACROSS THE
REGION. THIS COULD POSE A FREEZING DRIZZLE ISSUE ESPCLY BLUE RIDGE WITH
LOTS OF FREEZING FOG/LOW CLOUDS AROUND BUT QUITE IFFY. THUS WILL
GO WITH MORE CLOUDS AND SOME FREEZING FOG OVERNIGHT WHILE LEAVING
OUT ANY -FZDZ MENTION FOR NOW DESPITE DECENT DEPTH TO MOISTURE
UNDER THE INVERSION OFF THE NAM. LOW TEMPS ALSO REFLECT MOISTURE
DIFFERENCES WITH THE MAV MOS WELL INTO THE 20S MOST SPOTS WHILE
THE MET MOS A GOOD 5-10 DEGREES WARMER DUE TO CLOUDS. FOR
NOW...TWEAKED DOWN IN THE VALLEYS AND BLUE RIDGE WHILE LEAVING
THINGS A BIT WARMER WEST-SW WHERE LEFTOVER CLOUDS MORE OF A GOOD
BET IN THE WAKE OF TODAYS POSSIBLE PRECIP.

&&

.SHORT TERM /SUNDAY THROUGH TUESDAY NIGHT/...
AS OF 430 AM EST SATURDAY...

WILL START SUNDAY OFF WITH LOW PRESSURE DEVELOPING ALONG THE
SOUTHEAST COAST. HIGH PRESSURE OVER EASTERN CANADA WILL CONTINUE TO
BUILD SOUTHWARD ACROSS NEW ENGLAND AND THE MID ATLANTIC...BECOMING
INCREASINGLY WEDGED AGAINST THE EASTERN FACE OF THE APPALACHIANS.
WILL SEE WINDS SHIFT MORE EAST NORTHEASTERLY BY EVENING...WITH THE
UPSLOPE FLOW ALONG THE BLUE RIDGE SUPPORTING POCKETS OF LIGHT RAIN
OR DRIZZLE...MAINLY OVER THE NORTH CAROLINA HIGHLANDS BY SUNSET.

THE LOW WILL PASS ALONG THE CAROLINA COAST SUNDAY NIGHT...RESULTING
IN INCREASING PRECIPITATION CHANCES APPROACHING DAWN ON MONDAY. AS
TEMPERATURES COOL THROUGH THE NIGHT...EXPECT TO SEE LIGHT RAIN/
DRIZZLE CHANGE OVER TO A MIXTURE OF RAIN AND FREEZING DRIZZLE OR
SLEET ACROSS THE AREA...WITH MORE MIXED PRECIPITATION NORTH OF
HIGHWAY 460. FORECAST SOUNDINGS INDICATE THAT MOISTURE REMAINS
SHALLOW HOWEVER...SO EXPECT VERY LITTLE ICE ACCUMULATION...IF ANY.
20/00Z MODELS HAVE TRENDED SLIGHTLY WEAKER WITH THIS LOW...WITH SOME
MODELS INDICATING MOISTURE HAVING A HARD TIME MAKING IT INTO
SOUTHEAST WEST VIRGINIA/FAR WESTERN VIRGINIA...REMAINING MORE
CONFINED TO THE PIEDMONT AND BLUE RIDGE. PRECIPITATION AMOUNTS ARE
ALSO LOWER...GENERALLY A FEW HUNDREDTHS OF AN INCH ACROSS THE
WESTERN RIDGES...TO A TENTH OR TWO ACROSS THE PIEDMONT.

MODEST DAYTIME WARMING ON MONDAY WILL CAUSE ANY MIXED PRECIPITATION
TO CHANGE OVER TO LIQUID MOST AREAS...ALTHOUGH A FEW POCKETS OF
SLEET OR LIGHT FREEZING RAIN MAY LINGER IN THE COLDER AIR ALONG AND
NORTH OF THE INTERSTATE 64 CORRIDOR THROUGH THE DAY. THE BRUNT OF
THE ENERGY WILL PASS EAST DURING EARLY AFTERNOON...LEAVING ONLY
SPOTTY PRECIPITATION THROUGH THE REMAINDER OF THE DAY.

BEGINNING MONDAY NIGHT...WILL SEE A GRADUAL WARMING TREND TAKE SHAPE
AS A DEEP LOW PRESSURE SYSTEM DEVELOPS OVER THE SOUTHERN PLAINS. THE
HIGH PRESSURE WEDGE WILL REMAIN IN PLACE THROUGH THE NIGHT...HOWEVER
TEMPERATURES ARE EXPECTED TO REMAIN WARM ENOUGH MOST LOCATIONS FOR
PRECIPITATION TO REMAIN LIQUID.

LOW PRESSURE WILL PUSH NORTH TOWARD THE GREAT LAKES TUESDAY AND
TUESDAY NIGHT...RESULTING IN INCREASING RAIN CHANCES DURING THE
PERIOD. PRECIPITABLE WATER VALUES WILL INCREASE SIGNIFICANTLY...
ESPECIALLY TUESDAY NIGHT...RISING TO THE 1.1 TO 1.4 INCH RANGE...
WHICH IS SIGNIFICANTLY HIGHER THAN NORMAL FOR LATE DECEMBER. AS
SUCH...HAVE WENT WILL HIGHER PRECIPITATION CHANCES FOR TUESDAY
NIGHT...WITH A COLD FRONT APPROACHING FROM THE WEST. MAY ALSO SEE
GUSTY WINDS TUESDAY NIGHT ACROSS THE MOUNTAINS AS A 50KT TO 60KT LOW
LEVEL JET ENTERS THE AREA.
&&

.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 400 AM EST SATURDAY...

MODEL CONSENSUS OF GFS AND ECMWF IS THAT A SYNOPTIC UPPER TROUGH
OVER THE MISSISSIPPI VALLEY WILL EJECT A NEGATIVELY TILTED
THROUGH THE SOUTHEAST U. S. EARLY WEDNESDAY. WITH THE POSITION OF
THE ASSOCIATED SURFACE OCCLUDED FRONT AND THE TRIPLE POINT PASSING
SOMEWHERE NEAR OR JUST SOUTH OF OUR REGION...THERE IS THE
POTENTIAL FOR OUR REGION TO HAVE ACTIVE WEATHER WEDNESDAY WITH
PLENTY OF SHOWERS...PERHAPS VERY GUSTY WINDS AND A FEW
THUNDERSTORMS. LOOKS LIKE THE AXIS OF BETTER INSTABILITY MAY BE A
LITTLE FURTHER SOUTH ON THE 12Z MODEL RUN.

A COLD FRONT WILL MOVE EAST ACROSS OUR REGION WEDNESDAY INTO
WEDNESDAY NIGHT. HIGHS ON WEDNESDAY WILL WARM INTO THE LOWER 40S
IN THE WEST TO THE LOWER 50S IN THE EAST. RAIN AND SNOW SHOWERS
WILL CHANGEOVER TO SNOW SHOWERS AND SNOW FLURRIES IN THE WEST
WEDNESDAY NIGHT. LOW TEMPERATURES WEDNESDAY NIGHT WILL DROP INTO
THE MID 20S IN THE MOUNTAINS TO THE LOWER 30S IN THE PIEDMONT.
WEST TO NORTHWEST UPPER FLOW WILL CONTINUE INTO THURSDAY WITH
HIGHS FROM THE UPPER 20S IN THE MOUNTAINS TO AROUND 50 IN
PIEDMONT. WINDS WILL BE QUITE STRONG ON THURSDAY AS A 50 TO 55
KNOT 850MB JET PIVOTS ACROSS THE REGION. THE UPPER FLOW SHIFTS TO
THE SOUTHWEST THURSDAY NIGHT INTO FRIDAY AS TROF CURVES OUT IN THE
CENTRAL US WITH SFC INFLECTION OF LOW PRESSURE DEVELOPING OVER THE
TENNESSEE VALLEY BY FRIDAY MORNING. MOISTURE SLOWLY RETURN FRIDAY
NIGHT INTO SATURDAY AS THE HIGH CENTER SLIDE OFF THE COAST.

&&

.AVIATION /10Z SATURDAY THROUGH WEDNESDAY/...
AS OF 1125 PM EST FRIDAY...

HIGH CLOUDINESS COVERED THE REGION THIS MORNING...WITH MOSTLY VFR
CONDITIONS OBSERVED. LOW CLOUDS WITH IFR CIGS IN SOUTHEAST WV
NORTH OF KLWB AND KBLF ARE FORECAST REMAIN NORTH THESE LOCATIONS
TONIGHT.

THE TIMING FOR THE ARRIVAL OF LIGHT SNOW CONTINUES TO BE DELAYED
AS A DEEP LAYER OF DRY AIR OVER OUR AREA WILL TAKE TIME TO
SATURATE. THE LIGHT SNOW IS EXPECTED BEGIN ALONG THE SOUTHERN
BLUE RIDGE BETWEEN 10Z-13Z AND SPREAD NORTHWARD IN OUR AREA. CIGS
WILL FALL...BUT NOT EXPECTED TO DROP INTO THE MVFR RANGE. LIGHT
SNOW/FLURRIES WITH LITTLE RESTRICTIONS TO VISIBILITY SHOULD ARRIVE
AT MOST SITES BETWEEN 12Z-15Z

THIS SYSTEM MOVES OUT FAIRLY QUICK WITH MOST PRECIPITATION ENDING
BY SATURDAY AFTERNOON. HOWEVER...A SHALLOW LAYER OF MOISTURE
BANKING UP AGAINST THE WESTERN SLOPES WILL KEEP CLOUDS...LOWERING
TO MVFR LEVELS...AT KBLF AND KLWB AND POSSIBILITY KBCB LATE
SATURDAY AFTERNOON THROUGH THE NIGHT. SOME PATCHY DRIZZLE/LIGHT
SNOW IS ALSO POSSIBLE SATURDAY EVENING.

MEDIUM CONFIDENCE ON VISIBILITIES...WINDS AND CEILINGS DURING THE
TAF PERIOD.

EXTENDED DISCUSSION...

ONCE THIS FEATURE EXITS WILL SEE THE NEXT WAVE ALONG THE COAST
BRING ANOTHER ROUND OF SUB-VFR CONDITIONS FOR LATER SUNDAY NIGHT
INTO MONDAY. RAIN WILL BE THE PRIMARY PRECIPITATION TYPE WITH
THE POTENTIAL FOR POCKETS OF FREEZING RAIN LATE SUNDAY NIGHT INTO
MONDAY MORNING ACROSS COLDER NORTHERN PORTIONS OF FORECAST AREA WHICH
MIGHT IMPACT LWB IF TEMPERATURES ARE COLD ENOUGH.

RAIN WILL IMPACT AREAS ALONG AND EAST OF THE BLUE RIDGE...WITH
YET ANOTHER SYSTEM SLATED FOR LATE TUESDAY INTO WEDNESDAY AHEAD OF
A STRONG COLD FRONT. THESE SYSTEMS ARE EXPECTED TO BRING A PERIOD
MAINLY RAIN BUT COULD BE SOME WINTRY WX AS WELL ESPECIALLY IN THE
MOUNTAINS WITH THE SUNDAY NIGHT/MONDAY EVENT. EXPECT POTENTIAL LOW
LEVEL WIND SHEAR AS WELL AND POOR FLYING WEATHER FOR EARLY NEXT
WEEK. RAIN AND SNOW SHOWERS WILL CONTINUE INTO WEDNESDAY. GUSTY
NORTHWEST WINDS ARE POSSIBLE WEDNESDAY INTO THURSDAY. MOUNTAIN
SNOW SHOWERS AND SNOW FLURRIES EXPECTED WEDNESDAY NIGHT INTO
CHRISTMAS.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...JH/WP
NEAR TERM...JH
SHORT TERM...AMS/NF
LONG TERM...KK
AVIATION...PH/WP





000
FXUS61 KRNK 200844
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
344 AM EST SAT DEC 20 2014

.SYNOPSIS...
WEAK LOW PRESSURE ACROSS THE SOUTHEAST STATES WILL PASS EAST AND
OFFSHORE THIS AFTERNOON KEEPING MOST SIGNIFICANT PRECIPITATION TO
THE SOUTH OF THE REGION. HIGH PRESSURE WILL SPILL BACK SOUTH INTO
THE AREA TONIGHT THROUGH SUNDAY NIGHT AHEAD OF ANOTHER LOW
PRESSURE SYSTEM THAT WILL SLIDE UP THE COAST ON MONDAY. A STRONG
COLD FRONT APPROACHES FROM THE WEST TUESDAY INTO TUESDAY NIGHT
BEFORE PASSING THROUGH THE REGION ON WEDNESDAY.
&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 222 AM EST SATURDAY...

LIGHT PRECIP EVENT TO UNFOLD THIS MORNING STILL LOOKS ON TRACK AS
SURFACE LOW PRESSURE PASSES WELL TO THE SOUTH AND EAST OF THE
REGION THROUGH THIS EVENING. THIS SHOULD KEEP THE MAJORITY OF THE
BETTER LIFT AND DEEP MOISTURE OFF TO THE SE WITH ANY PRECIP OVER THE
REGION PRIMARILY DRIVEN VIA WEAK UPPER DIFFLUENCE BETWEEN MID LEVEL
WAVES. ONE SUCH SHORTWAVE BEING WITH THE LEAD SOUTHERNMOST IMPULSE
LOOKS TO SLIDE ACROSS NW N CAROLINA THIS MORNING AND COINCIDE WITH WEAK
SE FLOW UNDER THE LEFT FRONT OF THE PASSING SPEED MAX ALOFT. THIS
SHOULD HELP DEVELOP AN AXIS OF LIGHT SNOW FROM THE NC MOUNTAINS ALONG
THE I-77 CORRIDOR EARLY ON WITH SOME OF THIS SPREADING EAST BUT IN A
DIMINISHING STATE GIVEN DAMPENING SUPPORT AND RESIDUAL DRY AIR.

WITH THE LATEST MODELS ESPCLY SREF PRINTING OUT QPF OF AROUND A
TENTH OF AN INCH OR SO...BUMPED UP POPS TO HIGHER CHANCE SW AND
KEPT EXTENSION OF THE GOING CHANCE POPS ESPCLY SOUTH OF HIGHWAY
460 THIS MORNING. THIS MAY BRING A HALF INCH OF SNOW AT ELEVATION
FROM I-77 AND POINTS WEST EARLY ON BUT WITHOUT ANY HEADLINES AS
COULD EASILY END UP BEING SNOW SHOWERS/FLURRIES AT WORSE PER
LATEST RADAR TRENDS. ELSW EXPECT LITTLE OR NO ACCUMULATION GIVEN THE
VERY LIGHT PRECIP TYPE SCENARIO IF AT ALL AS SEEN OFF THE LATEST
HRRR. HIGH TEMPS REMAIN TRICKY AFTER SUCH A COLD START WITH
POTENTIAL TO SEE SOME BREAKS DEVELOP BLUE RIDGE AND ACROSS THE
NORTH/WEST LATER ON. THUS TRENDED VALUES UP A DEGREE OR TWO NORTH
WHILE DECREASING A CAT OR SO ESPCLY SE WHERE SOMEWHAT DEEPER
MOISTURE WILL BE LAST TO EXIT.

WEAK RIDGING TO THE NW DIPS BACK INTO THE AREA BEHIND THE DEPARTING
WAVE OVERNIGHT ALLOWING DRYING ALOFT TO TAKE SHAPE UNDER WEAK
SUBSIDENCE. HOWEVER JUST HOW MUCH LOW LEVEL MOISTURE REMAINS TRAPPED IN
QUESTION AND PARTLY DEPENDENT ON THE DEGREE OF MOISTENING TODAY WITH
THE CURRENT EVENT. GFS REMAINS RATHER DRY WITH WEAK NW FLOW THROUGH THE
COLUMN...WHILE THE NAM WETTER UNDER A LIGHT LOW LEVEL EAST/SE
COMPONENT THAT KEEPS QUITE A BIT OF BOUNDARY LAYER MOISTURE ACROSS THE
REGION. THIS COULD POSE A FREEZING DRIZZLE ISSUE ESPCLY BLUE RIDGE WITH
LOTS OF FREEZING FOG/LOW CLOUDS AROUND BUT QUITE IFFY. THUS WILL
GO WITH MORE CLOUDS AND SOME FREEZING FOG OVERNIGHT WHILE LEAVING
OUT ANY -FZDZ MENTION FOR NOW DESPITE DECENT DEPTH TO MOISTURE
UNDER THE INVERSION OFF THE NAM. LOW TEMPS ALSO REFLECT MOISTURE
DIFFERENCES WITH THE MAV MOS WELL INTO THE 20S MOST SPOTS WHILE
THE MET MOS A GOOD 5-10 DEGREES WARMER DUE TO CLOUDS. FOR
NOW...TWEAKED DOWN IN THE VALLEYS AND BLUE RIDGE WHILE LEAVING
THINGS A BIT WARMER WEST-SW WHERE LEFTOVER CLOUDS MORE OF A GOOD
BET IN THE WAKE OF TODAYS POSSIBLE PRECIP.
&&

.SHORT TERM /SUNDAY THROUGH MONDAY/...
AS OF 320 PM EST FRIDAY...

500 MB PATTERN SUNDAY HAD SLIGHTLY RISING HEIGHTS AND WEAK
RIDGING. THEN HIGHER AMPLITUDE LONG WAVE TROF BEGINS DIGGING IN
THE CENTRAL UNITED STATES. WPC IS FAVORING THE TIMING OFF THE
ECMWF FOR THE NEXT SOUTHERN STREAM SHORT WAVE WHICH CROSSES THE
FORECAST AREA ON MONDAY. WILL KEEP HIGHEST PROBABILITY OF
PRECIPITATION ON MONDAY.

850 MB TEMPERATURES RISE ABOVE ZERO ON SUNDAY. BY MONDAY STRONGER
SURFACE WEDGE WILL BE IN PLACE AS LOW PRESSURE DEVELOPS OFF THE
CAROLINA COAST. BY MONDAY MORNING...WARM NOSE ABOVE WEDGE REACHES
TEMPERATURES WARM ENOUGH TO MELT ANY FROZEN PRECIPITATION. POCKET OF
STRONGER WIND SPEEDS AT 850 MB WILL ENHANCE UPSLOPE ON EASTERN SIDE
OF THE BLUE RIDGE ON MONDAY. BUFKIT SOUNDINGS SHOWED THE POTENTIAL
FOR FREEZING RAIN AT LEWISBURG AND HOT SPRINGS. AMOUNT OF
PRECIPITATION THAT FAR NORTHWEST OF THE STORM WAS STILL UNCERTAIN.
HIGHEST AMOUNTS WILL BE CLOSER TO THE COAST.

WILL STAY CLOSE TO GUIDANCE FOR TEMPERATURES SUNDAY THROUGH
SUNDAY NIGHT. MONDAY WILL HAVE LITTLE TO NO TEMPERATURE RISE SINCE
REGION WILL BE IN A WELL ESTABLISHED RIDGE WITH PRECIPITATION AND
PLENTY OF CLOUDS.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 240 PM EST FRIDAY...

WEAK CAD EVENT WITH OVERRUNNING PRECIPITATION WILL CONTINUE MONDAY
NIGHT INTO TUESDAY. LIGHT RAIN...POSSIBLY WITH A FEW POCKETS OF
SLEET OR FREEZING RAIN EXPECTED. WITH CLOUDS AND PRECIPITATION KEPT
LOW TEMPERATURES COOLER THAN MOS WITH READINGS FROM AROUND FREEZING
TO THE UPPER 30S IN THE SOUTHEAST.

A DEEP LONGITUDINAL TROUGH DEVELOPS FROM GREAT LAKES SOUTH TO THE
GULF OF MEXICO ON TUESDAY WITH INCREASING SOUTHERLY LOW LEVEL FLOW
ACROSS OUR REGION...ACCOMPANIED BY INCREASING MOISTURE ADVECTION.
TEMPERATURES WILL WARM TUESDAY AHEAD OF THE COLD FRONT WITH HIGHS
FROM THE MID 40S IN THE MOUNTAINS TO THE LOWER 50S IN THE PIEDMONT.

MODEL CONSENSUS OF GFS AND ECMWF IS THAT A SYNOPTIC UPPER TROUGH
OVER THE MISSISSIPPI VALLEY WILL AMPLIFY TUESDAY AND THEN EJECT
NEGATIVELY TILTED THROUGH THE SOUTHEAST U. S. TUESDAY NIGHT INTO
WEDNESDAY. WITH THE POSITION OF THE ASSOCIATED SURFACE OCCLUDED
FRONT AND THE TRIPLE POINT PASSING SOMEWHERE NEAR OR JUST SOUTH OF
OUR REGION....THERE IS THE POTENTIAL FOR OUR REGION TO HAVE ACTIVE
WEATHER LATE TUESDAY NIGHT INTO WEDNESDAY WITH PLENTY OF
SHOWERS...PERHAPS VERY GUSTY WINDS AND A FEW THUNDERSTORMS. LOOKS
LIKE THE AXIS OF BETTER INSTABILITY MAY BE A LITTLE FURTHER SOUTH ON
THE 12Z MODEL RUN.

COLD AIR PUSHES INTO THE REGION TUESDAY NIGHT INTO WEDNESDAY
ALLOWING FOR SOME RAIN AND SNOW SHOWERS. IF ENOUGH COLD AIR
ARRIVES QUICKLY...THERE COULD BE SOME ACCUMULATING SNOW IN THE
WESTERN MOUNTAINS. LOW TEMPERATURES TUESDAY NIGHT WILL RANGE FROM
THE LOWER 30S IN THE MOUNTAINS TO THE LOWER 40S IN THE SOUTHEAST.

A COLD FRONT WILL MOVE EAST ACROSS OUR REGION WEDNESDAY INTO
WEDNESDAY NIGHT.  HIGHS ON WEDNESDAY WILL WARM INTO THE LOWER 40S IN
THE WEST TO THE LOWER 50S IN THE EAST. RAIN AND SNOW SHOWERS WILL
CHANGEOVER TO SNOW SHOWERS AND SNOW FLURRIES IN THE WEST WEDNESDAY
NIGHT. LOW TEMPERATURES WEDNESDAY NIGHT WILL DROP INTO THE MID 20S
IN THE MOUNTAINS TO THE LOWER 30S IN THE PIEDMONT. WEST TO NORTHWEST
UPPER FLOW WILL CONTINUE INTO THURSDAY WITH HIGHS FROM THE UPPER 20S
IN THE MOUNTAINS TO AROUND 50 IN PIEDMONT. WINDS WILL BE QUITE
STRONG ON THURSDAY AS A 50 TO 55 KNOT 850MB JET PIVOTS ACROSS THE
REGION. THE UPPER FLOW SHIFTS TO THE SOUTHWEST THURSDAY NIGHT INTO
FRIDAY AS TROF CURVES OUT IN THE CENTRAL US WITH SFC INFLECTION OF
LOW PRESSURE DEVELOPING OVER THE TENNESSEE VALLEY BY FRIDAY MORNING.
MOISTURE SLOWLY RETURN FRIDAY NIGHT INTO SATURDAY AS THE HIGH CENTER
SLIDE OFF THE COAST.

&&

.AVIATION /09Z SATURDAY THROUGH WEDNESDAY/...
AS OF 1125 PM EST FRIDAY...

HIGH CLOUDINESS COVERED THE REGION THIS MORNING...WITH MOSTLY VFR
CONDITIONS OBSERVED. LOW CLOUDS WITH IFR CIGS IN SOUTHEAST WV
NORTH OF KLWB AND KBLF ARE FORECAST REMAIN NORTH THESE LOCATIONS
TONIGHT.

THE TIMING FOR THE ARRIVAL OF LIGHT SNOW CONTINUES TO BE DELAYED
AS A DEEP LAYER OF DRY AIR OVER OUR AREA WILL TAKE TIME TO
SATURATE. THE LIGHT SNOW IS EXPECTED BEGIN ALONG THE SOUTHERN
BLUE RIDGE BETWEEN 10Z-13Z AND SPREAD NORTHWARD IN OUR AREA. CIGS
WILL FALL...BUT NOT EXPECTED TO DROP INTO THE MVFR RANGE. LIGHT
SNOW/FLURRIES WITH LITTLE RESTRICTIONS TO VISIBILITY SHOULD ARRIVE
AT MOST SITES BETWEEN 12Z-15Z

THIS SYSTEM MOVES OUT FAIRLY QUICK WITH MOST PRECIPITATION ENDING
BY SATURDAY AFTERNOON. HOWEVER...A SHALLOW LAYER OF MOISTURE
BANKING UP AGAINST THE WESTERN SLOPES WILL KEEP CLOUDS...LOWERING
TO MVFR LEVELS...AT KBLF AND KLWB AND POSSIBILITY KBCB LATE
SATURDAY AFTERNOON THROUGH THE NIGHT. SOME PATCHY DRIZZLE/LIGHT
SNOW IS ALSO POSSIBLE SATURDAY EVENING.

MEDIUM CONFIDENCE ON VISIBILITIES...WINDS AND CEILINGS DURING THE
TAF PERIOD.

EXTENDED DISCUSSION...

ONCE THIS FEATURE EXITS WILL SEE THE NEXT WAVE ALONG THE COAST
BRING ANOTHER ROUND OF SUB-VFR CONDITIONS FOR LATER SUNDAY NIGHT
INTO MONDAY. RAIN WILL BE THE PRIMARY PRECIPITATION TYPE WITH
THE POTENTIAL FOR POCKETS OF FREEZING RAIN LATE SUNDAY NIGHT INTO
MONDAY MORNING ACROSS COLDER NORTHERN PORTIONS OF FORECAST AREA WHICH
MIGHT IMPACT LWB IF TEMPERATURES ARE COLD ENOUGH.

RAIN WILL IMPACT AREAS ALONG AND EAST OF THE BLUE RIDGE...WITH
YET ANOTHER SYSTEM SLATED FOR LATE TUESDAY INTO WEDNESDAY AHEAD OF
A STRONG COLD FRONT. THESE SYSTEMS ARE EXPECTED TO BRING A PERIOD
MAINLY RAIN BUT COULD BE SOME WINTRY WX AS WELL ESPECIALLY IN THE
MOUNTAINS WITH THE SUNDAY NIGHT/MONDAY EVENT. EXPECT POTENTIAL LOW
LEVEL WIND SHEAR AS WELL AND POOR FLYING WEATHER FOR EARLY NEXT
WEEK. RAIN AND SNOW SHOWERS WILL CONTINUE INTO WEDNESDAY. GUSTY
NORTHWEST WINDS ARE POSSIBLE WEDNESDAY INTO THURSDAY. MOUNTAIN
SNOW SHOWERS AND SNOW FLURRIES EXPECTED WEDNESDAY NIGHT INTO
CHRISTMAS.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...JH/WP
NEAR TERM...JH
SHORT TERM...AMS
LONG TERM...KK
AVIATION...PH/WP





000
FXUS61 KRNK 200844
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
344 AM EST SAT DEC 20 2014

.SYNOPSIS...
WEAK LOW PRESSURE ACROSS THE SOUTHEAST STATES WILL PASS EAST AND
OFFSHORE THIS AFTERNOON KEEPING MOST SIGNIFICANT PRECIPITATION TO
THE SOUTH OF THE REGION. HIGH PRESSURE WILL SPILL BACK SOUTH INTO
THE AREA TONIGHT THROUGH SUNDAY NIGHT AHEAD OF ANOTHER LOW
PRESSURE SYSTEM THAT WILL SLIDE UP THE COAST ON MONDAY. A STRONG
COLD FRONT APPROACHES FROM THE WEST TUESDAY INTO TUESDAY NIGHT
BEFORE PASSING THROUGH THE REGION ON WEDNESDAY.
&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 222 AM EST SATURDAY...

LIGHT PRECIP EVENT TO UNFOLD THIS MORNING STILL LOOKS ON TRACK AS
SURFACE LOW PRESSURE PASSES WELL TO THE SOUTH AND EAST OF THE
REGION THROUGH THIS EVENING. THIS SHOULD KEEP THE MAJORITY OF THE
BETTER LIFT AND DEEP MOISTURE OFF TO THE SE WITH ANY PRECIP OVER THE
REGION PRIMARILY DRIVEN VIA WEAK UPPER DIFFLUENCE BETWEEN MID LEVEL
WAVES. ONE SUCH SHORTWAVE BEING WITH THE LEAD SOUTHERNMOST IMPULSE
LOOKS TO SLIDE ACROSS NW N CAROLINA THIS MORNING AND COINCIDE WITH WEAK
SE FLOW UNDER THE LEFT FRONT OF THE PASSING SPEED MAX ALOFT. THIS
SHOULD HELP DEVELOP AN AXIS OF LIGHT SNOW FROM THE NC MOUNTAINS ALONG
THE I-77 CORRIDOR EARLY ON WITH SOME OF THIS SPREADING EAST BUT IN A
DIMINISHING STATE GIVEN DAMPENING SUPPORT AND RESIDUAL DRY AIR.

WITH THE LATEST MODELS ESPCLY SREF PRINTING OUT QPF OF AROUND A
TENTH OF AN INCH OR SO...BUMPED UP POPS TO HIGHER CHANCE SW AND
KEPT EXTENSION OF THE GOING CHANCE POPS ESPCLY SOUTH OF HIGHWAY
460 THIS MORNING. THIS MAY BRING A HALF INCH OF SNOW AT ELEVATION
FROM I-77 AND POINTS WEST EARLY ON BUT WITHOUT ANY HEADLINES AS
COULD EASILY END UP BEING SNOW SHOWERS/FLURRIES AT WORSE PER
LATEST RADAR TRENDS. ELSW EXPECT LITTLE OR NO ACCUMULATION GIVEN THE
VERY LIGHT PRECIP TYPE SCENARIO IF AT ALL AS SEEN OFF THE LATEST
HRRR. HIGH TEMPS REMAIN TRICKY AFTER SUCH A COLD START WITH
POTENTIAL TO SEE SOME BREAKS DEVELOP BLUE RIDGE AND ACROSS THE
NORTH/WEST LATER ON. THUS TRENDED VALUES UP A DEGREE OR TWO NORTH
WHILE DECREASING A CAT OR SO ESPCLY SE WHERE SOMEWHAT DEEPER
MOISTURE WILL BE LAST TO EXIT.

WEAK RIDGING TO THE NW DIPS BACK INTO THE AREA BEHIND THE DEPARTING
WAVE OVERNIGHT ALLOWING DRYING ALOFT TO TAKE SHAPE UNDER WEAK
SUBSIDENCE. HOWEVER JUST HOW MUCH LOW LEVEL MOISTURE REMAINS TRAPPED IN
QUESTION AND PARTLY DEPENDENT ON THE DEGREE OF MOISTENING TODAY WITH
THE CURRENT EVENT. GFS REMAINS RATHER DRY WITH WEAK NW FLOW THROUGH THE
COLUMN...WHILE THE NAM WETTER UNDER A LIGHT LOW LEVEL EAST/SE
COMPONENT THAT KEEPS QUITE A BIT OF BOUNDARY LAYER MOISTURE ACROSS THE
REGION. THIS COULD POSE A FREEZING DRIZZLE ISSUE ESPCLY BLUE RIDGE WITH
LOTS OF FREEZING FOG/LOW CLOUDS AROUND BUT QUITE IFFY. THUS WILL
GO WITH MORE CLOUDS AND SOME FREEZING FOG OVERNIGHT WHILE LEAVING
OUT ANY -FZDZ MENTION FOR NOW DESPITE DECENT DEPTH TO MOISTURE
UNDER THE INVERSION OFF THE NAM. LOW TEMPS ALSO REFLECT MOISTURE
DIFFERENCES WITH THE MAV MOS WELL INTO THE 20S MOST SPOTS WHILE
THE MET MOS A GOOD 5-10 DEGREES WARMER DUE TO CLOUDS. FOR
NOW...TWEAKED DOWN IN THE VALLEYS AND BLUE RIDGE WHILE LEAVING
THINGS A BIT WARMER WEST-SW WHERE LEFTOVER CLOUDS MORE OF A GOOD
BET IN THE WAKE OF TODAYS POSSIBLE PRECIP.
&&

.SHORT TERM /SUNDAY THROUGH MONDAY/...
AS OF 320 PM EST FRIDAY...

500 MB PATTERN SUNDAY HAD SLIGHTLY RISING HEIGHTS AND WEAK
RIDGING. THEN HIGHER AMPLITUDE LONG WAVE TROF BEGINS DIGGING IN
THE CENTRAL UNITED STATES. WPC IS FAVORING THE TIMING OFF THE
ECMWF FOR THE NEXT SOUTHERN STREAM SHORT WAVE WHICH CROSSES THE
FORECAST AREA ON MONDAY. WILL KEEP HIGHEST PROBABILITY OF
PRECIPITATION ON MONDAY.

850 MB TEMPERATURES RISE ABOVE ZERO ON SUNDAY. BY MONDAY STRONGER
SURFACE WEDGE WILL BE IN PLACE AS LOW PRESSURE DEVELOPS OFF THE
CAROLINA COAST. BY MONDAY MORNING...WARM NOSE ABOVE WEDGE REACHES
TEMPERATURES WARM ENOUGH TO MELT ANY FROZEN PRECIPITATION. POCKET OF
STRONGER WIND SPEEDS AT 850 MB WILL ENHANCE UPSLOPE ON EASTERN SIDE
OF THE BLUE RIDGE ON MONDAY. BUFKIT SOUNDINGS SHOWED THE POTENTIAL
FOR FREEZING RAIN AT LEWISBURG AND HOT SPRINGS. AMOUNT OF
PRECIPITATION THAT FAR NORTHWEST OF THE STORM WAS STILL UNCERTAIN.
HIGHEST AMOUNTS WILL BE CLOSER TO THE COAST.

WILL STAY CLOSE TO GUIDANCE FOR TEMPERATURES SUNDAY THROUGH
SUNDAY NIGHT. MONDAY WILL HAVE LITTLE TO NO TEMPERATURE RISE SINCE
REGION WILL BE IN A WELL ESTABLISHED RIDGE WITH PRECIPITATION AND
PLENTY OF CLOUDS.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 240 PM EST FRIDAY...

WEAK CAD EVENT WITH OVERRUNNING PRECIPITATION WILL CONTINUE MONDAY
NIGHT INTO TUESDAY. LIGHT RAIN...POSSIBLY WITH A FEW POCKETS OF
SLEET OR FREEZING RAIN EXPECTED. WITH CLOUDS AND PRECIPITATION KEPT
LOW TEMPERATURES COOLER THAN MOS WITH READINGS FROM AROUND FREEZING
TO THE UPPER 30S IN THE SOUTHEAST.

A DEEP LONGITUDINAL TROUGH DEVELOPS FROM GREAT LAKES SOUTH TO THE
GULF OF MEXICO ON TUESDAY WITH INCREASING SOUTHERLY LOW LEVEL FLOW
ACROSS OUR REGION...ACCOMPANIED BY INCREASING MOISTURE ADVECTION.
TEMPERATURES WILL WARM TUESDAY AHEAD OF THE COLD FRONT WITH HIGHS
FROM THE MID 40S IN THE MOUNTAINS TO THE LOWER 50S IN THE PIEDMONT.

MODEL CONSENSUS OF GFS AND ECMWF IS THAT A SYNOPTIC UPPER TROUGH
OVER THE MISSISSIPPI VALLEY WILL AMPLIFY TUESDAY AND THEN EJECT
NEGATIVELY TILTED THROUGH THE SOUTHEAST U. S. TUESDAY NIGHT INTO
WEDNESDAY. WITH THE POSITION OF THE ASSOCIATED SURFACE OCCLUDED
FRONT AND THE TRIPLE POINT PASSING SOMEWHERE NEAR OR JUST SOUTH OF
OUR REGION....THERE IS THE POTENTIAL FOR OUR REGION TO HAVE ACTIVE
WEATHER LATE TUESDAY NIGHT INTO WEDNESDAY WITH PLENTY OF
SHOWERS...PERHAPS VERY GUSTY WINDS AND A FEW THUNDERSTORMS. LOOKS
LIKE THE AXIS OF BETTER INSTABILITY MAY BE A LITTLE FURTHER SOUTH ON
THE 12Z MODEL RUN.

COLD AIR PUSHES INTO THE REGION TUESDAY NIGHT INTO WEDNESDAY
ALLOWING FOR SOME RAIN AND SNOW SHOWERS. IF ENOUGH COLD AIR
ARRIVES QUICKLY...THERE COULD BE SOME ACCUMULATING SNOW IN THE
WESTERN MOUNTAINS. LOW TEMPERATURES TUESDAY NIGHT WILL RANGE FROM
THE LOWER 30S IN THE MOUNTAINS TO THE LOWER 40S IN THE SOUTHEAST.

A COLD FRONT WILL MOVE EAST ACROSS OUR REGION WEDNESDAY INTO
WEDNESDAY NIGHT.  HIGHS ON WEDNESDAY WILL WARM INTO THE LOWER 40S IN
THE WEST TO THE LOWER 50S IN THE EAST. RAIN AND SNOW SHOWERS WILL
CHANGEOVER TO SNOW SHOWERS AND SNOW FLURRIES IN THE WEST WEDNESDAY
NIGHT. LOW TEMPERATURES WEDNESDAY NIGHT WILL DROP INTO THE MID 20S
IN THE MOUNTAINS TO THE LOWER 30S IN THE PIEDMONT. WEST TO NORTHWEST
UPPER FLOW WILL CONTINUE INTO THURSDAY WITH HIGHS FROM THE UPPER 20S
IN THE MOUNTAINS TO AROUND 50 IN PIEDMONT. WINDS WILL BE QUITE
STRONG ON THURSDAY AS A 50 TO 55 KNOT 850MB JET PIVOTS ACROSS THE
REGION. THE UPPER FLOW SHIFTS TO THE SOUTHWEST THURSDAY NIGHT INTO
FRIDAY AS TROF CURVES OUT IN THE CENTRAL US WITH SFC INFLECTION OF
LOW PRESSURE DEVELOPING OVER THE TENNESSEE VALLEY BY FRIDAY MORNING.
MOISTURE SLOWLY RETURN FRIDAY NIGHT INTO SATURDAY AS THE HIGH CENTER
SLIDE OFF THE COAST.

&&

.AVIATION /09Z SATURDAY THROUGH WEDNESDAY/...
AS OF 1125 PM EST FRIDAY...

HIGH CLOUDINESS COVERED THE REGION THIS MORNING...WITH MOSTLY VFR
CONDITIONS OBSERVED. LOW CLOUDS WITH IFR CIGS IN SOUTHEAST WV
NORTH OF KLWB AND KBLF ARE FORECAST REMAIN NORTH THESE LOCATIONS
TONIGHT.

THE TIMING FOR THE ARRIVAL OF LIGHT SNOW CONTINUES TO BE DELAYED
AS A DEEP LAYER OF DRY AIR OVER OUR AREA WILL TAKE TIME TO
SATURATE. THE LIGHT SNOW IS EXPECTED BEGIN ALONG THE SOUTHERN
BLUE RIDGE BETWEEN 10Z-13Z AND SPREAD NORTHWARD IN OUR AREA. CIGS
WILL FALL...BUT NOT EXPECTED TO DROP INTO THE MVFR RANGE. LIGHT
SNOW/FLURRIES WITH LITTLE RESTRICTIONS TO VISIBILITY SHOULD ARRIVE
AT MOST SITES BETWEEN 12Z-15Z

THIS SYSTEM MOVES OUT FAIRLY QUICK WITH MOST PRECIPITATION ENDING
BY SATURDAY AFTERNOON. HOWEVER...A SHALLOW LAYER OF MOISTURE
BANKING UP AGAINST THE WESTERN SLOPES WILL KEEP CLOUDS...LOWERING
TO MVFR LEVELS...AT KBLF AND KLWB AND POSSIBILITY KBCB LATE
SATURDAY AFTERNOON THROUGH THE NIGHT. SOME PATCHY DRIZZLE/LIGHT
SNOW IS ALSO POSSIBLE SATURDAY EVENING.

MEDIUM CONFIDENCE ON VISIBILITIES...WINDS AND CEILINGS DURING THE
TAF PERIOD.

EXTENDED DISCUSSION...

ONCE THIS FEATURE EXITS WILL SEE THE NEXT WAVE ALONG THE COAST
BRING ANOTHER ROUND OF SUB-VFR CONDITIONS FOR LATER SUNDAY NIGHT
INTO MONDAY. RAIN WILL BE THE PRIMARY PRECIPITATION TYPE WITH
THE POTENTIAL FOR POCKETS OF FREEZING RAIN LATE SUNDAY NIGHT INTO
MONDAY MORNING ACROSS COLDER NORTHERN PORTIONS OF FORECAST AREA WHICH
MIGHT IMPACT LWB IF TEMPERATURES ARE COLD ENOUGH.

RAIN WILL IMPACT AREAS ALONG AND EAST OF THE BLUE RIDGE...WITH
YET ANOTHER SYSTEM SLATED FOR LATE TUESDAY INTO WEDNESDAY AHEAD OF
A STRONG COLD FRONT. THESE SYSTEMS ARE EXPECTED TO BRING A PERIOD
MAINLY RAIN BUT COULD BE SOME WINTRY WX AS WELL ESPECIALLY IN THE
MOUNTAINS WITH THE SUNDAY NIGHT/MONDAY EVENT. EXPECT POTENTIAL LOW
LEVEL WIND SHEAR AS WELL AND POOR FLYING WEATHER FOR EARLY NEXT
WEEK. RAIN AND SNOW SHOWERS WILL CONTINUE INTO WEDNESDAY. GUSTY
NORTHWEST WINDS ARE POSSIBLE WEDNESDAY INTO THURSDAY. MOUNTAIN
SNOW SHOWERS AND SNOW FLURRIES EXPECTED WEDNESDAY NIGHT INTO
CHRISTMAS.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...JH/WP
NEAR TERM...JH
SHORT TERM...AMS
LONG TERM...KK
AVIATION...PH/WP




000
FXUS61 KRNK 200425
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
1125 PM EST FRI DEC 19 2014

.SYNOPSIS...
HIGH PRESSURE BUILDS SOUTHEAST ACROSS THE AREA RESULTING IN
OVERALL DRY WEATHER INTO EARLY TONIGHT. A WEAK AREA OF LOW
PRESSURE WILL DEVELOP ALONG THE GULF COAST STATES LATE TONIGHT AND
MOVE EAST OVER THE SOUTHEAST STATES ON SATURDAY. THIS SYSTEM WILL
BRING A PERIOD OF LIGHT WINTRY PRECIPITATION TO MAINLY SOUTHERN
AND WESTERN AREAS SATURDAY. ANOTHER LOW DEVELOPS ACROSS THE
SOUTHEAST SUNDAY NIGHT MOVING UP THE COAST TO THE TIDEWATER OF
VIRGINIA BY MONDAY AFTERNOON.

&&

.NEAR TERM /THROUGH SATURDAY/...
AS OF 945 PM EST FRIDAY...

MOSAIC OF NWS DOPPLER RADARS INDICATES LEADING EDGE OF PRECIP
EXPANDING INTO SOUTHEAST TN...AND CENTRAL GA. HOWEVER...SFC OBS
SUGGEST MOST OF THE LEADING RADAR RETURNS ARE NOT REACHING THE
GROUND...AS SFC OBS SHOW PRECIP REPORTED IN ALABAMA.

HRRR...RUC/RAP...AND HI-RES ARW MODELS ALL ARE IN THE BALLPARK ON
WHERE PRECIP IS FALLING AT 02Z...AND NONE OF THESE MODELS BRING
LIGHT PRECIP INTO OUR FORECAST AREA UNTIL AFTER 09Z. COMBINE THIS
WITH THE FACT THAT THE OOZ SOUNDINGS FROM RNK AND GSO SHOW A
TREMENDOUS DRY LAYER (PWATS 0.25 AND 0.31 RESPECTFULLY) BELOW
400MB...AND CHANCES FOR MEANINGFUL MEASURABLE PRECIP WITH THIS
SYSTEM ARE DIMINISHING.

AS A RESULT...DELAYED THE ARRIVAL OF PRECIP FROM THE
SOUTHWEST. REDUCED POPS...ESPECIALLY NORTH OF 460...AND LOWERED
QPF/SNOWFALL AMOUNTS. HIGH CLOUDINESS IS GRADUALLY OVERSPREADING
THE REGION...BUT POCKETS OF CLEARING HAVE ALLOWED TEMPS IN SOME
AREAS LIKE DAN AND HSP TO FALL FASTER THAN ANTICIPATED. THEREFORE
LOWERED TEMPS A FEW DEGREES...BUT TEMP FALL SHOULD SLOW AS CLOUDS
THICKEN.

TEMPS WILL NOT RISE TOO MUCH SATURDAY WITH PRECIP AROUND...THINKING
MID TO UPPER 30S MOUNTAINS...TO LOWER 40S EAST.

MOISTURE BEGINS TO LIFT OUT BY MID-LATE AFTERNOON SUCH THAT
PRECIP SHOULD TAPER OFF.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
AS OF 320 PM EST FRIDAY...

500 MB PATTERN SATURDAY NIGHT AND SUNDAY HAD SLIGHTLY RISING HEIGHTS
AND WEAK RIDGING. THEN HIGHER AMPLITUDE LONG WAVE TROF BEGINS
DIGGING IN THE CENTRAL UNITED STATES. WPC IS FAVORING THE TIMING OFF
THE ECMWF FOR THE NEXT SOUTHERN STREAM SHORT WAVE WHICH CROSSES THE
FORECAST AREA ON MONDAY. WILL KEEP HIGHEST PROBABILITY OF
PRECIPITATION ON MONDAY.

850 MB TEMPERATURES RISE ABOVE ZERO ON SUNDAY. BY MONDAY STRONGER
SURFACE WEDGE WILL BE IN PLACE AS LOW PRESSURE DEVELOPS OFF THE
CAROLINA COAST. BY MONDAY MORNING...WARM NOSE ABOVE WEDGE REACHES
TEMPERATURES WARM ENOUGH TO MELT ANY FROZEN PRECIPITATION. POCKET OF
STRONGER WIND SPEEDS AT 850 MB WILL ENHANCE UPSLOPE ON EASTERN SIDE
OF THE BLUE RIDGE ON MONDAY. BUFKIT SOUNDINGS SHOWED THE POTENTIAL
FOR FREEZING RAIN AT LEWISBURG AND HOT SPRINGS. AMOUNT OF
PRECIPITATION THAT FAR NORTHWEST OF THE STORM WAS STILL UNCERTAIN.
HIGHEST AMOUNTS WILL BE CLOSER TO THE COAST.

WILL STAY CLOSE TO GUIDANCE FOR TEMPERATURES SATURDAY NIGHT THROUGH
SUNDAY NIGHT. MONDAY WILL HAVE LITTLE TO NO TEMPERATURE RISE SINCE
REGION WILL BE IN A WELL ESTABLISHED RIDGE WITH PRECIPITATION AND
PLENTY OF CLOUDS.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 240 PM EST FRIDAY...

WEAK CAD EVENT WITH OVERRUNNING PRECIPITATION WILL CONTINUE MONDAY
NIGHT INTO TUESDAY. LIGHT RAIN...POSSIBLY WITH A FEW POCKETS OF
SLEET OR FREEZING RAIN EXPECTED. WITH CLOUDS AND PRECIPITATION KEPT
LOW TEMPERATURES COOLER THAN MOS WITH READINGS FROM AROUND FREEZING
TO THE UPPER 30S IN THE SOUTHEAST.

A DEEP LONGITUDINAL TROUGH DEVELOPS FROM GREAT LAKES SOUTH TO THE
GULF OF MEXICO ON TUESDAY WITH INCREASING SOUTHERLY LOW LEVEL FLOW
ACROSS OUR REGION...ACCOMPANIED BY INCREASING MOISTURE ADVECTION.
TEMPERATURES WILL WARM TUESDAY AHEAD OF THE COLD FRONT WITH HIGHS
FROM THE MID 40S IN THE MOUNTAINS TO THE LOWER 50S IN THE PIEDMONT.

MODEL CONSENSUS OF GFS AND ECMWF IS THAT A SYNOPTIC UPPER TROUGH
OVER THE MISSISSIPPI VALLEY WILL AMPLIFY TUESDAY AND THEN EJECT
NEGATIVELY TILTED THROUGH THE SOUTHEAST U. S. TUESDAY NIGHT INTO
WEDNESDAY. WITH THE POSITION OF THE ASSOCIATED SURFACE OCCLUDED
FRONT AND THE TRIPLE POINT PASSING SOMEWHERE NEAR OR JUST SOUTH OF
OUR REGION....THERE IS THE POTENTIAL FOR OUR REGION TO HAVE ACTIVE
WEATHER LATE TUESDAY NIGHT INTO WEDNESDAY WITH PLENTY OF
SHOWERS...PERHAPS VERY GUSTY WINDS AND A FEW THUNDERSTORMS. LOOKS
LIKE THE AXIS OF BETTER INSTABILITY MAY BE A LITTLE FURTHER SOUTH ON
THE 12Z MODEL RUN.

COLD AIR PUSHES INTO THE REGION TUESDAY NIGHT INTO WEDNESDAY
ALLOWING FOR SOME RAIN AND SNOW SHOWERS. IF ENOUGH COLD AIR
ARRIVES QUICKLY...THERE COULD BE SOME ACCUMULATING SNOW IN THE
WESTERN MOUNTAINS. LOW TEMPERATURES TUESDAY NIGHT WILL RANGE FROM
THE LOWER 30S IN THE MOUNTAINS TO THE LOWER 40S IN THE SOUTHEAST.

A COLD FRONT WILL MOVE EAST ACROSS OUR REGION WEDNESDAY INTO
WEDNESDAY NIGHT.  HIGHS ON WEDNESDAY WILL WARM INTO THE LOWER 40S IN
THE WEST TO THE LOWER 50S IN THE EAST. RAIN AND SNOW SHOWERS WILL
CHANGEOVER TO SNOW SHOWERS AND SNOW FLURRIES IN THE WEST WEDNESDAY
NIGHT. LOW TEMPERATURES WEDNESDAY NIGHT WILL DROP INTO THE MID 20S
IN THE MOUNTAINS TO THE LOWER 30S IN THE PIEDMONT. WEST TO NORTHWEST
UPPER FLOW WILL CONTINUE INTO THURSDAY WITH HIGHS FROM THE UPPER 20S
IN THE MOUNTAINS TO AROUND 50 IN PIEDMONT. WINDS WILL BE QUITE
STRONG ON THURSDAY AS A 50 TO 55 KNOT 850MB JET PIVOTS ACROSS THE
REGION. THE UPPER FLOW SHIFTS TO THE SOUTHWEST THURSDAY NIGHT INTO
FRIDAY AS TROF CURVES OUT IN THE CENTRAL US WITH SFC INFLECTION OF
LOW PRESSURE DEVELOPING OVER THE TENNESSEE VALLEY BY FRIDAY MORNING.
MOISTURE SLOWLY RETURN FRIDAY NIGHT INTO SATURDAY AS THE HIGH CENTER
SLIDE OFF THE COAST.

&&

.AVIATION /04Z SATURDAY THROUGH WEDNESDAY/...
AS OF 1125 PM EST FRIDAY...

HIGH CLOUDINESS COVERED THE REGION THIS MORNING...WITH MOSTLY VFR
CONDITIONS OBSERVED. LOW CLOUDS WITH IFR CIGS IN SOUTHEAST WV
NORTH OF KLWB AND KBLF ARE FORECAST REMAIN NORTH THESE LOCATIONS
TONIGHT.

THE TIMING FOR THE ARRIVAL OF LIGHT SNOW CONTINUES TO BE DELAYED
AS A DEEP LAYER OF DRY AIR OVER OUR AREA WILL TAKE TIME TO
SATURATE. THE LIGHT SNOW IS EXPECTED BEGIN ALONG THE SOUTHERN
BLUE RIDGE BETWEEN 10Z-13Z AND SPREAD NORTHWARD IN OUR AREA. CIGS
WILL FALL...BUT NOT EXPECTED TO DROP INTO THE MVFR RANGE. LIGHT
SNOW/FLURRIES WITH LITTLE RESTRICTIONS TO VISIBILITY SHOULD ARRIVE
AT MOST SITES BETWEEN 12Z-15Z

THIS SYSTEM MOVES OUT FAIRLY QUICK WITH MOST PRECIPITATION ENDING
BY SATURDAY AFTERNOON. HOWEVER...A SHALLOW LAYER OF MOISTURE
BANKING UP AGAINST THE WESTERN SLOPES WILL KEEP CLOUDS...LOWERING
TO MVFR LEVELS...AT KBLF AND KLWB AND POSSIBILITY KBCB LATE
SATURDAY AFTERNOON THROUGH THE NIGHT. SOME PATCHY DRIZZLE/LIGHT
SNOW IS ALSO POSSIBLE SATURDAY EVENING.

MEDIUM CONFIDENCE ON VISIBILITIES...WINDS AND CEILINGS DURING THE
TAF PERIOD.

EXTENDED DISCUSSION...

ONCE THIS FEATURE EXITS WILL SEE THE NEXT WAVE ALONG THE COAST
BRING ANOTHER ROUND OF SUB-VFR CONDITIONS FOR LATER SUNDAY NIGHT
INTO MONDAY. RAIN WILL BE THE PRIMARY PRECIPITATION TYPE WITH
THE POTENTIAL FOR POCKETS OF FREEZING RAIN LATE SUNDAY NIGHT INTO
MONDAY MORNING ACROSS COLDER NORTHERN PORTIONS OF FORECAST AREA WHICH
MIGHT IMPACT LWB IF TEMPERATURES ARE COLD ENOUGH.

RAIN WILL IMPACT AREAS ALONG AND EAST OF THE BLUE RIDGE...WITH
YET ANOTHER SYSTEM SLATED FOR LATE TUESDAY INTO WEDNESDAY AHEAD OF
A STRONG COLD FRONT. THESE SYSTEMS ARE EXPECTED TO BRING A PERIOD
MAINLY RAIN BUT COULD BE SOME WINTRY WX AS WELL ESPECIALLY IN THE
MOUNTAINS WITH THE SUNDAY NIGHT/MONDAY EVENT. EXPECT POTENTIAL LOW
LEVEL WIND SHEAR AS WELL AND POOR FLYING WEATHER FOR EARLY NEXT
WEEK. RAIN AND SNOW SHOWERS WILL CONTINUE INTO WEDNESDAY. GUSTY
NORTHWEST WINDS ARE POSSIBLE WEDNESDAY INTO THURSDAY. MOUNTAIN
SNOW SHOWERS AND SNOW FLURRIES EXPECTED WEDNESDAY NIGHT INTO
CHRISTMAS.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...JH/WP
NEAR TERM...PH/WP
SHORT TERM...AMS
LONG TERM...KK
AVIATION...PH/WP





000
FXUS61 KRNK 200425
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
1125 PM EST FRI DEC 19 2014

.SYNOPSIS...
HIGH PRESSURE BUILDS SOUTHEAST ACROSS THE AREA RESULTING IN
OVERALL DRY WEATHER INTO EARLY TONIGHT. A WEAK AREA OF LOW
PRESSURE WILL DEVELOP ALONG THE GULF COAST STATES LATE TONIGHT AND
MOVE EAST OVER THE SOUTHEAST STATES ON SATURDAY. THIS SYSTEM WILL
BRING A PERIOD OF LIGHT WINTRY PRECIPITATION TO MAINLY SOUTHERN
AND WESTERN AREAS SATURDAY. ANOTHER LOW DEVELOPS ACROSS THE
SOUTHEAST SUNDAY NIGHT MOVING UP THE COAST TO THE TIDEWATER OF
VIRGINIA BY MONDAY AFTERNOON.

&&

.NEAR TERM /THROUGH SATURDAY/...
AS OF 945 PM EST FRIDAY...

MOSAIC OF NWS DOPPLER RADARS INDICATES LEADING EDGE OF PRECIP
EXPANDING INTO SOUTHEAST TN...AND CENTRAL GA. HOWEVER...SFC OBS
SUGGEST MOST OF THE LEADING RADAR RETURNS ARE NOT REACHING THE
GROUND...AS SFC OBS SHOW PRECIP REPORTED IN ALABAMA.

HRRR...RUC/RAP...AND HI-RES ARW MODELS ALL ARE IN THE BALLPARK ON
WHERE PRECIP IS FALLING AT 02Z...AND NONE OF THESE MODELS BRING
LIGHT PRECIP INTO OUR FORECAST AREA UNTIL AFTER 09Z. COMBINE THIS
WITH THE FACT THAT THE OOZ SOUNDINGS FROM RNK AND GSO SHOW A
TREMENDOUS DRY LAYER (PWATS 0.25 AND 0.31 RESPECTFULLY) BELOW
400MB...AND CHANCES FOR MEANINGFUL MEASURABLE PRECIP WITH THIS
SYSTEM ARE DIMINISHING.

AS A RESULT...DELAYED THE ARRIVAL OF PRECIP FROM THE
SOUTHWEST. REDUCED POPS...ESPECIALLY NORTH OF 460...AND LOWERED
QPF/SNOWFALL AMOUNTS. HIGH CLOUDINESS IS GRADUALLY OVERSPREADING
THE REGION...BUT POCKETS OF CLEARING HAVE ALLOWED TEMPS IN SOME
AREAS LIKE DAN AND HSP TO FALL FASTER THAN ANTICIPATED. THEREFORE
LOWERED TEMPS A FEW DEGREES...BUT TEMP FALL SHOULD SLOW AS CLOUDS
THICKEN.

TEMPS WILL NOT RISE TOO MUCH SATURDAY WITH PRECIP AROUND...THINKING
MID TO UPPER 30S MOUNTAINS...TO LOWER 40S EAST.

MOISTURE BEGINS TO LIFT OUT BY MID-LATE AFTERNOON SUCH THAT
PRECIP SHOULD TAPER OFF.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
AS OF 320 PM EST FRIDAY...

500 MB PATTERN SATURDAY NIGHT AND SUNDAY HAD SLIGHTLY RISING HEIGHTS
AND WEAK RIDGING. THEN HIGHER AMPLITUDE LONG WAVE TROF BEGINS
DIGGING IN THE CENTRAL UNITED STATES. WPC IS FAVORING THE TIMING OFF
THE ECMWF FOR THE NEXT SOUTHERN STREAM SHORT WAVE WHICH CROSSES THE
FORECAST AREA ON MONDAY. WILL KEEP HIGHEST PROBABILITY OF
PRECIPITATION ON MONDAY.

850 MB TEMPERATURES RISE ABOVE ZERO ON SUNDAY. BY MONDAY STRONGER
SURFACE WEDGE WILL BE IN PLACE AS LOW PRESSURE DEVELOPS OFF THE
CAROLINA COAST. BY MONDAY MORNING...WARM NOSE ABOVE WEDGE REACHES
TEMPERATURES WARM ENOUGH TO MELT ANY FROZEN PRECIPITATION. POCKET OF
STRONGER WIND SPEEDS AT 850 MB WILL ENHANCE UPSLOPE ON EASTERN SIDE
OF THE BLUE RIDGE ON MONDAY. BUFKIT SOUNDINGS SHOWED THE POTENTIAL
FOR FREEZING RAIN AT LEWISBURG AND HOT SPRINGS. AMOUNT OF
PRECIPITATION THAT FAR NORTHWEST OF THE STORM WAS STILL UNCERTAIN.
HIGHEST AMOUNTS WILL BE CLOSER TO THE COAST.

WILL STAY CLOSE TO GUIDANCE FOR TEMPERATURES SATURDAY NIGHT THROUGH
SUNDAY NIGHT. MONDAY WILL HAVE LITTLE TO NO TEMPERATURE RISE SINCE
REGION WILL BE IN A WELL ESTABLISHED RIDGE WITH PRECIPITATION AND
PLENTY OF CLOUDS.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 240 PM EST FRIDAY...

WEAK CAD EVENT WITH OVERRUNNING PRECIPITATION WILL CONTINUE MONDAY
NIGHT INTO TUESDAY. LIGHT RAIN...POSSIBLY WITH A FEW POCKETS OF
SLEET OR FREEZING RAIN EXPECTED. WITH CLOUDS AND PRECIPITATION KEPT
LOW TEMPERATURES COOLER THAN MOS WITH READINGS FROM AROUND FREEZING
TO THE UPPER 30S IN THE SOUTHEAST.

A DEEP LONGITUDINAL TROUGH DEVELOPS FROM GREAT LAKES SOUTH TO THE
GULF OF MEXICO ON TUESDAY WITH INCREASING SOUTHERLY LOW LEVEL FLOW
ACROSS OUR REGION...ACCOMPANIED BY INCREASING MOISTURE ADVECTION.
TEMPERATURES WILL WARM TUESDAY AHEAD OF THE COLD FRONT WITH HIGHS
FROM THE MID 40S IN THE MOUNTAINS TO THE LOWER 50S IN THE PIEDMONT.

MODEL CONSENSUS OF GFS AND ECMWF IS THAT A SYNOPTIC UPPER TROUGH
OVER THE MISSISSIPPI VALLEY WILL AMPLIFY TUESDAY AND THEN EJECT
NEGATIVELY TILTED THROUGH THE SOUTHEAST U. S. TUESDAY NIGHT INTO
WEDNESDAY. WITH THE POSITION OF THE ASSOCIATED SURFACE OCCLUDED
FRONT AND THE TRIPLE POINT PASSING SOMEWHERE NEAR OR JUST SOUTH OF
OUR REGION....THERE IS THE POTENTIAL FOR OUR REGION TO HAVE ACTIVE
WEATHER LATE TUESDAY NIGHT INTO WEDNESDAY WITH PLENTY OF
SHOWERS...PERHAPS VERY GUSTY WINDS AND A FEW THUNDERSTORMS. LOOKS
LIKE THE AXIS OF BETTER INSTABILITY MAY BE A LITTLE FURTHER SOUTH ON
THE 12Z MODEL RUN.

COLD AIR PUSHES INTO THE REGION TUESDAY NIGHT INTO WEDNESDAY
ALLOWING FOR SOME RAIN AND SNOW SHOWERS. IF ENOUGH COLD AIR
ARRIVES QUICKLY...THERE COULD BE SOME ACCUMULATING SNOW IN THE
WESTERN MOUNTAINS. LOW TEMPERATURES TUESDAY NIGHT WILL RANGE FROM
THE LOWER 30S IN THE MOUNTAINS TO THE LOWER 40S IN THE SOUTHEAST.

A COLD FRONT WILL MOVE EAST ACROSS OUR REGION WEDNESDAY INTO
WEDNESDAY NIGHT.  HIGHS ON WEDNESDAY WILL WARM INTO THE LOWER 40S IN
THE WEST TO THE LOWER 50S IN THE EAST. RAIN AND SNOW SHOWERS WILL
CHANGEOVER TO SNOW SHOWERS AND SNOW FLURRIES IN THE WEST WEDNESDAY
NIGHT. LOW TEMPERATURES WEDNESDAY NIGHT WILL DROP INTO THE MID 20S
IN THE MOUNTAINS TO THE LOWER 30S IN THE PIEDMONT. WEST TO NORTHWEST
UPPER FLOW WILL CONTINUE INTO THURSDAY WITH HIGHS FROM THE UPPER 20S
IN THE MOUNTAINS TO AROUND 50 IN PIEDMONT. WINDS WILL BE QUITE
STRONG ON THURSDAY AS A 50 TO 55 KNOT 850MB JET PIVOTS ACROSS THE
REGION. THE UPPER FLOW SHIFTS TO THE SOUTHWEST THURSDAY NIGHT INTO
FRIDAY AS TROF CURVES OUT IN THE CENTRAL US WITH SFC INFLECTION OF
LOW PRESSURE DEVELOPING OVER THE TENNESSEE VALLEY BY FRIDAY MORNING.
MOISTURE SLOWLY RETURN FRIDAY NIGHT INTO SATURDAY AS THE HIGH CENTER
SLIDE OFF THE COAST.

&&

.AVIATION /04Z SATURDAY THROUGH WEDNESDAY/...
AS OF 1125 PM EST FRIDAY...

HIGH CLOUDINESS COVERED THE REGION THIS MORNING...WITH MOSTLY VFR
CONDITIONS OBSERVED. LOW CLOUDS WITH IFR CIGS IN SOUTHEAST WV
NORTH OF KLWB AND KBLF ARE FORECAST REMAIN NORTH THESE LOCATIONS
TONIGHT.

THE TIMING FOR THE ARRIVAL OF LIGHT SNOW CONTINUES TO BE DELAYED
AS A DEEP LAYER OF DRY AIR OVER OUR AREA WILL TAKE TIME TO
SATURATE. THE LIGHT SNOW IS EXPECTED BEGIN ALONG THE SOUTHERN
BLUE RIDGE BETWEEN 10Z-13Z AND SPREAD NORTHWARD IN OUR AREA. CIGS
WILL FALL...BUT NOT EXPECTED TO DROP INTO THE MVFR RANGE. LIGHT
SNOW/FLURRIES WITH LITTLE RESTRICTIONS TO VISIBILITY SHOULD ARRIVE
AT MOST SITES BETWEEN 12Z-15Z

THIS SYSTEM MOVES OUT FAIRLY QUICK WITH MOST PRECIPITATION ENDING
BY SATURDAY AFTERNOON. HOWEVER...A SHALLOW LAYER OF MOISTURE
BANKING UP AGAINST THE WESTERN SLOPES WILL KEEP CLOUDS...LOWERING
TO MVFR LEVELS...AT KBLF AND KLWB AND POSSIBILITY KBCB LATE
SATURDAY AFTERNOON THROUGH THE NIGHT. SOME PATCHY DRIZZLE/LIGHT
SNOW IS ALSO POSSIBLE SATURDAY EVENING.

MEDIUM CONFIDENCE ON VISIBILITIES...WINDS AND CEILINGS DURING THE
TAF PERIOD.

EXTENDED DISCUSSION...

ONCE THIS FEATURE EXITS WILL SEE THE NEXT WAVE ALONG THE COAST
BRING ANOTHER ROUND OF SUB-VFR CONDITIONS FOR LATER SUNDAY NIGHT
INTO MONDAY. RAIN WILL BE THE PRIMARY PRECIPITATION TYPE WITH
THE POTENTIAL FOR POCKETS OF FREEZING RAIN LATE SUNDAY NIGHT INTO
MONDAY MORNING ACROSS COLDER NORTHERN PORTIONS OF FORECAST AREA WHICH
MIGHT IMPACT LWB IF TEMPERATURES ARE COLD ENOUGH.

RAIN WILL IMPACT AREAS ALONG AND EAST OF THE BLUE RIDGE...WITH
YET ANOTHER SYSTEM SLATED FOR LATE TUESDAY INTO WEDNESDAY AHEAD OF
A STRONG COLD FRONT. THESE SYSTEMS ARE EXPECTED TO BRING A PERIOD
MAINLY RAIN BUT COULD BE SOME WINTRY WX AS WELL ESPECIALLY IN THE
MOUNTAINS WITH THE SUNDAY NIGHT/MONDAY EVENT. EXPECT POTENTIAL LOW
LEVEL WIND SHEAR AS WELL AND POOR FLYING WEATHER FOR EARLY NEXT
WEEK. RAIN AND SNOW SHOWERS WILL CONTINUE INTO WEDNESDAY. GUSTY
NORTHWEST WINDS ARE POSSIBLE WEDNESDAY INTO THURSDAY. MOUNTAIN
SNOW SHOWERS AND SNOW FLURRIES EXPECTED WEDNESDAY NIGHT INTO
CHRISTMAS.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...JH/WP
NEAR TERM...PH/WP
SHORT TERM...AMS
LONG TERM...KK
AVIATION...PH/WP




000
FXUS61 KRNK 200238
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
938 PM EST FRI DEC 19 2014

.SYNOPSIS...
HIGH PRESSURE BUILDS SOUTHEAST ACROSS THE AREA RESULTING IN
OVERALL DRY WEATHER INTO EARLY TONIGHT. A WEAK AREA OF LOW
PRESSURE WILL DEVELOP ALONG THE GULF COAST STATES LATE TONIGHT AND
MOVE EAST OVER THE SOUTHEAST STATES ON SATURDAY. THIS SYSTEM WILL
BRING A PERIOD OF LIGHT WINTRY PRECIPITATION TO MAINLY SOUTHERN
AND WESTERN AREAS SATURDAY. ANOTHER LOW DEVELOPS ACROSS THE
SOUTHEAST SUNDAY NIGHT MOVING UP THE COAST TO THE TIDEWATER OF
VIRGINIA BY MONDAY AFTERNOON.

&&

.NEAR TERM /THROUGH SATURDAY/...
AS OF 945 PM EST FRIDAY...

MOSAIC OF NWS DOPPLER RADARS INDICATES LEADING EDGE OF PRECIP
EXPANDING INTO SOUTHEAST TN...AND CENTRAL GA. HOWEVER...SFC OBS
SUGGEST MOST OF THE LEADING RADAR RETURNS ARE NOT REACHING THE
GROUND...AS SFC OBS SHOW PRECIP REPORTED IN ALABAMA.

HRRR...RUC/RAP...AND HI-RES ARW MODELS ALL ARE IN THE BALLPARK ON
WHERE PRECIP IS FALLING AT 02Z...AND NONE OF THESE MODELS BRING
LIGHT PRECIP INTO OUR FORECAST AREA UNTIL AFTER 09Z. COMBINE THIS
WITH THE FACT THAT THE OOZ SOUNDINGS FROM RNK AND GSO SHOW A
TREMENDOUS DRY LAYER (PWATS 0.25 AND 0.31 RESPECTFULLY) BELOW
400MB...AND CHANCES FOR MEANINGFUL MEASURABLE PRECIP WITH THIS
SYSTEM ARE DIMINISHING.

AS A RESULT...DELAYED THE ARRIVAL OF PRECIP FROM THE
SOUTHWEST. REDUCED POPS...ESPECIALLY NORTH OF 460...AND LOWERED
QPF/SNOWFALL AMOUNTS. HIGH CLOUDINESS IS GRADUALLY OVERSPREADING
THE REGION...BUT POCKETS OF CLEARNING HAVE ALLOWED TEMPS IN SOME
AREAS LIKE DAN AND HSP TO FALL FASTER THAN ANTICIPATED. THEREFORE
LOWERED TEMPS A FEW DEGREES...BUT TEMP FALL SHOULD SLOW AS CLOUDS
THICKEN.

TEMPS WILL NOT RISE TOO MUCH SATURDAY WITH PRECIP AROUND...THINKING
MID TO UPPER 30S MOUNTAINS...TO LOWER 40S EAST.

MOISTURE BEGINS TO LIFT OUT BY MID-LATE AFTERNOON SUCH THAT
PRECIP SHOULD TAPER OFF.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
AS OF 320 PM EST FRIDAY...

500 MB PATTERN SATURDAY NIGHT AND SUNDAY HAD SLIGHTLY RISING HEIGHTS
AND WEAK RIDGING. THEN HIGHER AMPLITUDE LONG WAVE TROF BEGINS
DIGGING IN THE CENTRAL UNITED STATES. WPC IS FAVORING THE TIMING OFF
THE ECMWF FOR THE NEXT SOUTHERN STREAM SHORT WAVE WHICH CROSSES THE
FORECAST AREA ON MONDAY. WILL KEEP HIGHEST PROBABILITY OF
PRECIPITATION ON MONDAY.

850 MB TEMPERATURES RISE ABOVE ZERO ON SUNDAY. BY MONDAY STRONGER
SURFACE WEDGE WILL BE IN PLACE AS LOW PRESSURE DEVELOPS OFF THE
CAROLINA COAST. BY MONDAY MORNING...WARM NOSE ABOVE WEDGE REACHES
TEMPERATURES WARM ENOUGH TO MELT ANY FROZEN PRECIPITATION. POCKET OF
STRONGER WIND SPEEDS AT 850 MB WILL ENHANCE UPSLOPE ON EASTERN SIDE
OF THE BLUE RIDGE ON MONDAY. BUFKIT SOUNDINGS SHOWED THE POTENTIAL
FOR FREEZING RAIN AT LEWISBURG AND HOT SPRINGS. AMOUNT OF
PRECIPITATION THAT FAR NORTHWEST OF THE STORM WAS STILL UNCERTAIN.
HIGHEST AMOUNTS WILL BE CLOSER TO THE COAST.

WILL STAY CLOSE TO GUIDANCE FOR TEMPERATURES SATURDAY NIGHT THROUGH
SUNDAY NIGHT. MONDAY WILL HAVE LITTLE TO NO TEMPERATURE RISE SINCE
REGION WILL BE IN A WELL ESTABLISHED RIDGE WITH PRECIPITATION AND
PLENTY OF CLOUDS.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 240 PM EST FRIDAY...

WEAK CAD EVENT WITH OVERRUNNING PRECIPITATION WILL CONTINUE MONDAY
NIGHT INTO TUESDAY. LIGHT RAIN...POSSIBLY WITH A FEW POCKETS OF
SLEET OR FREEZING RAIN EXPECTED. WITH CLOUDS AND PRECIPITATION KEPT
LOW TEMPERATURES COOLER THAN MOS WITH READINGS FROM AROUND FREEZING
TO THE UPPER 30S IN THE SOUTHEAST.

A DEEP LONGITUDINAL TROUGH DEVELOPS FROM GREAT LAKES SOUTH TO THE
GULF OF MEXICO ON TUESDAY WITH INCREASING SOUTHERLY LOW LEVEL FLOW
ACROSS OUR REGION...ACCOMPANIED BY INCREASING MOISTURE ADVECTION.
TEMPERATURES WILL WARM TUESDAY AHEAD OF THE COLD FRONT WITH HIGHS
FROM THE MID 40S IN THE MOUNTAINS TO THE LOWER 50S IN THE PIEDMONT.

MODEL CONSENSUS OF GFS AND ECMWF IS THAT A SYNOPTIC UPPER TROUGH
OVER THE MISSISSIPPI VALLEY WILL AMPLIFY TUESDAY AND THEN EJECT
NEGATIVELY TILTED THROUGH THE SOUTHEAST U. S. TUESDAY NIGHT INTO
WEDNESDAY. WITH THE POSITION OF THE ASSOCIATED SURFACE OCCLUDED
FRONT AND THE TRIPLE POINT PASSING SOMEWHERE NEAR OR JUST SOUTH OF
OUR REGION....THERE IS THE POTENTIAL FOR OUR REGION TO HAVE ACTIVE
WEATHER LATE TUESDAY NIGHT INTO WEDNESDAY WITH PLENTY OF
SHOWERS...PERHAPS VERY GUSTY WINDS AND A FEW THUNDERSTORMS. LOOKS
LIKE THE AXIS OF BETTER INSTABILITY MAY BE A LITTLE FURTHER SOUTH ON
THE 12Z MODEL RUN.

COLD AIR PUSHES INTO THE REGION TUESDAY NIGHT INTO WEDNESDAY
ALLOWING FOR SOME RAIN AND SNOW SHOWERS. IF ENOUGH COLD AIR
ARRIVES QUICKLY...THERE COULD BE SOME ACCUMULATING SNOW IN THE
WESTERN MOUNTAINS. LOW TEMPERATURES TUESDAY NIGHT WILL RANGE FROM
THE LOWER 30S IN THE MOUNTAINS TO THE LOWER 40S IN THE SOUTHEAST.

A COLD FRONT WILL MOVE EAST ACROSS OUR REGION WEDNESDAY INTO
WEDNESDAY NIGHT.  HIGHS ON WEDNESDAY WILL WARM INTO THE LOWER 40S IN
THE WEST TO THE LOWER 50S IN THE EAST. RAIN AND SNOW SHOWERS WILL
CHANGEOVER TO SNOW SHOWERS AND SNOW FLURRIES IN THE WEST WEDNESDAY
NIGHT. LOW TEMPERATURES WEDNESDAY NIGHT WILL DROP INTO THE MID 20S
IN THE MOUNTAINS TO THE LOWER 30S IN THE PIEDMONT. WEST TO NORTHWEST
UPPER FLOW WILL CONTINUE INTO THURSDAY WITH HIGHS FROM THE UPPER 20S
IN THE MOUNTAINS TO AROUND 50 IN PIEDMONT. WINDS WILL BE QUITE
STRONG ON THURSDAY AS A 50 TO 55 KNOT 850MB JET PIVOTS ACROSS THE
REGION. THE UPPER FLOW SHIFTS TO THE SOUTHWEST THURSDAY NIGHT INTO
FRIDAY AS TROF CURVES OUT IN THE CENTRAL US WITH SFC INFLECTION OF
LOW PRESSURE DEVELOPING OVER THE TENNESSEE VALLEY BY FRIDAY MORNING.
MOISTURE SLOWLY RETURN FRIDAY NIGHT INTO SATURDAY AS THE HIGH CENTER
SLIDE OFF THE COAST.

&&

.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
AS OF 650 PM EST FRIDAY...

VFR CONDITIONS EXPECTED THIS EVENING INTO TONIGHT. HIGH CLOUDS
INCREASE THIS EVENING...THEN LOWER TO A MID DECK AROUND MIDNIGHT.
A LIGHT SNOW EVENT ON TAP SATURDAY FOR OUR REGION. LIGHT SNOW WILL
BEGIN ALONG THE SOUTHERN BLUE RIDGE BETWEEN 4-7 AM AND SPREAD
NORTHWARD IN OUR AREA. SOME LIGHT SNOW/FLURRIES EXPECTED AT ALL
SITES BEFORE 18Z...WITH HIGHEST IMPACT FOR AVIATION LOOKING TO
STAY SOUTH OF A TRI-FVX LINE...SO WENT WITH MVFR VSBYS/CIGS AT DAN
AROUND 15Z...WITH POSSIBLE MVFR CIGS AT BLF. THIS SYSTEM MOVES OUT
FAIRLY QUICK WITH PRECIPITATION ENDING SATURDAY AFTERNOON INTO
SATURDAY EVENING.

MEDIUM CONFIDENCE ON VISIBILITIES...WINDS AND CEILINGS DURING THE
TAF PERIOD.

EXTENDED DISCUSSION...

ONCE THIS FEATURE EXITS WILL SEE THE NEXT WAVE ALONG THE COAST
BRING ANOTHER ROUND OF SUB-VFR CONDITIONS FOR LATER SUNDAY NIGHT
INTO MONDAY. RAIN WILL BE THE PRIMARY PRECIPITATION TYPE WITH
THE POTENTIAL FOR POCKETS OF FREEZING RAIN LATE SUNDAY NIGHT INTO
MONDAY MORNING ACROSS COLDER NORTHERN PORTIONS OF FORECAST AREA WHICH
MIGHT IMPACT LWB IF TEMPERATURES ARE COLD ENOUGH.

RAIN WILL IMPACT AREAS ALONG AND EAST OF THE BLUE RIDGE...WITH
YET ANOTHER SYSTEM SLATED FOR LATE TUESDAY INTO WEDNESDAY AHEAD OF
A STRONG COLD FRONT. THESE SYSTEMS ARE EXPECTED TO BRING A PERIOD
MAINLY RAIN BUT COULD BE SOME WINTRY WX AS WELL ESPECIALLY IN THE
MOUNTAINS WITH THE SUNDAY NIGHT/MONDAY EVENT. EXPECT POTENTIAL LOW
LEVEL WIND SHEAR AS WELL AND POOR FLYING WEATHER FOR EARLY NEXT
WEEK. RAIN AND SNOW SHOWERS WILL CONTINUE INTO WEDNESDAY. GUSTY
NORTHWEST WINDS ARE POSSIBLE WEDNESDAY INTO THURSDAY. MOUNTAIN
SNOW SHOWERS AND SNOW FLURRIES EXPECTED WEDNESDAY NIGHT INTO
CHRISTMAS.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...JH/WP
NEAR TERM...PH/WP
SHORT TERM...AMS
LONG TERM...KK
AVIATION...JH/KK/WP





000
FXUS61 KRNK 200238
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
938 PM EST FRI DEC 19 2014

.SYNOPSIS...
HIGH PRESSURE BUILDS SOUTHEAST ACROSS THE AREA RESULTING IN
OVERALL DRY WEATHER INTO EARLY TONIGHT. A WEAK AREA OF LOW
PRESSURE WILL DEVELOP ALONG THE GULF COAST STATES LATE TONIGHT AND
MOVE EAST OVER THE SOUTHEAST STATES ON SATURDAY. THIS SYSTEM WILL
BRING A PERIOD OF LIGHT WINTRY PRECIPITATION TO MAINLY SOUTHERN
AND WESTERN AREAS SATURDAY. ANOTHER LOW DEVELOPS ACROSS THE
SOUTHEAST SUNDAY NIGHT MOVING UP THE COAST TO THE TIDEWATER OF
VIRGINIA BY MONDAY AFTERNOON.

&&

.NEAR TERM /THROUGH SATURDAY/...
AS OF 945 PM EST FRIDAY...

MOSAIC OF NWS DOPPLER RADARS INDICATES LEADING EDGE OF PRECIP
EXPANDING INTO SOUTHEAST TN...AND CENTRAL GA. HOWEVER...SFC OBS
SUGGEST MOST OF THE LEADING RADAR RETURNS ARE NOT REACHING THE
GROUND...AS SFC OBS SHOW PRECIP REPORTED IN ALABAMA.

HRRR...RUC/RAP...AND HI-RES ARW MODELS ALL ARE IN THE BALLPARK ON
WHERE PRECIP IS FALLING AT 02Z...AND NONE OF THESE MODELS BRING
LIGHT PRECIP INTO OUR FORECAST AREA UNTIL AFTER 09Z. COMBINE THIS
WITH THE FACT THAT THE OOZ SOUNDINGS FROM RNK AND GSO SHOW A
TREMENDOUS DRY LAYER (PWATS 0.25 AND 0.31 RESPECTFULLY) BELOW
400MB...AND CHANCES FOR MEANINGFUL MEASURABLE PRECIP WITH THIS
SYSTEM ARE DIMINISHING.

AS A RESULT...DELAYED THE ARRIVAL OF PRECIP FROM THE
SOUTHWEST. REDUCED POPS...ESPECIALLY NORTH OF 460...AND LOWERED
QPF/SNOWFALL AMOUNTS. HIGH CLOUDINESS IS GRADUALLY OVERSPREADING
THE REGION...BUT POCKETS OF CLEARNING HAVE ALLOWED TEMPS IN SOME
AREAS LIKE DAN AND HSP TO FALL FASTER THAN ANTICIPATED. THEREFORE
LOWERED TEMPS A FEW DEGREES...BUT TEMP FALL SHOULD SLOW AS CLOUDS
THICKEN.

TEMPS WILL NOT RISE TOO MUCH SATURDAY WITH PRECIP AROUND...THINKING
MID TO UPPER 30S MOUNTAINS...TO LOWER 40S EAST.

MOISTURE BEGINS TO LIFT OUT BY MID-LATE AFTERNOON SUCH THAT
PRECIP SHOULD TAPER OFF.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
AS OF 320 PM EST FRIDAY...

500 MB PATTERN SATURDAY NIGHT AND SUNDAY HAD SLIGHTLY RISING HEIGHTS
AND WEAK RIDGING. THEN HIGHER AMPLITUDE LONG WAVE TROF BEGINS
DIGGING IN THE CENTRAL UNITED STATES. WPC IS FAVORING THE TIMING OFF
THE ECMWF FOR THE NEXT SOUTHERN STREAM SHORT WAVE WHICH CROSSES THE
FORECAST AREA ON MONDAY. WILL KEEP HIGHEST PROBABILITY OF
PRECIPITATION ON MONDAY.

850 MB TEMPERATURES RISE ABOVE ZERO ON SUNDAY. BY MONDAY STRONGER
SURFACE WEDGE WILL BE IN PLACE AS LOW PRESSURE DEVELOPS OFF THE
CAROLINA COAST. BY MONDAY MORNING...WARM NOSE ABOVE WEDGE REACHES
TEMPERATURES WARM ENOUGH TO MELT ANY FROZEN PRECIPITATION. POCKET OF
STRONGER WIND SPEEDS AT 850 MB WILL ENHANCE UPSLOPE ON EASTERN SIDE
OF THE BLUE RIDGE ON MONDAY. BUFKIT SOUNDINGS SHOWED THE POTENTIAL
FOR FREEZING RAIN AT LEWISBURG AND HOT SPRINGS. AMOUNT OF
PRECIPITATION THAT FAR NORTHWEST OF THE STORM WAS STILL UNCERTAIN.
HIGHEST AMOUNTS WILL BE CLOSER TO THE COAST.

WILL STAY CLOSE TO GUIDANCE FOR TEMPERATURES SATURDAY NIGHT THROUGH
SUNDAY NIGHT. MONDAY WILL HAVE LITTLE TO NO TEMPERATURE RISE SINCE
REGION WILL BE IN A WELL ESTABLISHED RIDGE WITH PRECIPITATION AND
PLENTY OF CLOUDS.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 240 PM EST FRIDAY...

WEAK CAD EVENT WITH OVERRUNNING PRECIPITATION WILL CONTINUE MONDAY
NIGHT INTO TUESDAY. LIGHT RAIN...POSSIBLY WITH A FEW POCKETS OF
SLEET OR FREEZING RAIN EXPECTED. WITH CLOUDS AND PRECIPITATION KEPT
LOW TEMPERATURES COOLER THAN MOS WITH READINGS FROM AROUND FREEZING
TO THE UPPER 30S IN THE SOUTHEAST.

A DEEP LONGITUDINAL TROUGH DEVELOPS FROM GREAT LAKES SOUTH TO THE
GULF OF MEXICO ON TUESDAY WITH INCREASING SOUTHERLY LOW LEVEL FLOW
ACROSS OUR REGION...ACCOMPANIED BY INCREASING MOISTURE ADVECTION.
TEMPERATURES WILL WARM TUESDAY AHEAD OF THE COLD FRONT WITH HIGHS
FROM THE MID 40S IN THE MOUNTAINS TO THE LOWER 50S IN THE PIEDMONT.

MODEL CONSENSUS OF GFS AND ECMWF IS THAT A SYNOPTIC UPPER TROUGH
OVER THE MISSISSIPPI VALLEY WILL AMPLIFY TUESDAY AND THEN EJECT
NEGATIVELY TILTED THROUGH THE SOUTHEAST U. S. TUESDAY NIGHT INTO
WEDNESDAY. WITH THE POSITION OF THE ASSOCIATED SURFACE OCCLUDED
FRONT AND THE TRIPLE POINT PASSING SOMEWHERE NEAR OR JUST SOUTH OF
OUR REGION....THERE IS THE POTENTIAL FOR OUR REGION TO HAVE ACTIVE
WEATHER LATE TUESDAY NIGHT INTO WEDNESDAY WITH PLENTY OF
SHOWERS...PERHAPS VERY GUSTY WINDS AND A FEW THUNDERSTORMS. LOOKS
LIKE THE AXIS OF BETTER INSTABILITY MAY BE A LITTLE FURTHER SOUTH ON
THE 12Z MODEL RUN.

COLD AIR PUSHES INTO THE REGION TUESDAY NIGHT INTO WEDNESDAY
ALLOWING FOR SOME RAIN AND SNOW SHOWERS. IF ENOUGH COLD AIR
ARRIVES QUICKLY...THERE COULD BE SOME ACCUMULATING SNOW IN THE
WESTERN MOUNTAINS. LOW TEMPERATURES TUESDAY NIGHT WILL RANGE FROM
THE LOWER 30S IN THE MOUNTAINS TO THE LOWER 40S IN THE SOUTHEAST.

A COLD FRONT WILL MOVE EAST ACROSS OUR REGION WEDNESDAY INTO
WEDNESDAY NIGHT.  HIGHS ON WEDNESDAY WILL WARM INTO THE LOWER 40S IN
THE WEST TO THE LOWER 50S IN THE EAST. RAIN AND SNOW SHOWERS WILL
CHANGEOVER TO SNOW SHOWERS AND SNOW FLURRIES IN THE WEST WEDNESDAY
NIGHT. LOW TEMPERATURES WEDNESDAY NIGHT WILL DROP INTO THE MID 20S
IN THE MOUNTAINS TO THE LOWER 30S IN THE PIEDMONT. WEST TO NORTHWEST
UPPER FLOW WILL CONTINUE INTO THURSDAY WITH HIGHS FROM THE UPPER 20S
IN THE MOUNTAINS TO AROUND 50 IN PIEDMONT. WINDS WILL BE QUITE
STRONG ON THURSDAY AS A 50 TO 55 KNOT 850MB JET PIVOTS ACROSS THE
REGION. THE UPPER FLOW SHIFTS TO THE SOUTHWEST THURSDAY NIGHT INTO
FRIDAY AS TROF CURVES OUT IN THE CENTRAL US WITH SFC INFLECTION OF
LOW PRESSURE DEVELOPING OVER THE TENNESSEE VALLEY BY FRIDAY MORNING.
MOISTURE SLOWLY RETURN FRIDAY NIGHT INTO SATURDAY AS THE HIGH CENTER
SLIDE OFF THE COAST.

&&

.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
AS OF 650 PM EST FRIDAY...

VFR CONDITIONS EXPECTED THIS EVENING INTO TONIGHT. HIGH CLOUDS
INCREASE THIS EVENING...THEN LOWER TO A MID DECK AROUND MIDNIGHT.
A LIGHT SNOW EVENT ON TAP SATURDAY FOR OUR REGION. LIGHT SNOW WILL
BEGIN ALONG THE SOUTHERN BLUE RIDGE BETWEEN 4-7 AM AND SPREAD
NORTHWARD IN OUR AREA. SOME LIGHT SNOW/FLURRIES EXPECTED AT ALL
SITES BEFORE 18Z...WITH HIGHEST IMPACT FOR AVIATION LOOKING TO
STAY SOUTH OF A TRI-FVX LINE...SO WENT WITH MVFR VSBYS/CIGS AT DAN
AROUND 15Z...WITH POSSIBLE MVFR CIGS AT BLF. THIS SYSTEM MOVES OUT
FAIRLY QUICK WITH PRECIPITATION ENDING SATURDAY AFTERNOON INTO
SATURDAY EVENING.

MEDIUM CONFIDENCE ON VISIBILITIES...WINDS AND CEILINGS DURING THE
TAF PERIOD.

EXTENDED DISCUSSION...

ONCE THIS FEATURE EXITS WILL SEE THE NEXT WAVE ALONG THE COAST
BRING ANOTHER ROUND OF SUB-VFR CONDITIONS FOR LATER SUNDAY NIGHT
INTO MONDAY. RAIN WILL BE THE PRIMARY PRECIPITATION TYPE WITH
THE POTENTIAL FOR POCKETS OF FREEZING RAIN LATE SUNDAY NIGHT INTO
MONDAY MORNING ACROSS COLDER NORTHERN PORTIONS OF FORECAST AREA WHICH
MIGHT IMPACT LWB IF TEMPERATURES ARE COLD ENOUGH.

RAIN WILL IMPACT AREAS ALONG AND EAST OF THE BLUE RIDGE...WITH
YET ANOTHER SYSTEM SLATED FOR LATE TUESDAY INTO WEDNESDAY AHEAD OF
A STRONG COLD FRONT. THESE SYSTEMS ARE EXPECTED TO BRING A PERIOD
MAINLY RAIN BUT COULD BE SOME WINTRY WX AS WELL ESPECIALLY IN THE
MOUNTAINS WITH THE SUNDAY NIGHT/MONDAY EVENT. EXPECT POTENTIAL LOW
LEVEL WIND SHEAR AS WELL AND POOR FLYING WEATHER FOR EARLY NEXT
WEEK. RAIN AND SNOW SHOWERS WILL CONTINUE INTO WEDNESDAY. GUSTY
NORTHWEST WINDS ARE POSSIBLE WEDNESDAY INTO THURSDAY. MOUNTAIN
SNOW SHOWERS AND SNOW FLURRIES EXPECTED WEDNESDAY NIGHT INTO
CHRISTMAS.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...JH/WP
NEAR TERM...PH/WP
SHORT TERM...AMS
LONG TERM...KK
AVIATION...JH/KK/WP




000
FXUS61 KRNK 192350
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
650 PM EST FRI DEC 19 2014

.SYNOPSIS...
HIGH PRESSURE BUILDS SOUTHEAST ACROSS THE AREA RESULTING IN
OVERALL DRY WEATHER INTO EARLY TONIGHT. A WEAK AREA OF LOW
PRESSURE WILL DEVELOP ALONG THE GULF COAST STATES LATE TONIGHT AND
MOVE EAST OVER THE SOUTHEAST STATES ON SATURDAY. THIS SYSTEM WILL
BRING A PERIOD OF LIGHT WINTRY PRECIPITATION TO MAINLY SOUTHERN
AND WESTERN AREAS SATURDAY. ANOTHER LOW DEVELOPS ACROSS THE
SOUTHEAST SUNDAY NIGHT MOVING UP THE COAST TO THE TIDEWATER OF
VIRGINIA BY MONDAY AFTERNOON.

&&

.NEAR TERM /THROUGH SATURDAY/...
AS OF 145 PM EST FRIDAY...

UPPER TROUGH AND SHORTWAVE MOVING OUT OF TEXAS INTO THE LOWER AND
MID MISSISSIPPI VALLEY WILL SHIFT TOWARD OUR REGION OVERNIGHT INTO
SATURDAY. MODELS SEEM TO BE AGREEING ON A NON-EVENT...MEANING NO
ADVISORIES OR WARNINGS AS THE SYSTEM MOVES BY FAIRLY QUICK
PREVENTING SUFFICIENT MOISTURE INFLOW TO ADVANCE NWD. THIS SYSTEM
HAS ENOUGH DYNAMICS ALOFT TO GIVE A LIGHT COATING OF SNOW TO AS MUCH
AS 1-2 INCHES...BUT OVERALL SPEED WILL AGAIN LIMIT THIS.

FORECAST FROM PREVIOUS SHIFT WAS NOT THAT DIFFERENT FROM HOW THE 12Z
MODELS DEPICT THINGS. ONLY ADJUSTMENTS WERE TO LOWER POPS FURTHER
NORTH FROM ROUGH LEWISBURG TO ROANOKE TO LYNCHBURG. FEEL MODELS
HIGHLIGHT BEST LIFT AND MOISTURE CONVERGENCE WITH THE SHORTWAVE
ACROSS THE NC/VA BORDER...SO KEPT LIKELY POPS FROM THE GRAYSON
HIGHLANDS AND NC MTNS EAST TOWARD DANVILLE/MARTINSVILLE AND
REIDSVILLE...TAPERING TO SLIGHT CHANCE NORTH OF HIGHWAY 460.

QPF WILL BE LESS THAN A TENTH OF AN INCH...WHICH TRANSLATES TO LESS
THAN 1 INCH OF SNOW...THOUGH POSSIBLE NARROW AXIS OF HEAVIER BAND
COULD BRING AN INCH OR TWO THE HIGHER TERRAIN OF NC SAT MORNING.

AT ISSUE EARLY WILL BE THE EVER INCREASING HIGH CLOUDS AND HOW COOL
WILL WE GET BEFORE CLOUDS BLANKET THE SKIES SLOWING THE FALL. TEMPS
AT THE SFC AND ALOFT BASED ON THE FORECAST SOUNDINGS LEAD TO
SNOW/SOME SLEET STARTING LATE TONIGHT IN THE SOUTH THEN
TRANSITIONING TO RAIN BY LATE MORNING...EXCEPT THE MTNS WHERE IT
WILL STAY MIXED AND NEAR THE 0C ISOTHERM. LOWS GIVEN INCREASING
CLOUDS WILL RANGE FROM TEH MID 20S OVER THE ALLEGHANY HIGHLANDS...TO
UPPER 20S SW VA/SRN WV AND PIEDMONT NORTH OF DANVILLE...WITH LOWER
30S NC MTNS-ROANOKE...SOUTHSIDE VA...INTO THE NC FOOTHILLS.

TEMPS WILL NOT RISE TOO MUCH SATURDAY WITH PRECIP AROUND...THINKING
MID TO UPPER 30S MOUNTAINS...TO LOWER 40S EAST.

DEEP MOISTURE BEGINS TO LIFT OUT BY MID-LATE AFTERNOON SUCH THAT
PRECIP SHOULD TAPER OFF.

IN SUMMARY...NO ADVISORIES OR WARNINGS...BUT MAY NEED A SPECIAL
WEATHER STATEMENT FOR THE SW MTNS OF VA INTO NC LATER AS SNOW COMING
IN BEFORE DAWN WILL STICK TO UNTREATED ROADS...THOUGH INTENSITY/RATE
OF SNOWFALL DOES NOT LOOK ALL THAT IMPRESSIVE.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
AS OF 320 PM EST FRIDAY...

500 MB PATTERN SATURDAY NIGHT AND SUNDAY HAD SLIGHTLY RISING HEIGHTS
AND WEAK RIDGING. THEN HIGHER AMPLITUDE LONG WAVE TROF BEGINS
DIGGING IN THE CENTRAL UNITED STATES. WPC IS FAVORING THE TIMING OFF
THE ECMWF FOR THE NEXT SOUTHERN STREAM SHORT WAVE WHICH CROSSES THE
FORECAST AREA ON MONDAY. WILL KEEP HIGHEST PROBABILITY OF
PRECIPITATION ON MONDAY.

850 MB TEMPERATURES RISE ABOVE ZERO ON SUNDAY. BY MONDAY STRONGER
SURFACE WEDGE WILL BE IN PLACE AS LOW PRESSURE DEVELOPS OFF THE
CAROLINA COAST. BY MONDAY MORNING...WARM NOSE ABOVE WEDGE REACHES
TEMPERATURES WARM ENOUGH TO MELT ANY FROZEN PRECIPITATION. POCKET OF
STRONGER WIND SPEEDS AT 850 MB WILL ENHANCE UPSLOPE ON EASTERN SIDE
OF THE BLUE RIDGE ON MONDAY. BUFKIT SOUNDINGS SHOWED THE POTENTIAL
FOR FREEZING RAIN AT LEWISBURG AND HOT SPRINGS. AMOUNT OF
PRECIPITATION THAT FAR NORTHWEST OF THE STORM WAS STILL UNCERTAIN.
HIGHEST AMOUNTS WILL BE CLOSER TO THE COAST.

WILL STAY CLOSE TO GUIDANCE FOR TEMPERATURES SATURDAY NIGHT THROUGH
SUNDAY NIGHT. MONDAY WILL HAVE LITTLE TO NO TEMPERATURE RISE SINCE
REGION WILL BE IN A WELL ESTABLISHED RIDGE WITH PRECIPITATION AND
PLENTY OF CLOUDS.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 240 PM EST FRIDAY...

WEAK CAD EVENT WITH OVERRUNNING PRECIPITATION WILL CONTINUE MONDAY
NIGHT INTO TUESDAY. LIGHT RAIN...POSSIBLY WITH A FEW POCKETS OF
SLEET OR FREEZING RAIN EXPECTED. WITH CLOUDS AND PRECIPITATION KEPT
LOW TEMPERATURES COOLER THAN MOS WITH READINGS FROM AROUND FREEZING
TO THE UPPER 30S IN THE SOUTHEAST.

A DEEP LONGITUDINAL TROUGH DEVELOPS FROM GREAT LAKES SOUTH TO THE
GULF OF MEXICO ON TUESDAY WITH INCREASING SOUTHERLY LOW LEVEL FLOW
ACROSS OUR REGION...ACCOMPANIED BY INCREASING MOISTURE ADVECTION.
TEMPERATURES WILL WARM TUESDAY AHEAD OF THE COLD FRONT WITH HIGHS
FROM THE MID 40S IN THE MOUNTAINS TO THE LOWER 50S IN THE PIEDMONT.

MODEL CONSENSUS OF GFS AND ECMWF IS THAT A SYNOPTIC UPPER TROUGH
OVER THE MISSISSIPPI VALLEY WILL AMPLIFY TUESDAY AND THEN EJECT
NEGATIVELY TILTED THROUGH THE SOUTHEAST U. S. TUESDAY NIGHT INTO
WEDNESDAY. WITH THE POSITION OF THE ASSOCIATED SURFACE OCCLUDED
FRONT AND THE TRIPLE POINT PASSING SOMEWHERE NEAR OR JUST SOUTH OF
OUR REGION....THERE IS THE POTENTIAL FOR OUR REGION TO HAVE ACTIVE
WEATHER LATE TUESDAY NIGHT INTO WEDNESDAY WITH PLENTY OF
SHOWERS...PERHAPS VERY GUSTY WINDS AND A FEW THUNDERSTORMS. LOOKS
LIKE THE AXIS OF BETTER INSTABILITY MAY BE A LITTLE FURTHER SOUTH ON
THE 12Z MODEL RUN.

COLD AIR PUSHES INTO THE REGION TUESDAY NIGHT INTO WEDNESDAY
ALLOWING FOR SOME RAIN AND SNOW SHOWERS. IF ENOUGH COLD AIR
ARRIVES QUICKLY...THERE COULD BE SOME ACCUMULATING SNOW IN THE
WESTERN MOUNTAINS. LOW TEMPERATURES TUESDAY NIGHT WILL RANGE FROM
THE LOWER 30S IN THE MOUNTAINS TO THE LOWER 40S IN THE SOUTHEAST.

A COLD FRONT WILL MOVE EAST ACROSS OUR REGION WEDNESDAY INTO
WEDNESDAY NIGHT.  HIGHS ON WEDNESDAY WILL WARM INTO THE LOWER 40S IN
THE WEST TO THE LOWER 50S IN THE EAST. RAIN AND SNOW SHOWERS WILL
CHANGEOVER TO SNOW SHOWERS AND SNOW FLURRIES IN THE WEST WEDNESDAY
NIGHT. LOW TEMPERATURES WEDNESDAY NIGHT WILL DROP INTO THE MID 20S
IN THE MOUNTAINS TO THE LOWER 30S IN THE PIEDMONT. WEST TO NORTHWEST
UPPER FLOW WILL CONTINUE INTO THURSDAY WITH HIGHS FROM THE UPPER 20S
IN THE MOUNTAINS TO AROUND 50 IN PIEDMONT. WINDS WILL BE QUITE
STRONG ON THURSDAY AS A 50 TO 55 KNOT 850MB JET PIVOTS ACROSS THE
REGION. THE UPPER FLOW SHIFTS TO THE SOUTHWEST THURSDAY NIGHT INTO
FRIDAY AS TROF CURVES OUT IN THE CENTRAL US WITH SFC INFLECTION OF
LOW PRESSURE DEVELOPING OVER THE TENNESSEE VALLEY BY FRIDAY MORNING.
MOISTURE SLOWLY RETURN FRIDAY NIGHT INTO SATURDAY AS THE HIGH CENTER
SLIDE OFF THE COAST.

&&

.AVIATION /00Z SATURDAY THROUGH THURSDAY/...
AS OF 650 PM EST FRIDAY...

VFR CONDITIONS EXPECTED THIS EVENING INTO TONIGHT. HIGH CLOUDS
INCREASE THIS EVENING...THEN LOWER TO A MID DECK AROUND MIDNIGHT.
A LIGHT SNOW EVENT ON TAP SATURDAY FOR OUR REGION. LIGHT SNOW WILL
BEGIN ALONG THE SOUTHERN BLUE RIDGE BETWEEN 4-7 AM AND SPREAD
NORTHWARD IN OUR AREA. SOME LIGHT SNOW/FLURRIES EXPECTED AT ALL
SITES BEFORE 18Z...WITH HIGHEST IMPACT FOR AVIATION LOOKING TO
STAY SOUTH OF A TRI-FVX LINE...SO WENT WITH MVFR VSBYS/CIGS AT DAN
AROUND 15Z...WITH POSSIBLE MVFR CIGS AT BLF. THIS SYSTEM MOVES OUT
FAIRLY QUICK WITH PRECIPITATION ENDING SATURDAY AFTERNOON INTO
SATURDAY EVENING.

MEDIUM CONFIDENCE ON VISIBILITIES...WINDS AND CEILINGS DURING THE
TAF PERIOD.

EXTENDED DISCUSSION...

ONCE THIS FEATURE EXITS WILL SEE THE NEXT WAVE ALONG THE COAST
BRING ANOTHER ROUND OF SUB-VFR CONDITIONS FOR LATER SUNDAY NIGHT
INTO MONDAY. RAIN WILL BE THE PRIMARY PRECIPITATION TYPE WITH
THE POTENTIAL FOR POCKETS OF FREEZING RAIN LATE SUNDAY NIGHT INTO
MONDAY MORNING ACROSS COLDER NORTHERN PORTIONS OF FORECAST AREA WHICH
MIGHT IMPACT LWB IF TEMPERATURES ARE COLD ENOUGH.

RAIN WILL IMPACT AREAS ALONG AND EAST OF THE BLUE RIDGE...WITH
YET ANOTHER SYSTEM SLATED FOR LATE TUESDAY INTO WEDNESDAY AHEAD OF
A STRONG COLD FRONT. THESE SYSTEMS ARE EXPECTED TO BRING A PERIOD
MAINLY RAIN BUT COULD BE SOME WINTRY WX AS WELL ESPECIALLY IN THE
MOUNTAINS WITH THE SUNDAY NIGHT/MONDAY EVENT. EXPECT POTENTIAL LOW
LEVEL WIND SHEAR AS WELL AND POOR FLYING WEATHER FOR EARLY NEXT
WEEK. RAIN AND SNOW SHOWERS WILL CONTINUE INTO WEDNESDAY. GUSTY
NORTHWEST WINDS ARE POSSIBLE WEDNESDAY INTO THURSDAY. MOUNTAIN
SNOW SHOWERS AND SNOW FLURRIES EXPECTED WEDNESDAY NIGHT INTO
CHRISTMAS.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

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





000
FXUS61 KRNK 192350
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
650 PM EST FRI DEC 19 2014

.SYNOPSIS...
HIGH PRESSURE BUILDS SOUTHEAST ACROSS THE AREA RESULTING IN
OVERALL DRY WEATHER INTO EARLY TONIGHT. A WEAK AREA OF LOW
PRESSURE WILL DEVELOP ALONG THE GULF COAST STATES LATE TONIGHT AND
MOVE EAST OVER THE SOUTHEAST STATES ON SATURDAY. THIS SYSTEM WILL
BRING A PERIOD OF LIGHT WINTRY PRECIPITATION TO MAINLY SOUTHERN
AND WESTERN AREAS SATURDAY. ANOTHER LOW DEVELOPS ACROSS THE
SOUTHEAST SUNDAY NIGHT MOVING UP THE COAST TO THE TIDEWATER OF
VIRGINIA BY MONDAY AFTERNOON.

&&

.NEAR TERM /THROUGH SATURDAY/...
AS OF 145 PM EST FRIDAY...

UPPER TROUGH AND SHORTWAVE MOVING OUT OF TEXAS INTO THE LOWER AND
MID MISSISSIPPI VALLEY WILL SHIFT TOWARD OUR REGION OVERNIGHT INTO
SATURDAY. MODELS SEEM TO BE AGREEING ON A NON-EVENT...MEANING NO
ADVISORIES OR WARNINGS AS THE SYSTEM MOVES BY FAIRLY QUICK
PREVENTING SUFFICIENT MOISTURE INFLOW TO ADVANCE NWD. THIS SYSTEM
HAS ENOUGH DYNAMICS ALOFT TO GIVE A LIGHT COATING OF SNOW TO AS MUCH
AS 1-2 INCHES...BUT OVERALL SPEED WILL AGAIN LIMIT THIS.

FORECAST FROM PREVIOUS SHIFT WAS NOT THAT DIFFERENT FROM HOW THE 12Z
MODELS DEPICT THINGS. ONLY ADJUSTMENTS WERE TO LOWER POPS FURTHER
NORTH FROM ROUGH LEWISBURG TO ROANOKE TO LYNCHBURG. FEEL MODELS
HIGHLIGHT BEST LIFT AND MOISTURE CONVERGENCE WITH THE SHORTWAVE
ACROSS THE NC/VA BORDER...SO KEPT LIKELY POPS FROM THE GRAYSON
HIGHLANDS AND NC MTNS EAST TOWARD DANVILLE/MARTINSVILLE AND
REIDSVILLE...TAPERING TO SLIGHT CHANCE NORTH OF HIGHWAY 460.

QPF WILL BE LESS THAN A TENTH OF AN INCH...WHICH TRANSLATES TO LESS
THAN 1 INCH OF SNOW...THOUGH POSSIBLE NARROW AXIS OF HEAVIER BAND
COULD BRING AN INCH OR TWO THE HIGHER TERRAIN OF NC SAT MORNING.

AT ISSUE EARLY WILL BE THE EVER INCREASING HIGH CLOUDS AND HOW COOL
WILL WE GET BEFORE CLOUDS BLANKET THE SKIES SLOWING THE FALL. TEMPS
AT THE SFC AND ALOFT BASED ON THE FORECAST SOUNDINGS LEAD TO
SNOW/SOME SLEET STARTING LATE TONIGHT IN THE SOUTH THEN
TRANSITIONING TO RAIN BY LATE MORNING...EXCEPT THE MTNS WHERE IT
WILL STAY MIXED AND NEAR THE 0C ISOTHERM. LOWS GIVEN INCREASING
CLOUDS WILL RANGE FROM TEH MID 20S OVER THE ALLEGHANY HIGHLANDS...TO
UPPER 20S SW VA/SRN WV AND PIEDMONT NORTH OF DANVILLE...WITH LOWER
30S NC MTNS-ROANOKE...SOUTHSIDE VA...INTO THE NC FOOTHILLS.

TEMPS WILL NOT RISE TOO MUCH SATURDAY WITH PRECIP AROUND...THINKING
MID TO UPPER 30S MOUNTAINS...TO LOWER 40S EAST.

DEEP MOISTURE BEGINS TO LIFT OUT BY MID-LATE AFTERNOON SUCH THAT
PRECIP SHOULD TAPER OFF.

IN SUMMARY...NO ADVISORIES OR WARNINGS...BUT MAY NEED A SPECIAL
WEATHER STATEMENT FOR THE SW MTNS OF VA INTO NC LATER AS SNOW COMING
IN BEFORE DAWN WILL STICK TO UNTREATED ROADS...THOUGH INTENSITY/RATE
OF SNOWFALL DOES NOT LOOK ALL THAT IMPRESSIVE.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
AS OF 320 PM EST FRIDAY...

500 MB PATTERN SATURDAY NIGHT AND SUNDAY HAD SLIGHTLY RISING HEIGHTS
AND WEAK RIDGING. THEN HIGHER AMPLITUDE LONG WAVE TROF BEGINS
DIGGING IN THE CENTRAL UNITED STATES. WPC IS FAVORING THE TIMING OFF
THE ECMWF FOR THE NEXT SOUTHERN STREAM SHORT WAVE WHICH CROSSES THE
FORECAST AREA ON MONDAY. WILL KEEP HIGHEST PROBABILITY OF
PRECIPITATION ON MONDAY.

850 MB TEMPERATURES RISE ABOVE ZERO ON SUNDAY. BY MONDAY STRONGER
SURFACE WEDGE WILL BE IN PLACE AS LOW PRESSURE DEVELOPS OFF THE
CAROLINA COAST. BY MONDAY MORNING...WARM NOSE ABOVE WEDGE REACHES
TEMPERATURES WARM ENOUGH TO MELT ANY FROZEN PRECIPITATION. POCKET OF
STRONGER WIND SPEEDS AT 850 MB WILL ENHANCE UPSLOPE ON EASTERN SIDE
OF THE BLUE RIDGE ON MONDAY. BUFKIT SOUNDINGS SHOWED THE POTENTIAL
FOR FREEZING RAIN AT LEWISBURG AND HOT SPRINGS. AMOUNT OF
PRECIPITATION THAT FAR NORTHWEST OF THE STORM WAS STILL UNCERTAIN.
HIGHEST AMOUNTS WILL BE CLOSER TO THE COAST.

WILL STAY CLOSE TO GUIDANCE FOR TEMPERATURES SATURDAY NIGHT THROUGH
SUNDAY NIGHT. MONDAY WILL HAVE LITTLE TO NO TEMPERATURE RISE SINCE
REGION WILL BE IN A WELL ESTABLISHED RIDGE WITH PRECIPITATION AND
PLENTY OF CLOUDS.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 240 PM EST FRIDAY...

WEAK CAD EVENT WITH OVERRUNNING PRECIPITATION WILL CONTINUE MONDAY
NIGHT INTO TUESDAY. LIGHT RAIN...POSSIBLY WITH A FEW POCKETS OF
SLEET OR FREEZING RAIN EXPECTED. WITH CLOUDS AND PRECIPITATION KEPT
LOW TEMPERATURES COOLER THAN MOS WITH READINGS FROM AROUND FREEZING
TO THE UPPER 30S IN THE SOUTHEAST.

A DEEP LONGITUDINAL TROUGH DEVELOPS FROM GREAT LAKES SOUTH TO THE
GULF OF MEXICO ON TUESDAY WITH INCREASING SOUTHERLY LOW LEVEL FLOW
ACROSS OUR REGION...ACCOMPANIED BY INCREASING MOISTURE ADVECTION.
TEMPERATURES WILL WARM TUESDAY AHEAD OF THE COLD FRONT WITH HIGHS
FROM THE MID 40S IN THE MOUNTAINS TO THE LOWER 50S IN THE PIEDMONT.

MODEL CONSENSUS OF GFS AND ECMWF IS THAT A SYNOPTIC UPPER TROUGH
OVER THE MISSISSIPPI VALLEY WILL AMPLIFY TUESDAY AND THEN EJECT
NEGATIVELY TILTED THROUGH THE SOUTHEAST U. S. TUESDAY NIGHT INTO
WEDNESDAY. WITH THE POSITION OF THE ASSOCIATED SURFACE OCCLUDED
FRONT AND THE TRIPLE POINT PASSING SOMEWHERE NEAR OR JUST SOUTH OF
OUR REGION....THERE IS THE POTENTIAL FOR OUR REGION TO HAVE ACTIVE
WEATHER LATE TUESDAY NIGHT INTO WEDNESDAY WITH PLENTY OF
SHOWERS...PERHAPS VERY GUSTY WINDS AND A FEW THUNDERSTORMS. LOOKS
LIKE THE AXIS OF BETTER INSTABILITY MAY BE A LITTLE FURTHER SOUTH ON
THE 12Z MODEL RUN.

COLD AIR PUSHES INTO THE REGION TUESDAY NIGHT INTO WEDNESDAY
ALLOWING FOR SOME RAIN AND SNOW SHOWERS. IF ENOUGH COLD AIR
ARRIVES QUICKLY...THERE COULD BE SOME ACCUMULATING SNOW IN THE
WESTERN MOUNTAINS. LOW TEMPERATURES TUESDAY NIGHT WILL RANGE FROM
THE LOWER 30S IN THE MOUNTAINS TO THE LOWER 40S IN THE SOUTHEAST.

A COLD FRONT WILL MOVE EAST ACROSS OUR REGION WEDNESDAY INTO
WEDNESDAY NIGHT.  HIGHS ON WEDNESDAY WILL WARM INTO THE LOWER 40S IN
THE WEST TO THE LOWER 50S IN THE EAST. RAIN AND SNOW SHOWERS WILL
CHANGEOVER TO SNOW SHOWERS AND SNOW FLURRIES IN THE WEST WEDNESDAY
NIGHT. LOW TEMPERATURES WEDNESDAY NIGHT WILL DROP INTO THE MID 20S
IN THE MOUNTAINS TO THE LOWER 30S IN THE PIEDMONT. WEST TO NORTHWEST
UPPER FLOW WILL CONTINUE INTO THURSDAY WITH HIGHS FROM THE UPPER 20S
IN THE MOUNTAINS TO AROUND 50 IN PIEDMONT. WINDS WILL BE QUITE
STRONG ON THURSDAY AS A 50 TO 55 KNOT 850MB JET PIVOTS ACROSS THE
REGION. THE UPPER FLOW SHIFTS TO THE SOUTHWEST THURSDAY NIGHT INTO
FRIDAY AS TROF CURVES OUT IN THE CENTRAL US WITH SFC INFLECTION OF
LOW PRESSURE DEVELOPING OVER THE TENNESSEE VALLEY BY FRIDAY MORNING.
MOISTURE SLOWLY RETURN FRIDAY NIGHT INTO SATURDAY AS THE HIGH CENTER
SLIDE OFF THE COAST.

&&

.AVIATION /00Z SATURDAY THROUGH THURSDAY/...
AS OF 650 PM EST FRIDAY...

VFR CONDITIONS EXPECTED THIS EVENING INTO TONIGHT. HIGH CLOUDS
INCREASE THIS EVENING...THEN LOWER TO A MID DECK AROUND MIDNIGHT.
A LIGHT SNOW EVENT ON TAP SATURDAY FOR OUR REGION. LIGHT SNOW WILL
BEGIN ALONG THE SOUTHERN BLUE RIDGE BETWEEN 4-7 AM AND SPREAD
NORTHWARD IN OUR AREA. SOME LIGHT SNOW/FLURRIES EXPECTED AT ALL
SITES BEFORE 18Z...WITH HIGHEST IMPACT FOR AVIATION LOOKING TO
STAY SOUTH OF A TRI-FVX LINE...SO WENT WITH MVFR VSBYS/CIGS AT DAN
AROUND 15Z...WITH POSSIBLE MVFR CIGS AT BLF. THIS SYSTEM MOVES OUT
FAIRLY QUICK WITH PRECIPITATION ENDING SATURDAY AFTERNOON INTO
SATURDAY EVENING.

MEDIUM CONFIDENCE ON VISIBILITIES...WINDS AND CEILINGS DURING THE
TAF PERIOD.

EXTENDED DISCUSSION...

ONCE THIS FEATURE EXITS WILL SEE THE NEXT WAVE ALONG THE COAST
BRING ANOTHER ROUND OF SUB-VFR CONDITIONS FOR LATER SUNDAY NIGHT
INTO MONDAY. RAIN WILL BE THE PRIMARY PRECIPITATION TYPE WITH
THE POTENTIAL FOR POCKETS OF FREEZING RAIN LATE SUNDAY NIGHT INTO
MONDAY MORNING ACROSS COLDER NORTHERN PORTIONS OF FORECAST AREA WHICH
MIGHT IMPACT LWB IF TEMPERATURES ARE COLD ENOUGH.

RAIN WILL IMPACT AREAS ALONG AND EAST OF THE BLUE RIDGE...WITH
YET ANOTHER SYSTEM SLATED FOR LATE TUESDAY INTO WEDNESDAY AHEAD OF
A STRONG COLD FRONT. THESE SYSTEMS ARE EXPECTED TO BRING A PERIOD
MAINLY RAIN BUT COULD BE SOME WINTRY WX AS WELL ESPECIALLY IN THE
MOUNTAINS WITH THE SUNDAY NIGHT/MONDAY EVENT. EXPECT POTENTIAL LOW
LEVEL WIND SHEAR AS WELL AND POOR FLYING WEATHER FOR EARLY NEXT
WEEK. RAIN AND SNOW SHOWERS WILL CONTINUE INTO WEDNESDAY. GUSTY
NORTHWEST WINDS ARE POSSIBLE WEDNESDAY INTO THURSDAY. MOUNTAIN
SNOW SHOWERS AND SNOW FLURRIES EXPECTED WEDNESDAY NIGHT INTO
CHRISTMAS.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

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




000
FXUS61 KRNK 192029
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
329 PM EST FRI DEC 19 2014

.SYNOPSIS...
HIGH PRESSURE BUILDS SOUTHEAST ACROSS THE AREA RESULTING IN
OVERALL DRY WEATHER INTO EARLY TONIGHT. A WEAK AREA OF LOW
PRESSURE WILL DEVELOP ALONG THE GULF COAST STATES LATE TONIGHT AND
MOVE EAST OVER THE SOUTHEAST STATES ON SATURDAY. THIS SYSTEM WILL
BRING A PERIOD OF LIGHT WINTRY PRECIPITATION TO MAINLY SOUTHERN
AND WESTERN AREAS SATURDAY. ANOTHER LOW DEVELOPS ACROSS THE
SOUTHEAST SUNDAY NIGHT MOVING UP THE COAST TO THE TIDEWATER OF
VIRGINIA BY MONDAY AFTERNOON.

&&

.NEAR TERM /THROUGH SATURDAY/...
AS OF 145 PM EST FRIDAY...

UPPER TROUGH AND SHORTWAVE MOVING OUT OF TEXAS INTO THE LOWER AND
MID MISSISSIPPI VALLEY WILL SHIFT TOWARD OUR REGION OVERNIGHT INTO
SATURDAY. MODELS SEEM TO BE AGREEING ON A NON-EVENT...MEANING NO
ADVISORIES OR WARNINGS AS THE SYSTEM MOVES BY FAIRLY QUICK
PREVENTING SUFFICIENT MOISTURE INFLOW TO ADVANCE NWD. THIS SYSTEM
HAS ENOUGH DYNAMICS ALOFT TO GIVE A LIGHT COATING OF SNOW TO AS MUCH
AS 1-2 INCHES...BUT OVERALL SPEED WILL AGAIN LIMIT THIS.

FORECAST FROM PREVIOUS SHIFT WAS NOT THAT DIFFERENT FROM HOW THE 12Z
MODELS DEPICT THINGS. ONLY ADJUSTMENTS WERE TO LOWER POPS FURTHER
NORTH FROM ROUGH LEWISBURG TO ROANOKE TO LYNCHBURG. FEEL MODELS
HIGHLIGHT BEST LIFT AND MOISTURE CONVERGENCE WITH THE SHORTWAVE
ACROSS THE NC/VA BORDER...SO KEPT LIKELY POPS FROM THE GRAYSON
HIGHLANDS AND NC MTNS EAST TOWARD DANVILLE/MARTINSVILLE AND
REIDSVILLE...TAPERING TO SLIGHT CHANCE NORTH OF HIGHWAY 460.

QPF WILL BE LESS THAN A TENTH OF AN INCH...WHICH TRANSLATES TO LESS
THAN 1 INCH OF SNOW...THOUGH POSSIBLE NARROW AXIS OF HEAVIER BAND
COULD BRING AN INCH OR TWO THE HIGHER TERRAIN OF NC SAT MORNING.

AT ISSUE EARLY WILL BE THE EVER INCREASING HIGH CLOUDS AND HOW COOL
WILL WE GET BEFORE CLOUDS BLANKET THE SKIES SLOWING THE FALL. TEMPS
AT THE SFC AND ALOFT BASED ON THE FORECAST SOUNDINGS LEAD TO
SNOW/SOME SLEET STARTING LATE TONIGHT IN THE SOUTH THEN
TRANSITIONING TO RAIN BY LATE MORNING...EXCEPT THE MTNS WHERE IT
WILL STAY MIXED AND NEAR THE 0C ISOTHERM. LOWS GIVEN INCREASING
CLOUDS WILL RANGE FROM TEH MID 20S OVER THE ALLEGHANY HIGHLANDS...TO
UPPER 20S SW VA/SRN WV AND PIEDMONT NORTH OF DANVILLE...WITH LOWER
30S NC MTNS-ROANOKE...SOUTHSIDE VA...INTO THE NC FOOTHILLS.

TEMPS WILL NOT RISE TOO MUCH SATURDAY WITH PRECIP AROUND...THINKING
MID TO UPPER 30S MOUNTAINS...TO LOWER 40S EAST.

DEEP MOISTURE BEGINS TO LIFT OUT BY MID-LATE AFTERNOON SUCH THAT
PRECIP SHOULD TAPER OFF.

IN SUMMARY...NO ADVISORIES OR WARNINGS...BUT MAY NEED A SPECIAL
WEATHER STATEMENT FOR THE SW MTNS OF VA INTO NC LATER AS SNOW COMING
IN BEFORE DAWN WILL STICK TO UNTREATED ROADS...THOUGH INTENSITY/RATE
OF SNOWFALL DOES NOT LOOK ALL THAT IMPRESSIVE.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
AS OF 320 PM EST FRIDAY...

500 MB PATTERN SATURDAY NIGHT AND SUNDAY HAD SLIGHTLY RISING HEIGHTS
AND WEAK RIDGING. THEN HIGHER AMPLITUDE LONG WAVE TROF BEGINS
DIGGING IN THE CENTRAL UNITED STATES. WPC IS FAVORING THE TIMING OFF
THE ECMWF FOR THE NEXT SOUTHERN STREAM SHORT WAVE WHICH CROSSES THE
FORECAST AREA ON MONDAY. WILL KEEP HIGHEST PROBABILITY OF
PRECIPITATION ON MONDAY.

850 MB TEMPERATURES RISE ABOVE ZERO ON SUNDAY. BY MONDAY STRONGER
SURFACE WEDGE WILL BE IN PLACE AS LOW PRESSURE DEVELOPS OFF THE
CAROLINA COAST. BY MONDAY MORNING...WARM NOSE ABOVE WEDGE REACHES
TEMPERATURES WARM ENOUGH TO MELT ANY FROZEN PRECIPITATION. POCKET OF
STRONGER WIND SPEEDS AT 850 MB WILL ENHANCE UPSLOPE ON EASTERN SIDE
OF THE BLUE RIDGE ON MONDAY. BUFKIT SOUNDINGS SHOWED THE POTENTIAL
FOR FREEZING RAIN AT LEWISBURG AND HOT SPRINGS. AMOUNT OF
PRECIPITATION THAT FAR NORTHWEST OF THE STORM WAS STILL UNCERTAIN.
HIGHEST AMOUNTS WILL BE CLOSER TO THE COAST.

WILL STAY CLOSE TO GUIDANCE FOR TEMPERATURES SATURDAY NIGHT THROUGH
SUNDAY NIGHT. MONDAY WILL HAVE LITTLE TO NO TEMPERATURE RISE SINCE
REGION WILL BE IN A WELL ESTABLISHED RIDGE WITH PRECIPITATION AND
PLENTY OF CLOUDS.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 240 PM EST FRIDAY...

WEAK CAD EVENT WITH OVERRUNNING PRECIPITATION WILL CONTINUE MONDAY
NIGHT INTO TUESDAY. LIGHT RAIN...POSSIBLY WITH A FEW POCKETS OF
SLEET OR FREEZING RAIN EXPECTED. WITH CLOUDS AND PRECIPITATION KEPT
LOW TEMPERATURES COOLER THAN MOS WITH READINGS FROM AROUND FREEZING
TO THE UPPER 30S IN THE SOUTHEAST.

A DEEP LONGITUDINAL TROUGH DEVELOPS FROM GREAT LAKES SOUTH TO THE
GULF OF MEXICO ON TUESDAY WITH INCREASING SOUTHERLY LOW LEVEL FLOW
ACROSS OUR REGION...ACCOMPANIED BY INCREASING MOISTURE ADVECTION.
TEMPERATURES WILL WARM TUESDAY AHEAD OF THE COLD FRONT WITH HIGHS
FROM THE MID 40S IN THE MOUNTAINS TO THE LOWER 50S IN THE PIEDMONT.

MODEL CONSENSUS OF GFS AND ECMWF IS THAT A SYNOPTIC UPPER TROUGH
OVER THE MISSISSIPPI VALLEY WILL AMPLIFY TUESDAY AND THEN EJECT
NEGATIVELY TILTED THROUGH THE SOUTHEAST U. S. TUESDAY NIGHT INTO
WEDNESDAY. WITH THE POSITION OF THE ASSOCIATED SURFACE OCCLUDED
FRONT AND THE TRIPLE POINT PASSING SOMEWHERE NEAR OR JUST SOUTH OF
OUR REGION....THERE IS THE POTENTIAL FOR OUR REGION TO HAVE ACTIVE
WEATHER LATE TUESDAY NIGHT INTO WEDNESDAY WITH PLENTY OF
SHOWERS...PERHAPS VERY GUSTY WINDS AND A FEW THUNDERSTORMS. LOOKS
LIKE THE AXIS OF BETTER INSTABILITY MAY BE A LITTLE FURTHER SOUTH ON
THE 12Z MODEL RUN.

COLD AIR PUSHES INTO THE REGION TUESDAY NIGHT INTO WEDNESDAY
ALLOWING FOR SOME RAIN AND SNOW SHOWERS. IF ENOUGH COLD AIR
ARRIVES QUICKLY...THERE COULD BE SOME ACCUMULATING SNOW IN THE
WESTERN MOUNTAINS. LOW TEMPERATURES TUESDAY NIGHT WILL RANGE FROM
THE LOWER 30S IN THE MOUNTAINS TO THE LOWER 40S IN THE SOUTHEAST.

A COLD FRONT WILL MOVE EAST ACROSS OUR REGION WEDNESDAY INTO
WEDNESDAY NIGHT.  HIGHS ON WEDNESDAY WILL WARM INTO THE LOWER 40S IN
THE WEST TO THE LOWER 50S IN THE EAST. RAIN AND SNOW SHOWERS WILL
CHANGEOVER TO SNOW SHOWERS AND SNOW FLURRIES IN THE WEST WEDNESDAY
NIGHT. LOW TEMPERATURES WEDNESDAY NIGHT WILL DROP INTO THE MID 20S
IN THE MOUNTAINS TO THE LOWER 30S IN THE PIEDMONT. WEST TO NORTHWEST
UPPER FLOW WILL CONTINUE INTO THURSDAY WITH HIGHS FROM THE UPPER 20S
IN THE MOUNTAINS TO AROUND 50 IN PIEDMONT. WINDS WILL BE QUITE
STRONG ON THURSDAY AS A 50 TO 55 KNOT 850MB JET PIVOTS ACROSS THE
REGION. THE UPPER FLOW SHIFTS TO THE SOUTHWEST THURSDAY NIGHT INTO
FRIDAY AS TROF CURVES OUT IN THE CENTRAL US WITH SFC INFLECTION OF
LOW PRESSURE DEVELOPING OVER THE TENNESSEE VALLEY BY FRIDAY MORNING.
MOISTURE SLOWLY RETURN FRIDAY NIGHT INTO SATURDAY AS THE HIGH CENTER
SLIDE OFF THE COAST.
&&

.AVIATION /21Z FRIDAY THROUGH WEDNESDAY/...
AS OF 1230 PM EST FRIDAY...

VFR EXPECTED THROUGH EARLY TONIGHT WITH LOW CLOUDS SHRINKING WEST
OF BLF-LWB THIS AFTERNOON. HIGH CLOUDS INCREASE THROUGH THIS
EVENING THEN LOWER TO A MID DECK BY MIDNIGHT.

LATEST MODELS CONTINUE THE TREND OF LESS PRECIP FOR SAT MORNING
BUT STILL CAN EXPECT SOME LIGHT SNOW/FLURRIES AT ALL SITES BEFORE
18Z...WITH HIGHEST IMPACT FOR AVIATION LOOKING TO STAY SOUTH OF A
TRI-FVX LINE...SO WENT WITH MVFR VSBYS/CIGS AT DAN AROUND
15Z...WITH POSSIBLE MVFR CIGS AT BLF.



EXTENDED DISCUSSION...

THIS SYSTEM MOVES OUT FAIRLY QUICK WITH PRECIP ENDING SAT
AFTERNOON.

ONCE THIS FEATURE EXITS WILL SEE THE NEXT WAVE ALONG THE COAST
BRING ANOTHER ROUND OF SUB-VFR CONDITIONS FOR LATER SUNDAY NIGHT
INTO MONDAY. THIS SYSTEM LOOKS TO IMPACT AREAS ALONG AND EAST OF
THE BLUE RIDGE...WITH YET ANOTHER SYSTEM SLATED FOR LATE TUESDAY
INTO WEDNESDAY AHEAD OF A STRONG COLD FRONT. THESE SYSTEMS ARE
EXPECTED TO BRING A PERIOD MAINLY RAIN BUT COULD BE SOME WINTRY WX
AS WELL ESPECIALLY IN THE MOUNTAINS WITH THE SUNDAY NIGHT/MONDAY
EVENT. EXPECT POTENTIAL LOW LEVEL WIND SHEAR AS WELL AND POOR
FLYING WEATHER FOR EARLY NEXT WEEK.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

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




000
FXUS61 KRNK 191736
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
1236 PM EST FRI DEC 19 2014

.SYNOPSIS...
HIGH PRESSURE OVER THE UPPER MIDWEST WILL GRADUALLY BUILD SOUTHEAST
ACROSS THE AREA RESULTING IN OVERALL DRY WEATHER INTO TONIGHT. A
WEAK AREA OF LOW PRESSURE WILL DEVELOP ALONG THE GULF COAST
STATES LATE TONIGHT AND MOVE EAST OVER THE SOUTHEAST STATES ON
SATURDAY. THIS SYSTEM WILL BRING A PERIOD OF LIGHT WINTRY
PRECIPITATION TO MAINLY SOUTHERN AND WESTERN AREAS SATURDAY
MORNING BEFORE TAPERING OFF SATURDAY AFTERNOON.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 1228 PM EST FRIDAY...

DRYING TAKING PLACE IN THE LOW LVLS WITH LOW CLOUDS SHRINKING OVER
THE WV MTNS. JUST A FEW SC/CU THIS AFTERNOON LEFT IN THE MTNS WITH
HIGH CLOUDS STARTING TO INCREASE...MAINLY THIN BUT WILL LEAD TO A
MILKY SKY BY LATE AFTERNOON IN THE SW.

MADE MINOR ADJUSTMENTS TO TEMPS BUT OVERALL STILL LOOKING AT MID
30S FOR HIGHS IN THE HIGHER MOUNTAINS TO LOWER 50S SOUTHEAST.



PREVIOUS VALID DISCUSSION...

MID LEVEL WAVE OVER TX LATE THIS MORNING WILL GIVE RISE TO WEAK
SURFACE LOW PRESSURE ALONG THE NORTHERN GULF LATE TONIGHT WITH
PLENTY OF SHEARED MOISTURE ZIPPING NE INTO THE REGION OVERNIGHT.
HOWEVER THE SYSTEM STILL LOOKS TO REMAIN WEAK GIVEN THE MAIN UPPER
JET WELL TO THE SOUTH AND DAMPENING OF THE MID LEVEL SHORTWAVE AS
IT GETS BOOTED EAST WITHOUT PHASING VIA A SEPARATE NORTHERN STREAM
VORT. BEST MOISTURE TRANSPORT WITH THE WEAK SURFACE LOW WILL STAY
SOUTH WITH PERHAPS A SECOND ZONE OF LIGHT PRECIP FARTHER NORTH
DRIVEN BY THE COMBO OF THE WAVE ALOFT AND WEAK ISENTROPIC LIFT
INTO SW SECTIONS LATE. MODELS CONTINUE TO ONLY SHOW VERY LIGHT QPF
AND WOULDN`T TAKE MUCH LIFT TO THE SOUTH TO TOTALLY CUT OFF
MOISTURE INTO THE CWA PER LATEST EURO. HOWEVER WITH SOME SPOTTY
QPF OF UP TO A TENTH OF AN INCH OFF THE NAM OVER THE NW NC
MOUNTAINS...BROUGHT IN LOW LIKELYS THERE BY DAYBREAK WHILE
SPREADING LOW CHANCES FARTHER NORTH ACROSS MOST OF THE
MOUNTAINS/FOOTHILLS UNDER THE WAVE AXIS. FORECAST SOUNDINGS SHOW
MOST OF THE REGION BELOW FREEZING ALOFT SO PTYPE MAINLY SNOW WITH
PERHAPS THE WARMER BOUNDARY LAYER IN SPOTS CAUSING A BIT MORE RAIN
TO INIT FOOTHILLS EAST. SOME SLEET ALSO POSSIBLE DURING THE CHANGE
TO SNOW AT THE ONSET IN THESE SPOTS AS WELL SO INCLUDED MENTION.

OVERALL SNOWFALL LOOKS TO BE LESS THAN A HALF INCH AT BEST BY
MORNING...THUS NO HEADLINES GIVEN LIGHT AMOUNTS AND POTENTIAL FOR JUST
MORE CLOUDS THAN SIGNIFICANT QPF AT THIS POINT. OTRW BECOMING CLOUDY
ALL SECTIONS WITH LOWS IN THE 20S TO LOW 30S...MAINLY THIS
EVENING...THEN STEADYING OR RISING LATE AS CLOUDS THICKEN.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
AS OF 330 AM EST FRIDAY...

WEATHER FORECAST MODELS OVER THE PAST FEW RUNS ARE SETTLING ON A
MODEST UPPER LEVEL TROUGH PASSING ACROSS THE AREA ON SATURDAY...WITH
A WEAK LOW PRESSURE SYSTEM MOVING NORTHEAST ALONG THE ATLANTIC
COAST. THIS WILL BRING LIGHT SNOW ACROSS THE AREA DURING THE MORNING
AND AFTERNOON...WITH SPOTTY ACCUMULATIONS...MOSTLY LESS THAN AN
INCH...CONFINED TO THE HIGHER RIDGES...PARTICULARLY ALONG THE BLUE
RIDGE PARKWAY SOUTH OF ROANOKE INTO THE MOUNTAIN EMPIRE. ENERGY
ASSOCIATED WITH THE UPPER TROUGH WILL EXIT TO THE EAST DURING THE
AFTERNOON...LEAVING ONLY LIGHT SNOW SHOWERS ALONG THE WESTERN RIDGES
DURING THE EVENING. OTHERWISE...WILL BE LOOKING AT DRY WEATHER
THROUGH SATURDAY NIGHT...AS ANOTHER ROUND OF HIGH PRESSURE PASSES
ACROSS EASTERN CANADA...AND BUILDS SOUTHWARD ACROSS NEW ENGLAND AND
THE MID ATLANTIC TO WEDGE AGAINST THE EASTERN FACE OF THE
APPALACHIANS.

YET ANOTHER TROUGH WILL APPROACH FROM THE WEST ON SUNDAY...
SUPPORTING DEVELOPMENT OF LOW PRESSURE ALONG THE CENTRAL GULF COAST.
SOUTHERLY FLOW OFF THE SURFACE WILL PUSH WARM GULF AIR ALONG THE
CENTRAL APPALACHIANS TO OVERRUN THE COLD NORTHEASTERLY WIND FLOW
ASSOCIATED WITH THE HIGH PRESSURE WEDGE. AS SUCH...EXPECT TO SEE A
WINTRY MIX DEVELOP SUNDAY NIGHT AS PRECIPITATION ENTERS OUR AREA.
FORECAST MODEL SOUNDINGS INDICATE THAT THE COLD AIR ASSOCIATED WITH
THE WEDGE IS DEEP ENOUGH TO CAUSE MUCH OF THE PRECIPITATION ACROSS
THE MOUNTAINS TO FALL AS A MIXTURE OF SLEET AND RAIN NORTH OF
HIGHWAY 460...WITH TEMPERATURES TOWARD THE INTERSTATE 64 CORRIDOR
BECOMING COLD ENOUGH THAT SNOW WILL BECOME MORE OF A POSSIBILITY.
STILL A LITTLE EARLY TO DISCUSS ACCUMULATIONS...BUT AS OF THIS
MORNING...IT IS LOOKING MORE LIKE AN ADVISORY CRITERIA EVENT RATHER
THAN A WARNING EVENT...ALTHOUGH THIS CAN EASILY CHANGE OVER THE NEXT
DAY OR TWO.

TEMPERATURES WILL WARM ENOUGH BY EARLY MONDAY AFTERNOON TO ALLOW
PRECIPITATION TO CHANGE MAINLY TO RAIN...POSSIBLY WITH A FEW POCKETS
OF SLEET OR FREEZING RAIN REMAINING THROUGH THE DAY. THE MAIN ENERGY
ASSOCIATED WITH THE SYSTEM WILL PASS EAST DURING MONDAY
EVENING...LEAVING ONLY PATCHES OF LIGHT PRECIPITATION TO PASS ACROSS
THE AREA OVERNIGHT.

&&

.LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 230 PM EST THURSDAY...

A DEEP LONGITUDINAL TROUGH DEVELOPS SOUTH TO THE GULF OF MEXICO ON
TUESDAY WITH INCREASING SOUTHERLY LOW LEVEL FLOW ACROSS OUR
REGION...ACCOMPANIED BY INCREASING MOISTURE ADVECTION. TEMPERATURES
WILL TREND MILDER FOR HIGHS TUESDAY FROM THE MID 40S TO THE LOWER
50S.

BY TUESDAY NIGHT INTO WEDNESDAY...BOTH GFS AND ECWMF DEEPEN THE
UPPER LOW AND ASSOCIATED TROUGH AND NEGATIVELY TILT THE FEATURE SO
THAT THE TROUGH AXIS SHIFTS TO OFF THE NORTH CAROLINA COAST...
COINCIDENT TO THE POSITION OF THE ASSOCIATED SURFACE OCCLUDED
FRONT...WITH THE TRIPLE POINT PASSING SOMEWHERE NEAR OR JUST SOUTH
OF OUR REGION. AT THIS TIME...SPC DOES NOT HAVE ANY THUNDERSTORMS IN
ITS DAY 4-8 CONVECTIVE OUTLOOK. IT LOOKS LIKE...THERE IS THE
POTENTIAL FOR OUR REGION TO HAVE ACTIVE WEATHER LATE TUESDAY NIGHT
INTO WEDNESDAY WITH PLENTY OF SHOWERS...PERHAPS VERY GUSTY WINDS AND
A FEW THUNDERSTORMS.

COLD AIR PUSHES INTO THE REGION TUESDAY NIGHT INTO WEDNESDAY
MORNING...ALLOWING FOR SOME RAIN AND SNOW SHOWERS. IF ENOUGH COLD
AIR ARRIVES QUICKLY...THERE COULD BE SOME ACCUMULATING SNOW IN THE
WESTERN MOUNTAINS. KEPT THE HIGHEST POPS OF RAIN AND SNOW SHOWERS IN
THE WEST AS THE LOW CENTER MARCHES NORTHEAST PUSHES A COLD FRONT TO
THE COAST. IN THE WAKE OF THE COLD FRONT A COOLING TRENDS WILL
CONTINUE WEDNESDAY INTO THURSDAY...WITH WEST TO NORTHWEST FLOW
ALOFT. UPPER FLOW SHIFTS TO THE SOUTHWEST AS TROF CURVES OUT IN THE
CENTRAL US WITH SFC INFLECTION OF LOW PRESSURE DEVELOPS OVER THE
TENNESSEE VALLEY BY FRIDAY MORNING.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 1230 PM EST FRIDAY...

VFR EXPECTED THROUGH EARLY TONIGHT WITH LOW CLOUDS SHRINKING WEST
OF BLF-LWB THIS AFTERNOON. HIGH CLOUDS INCREASE THROUGH THIS
EVENING THEN LOWER TO A MID DECK BY MIDNIGHT.

LATEST MODELS CONTINUE THE TREND OF LESS PRECIP FOR SAT MORNING
BUT STILL CAN EXPECT SOME LIGHT SNOW/FLURRIES AT ALL SITES BEFORE
18Z...WITH HIGHEST IMPACT FOR AVIATION LOOKING TO STAY SOUTH OF A
TRI-FVX LINE...SO WENT WITH MVFR VSBYS/CIGS AT DAN AROUND
15Z...WITH POSSIBLE MVFR CIGS AT BLF.



EXTENDED DISCUSSION...

THIS SYSTEM MOVES OUT FAIRLY QUICK WITH PRECIP ENDING SAT
AFTERNOON.

ONCE THIS FEATURE EXITS WILL SEE THE NEXT WAVE ALONG THE COAST
BRING ANOTHER ROUND OF SUB-VFR CONDITIONS FOR LATER SUNDAY NIGHT
INTO MONDAY. THIS SYSTEM LOOKS TO IMPACT AREAS ALONG AND EAST OF
THE BLUE RIDGE...WITH YET ANOTHER SYSTEM SLATED FOR LATE TUESDAY
INTO WEDNESDAY AHEAD OF A STRONG COLD FRONT. THESE SYSTEMS ARE
EXPECTED TO BRING A PERIOD MAINLY RAIN BUT COULD BE SOME WINTRY WX
AS WELL ESPECIALLY IN THE MOUNTAINS WITH THE SUNDAY NIGHT/MONDAY
EVENT. EXPECT POTENTIAL LOW LEVEL WIND SHEAR AS WELL AND POOR
FLYING WEATHER FOR EARLY NEXT WEEK.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...JH/RCS
NEAR TERM...JH/WP
SHORT TERM...NF
LONG TERM...KK
AVIATION...JH/WP




000
FXUS61 KRNK 191736
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
1236 PM EST FRI DEC 19 2014

.SYNOPSIS...
HIGH PRESSURE OVER THE UPPER MIDWEST WILL GRADUALLY BUILD SOUTHEAST
ACROSS THE AREA RESULTING IN OVERALL DRY WEATHER INTO TONIGHT. A
WEAK AREA OF LOW PRESSURE WILL DEVELOP ALONG THE GULF COAST
STATES LATE TONIGHT AND MOVE EAST OVER THE SOUTHEAST STATES ON
SATURDAY. THIS SYSTEM WILL BRING A PERIOD OF LIGHT WINTRY
PRECIPITATION TO MAINLY SOUTHERN AND WESTERN AREAS SATURDAY
MORNING BEFORE TAPERING OFF SATURDAY AFTERNOON.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 1228 PM EST FRIDAY...

DRYING TAKING PLACE IN THE LOW LVLS WITH LOW CLOUDS SHRINKING OVER
THE WV MTNS. JUST A FEW SC/CU THIS AFTERNOON LEFT IN THE MTNS WITH
HIGH CLOUDS STARTING TO INCREASE...MAINLY THIN BUT WILL LEAD TO A
MILKY SKY BY LATE AFTERNOON IN THE SW.

MADE MINOR ADJUSTMENTS TO TEMPS BUT OVERALL STILL LOOKING AT MID
30S FOR HIGHS IN THE HIGHER MOUNTAINS TO LOWER 50S SOUTHEAST.



PREVIOUS VALID DISCUSSION...

MID LEVEL WAVE OVER TX LATE THIS MORNING WILL GIVE RISE TO WEAK
SURFACE LOW PRESSURE ALONG THE NORTHERN GULF LATE TONIGHT WITH
PLENTY OF SHEARED MOISTURE ZIPPING NE INTO THE REGION OVERNIGHT.
HOWEVER THE SYSTEM STILL LOOKS TO REMAIN WEAK GIVEN THE MAIN UPPER
JET WELL TO THE SOUTH AND DAMPENING OF THE MID LEVEL SHORTWAVE AS
IT GETS BOOTED EAST WITHOUT PHASING VIA A SEPARATE NORTHERN STREAM
VORT. BEST MOISTURE TRANSPORT WITH THE WEAK SURFACE LOW WILL STAY
SOUTH WITH PERHAPS A SECOND ZONE OF LIGHT PRECIP FARTHER NORTH
DRIVEN BY THE COMBO OF THE WAVE ALOFT AND WEAK ISENTROPIC LIFT
INTO SW SECTIONS LATE. MODELS CONTINUE TO ONLY SHOW VERY LIGHT QPF
AND WOULDN`T TAKE MUCH LIFT TO THE SOUTH TO TOTALLY CUT OFF
MOISTURE INTO THE CWA PER LATEST EURO. HOWEVER WITH SOME SPOTTY
QPF OF UP TO A TENTH OF AN INCH OFF THE NAM OVER THE NW NC
MOUNTAINS...BROUGHT IN LOW LIKELYS THERE BY DAYBREAK WHILE
SPREADING LOW CHANCES FARTHER NORTH ACROSS MOST OF THE
MOUNTAINS/FOOTHILLS UNDER THE WAVE AXIS. FORECAST SOUNDINGS SHOW
MOST OF THE REGION BELOW FREEZING ALOFT SO PTYPE MAINLY SNOW WITH
PERHAPS THE WARMER BOUNDARY LAYER IN SPOTS CAUSING A BIT MORE RAIN
TO INIT FOOTHILLS EAST. SOME SLEET ALSO POSSIBLE DURING THE CHANGE
TO SNOW AT THE ONSET IN THESE SPOTS AS WELL SO INCLUDED MENTION.

OVERALL SNOWFALL LOOKS TO BE LESS THAN A HALF INCH AT BEST BY
MORNING...THUS NO HEADLINES GIVEN LIGHT AMOUNTS AND POTENTIAL FOR JUST
MORE CLOUDS THAN SIGNIFICANT QPF AT THIS POINT. OTRW BECOMING CLOUDY
ALL SECTIONS WITH LOWS IN THE 20S TO LOW 30S...MAINLY THIS
EVENING...THEN STEADYING OR RISING LATE AS CLOUDS THICKEN.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
AS OF 330 AM EST FRIDAY...

WEATHER FORECAST MODELS OVER THE PAST FEW RUNS ARE SETTLING ON A
MODEST UPPER LEVEL TROUGH PASSING ACROSS THE AREA ON SATURDAY...WITH
A WEAK LOW PRESSURE SYSTEM MOVING NORTHEAST ALONG THE ATLANTIC
COAST. THIS WILL BRING LIGHT SNOW ACROSS THE AREA DURING THE MORNING
AND AFTERNOON...WITH SPOTTY ACCUMULATIONS...MOSTLY LESS THAN AN
INCH...CONFINED TO THE HIGHER RIDGES...PARTICULARLY ALONG THE BLUE
RIDGE PARKWAY SOUTH OF ROANOKE INTO THE MOUNTAIN EMPIRE. ENERGY
ASSOCIATED WITH THE UPPER TROUGH WILL EXIT TO THE EAST DURING THE
AFTERNOON...LEAVING ONLY LIGHT SNOW SHOWERS ALONG THE WESTERN RIDGES
DURING THE EVENING. OTHERWISE...WILL BE LOOKING AT DRY WEATHER
THROUGH SATURDAY NIGHT...AS ANOTHER ROUND OF HIGH PRESSURE PASSES
ACROSS EASTERN CANADA...AND BUILDS SOUTHWARD ACROSS NEW ENGLAND AND
THE MID ATLANTIC TO WEDGE AGAINST THE EASTERN FACE OF THE
APPALACHIANS.

YET ANOTHER TROUGH WILL APPROACH FROM THE WEST ON SUNDAY...
SUPPORTING DEVELOPMENT OF LOW PRESSURE ALONG THE CENTRAL GULF COAST.
SOUTHERLY FLOW OFF THE SURFACE WILL PUSH WARM GULF AIR ALONG THE
CENTRAL APPALACHIANS TO OVERRUN THE COLD NORTHEASTERLY WIND FLOW
ASSOCIATED WITH THE HIGH PRESSURE WEDGE. AS SUCH...EXPECT TO SEE A
WINTRY MIX DEVELOP SUNDAY NIGHT AS PRECIPITATION ENTERS OUR AREA.
FORECAST MODEL SOUNDINGS INDICATE THAT THE COLD AIR ASSOCIATED WITH
THE WEDGE IS DEEP ENOUGH TO CAUSE MUCH OF THE PRECIPITATION ACROSS
THE MOUNTAINS TO FALL AS A MIXTURE OF SLEET AND RAIN NORTH OF
HIGHWAY 460...WITH TEMPERATURES TOWARD THE INTERSTATE 64 CORRIDOR
BECOMING COLD ENOUGH THAT SNOW WILL BECOME MORE OF A POSSIBILITY.
STILL A LITTLE EARLY TO DISCUSS ACCUMULATIONS...BUT AS OF THIS
MORNING...IT IS LOOKING MORE LIKE AN ADVISORY CRITERIA EVENT RATHER
THAN A WARNING EVENT...ALTHOUGH THIS CAN EASILY CHANGE OVER THE NEXT
DAY OR TWO.

TEMPERATURES WILL WARM ENOUGH BY EARLY MONDAY AFTERNOON TO ALLOW
PRECIPITATION TO CHANGE MAINLY TO RAIN...POSSIBLY WITH A FEW POCKETS
OF SLEET OR FREEZING RAIN REMAINING THROUGH THE DAY. THE MAIN ENERGY
ASSOCIATED WITH THE SYSTEM WILL PASS EAST DURING MONDAY
EVENING...LEAVING ONLY PATCHES OF LIGHT PRECIPITATION TO PASS ACROSS
THE AREA OVERNIGHT.

&&

.LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 230 PM EST THURSDAY...

A DEEP LONGITUDINAL TROUGH DEVELOPS SOUTH TO THE GULF OF MEXICO ON
TUESDAY WITH INCREASING SOUTHERLY LOW LEVEL FLOW ACROSS OUR
REGION...ACCOMPANIED BY INCREASING MOISTURE ADVECTION. TEMPERATURES
WILL TREND MILDER FOR HIGHS TUESDAY FROM THE MID 40S TO THE LOWER
50S.

BY TUESDAY NIGHT INTO WEDNESDAY...BOTH GFS AND ECWMF DEEPEN THE
UPPER LOW AND ASSOCIATED TROUGH AND NEGATIVELY TILT THE FEATURE SO
THAT THE TROUGH AXIS SHIFTS TO OFF THE NORTH CAROLINA COAST...
COINCIDENT TO THE POSITION OF THE ASSOCIATED SURFACE OCCLUDED
FRONT...WITH THE TRIPLE POINT PASSING SOMEWHERE NEAR OR JUST SOUTH
OF OUR REGION. AT THIS TIME...SPC DOES NOT HAVE ANY THUNDERSTORMS IN
ITS DAY 4-8 CONVECTIVE OUTLOOK. IT LOOKS LIKE...THERE IS THE
POTENTIAL FOR OUR REGION TO HAVE ACTIVE WEATHER LATE TUESDAY NIGHT
INTO WEDNESDAY WITH PLENTY OF SHOWERS...PERHAPS VERY GUSTY WINDS AND
A FEW THUNDERSTORMS.

COLD AIR PUSHES INTO THE REGION TUESDAY NIGHT INTO WEDNESDAY
MORNING...ALLOWING FOR SOME RAIN AND SNOW SHOWERS. IF ENOUGH COLD
AIR ARRIVES QUICKLY...THERE COULD BE SOME ACCUMULATING SNOW IN THE
WESTERN MOUNTAINS. KEPT THE HIGHEST POPS OF RAIN AND SNOW SHOWERS IN
THE WEST AS THE LOW CENTER MARCHES NORTHEAST PUSHES A COLD FRONT TO
THE COAST. IN THE WAKE OF THE COLD FRONT A COOLING TRENDS WILL
CONTINUE WEDNESDAY INTO THURSDAY...WITH WEST TO NORTHWEST FLOW
ALOFT. UPPER FLOW SHIFTS TO THE SOUTHWEST AS TROF CURVES OUT IN THE
CENTRAL US WITH SFC INFLECTION OF LOW PRESSURE DEVELOPS OVER THE
TENNESSEE VALLEY BY FRIDAY MORNING.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 1230 PM EST FRIDAY...

VFR EXPECTED THROUGH EARLY TONIGHT WITH LOW CLOUDS SHRINKING WEST
OF BLF-LWB THIS AFTERNOON. HIGH CLOUDS INCREASE THROUGH THIS
EVENING THEN LOWER TO A MID DECK BY MIDNIGHT.

LATEST MODELS CONTINUE THE TREND OF LESS PRECIP FOR SAT MORNING
BUT STILL CAN EXPECT SOME LIGHT SNOW/FLURRIES AT ALL SITES BEFORE
18Z...WITH HIGHEST IMPACT FOR AVIATION LOOKING TO STAY SOUTH OF A
TRI-FVX LINE...SO WENT WITH MVFR VSBYS/CIGS AT DAN AROUND
15Z...WITH POSSIBLE MVFR CIGS AT BLF.



EXTENDED DISCUSSION...

THIS SYSTEM MOVES OUT FAIRLY QUICK WITH PRECIP ENDING SAT
AFTERNOON.

ONCE THIS FEATURE EXITS WILL SEE THE NEXT WAVE ALONG THE COAST
BRING ANOTHER ROUND OF SUB-VFR CONDITIONS FOR LATER SUNDAY NIGHT
INTO MONDAY. THIS SYSTEM LOOKS TO IMPACT AREAS ALONG AND EAST OF
THE BLUE RIDGE...WITH YET ANOTHER SYSTEM SLATED FOR LATE TUESDAY
INTO WEDNESDAY AHEAD OF A STRONG COLD FRONT. THESE SYSTEMS ARE
EXPECTED TO BRING A PERIOD MAINLY RAIN BUT COULD BE SOME WINTRY WX
AS WELL ESPECIALLY IN THE MOUNTAINS WITH THE SUNDAY NIGHT/MONDAY
EVENT. EXPECT POTENTIAL LOW LEVEL WIND SHEAR AS WELL AND POOR
FLYING WEATHER FOR EARLY NEXT WEEK.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...JH/RCS
NEAR TERM...JH/WP
SHORT TERM...NF
LONG TERM...KK
AVIATION...JH/WP





000
FXUS61 KRNK 191432
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
932 AM EST FRI DEC 19 2014

.SYNOPSIS...
HIGH PRESSURE OVER THE UPPER MIDWEST WILL GRADUALLY BUILD SOUTHEAST
ACROSS THE AREA RESULTING IN OVERALL DRY WEATHER INTO TONIGHT. A
WEAK AREA OF LOW PRESSURE WILL DEVELOP ALONG THE GULF COAST
STATES LATE TONIGHT AND MOVE EAST OVER THE SOUTHEAST STATES ON
SATURDAY. THIS SYSTEM WILL BRING A PERIOD OF LIGHT WINTRY
PRECIPITATION TO MAINLY SOUTHERN AND WESTERN AREAS SATURDAY
MORNING BEFORE TAPERING OFF SATURDAY AFTERNOON.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 928 AM EST FRIDAY...

VERY LITTLE TO CHANGE IN THE FORECAST. LOWER CLOUDS STICKING
AROUND TIL ABOUT NOON IN THE WRN SLOPES...WITH MOST AREAS STAYING
SUNNY. WILL SEE SOME THIN HIGH CLOUDS ARRIVING FROM THE SOUTHWEST
THROUGH THE AFTERNOON...BECOMING MORE OPAQUE AS WE HEAD TOWARD
DUSK.

PREVIOUS VALID DISCUSSION...

HIGH TEMPS REMAIN A BIT TRICKY GIVEN THE WIDE RANGE OF VALUES TO
INIT THIS MORNING AND TIMING OF CLOUD EXODUS THIS AFTERNOON.
OVERALL MOS A BIT COOLER THAN PREVIOUS SO LOWERED A DEGREE OR TWO
IN SPOTS BUT NOT AS COOL AS THE MET TODAY PER MORE EXPECTED
INSOLATION.

MID LEVEL WAVE CURRENTLY HEADING NE OUT OF NEW MEXICO WILL GIVE RISE TO
WEAK SURFACE LOW PRESSURE ALONG THE NORTHERN GULF LATE TONIGHT WITH
PLENTY OF SHEARED MOISTURE ZIPPING NE INTO THE REGION OVERNIGHT.
HOWEVER THE SYSTEM STILL LOOKS TO REMAIN WEAK GIVEN THE MAIN UPPER JET
WELL TO THE SOUTH AND DAMPENING OF THE MID LEVEL SHORTWAVE AS IT GETS
BOOTED EAST WITHOUT PHASING VIA A SEPARATE NORTHERN STREAM VORT. BEST
MOISTURE TRANSPORT WITH THE WEAK SURFACE LOW WILL STAY SOUTH WITH
PERHAPS A SECOND ZONE OF LIGHT PRECIP FARTHER NORTH DRIVEN BY THE COMBO
OF THE WAVE ALOFT AND WEAK ISENTROPIC LIFT INTO SW SECTIONS LATE.
MODELS CONTINUE TO ONLY SHOW VERY LIGHT QPF AND WOULDN`T TAKE
MUCH LIFT TO THE SOUTH TO TOTALLY CUT OFF MOISTURE INTO THE CWA
PER LATEST EURO. HOWEVER WITH SOME SPOTTY QPF OF UP TO A TENTH OF
AN INCH OFF THE NAM OVER THE NW NC MOUNTAINS...BROUGHT IN LOW
LIKELYS THERE BY DAYBREAK WHILE SPREADING LOW CHANCES FARTHER
NORTH ACROSS MOST OF THE MOUNTAINS/FOOTHILLS UNDER THE WAVE AXIS.
FORECAST SOUNDINGS SHOW MOST OF THE REGION BELOW FREEZING ALOFT SO
PTYPE MAINLY SNOW WITH PERHAPS THE WARMER BOUNDARY LAYER IN SPOTS
CAUSING A BIT MORE RAIN TO INIT FOOTHILLS EAST. SOME SLEET ALSO
POSSIBLE DURING THE CHANGE TO SNOW AT THE ONSET IN THESE SPOTS AS
WELL SO INCLUDED MENTION.

OVERALL SNOWFALL LOOKS TO BE LESS THAN A HALF INCH AT BEST BY
MORNING...THUS NO HEADLINES GIVEN LIGHT AMOUNTS AND POTENTIAL FOR JUST
MORE CLOUDS THAN SIGNIFICANT QPF AT THIS POINT. OTRW BECOMING CLOUDY
ALL SECTIONS WITH LOWS IN THE 20S TO LOW 30S...MAINLY THIS
EVENING...THEN STEADYING OR RISING LATE AS CLOUDS THICKEN.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
AS OF 330 AM EST FRIDAY...

WEATHER FORECAST MODELS OVER THE PAST FEW RUNS ARE SETTLING ON A
MODEST UPPER LEVEL TROUGH PASSING ACROSS THE AREA ON SATURDAY...WITH
A WEAK LOW PRESSURE SYSTEM MOVING NORTHEAST ALONG THE ATLANTIC
COAST. THIS WILL BRING LIGHT SNOW ACROSS THE AREA DURING THE MORNING
AND AFTERNOON...WITH SPOTTY ACCUMULATIONS...MOSTLY LESS THAN AN
INCH...CONFINED TO THE HIGHER RIDGES...PARTICULARLY ALONG THE BLUE
RIDGE PARKWAY SOUTH OF ROANOKE INTO THE MOUNTAIN EMPIRE. ENERGY
ASSOCIATED WITH THE UPPER TROUGH WILL EXIT TO THE EAST DURING THE
AFTERNOON...LEAVING ONLY LIGHT SNOW SHOWERS ALONG THE WESTERN RIDGES
DURING THE EVENING. OTHERWISE...WILL BE LOOKING AT DRY WEATHER
THROUGH SATURDAY NIGHT...AS ANOTHER ROUND OF HIGH PRESSURE PASSES
ACROSS EASTERN CANADA...AND BUILDS SOUTHWARD ACROSS NEW ENGLAND AND
THE MID ATLANTIC TO WEDGE AGAINST THE EASTERN FACE OF THE
APPALACHIANS.

YET ANOTHER TROUGH WILL APPROACH FROM THE WEST ON SUNDAY...
SUPPORTING DEVELOPMENT OF LOW PRESSURE ALONG THE CENTRAL GULF COAST.
SOUTHERLY FLOW OFF THE SURFACE WILL PUSH WARM GULF AIR ALONG THE
CENTRAL APPALACHIANS TO OVERRUN THE COLD NORTHEASTERLY WIND FLOW
ASSOCIATED WITH THE HIGH PRESSURE WEDGE. AS SUCH...EXPECT TO SEE A
WINTRY MIX DEVELOP SUNDAY NIGHT AS PRECIPITATION ENTERS OUR AREA.
FORECAST MODEL SOUNDINGS INDICATE THAT THE COLD AIR ASSOCIATED WITH
THE WEDGE IS DEEP ENOUGH TO CAUSE MUCH OF THE PRECIPITATION ACROSS
THE MOUNTAINS TO FALL AS A MIXTURE OF SLEET AND RAIN NORTH OF
HIGHWAY 460...WITH TEMPERATURES TOWARD THE INTERSTATE 64 CORRIDOR
BECOMING COLD ENOUGH THAT SNOW WILL BECOME MORE OF A POSSIBILITY.
STILL A LITTLE EARLY TO DISCUSS ACCUMULATIONS...BUT AS OF THIS
MORNING...IT IS LOOKING MORE LIKE AN ADVISORY CRITERIA EVENT RATHER
THAN A WARNING EVENT...ALTHOUGH THIS CAN EASILY CHANGE OVER THE NEXT
DAY OR TWO.

TEMPERATURES WILL WARM ENOUGH BY EARLY MONDAY AFTERNOON TO ALLOW
PRECIPITATION TO CHANGE MAINLY TO RAIN...POSSIBLY WITH A FEW POCKETS
OF SLEET OR FREEZING RAIN REMAINING THROUGH THE DAY. THE MAIN ENERGY
ASSOCIATED WITH THE SYSTEM WILL PASS EAST DURING MONDAY
EVENING...LEAVING ONLY PATCHES OF LIGHT PRECIPITATION TO PASS ACROSS
THE AREA OVERNIGHT.

&&

.LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 230 PM EST THURSDAY...

A DEEP LONGITUDINAL TROUGH DEVELOPS SOUTH TO THE GULF OF MEXICO ON
TUESDAY WITH INCREASING SOUTHERLY LOW LEVEL FLOW ACROSS OUR
REGION...ACCOMPANIED BY INCREASING MOISTURE ADVECTION. TEMPERATURES
WILL TREND MILDER FOR HIGHS TUESDAY FROM THE MID 40S TO THE LOWER
50S.

BY TUESDAY NIGHT INTO WEDNESDAY...BOTH GFS AND ECWMF DEEPEN THE
UPPER LOW AND ASSOCIATED TROUGH AND NEGATIVELY TILT THE FEATURE SO
THAT THE TROUGH AXIS SHIFTS TO OFF THE NORTH CAROLINA COAST...
COINCIDENT TO THE POSITION OF THE ASSOCIATED SURFACE OCCLUDED
FRONT...WITH THE TRIPLE POINT PASSING SOMEWHERE NEAR OR JUST SOUTH
OF OUR REGION. AT THIS TIME...SPC DOES NOT HAVE ANY THUNDERSTORMS IN
ITS DAY 4-8 CONVECTIVE OUTLOOK. IT LOOKS LIKE...THERE IS THE
POTENTIAL FOR OUR REGION TO HAVE ACTIVE WEATHER LATE TUESDAY NIGHT
INTO WEDNESDAY WITH PLENTY OF SHOWERS...PERHAPS VERY GUSTY WINDS AND
A FEW THUNDERSTORMS.

COLD AIR PUSHES INTO THE REGION TUESDAY NIGHT INTO WEDNESDAY
MORNING...ALLOWING FOR SOME RAIN AND SNOW SHOWERS. IF ENOUGH COLD
AIR ARRIVES QUICKLY...THERE COULD BE SOME ACCUMULATING SNOW IN THE
WESTERN MOUNTAINS. KEPT THE HIGHEST POPS OF RAIN AND SNOW SHOWERS IN
THE WEST AS THE LOW CENTER MARCHES NORTHEAST PUSHES A COLD FRONT TO
THE COAST. IN THE WAKE OF THE COLD FRONT A COOLING TRENDS WILL
CONTINUE WEDNESDAY INTO THURSDAY...WITH WEST TO NORTHWEST FLOW
ALOFT. UPPER FLOW SHIFTS TO THE SOUTHWEST AS TROF CURVES OUT IN THE
CENTRAL US WITH SFC INFLECTION OF LOW PRESSURE DEVELOPS OVER THE
TENNESSEE VALLEY BY FRIDAY MORNING.

&&

.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
AS OF 605 AM EST FRIDAY...

FLYING CONDITIONS SLOWLY IMPROVING THIS MORNING BUT STILL LOOKING
AT MVFR/OCNL IFR CIGS AT KBLF WITH LOW CLOUDS BANKED UP ALONG THE
WESTERN SLOPES...AND PERHAPS A PERIOD OF MVFR AT KLWB. LATEST
BUFKIT SOUNDINGS SUGGEST THAT MOST RESIDUAL UPSTREAM LOW CLOUDS
SHOULD MIX OUT LATER THIS MORNING WITH ALL WESTERN LOCATIONS
BECOMING VFR AROUND MID MORNING. SOME LOW END VFR SCT-BKN CLOUDS
POSSIBLE OUT EAST THIS MORNING AS WELL BUT SHOULD ONLY LAST A FEW
MORE HOURS AT BEST. OTRW SHOULD SEE WIDESPREAD VFR THIS AFTERNOON/
EVENING UNDER REDUCED CLOUDINESS BEFORE MID/HIGH LEVEL MOISTURE
STARTS TO RETURN FROM THE SW...AND LOW CLOUDS POSSIBLY SNEAK BACK
INTO KBLF/KLWB LATE WHERE INCLUDED SOME MVFR CIGS LATE.

LIGHT PRECIP WITH WEAK LOW PRESSURE TO THE SOUTH SHOULD APPROACH
THE REGION VERY LATE TONIGHT WHILE LATEST FORECAST SOUNDINGS
SUGGEST ENOUGH LOW LEVEL DRY AIR TO PRECLUDE MUCH FROM REACHING
THE SURFACE. THEREFORE MAINTAINING VFR UNDER LOWERING CIGS ELSW
OUTSIDE OF THE SE WEST VA SITES BUT WITHOUT ANY PRECIP MENTION AT
THIS POINT.

EXTENDED DISCUSSION...

WEAK SYSTEM WILL PASS TO THE SOUTH AND EAST SATURDAY PERHAPS
BRINGING A PERIOD OF SNOW OR WINTRY MIX ACROSS SOUTHERN/SW
SECTIONS INTO EARLY AFTERNOON BEFORE TAPERING. HOWEVER WITH THE
MAJORITY OF THE PRECIP LOOKING TO PASS SOUTH ONLY LOOKING AT BRIEF
VSBY REDUCTIONS AT WORSE...MAINLY ALONG THE KBLF-KBCB-KDAN
CORRIDOR...WHERE A PERIOD OF MVFR CIGS LOOKS LIKELY INTO SATURDAY
AFTERNOON.

ONCE THIS FEATURE EXITS BY LATE SATURDAY...WILL SEE THE NEXT WAVE
ALONG THE COAST BRING ANOTHER ROUND OF SUB-VFR CONDITIONS FOR
LATER SUNDAY NIGHT INTO MONDAY. THIS SYSTEM LOOKS TO IMPACT
AREAS ALONG AND EAST OF THE BLUE RIDGE...WITH YET ANOTHER SYSTEM
SLATED FOR LATE TUESDAY INTO WEDNESDAY AHEAD OF A STRONG COLD
FRONT. THESE SYSTEMS ARE EXPECTED TO BRING A PERIOD MAINLY RAIN
BUT COULD BE SOME WINTRY WX AS WELL ESPECIALLY IN THE MOUNTAINS
WITH THE SUNDAY NIGHT/MONDAY EVENT. EXPECT POTENTIAL LOW LEVEL
WIND SHEAR AS WELL AND POOR FLYING WEATHER FOR EARLY NEXT WEEK.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...JH/RCS
NEAR TERM...JH/WP
SHORT TERM...NF
LONG TERM...KK
AVIATION...JH/RCS/WP




000
FXUS61 KRNK 191432
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
932 AM EST FRI DEC 19 2014

.SYNOPSIS...
HIGH PRESSURE OVER THE UPPER MIDWEST WILL GRADUALLY BUILD SOUTHEAST
ACROSS THE AREA RESULTING IN OVERALL DRY WEATHER INTO TONIGHT. A
WEAK AREA OF LOW PRESSURE WILL DEVELOP ALONG THE GULF COAST
STATES LATE TONIGHT AND MOVE EAST OVER THE SOUTHEAST STATES ON
SATURDAY. THIS SYSTEM WILL BRING A PERIOD OF LIGHT WINTRY
PRECIPITATION TO MAINLY SOUTHERN AND WESTERN AREAS SATURDAY
MORNING BEFORE TAPERING OFF SATURDAY AFTERNOON.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 928 AM EST FRIDAY...

VERY LITTLE TO CHANGE IN THE FORECAST. LOWER CLOUDS STICKING
AROUND TIL ABOUT NOON IN THE WRN SLOPES...WITH MOST AREAS STAYING
SUNNY. WILL SEE SOME THIN HIGH CLOUDS ARRIVING FROM THE SOUTHWEST
THROUGH THE AFTERNOON...BECOMING MORE OPAQUE AS WE HEAD TOWARD
DUSK.

PREVIOUS VALID DISCUSSION...

HIGH TEMPS REMAIN A BIT TRICKY GIVEN THE WIDE RANGE OF VALUES TO
INIT THIS MORNING AND TIMING OF CLOUD EXODUS THIS AFTERNOON.
OVERALL MOS A BIT COOLER THAN PREVIOUS SO LOWERED A DEGREE OR TWO
IN SPOTS BUT NOT AS COOL AS THE MET TODAY PER MORE EXPECTED
INSOLATION.

MID LEVEL WAVE CURRENTLY HEADING NE OUT OF NEW MEXICO WILL GIVE RISE TO
WEAK SURFACE LOW PRESSURE ALONG THE NORTHERN GULF LATE TONIGHT WITH
PLENTY OF SHEARED MOISTURE ZIPPING NE INTO THE REGION OVERNIGHT.
HOWEVER THE SYSTEM STILL LOOKS TO REMAIN WEAK GIVEN THE MAIN UPPER JET
WELL TO THE SOUTH AND DAMPENING OF THE MID LEVEL SHORTWAVE AS IT GETS
BOOTED EAST WITHOUT PHASING VIA A SEPARATE NORTHERN STREAM VORT. BEST
MOISTURE TRANSPORT WITH THE WEAK SURFACE LOW WILL STAY SOUTH WITH
PERHAPS A SECOND ZONE OF LIGHT PRECIP FARTHER NORTH DRIVEN BY THE COMBO
OF THE WAVE ALOFT AND WEAK ISENTROPIC LIFT INTO SW SECTIONS LATE.
MODELS CONTINUE TO ONLY SHOW VERY LIGHT QPF AND WOULDN`T TAKE
MUCH LIFT TO THE SOUTH TO TOTALLY CUT OFF MOISTURE INTO THE CWA
PER LATEST EURO. HOWEVER WITH SOME SPOTTY QPF OF UP TO A TENTH OF
AN INCH OFF THE NAM OVER THE NW NC MOUNTAINS...BROUGHT IN LOW
LIKELYS THERE BY DAYBREAK WHILE SPREADING LOW CHANCES FARTHER
NORTH ACROSS MOST OF THE MOUNTAINS/FOOTHILLS UNDER THE WAVE AXIS.
FORECAST SOUNDINGS SHOW MOST OF THE REGION BELOW FREEZING ALOFT SO
PTYPE MAINLY SNOW WITH PERHAPS THE WARMER BOUNDARY LAYER IN SPOTS
CAUSING A BIT MORE RAIN TO INIT FOOTHILLS EAST. SOME SLEET ALSO
POSSIBLE DURING THE CHANGE TO SNOW AT THE ONSET IN THESE SPOTS AS
WELL SO INCLUDED MENTION.

OVERALL SNOWFALL LOOKS TO BE LESS THAN A HALF INCH AT BEST BY
MORNING...THUS NO HEADLINES GIVEN LIGHT AMOUNTS AND POTENTIAL FOR JUST
MORE CLOUDS THAN SIGNIFICANT QPF AT THIS POINT. OTRW BECOMING CLOUDY
ALL SECTIONS WITH LOWS IN THE 20S TO LOW 30S...MAINLY THIS
EVENING...THEN STEADYING OR RISING LATE AS CLOUDS THICKEN.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
AS OF 330 AM EST FRIDAY...

WEATHER FORECAST MODELS OVER THE PAST FEW RUNS ARE SETTLING ON A
MODEST UPPER LEVEL TROUGH PASSING ACROSS THE AREA ON SATURDAY...WITH
A WEAK LOW PRESSURE SYSTEM MOVING NORTHEAST ALONG THE ATLANTIC
COAST. THIS WILL BRING LIGHT SNOW ACROSS THE AREA DURING THE MORNING
AND AFTERNOON...WITH SPOTTY ACCUMULATIONS...MOSTLY LESS THAN AN
INCH...CONFINED TO THE HIGHER RIDGES...PARTICULARLY ALONG THE BLUE
RIDGE PARKWAY SOUTH OF ROANOKE INTO THE MOUNTAIN EMPIRE. ENERGY
ASSOCIATED WITH THE UPPER TROUGH WILL EXIT TO THE EAST DURING THE
AFTERNOON...LEAVING ONLY LIGHT SNOW SHOWERS ALONG THE WESTERN RIDGES
DURING THE EVENING. OTHERWISE...WILL BE LOOKING AT DRY WEATHER
THROUGH SATURDAY NIGHT...AS ANOTHER ROUND OF HIGH PRESSURE PASSES
ACROSS EASTERN CANADA...AND BUILDS SOUTHWARD ACROSS NEW ENGLAND AND
THE MID ATLANTIC TO WEDGE AGAINST THE EASTERN FACE OF THE
APPALACHIANS.

YET ANOTHER TROUGH WILL APPROACH FROM THE WEST ON SUNDAY...
SUPPORTING DEVELOPMENT OF LOW PRESSURE ALONG THE CENTRAL GULF COAST.
SOUTHERLY FLOW OFF THE SURFACE WILL PUSH WARM GULF AIR ALONG THE
CENTRAL APPALACHIANS TO OVERRUN THE COLD NORTHEASTERLY WIND FLOW
ASSOCIATED WITH THE HIGH PRESSURE WEDGE. AS SUCH...EXPECT TO SEE A
WINTRY MIX DEVELOP SUNDAY NIGHT AS PRECIPITATION ENTERS OUR AREA.
FORECAST MODEL SOUNDINGS INDICATE THAT THE COLD AIR ASSOCIATED WITH
THE WEDGE IS DEEP ENOUGH TO CAUSE MUCH OF THE PRECIPITATION ACROSS
THE MOUNTAINS TO FALL AS A MIXTURE OF SLEET AND RAIN NORTH OF
HIGHWAY 460...WITH TEMPERATURES TOWARD THE INTERSTATE 64 CORRIDOR
BECOMING COLD ENOUGH THAT SNOW WILL BECOME MORE OF A POSSIBILITY.
STILL A LITTLE EARLY TO DISCUSS ACCUMULATIONS...BUT AS OF THIS
MORNING...IT IS LOOKING MORE LIKE AN ADVISORY CRITERIA EVENT RATHER
THAN A WARNING EVENT...ALTHOUGH THIS CAN EASILY CHANGE OVER THE NEXT
DAY OR TWO.

TEMPERATURES WILL WARM ENOUGH BY EARLY MONDAY AFTERNOON TO ALLOW
PRECIPITATION TO CHANGE MAINLY TO RAIN...POSSIBLY WITH A FEW POCKETS
OF SLEET OR FREEZING RAIN REMAINING THROUGH THE DAY. THE MAIN ENERGY
ASSOCIATED WITH THE SYSTEM WILL PASS EAST DURING MONDAY
EVENING...LEAVING ONLY PATCHES OF LIGHT PRECIPITATION TO PASS ACROSS
THE AREA OVERNIGHT.

&&

.LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 230 PM EST THURSDAY...

A DEEP LONGITUDINAL TROUGH DEVELOPS SOUTH TO THE GULF OF MEXICO ON
TUESDAY WITH INCREASING SOUTHERLY LOW LEVEL FLOW ACROSS OUR
REGION...ACCOMPANIED BY INCREASING MOISTURE ADVECTION. TEMPERATURES
WILL TREND MILDER FOR HIGHS TUESDAY FROM THE MID 40S TO THE LOWER
50S.

BY TUESDAY NIGHT INTO WEDNESDAY...BOTH GFS AND ECWMF DEEPEN THE
UPPER LOW AND ASSOCIATED TROUGH AND NEGATIVELY TILT THE FEATURE SO
THAT THE TROUGH AXIS SHIFTS TO OFF THE NORTH CAROLINA COAST...
COINCIDENT TO THE POSITION OF THE ASSOCIATED SURFACE OCCLUDED
FRONT...WITH THE TRIPLE POINT PASSING SOMEWHERE NEAR OR JUST SOUTH
OF OUR REGION. AT THIS TIME...SPC DOES NOT HAVE ANY THUNDERSTORMS IN
ITS DAY 4-8 CONVECTIVE OUTLOOK. IT LOOKS LIKE...THERE IS THE
POTENTIAL FOR OUR REGION TO HAVE ACTIVE WEATHER LATE TUESDAY NIGHT
INTO WEDNESDAY WITH PLENTY OF SHOWERS...PERHAPS VERY GUSTY WINDS AND
A FEW THUNDERSTORMS.

COLD AIR PUSHES INTO THE REGION TUESDAY NIGHT INTO WEDNESDAY
MORNING...ALLOWING FOR SOME RAIN AND SNOW SHOWERS. IF ENOUGH COLD
AIR ARRIVES QUICKLY...THERE COULD BE SOME ACCUMULATING SNOW IN THE
WESTERN MOUNTAINS. KEPT THE HIGHEST POPS OF RAIN AND SNOW SHOWERS IN
THE WEST AS THE LOW CENTER MARCHES NORTHEAST PUSHES A COLD FRONT TO
THE COAST. IN THE WAKE OF THE COLD FRONT A COOLING TRENDS WILL
CONTINUE WEDNESDAY INTO THURSDAY...WITH WEST TO NORTHWEST FLOW
ALOFT. UPPER FLOW SHIFTS TO THE SOUTHWEST AS TROF CURVES OUT IN THE
CENTRAL US WITH SFC INFLECTION OF LOW PRESSURE DEVELOPS OVER THE
TENNESSEE VALLEY BY FRIDAY MORNING.

&&

.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
AS OF 605 AM EST FRIDAY...

FLYING CONDITIONS SLOWLY IMPROVING THIS MORNING BUT STILL LOOKING
AT MVFR/OCNL IFR CIGS AT KBLF WITH LOW CLOUDS BANKED UP ALONG THE
WESTERN SLOPES...AND PERHAPS A PERIOD OF MVFR AT KLWB. LATEST
BUFKIT SOUNDINGS SUGGEST THAT MOST RESIDUAL UPSTREAM LOW CLOUDS
SHOULD MIX OUT LATER THIS MORNING WITH ALL WESTERN LOCATIONS
BECOMING VFR AROUND MID MORNING. SOME LOW END VFR SCT-BKN CLOUDS
POSSIBLE OUT EAST THIS MORNING AS WELL BUT SHOULD ONLY LAST A FEW
MORE HOURS AT BEST. OTRW SHOULD SEE WIDESPREAD VFR THIS AFTERNOON/
EVENING UNDER REDUCED CLOUDINESS BEFORE MID/HIGH LEVEL MOISTURE
STARTS TO RETURN FROM THE SW...AND LOW CLOUDS POSSIBLY SNEAK BACK
INTO KBLF/KLWB LATE WHERE INCLUDED SOME MVFR CIGS LATE.

LIGHT PRECIP WITH WEAK LOW PRESSURE TO THE SOUTH SHOULD APPROACH
THE REGION VERY LATE TONIGHT WHILE LATEST FORECAST SOUNDINGS
SUGGEST ENOUGH LOW LEVEL DRY AIR TO PRECLUDE MUCH FROM REACHING
THE SURFACE. THEREFORE MAINTAINING VFR UNDER LOWERING CIGS ELSW
OUTSIDE OF THE SE WEST VA SITES BUT WITHOUT ANY PRECIP MENTION AT
THIS POINT.

EXTENDED DISCUSSION...

WEAK SYSTEM WILL PASS TO THE SOUTH AND EAST SATURDAY PERHAPS
BRINGING A PERIOD OF SNOW OR WINTRY MIX ACROSS SOUTHERN/SW
SECTIONS INTO EARLY AFTERNOON BEFORE TAPERING. HOWEVER WITH THE
MAJORITY OF THE PRECIP LOOKING TO PASS SOUTH ONLY LOOKING AT BRIEF
VSBY REDUCTIONS AT WORSE...MAINLY ALONG THE KBLF-KBCB-KDAN
CORRIDOR...WHERE A PERIOD OF MVFR CIGS LOOKS LIKELY INTO SATURDAY
AFTERNOON.

ONCE THIS FEATURE EXITS BY LATE SATURDAY...WILL SEE THE NEXT WAVE
ALONG THE COAST BRING ANOTHER ROUND OF SUB-VFR CONDITIONS FOR
LATER SUNDAY NIGHT INTO MONDAY. THIS SYSTEM LOOKS TO IMPACT
AREAS ALONG AND EAST OF THE BLUE RIDGE...WITH YET ANOTHER SYSTEM
SLATED FOR LATE TUESDAY INTO WEDNESDAY AHEAD OF A STRONG COLD
FRONT. THESE SYSTEMS ARE EXPECTED TO BRING A PERIOD MAINLY RAIN
BUT COULD BE SOME WINTRY WX AS WELL ESPECIALLY IN THE MOUNTAINS
WITH THE SUNDAY NIGHT/MONDAY EVENT. EXPECT POTENTIAL LOW LEVEL
WIND SHEAR AS WELL AND POOR FLYING WEATHER FOR EARLY NEXT WEEK.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...JH/RCS
NEAR TERM...JH/WP
SHORT TERM...NF
LONG TERM...KK
AVIATION...JH/RCS/WP





000
FXUS61 KRNK 191123
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
623 AM EST FRI DEC 19 2014

.SYNOPSIS...
HIGH PRESSURE OVER THE UPPER MIDWEST WILL GRADUALLY BUILD SOUTHEAST
ACROSS THE AREA RESULTING IN OVERALL DRY WEATHER INTO TONIGHT. A
WEAK AREA OF LOW PRESSURE WILL DEVELOP ALONG THE GULF COAST
STATES LATE TONIGHT AND MOVE EAST OVER THE SOUTHEAST STATES ON
SATURDAY. THIS SYSTEM WILL BRING A PERIOD OF LIGHT WINTRY
PRECIPITATION TO MAINLY SOUTHERN AND WESTERN AREAS SATURDAY
MORNING BEFORE TAPERING OFF SATURDAY AFTERNOON.
&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 218 AM EST FRIDAY...

CLOUDS AGAIN THE MAIN CONCERN TODAY AS SHORTWAVE EXITS EARLY THIS
MORNING AND WEAK SUBSIDENCE FILLS IN BEFORE THE NEXT WAVE APPROACHES
FROM THE SW LATE TONIGHT. IR PICS SHOW A VARIETY OF MID DECK AS WELL AS
HIGH END STRATO-CU PASSING ACROSS WITH LINGERING LOW CLOUDS PINNED
ALONG THE NW SLOPES. GUIDANCE HANGS ON TO THIS SCENARIO INTO MID
MORNING BEFORE SHOWING PERHAPS ENOUGH DRYING ALOFT TO AID CLEARING BY
EARLY AFTERNOON AS BRIEF SHORTWAVE RIDGING BUILDS EAST. THIS SUPPORTS
GOING WITH MORE SUN BY THIS AFTERNOON BEFORE HIGH/MID CLOUDS
MAKE A RETURN OVER THE SW LATE. HIGH TEMPS REMAIN A BIT TRICKY GIVEN THE
WIDE RANGE OF VALUES TO INIT THIS MORNING AND TIMING OF CLOUD EXODUS
THIS AFTERNOON. OVERALL MOS A BIT COOLER THAN PREVIOUS SO LOWERED A
DEGREE OR TWO IN SPOTS BUT NOT AS COOL AS THE MET TODAY PER MORE
EXPECTED INSOLATION.

MID LEVEL WAVE CURRENTLY HEADING NE OUT OF NEW MEXICO WILL GIVE RISE TO
WEAK SURFACE LOW PRESSURE ALONG THE NORTHERN GULF LATE TONIGHT WITH
PLENTY OF SHEARED MOISTURE ZIPPING NE INTO THE REGION OVERNIGHT.
HOWEVER THE SYSTEM STILL LOOKS TO REMAIN WEAK GIVEN THE MAIN UPPER JET
WELL TO THE SOUTH AND DAMPENING OF THE MID LEVEL SHORTWAVE AS IT GETS
BOOTED EAST WITHOUT PHASING VIA A SEPARATE NORTHERN STREAM VORT. BEST
MOISTURE TRANSPORT WITH THE WEAK SURFACE LOW WILL STAY SOUTH WITH
PERHAPS A SECOND ZONE OF LIGHT PRECIP FARTHER NORTH DRIVEN BY THE COMBO
OF THE WAVE ALOFT AND WEAK ISENTROPIC LIFT INTO SW SECTIONS LATE.
MODELS CONTINUE TO ONLY SHOW VERY LIGHT QPF AND WOULDNT TAKE MUCH LIFT
TO THE SOUTH TO TOTALLY CUT OFF MOISTURE INTO THE CWA PER LATEST EURO.
HOWEVER WITH SOME SPOTTY QPF OF UP TO A TENTH OF AN INCH OFF THE NAM
OVER THE NW NC MOUNTAINS...BROUGHT IN LOW LIKELYS THERE BY DAYBREAK
WHILE SPREADING LOW CHANCES FARTHER NORTH ACROSS MOST OF THE
MOUNTAINS/FOOTHILLS UNDER THE WAVE AXIS. FORECAST SOUNDINGS SHOW MOST
OF THE REGION BELOW FREEZING ALOFT SO PTYPE MAINLY SNOW WITH PERHAPS
THE WARMER BOUNDARY LAYER IN SPOTS CAUSING A BIT MORE RAIN TO INIT
FOOTHILLS EAST. SOME SLEET ALSO POSSIBLE DURING THE CHANGE TO SNOW
AT THE ONSET IN THESE SPOTS AS WELL SO INCLUDED MENTION.

OVERALL SNOWFALL LOOKS TO BE LESS THAN A HALF INCH AT BEST BY
MORNING...THUS NO HEADLINES GIVEN LIGHT AMOUNTS AND POTENTIAL FOR JUST
MORE CLOUDS THAN SIGNIFICANT QPF AT THIS POINT. OTRW BECOMING CLOUDY
ALL SECTIONS WITH LOWS IN THE 20S TO LOW 30S...MAINLY THIS
EVENING...THEN STEADYING OR RISING LATE AS CLOUDS THICKEN.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
AS OF 330 AM EST FRIDAY...

WEATHER FORECAST MODELS OVER THE PAST FEW RUNS ARE SETTLING ON A
MODEST UPPER LEVEL TROUGH PASSING ACROSS THE AREA ON SATURDAY...WITH
A WEAK LOW PRESSURE SYSTEM MOVING NORTHEAST ALONG THE ATLANTIC
COAST. THIS WILL BRING LIGHT SNOW ACROSS THE AREA DURING THE MORNING
AND AFTERNOON...WITH SPOTTY ACCUMULATIONS...MOSTLY LESS THAN AN
INCH...CONFINED TO THE HIGHER RIDGES...PARTICULARLY ALONG THE BLUE
RIDGE PARKWAY SOUTH OF ROANOKE INTO THE MOUNTAIN EMPIRE. ENERGY
ASSOCIATED WITH THE UPPER TROUGH WILL EXIT TO THE EAST DURING THE
AFTERNOON...LEAVING ONLY LIGHT SNOW SHOWERS ALONG THE WESTERN RIDGES
DURING THE EVENING. OTHERWISE...WILL BE LOOKING AT DRY WEATHER
THROUGH SATURDAY NIGHT...AS ANOTHER ROUND OF HIGH PRESSURE PASSES
ACROSS EASTERN CANADA...AND BUILDS SOUTHWARD ACROSS NEW ENGLAND AND
THE MID ATLANTIC TO WEDGE AGAINST THE EASTERN FACE OF THE
APPALACHIANS.

YET ANOTHER TROUGH WILL APPROACH FROM THE WEST ON SUNDAY...
SUPPORTING DEVELOPMENT OF LOW PRESSURE ALONG THE CENTRAL GULF COAST.
SOUTHERLY FLOW OFF THE SURFACE WILL PUSH WARM GULF AIR ALONG THE
CENTRAL APPALACHIANS TO OVERRUN THE COLD NORTHEASTERLY WIND FLOW
ASSOCIATED WITH THE HIGH PRESSURE WEDGE. AS SUCH...EXPECT TO SEE A
WINTRY MIX DEVELOP SUNDAY NIGHT AS PRECIPITATION ENTERS OUR AREA.
FORECAST MODEL SOUNDINGS INDICATE THAT THE COLD AIR ASSOCIATED WITH
THE WEDGE IS DEEP ENOUGH TO CAUSE MUCH OF THE PRECIPITATION ACROSS
THE MOUNTAINS TO FALL AS A MIXTURE OF SLEET AND RAIN NORTH OF
HIGHWAY 460...WITH TEMPERATURES TOWARD THE INTERSTATE 64 CORRIDOR
BECOMING COLD ENOUGH THAT SNOW WILL BECOME MORE OF A POSSIBILITY.
STILL A LITTLE EARLY TO DISCUSS ACCUMULATIONS...BUT AS OF THIS
MORNING...IT IS LOOKING MORE LIKE AN ADVISORY CRITERIA EVENT RATHER
THAN A WARNING EVENT...ALTHOUGH THIS CAN EASILY CHANGE OVER THE NEXT
DAY OR TWO.

TEMPERATURES WILL WARM ENOUGH BY EARLY MONDAY AFTERNOON TO ALLOW
PRECIPITATION TO CHANGE MAINLY TO RAIN...POSSIBLY WITH A FEW POCKETS
OF SLEET OR FREEZING RAIN REMAINING THROUGH THE DAY. THE MAIN ENERGY
ASSOCIATED WITH THE SYSTEM WILL PASS EAST DURING MONDAY
EVENING...LEAVING ONLY PATCHES OF LIGHT PRECIPITATION TO PASS ACROSS
THE AREA OVERNIGHT.

&&

.LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 230 PM EST THURSDAY...

A DEEP LONGITUDINAL TROUGH DEVELOPS SOUTH TO THE GULF OF MEXICO ON
TUESDAY WITH INCREASING SOUTHERLY LOW LEVEL FLOW ACROSS OUR
REGION...ACCOMPANIED BY INCREASING MOISTURE ADVECTION. TEMPERATURES
WILL TREND MILDER FOR HIGHS TUESDAY FROM THE MID 40S TO THE LOWER
50S.

BY TUESDAY NIGHT INTO WEDNESDAY...BOTH GFS AND ECWMF DEEPEN THE
UPPER LOW AND ASSOCIATED TROUGH AND NEGATIVELY TILT THE FEATURE SO
THAT THE TROUGH AXIS SHIFTS TO OFF THE NORTH CAROLINA COAST...
COINCIDENT TO THE POSITION OF THE ASSOCIATED SURFACE OCCLUDED
FRONT...WITH THE TRIPLE POINT PASSING SOMEWHERE NEAR OR JUST SOUTH
OF OUR REGION. AT THIS TIME...SPC DOES NOT HAVE ANY THUNDERSTORMS IN
ITS DAY 4-8 CONVECTIVE OUTLOOK. IT LOOKS LIKE...THERE IS THE
POTENTIAL FOR OUR REGION TO HAVE ACTIVE WEATHER LATE TUESDAY NIGHT
INTO WEDNESDAY WITH PLENTY OF SHOWERS...PERHAPS VERY GUSTY WINDS AND
A FEW THUNDERSTORMS.

COLD AIR PUSHES INTO THE REGION TUESDAY NIGHT INTO WEDNESDAY
MORNING...ALLOWING FOR SOME RAIN AND SNOW SHOWERS. IF ENOUGH COLD
AIR ARRIVES QUICKLY...THERE COULD BE SOME ACCUMULATING SNOW IN THE
WESTERN MOUNTAINS. KEPT THE HIGHEST POPS OF RAIN AND SNOW SHOWERS IN
THE WEST AS THE LOW CENTER MARCHES NORTHEAST PUSHES A COLD FRONT TO
THE COAST. IN THE WAKE OF THE COLD FRONT A COOLING TRENDS WILL
CONTINUE WEDNESDAY INTO THURSDAY...WITH WEST TO NORTHWEST FLOW
ALOFT. UPPER FLOW SHIFTS TO THE SOUTHWEST AS TROF CURVES OUT IN THE
CENTRAL US WITH SFC INFLECTION OF LOW PRESSURE DEVELOPS OVER THE
TENNESSEE VALLEY BY FRIDAY MORNING.

&&

.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
AS OF 605 AM EST FRIDAY...

FLYING CONDITIONS SLOWLY IMPROVING THIS MORNING BUT STILL LOOKING
AT MVFR/OCNL IFR CIGS AT KBLF WITH LOW CLOUDS BANKED UP ALONG THE
WESTERN SLOPES...AND PERHAPS A PERIOD OF MVFR AT KLWB. LATEST
BUFKIT SOUNDINGS SUGGEST THAT MOST RESIDUAL UPSTREAM LOW CLOUDS
SHOULD MIX OUT LATER THIS MORNING WITH ALL WESTERN LOCATIONS
BECOMING VFR AROUND MID MORNING. SOME LOW END VFR SCT-BKN CLOUDS
POSSIBLE OUT EAST THIS MORNING AS WELL BUT SHOULD ONLY LAST A FEW
MORE HOURS AT BEST. OTRW SHOULD SEE WIDESPREAD VFR THIS AFTERNOON/
EVENING UNDER REDUCED CLOUDINESS BEFORE MID/HIGH LEVEL MOISTURE
STARTS TO RETURN FROM THE SW...AND LOW CLOUDS POSSIBLY SNEAK BACK
INTO KBLF/KLWB LATE WHERE INCLUDED SOME MVFR CIGS LATE.

LIGHT PRECIP WITH WEAK LOW PRESSURE TO THE SOUTH SHOULD APPROACH
THE REGION VERY LATE TONIGHT WHILE LATEST FORECAST SOUNDINGS
SUGGEST ENOUGH LOW LEVEL DRY AIR TO PRECLUDE MUCH FROM REACHING
THE SURFACE. THEREFORE MAINTAINING VFR UNDER LOWERING CIGS ELSW
OUTSIDE OF THE SE WEST VA SITES BUT WITHOUT ANY PRECIP MENTION AT
THIS POINT.

EXTENDED DISCUSSION...

WEAK SYSTEM WILL PASS TO THE SOUTH AND EAST SATURDAY PERHAPS
BRINGING A PERIOD OF SNOW OR WINTRY MIX ACROSS SOUTHERN/SW
SECTIONS INTO EARLY AFTERNOON BEFORE TAPERING. HOWEVER WITH THE
MAJORITY OF THE PRECIP LOOKING TO PASS SOUTH ONLY LOOKING AT BRIEF
VSBY REDUCTIONS AT WORSE...MAINLY ALONG THE KBLF-KBCB-KDAN
CORRIDOR...WHERE A PERIOD OF MVFR CIGS LOOKS LIKELY INTO SATURDAY
AFTERNOON.

ONCE THIS FEATURE EXITS BY LATE SATURDAY...WILL SEE THE NEXT WAVE
ALONG THE COAST BRING ANOTHER ROUND OF SUB-VFR CONDITIONS FOR
LATER SUNDAY NIGHT INTO MONDAY. THIS SYSTEM LOOKS TO IMPACT
AREAS ALONG AND EAST OF THE BLUE RIDGE...WITH YET ANOTHER SYSTEM
SLATED FOR LATE TUESDAY INTO WEDNESDAY AHEAD OF A STRONG COLD
FRONT. THESE SYSTEMS ARE EXPECTED TO BRING A PERIOD MAINLY RAIN
BUT COULD BE SOME WINTRY WX AS WELL ESPECIALLY IN THE MOUNTAINS
WITH THE SUNDAY NIGHT/MONDAY EVENT. EXPECT POTENTIAL LOW LEVEL
WIND SHEAR AS WELL AND POOR FLYING WEATHER FOR EARLY NEXT WEEK.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...JH/RCS
NEAR TERM...JH
SHORT TERM...NF
LONG TERM...KK
AVIATION...JH/RCS/WP




000
FXUS61 KRNK 191123
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
623 AM EST FRI DEC 19 2014

.SYNOPSIS...
HIGH PRESSURE OVER THE UPPER MIDWEST WILL GRADUALLY BUILD SOUTHEAST
ACROSS THE AREA RESULTING IN OVERALL DRY WEATHER INTO TONIGHT. A
WEAK AREA OF LOW PRESSURE WILL DEVELOP ALONG THE GULF COAST
STATES LATE TONIGHT AND MOVE EAST OVER THE SOUTHEAST STATES ON
SATURDAY. THIS SYSTEM WILL BRING A PERIOD OF LIGHT WINTRY
PRECIPITATION TO MAINLY SOUTHERN AND WESTERN AREAS SATURDAY
MORNING BEFORE TAPERING OFF SATURDAY AFTERNOON.
&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 218 AM EST FRIDAY...

CLOUDS AGAIN THE MAIN CONCERN TODAY AS SHORTWAVE EXITS EARLY THIS
MORNING AND WEAK SUBSIDENCE FILLS IN BEFORE THE NEXT WAVE APPROACHES
FROM THE SW LATE TONIGHT. IR PICS SHOW A VARIETY OF MID DECK AS WELL AS
HIGH END STRATO-CU PASSING ACROSS WITH LINGERING LOW CLOUDS PINNED
ALONG THE NW SLOPES. GUIDANCE HANGS ON TO THIS SCENARIO INTO MID
MORNING BEFORE SHOWING PERHAPS ENOUGH DRYING ALOFT TO AID CLEARING BY
EARLY AFTERNOON AS BRIEF SHORTWAVE RIDGING BUILDS EAST. THIS SUPPORTS
GOING WITH MORE SUN BY THIS AFTERNOON BEFORE HIGH/MID CLOUDS
MAKE A RETURN OVER THE SW LATE. HIGH TEMPS REMAIN A BIT TRICKY GIVEN THE
WIDE RANGE OF VALUES TO INIT THIS MORNING AND TIMING OF CLOUD EXODUS
THIS AFTERNOON. OVERALL MOS A BIT COOLER THAN PREVIOUS SO LOWERED A
DEGREE OR TWO IN SPOTS BUT NOT AS COOL AS THE MET TODAY PER MORE
EXPECTED INSOLATION.

MID LEVEL WAVE CURRENTLY HEADING NE OUT OF NEW MEXICO WILL GIVE RISE TO
WEAK SURFACE LOW PRESSURE ALONG THE NORTHERN GULF LATE TONIGHT WITH
PLENTY OF SHEARED MOISTURE ZIPPING NE INTO THE REGION OVERNIGHT.
HOWEVER THE SYSTEM STILL LOOKS TO REMAIN WEAK GIVEN THE MAIN UPPER JET
WELL TO THE SOUTH AND DAMPENING OF THE MID LEVEL SHORTWAVE AS IT GETS
BOOTED EAST WITHOUT PHASING VIA A SEPARATE NORTHERN STREAM VORT. BEST
MOISTURE TRANSPORT WITH THE WEAK SURFACE LOW WILL STAY SOUTH WITH
PERHAPS A SECOND ZONE OF LIGHT PRECIP FARTHER NORTH DRIVEN BY THE COMBO
OF THE WAVE ALOFT AND WEAK ISENTROPIC LIFT INTO SW SECTIONS LATE.
MODELS CONTINUE TO ONLY SHOW VERY LIGHT QPF AND WOULDNT TAKE MUCH LIFT
TO THE SOUTH TO TOTALLY CUT OFF MOISTURE INTO THE CWA PER LATEST EURO.
HOWEVER WITH SOME SPOTTY QPF OF UP TO A TENTH OF AN INCH OFF THE NAM
OVER THE NW NC MOUNTAINS...BROUGHT IN LOW LIKELYS THERE BY DAYBREAK
WHILE SPREADING LOW CHANCES FARTHER NORTH ACROSS MOST OF THE
MOUNTAINS/FOOTHILLS UNDER THE WAVE AXIS. FORECAST SOUNDINGS SHOW MOST
OF THE REGION BELOW FREEZING ALOFT SO PTYPE MAINLY SNOW WITH PERHAPS
THE WARMER BOUNDARY LAYER IN SPOTS CAUSING A BIT MORE RAIN TO INIT
FOOTHILLS EAST. SOME SLEET ALSO POSSIBLE DURING THE CHANGE TO SNOW
AT THE ONSET IN THESE SPOTS AS WELL SO INCLUDED MENTION.

OVERALL SNOWFALL LOOKS TO BE LESS THAN A HALF INCH AT BEST BY
MORNING...THUS NO HEADLINES GIVEN LIGHT AMOUNTS AND POTENTIAL FOR JUST
MORE CLOUDS THAN SIGNIFICANT QPF AT THIS POINT. OTRW BECOMING CLOUDY
ALL SECTIONS WITH LOWS IN THE 20S TO LOW 30S...MAINLY THIS
EVENING...THEN STEADYING OR RISING LATE AS CLOUDS THICKEN.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
AS OF 330 AM EST FRIDAY...

WEATHER FORECAST MODELS OVER THE PAST FEW RUNS ARE SETTLING ON A
MODEST UPPER LEVEL TROUGH PASSING ACROSS THE AREA ON SATURDAY...WITH
A WEAK LOW PRESSURE SYSTEM MOVING NORTHEAST ALONG THE ATLANTIC
COAST. THIS WILL BRING LIGHT SNOW ACROSS THE AREA DURING THE MORNING
AND AFTERNOON...WITH SPOTTY ACCUMULATIONS...MOSTLY LESS THAN AN
INCH...CONFINED TO THE HIGHER RIDGES...PARTICULARLY ALONG THE BLUE
RIDGE PARKWAY SOUTH OF ROANOKE INTO THE MOUNTAIN EMPIRE. ENERGY
ASSOCIATED WITH THE UPPER TROUGH WILL EXIT TO THE EAST DURING THE
AFTERNOON...LEAVING ONLY LIGHT SNOW SHOWERS ALONG THE WESTERN RIDGES
DURING THE EVENING. OTHERWISE...WILL BE LOOKING AT DRY WEATHER
THROUGH SATURDAY NIGHT...AS ANOTHER ROUND OF HIGH PRESSURE PASSES
ACROSS EASTERN CANADA...AND BUILDS SOUTHWARD ACROSS NEW ENGLAND AND
THE MID ATLANTIC TO WEDGE AGAINST THE EASTERN FACE OF THE
APPALACHIANS.

YET ANOTHER TROUGH WILL APPROACH FROM THE WEST ON SUNDAY...
SUPPORTING DEVELOPMENT OF LOW PRESSURE ALONG THE CENTRAL GULF COAST.
SOUTHERLY FLOW OFF THE SURFACE WILL PUSH WARM GULF AIR ALONG THE
CENTRAL APPALACHIANS TO OVERRUN THE COLD NORTHEASTERLY WIND FLOW
ASSOCIATED WITH THE HIGH PRESSURE WEDGE. AS SUCH...EXPECT TO SEE A
WINTRY MIX DEVELOP SUNDAY NIGHT AS PRECIPITATION ENTERS OUR AREA.
FORECAST MODEL SOUNDINGS INDICATE THAT THE COLD AIR ASSOCIATED WITH
THE WEDGE IS DEEP ENOUGH TO CAUSE MUCH OF THE PRECIPITATION ACROSS
THE MOUNTAINS TO FALL AS A MIXTURE OF SLEET AND RAIN NORTH OF
HIGHWAY 460...WITH TEMPERATURES TOWARD THE INTERSTATE 64 CORRIDOR
BECOMING COLD ENOUGH THAT SNOW WILL BECOME MORE OF A POSSIBILITY.
STILL A LITTLE EARLY TO DISCUSS ACCUMULATIONS...BUT AS OF THIS
MORNING...IT IS LOOKING MORE LIKE AN ADVISORY CRITERIA EVENT RATHER
THAN A WARNING EVENT...ALTHOUGH THIS CAN EASILY CHANGE OVER THE NEXT
DAY OR TWO.

TEMPERATURES WILL WARM ENOUGH BY EARLY MONDAY AFTERNOON TO ALLOW
PRECIPITATION TO CHANGE MAINLY TO RAIN...POSSIBLY WITH A FEW POCKETS
OF SLEET OR FREEZING RAIN REMAINING THROUGH THE DAY. THE MAIN ENERGY
ASSOCIATED WITH THE SYSTEM WILL PASS EAST DURING MONDAY
EVENING...LEAVING ONLY PATCHES OF LIGHT PRECIPITATION TO PASS ACROSS
THE AREA OVERNIGHT.

&&

.LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 230 PM EST THURSDAY...

A DEEP LONGITUDINAL TROUGH DEVELOPS SOUTH TO THE GULF OF MEXICO ON
TUESDAY WITH INCREASING SOUTHERLY LOW LEVEL FLOW ACROSS OUR
REGION...ACCOMPANIED BY INCREASING MOISTURE ADVECTION. TEMPERATURES
WILL TREND MILDER FOR HIGHS TUESDAY FROM THE MID 40S TO THE LOWER
50S.

BY TUESDAY NIGHT INTO WEDNESDAY...BOTH GFS AND ECWMF DEEPEN THE
UPPER LOW AND ASSOCIATED TROUGH AND NEGATIVELY TILT THE FEATURE SO
THAT THE TROUGH AXIS SHIFTS TO OFF THE NORTH CAROLINA COAST...
COINCIDENT TO THE POSITION OF THE ASSOCIATED SURFACE OCCLUDED
FRONT...WITH THE TRIPLE POINT PASSING SOMEWHERE NEAR OR JUST SOUTH
OF OUR REGION. AT THIS TIME...SPC DOES NOT HAVE ANY THUNDERSTORMS IN
ITS DAY 4-8 CONVECTIVE OUTLOOK. IT LOOKS LIKE...THERE IS THE
POTENTIAL FOR OUR REGION TO HAVE ACTIVE WEATHER LATE TUESDAY NIGHT
INTO WEDNESDAY WITH PLENTY OF SHOWERS...PERHAPS VERY GUSTY WINDS AND
A FEW THUNDERSTORMS.

COLD AIR PUSHES INTO THE REGION TUESDAY NIGHT INTO WEDNESDAY
MORNING...ALLOWING FOR SOME RAIN AND SNOW SHOWERS. IF ENOUGH COLD
AIR ARRIVES QUICKLY...THERE COULD BE SOME ACCUMULATING SNOW IN THE
WESTERN MOUNTAINS. KEPT THE HIGHEST POPS OF RAIN AND SNOW SHOWERS IN
THE WEST AS THE LOW CENTER MARCHES NORTHEAST PUSHES A COLD FRONT TO
THE COAST. IN THE WAKE OF THE COLD FRONT A COOLING TRENDS WILL
CONTINUE WEDNESDAY INTO THURSDAY...WITH WEST TO NORTHWEST FLOW
ALOFT. UPPER FLOW SHIFTS TO THE SOUTHWEST AS TROF CURVES OUT IN THE
CENTRAL US WITH SFC INFLECTION OF LOW PRESSURE DEVELOPS OVER THE
TENNESSEE VALLEY BY FRIDAY MORNING.

&&

.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
AS OF 605 AM EST FRIDAY...

FLYING CONDITIONS SLOWLY IMPROVING THIS MORNING BUT STILL LOOKING
AT MVFR/OCNL IFR CIGS AT KBLF WITH LOW CLOUDS BANKED UP ALONG THE
WESTERN SLOPES...AND PERHAPS A PERIOD OF MVFR AT KLWB. LATEST
BUFKIT SOUNDINGS SUGGEST THAT MOST RESIDUAL UPSTREAM LOW CLOUDS
SHOULD MIX OUT LATER THIS MORNING WITH ALL WESTERN LOCATIONS
BECOMING VFR AROUND MID MORNING. SOME LOW END VFR SCT-BKN CLOUDS
POSSIBLE OUT EAST THIS MORNING AS WELL BUT SHOULD ONLY LAST A FEW
MORE HOURS AT BEST. OTRW SHOULD SEE WIDESPREAD VFR THIS AFTERNOON/
EVENING UNDER REDUCED CLOUDINESS BEFORE MID/HIGH LEVEL MOISTURE
STARTS TO RETURN FROM THE SW...AND LOW CLOUDS POSSIBLY SNEAK BACK
INTO KBLF/KLWB LATE WHERE INCLUDED SOME MVFR CIGS LATE.

LIGHT PRECIP WITH WEAK LOW PRESSURE TO THE SOUTH SHOULD APPROACH
THE REGION VERY LATE TONIGHT WHILE LATEST FORECAST SOUNDINGS
SUGGEST ENOUGH LOW LEVEL DRY AIR TO PRECLUDE MUCH FROM REACHING
THE SURFACE. THEREFORE MAINTAINING VFR UNDER LOWERING CIGS ELSW
OUTSIDE OF THE SE WEST VA SITES BUT WITHOUT ANY PRECIP MENTION AT
THIS POINT.

EXTENDED DISCUSSION...

WEAK SYSTEM WILL PASS TO THE SOUTH AND EAST SATURDAY PERHAPS
BRINGING A PERIOD OF SNOW OR WINTRY MIX ACROSS SOUTHERN/SW
SECTIONS INTO EARLY AFTERNOON BEFORE TAPERING. HOWEVER WITH THE
MAJORITY OF THE PRECIP LOOKING TO PASS SOUTH ONLY LOOKING AT BRIEF
VSBY REDUCTIONS AT WORSE...MAINLY ALONG THE KBLF-KBCB-KDAN
CORRIDOR...WHERE A PERIOD OF MVFR CIGS LOOKS LIKELY INTO SATURDAY
AFTERNOON.

ONCE THIS FEATURE EXITS BY LATE SATURDAY...WILL SEE THE NEXT WAVE
ALONG THE COAST BRING ANOTHER ROUND OF SUB-VFR CONDITIONS FOR
LATER SUNDAY NIGHT INTO MONDAY. THIS SYSTEM LOOKS TO IMPACT
AREAS ALONG AND EAST OF THE BLUE RIDGE...WITH YET ANOTHER SYSTEM
SLATED FOR LATE TUESDAY INTO WEDNESDAY AHEAD OF A STRONG COLD
FRONT. THESE SYSTEMS ARE EXPECTED TO BRING A PERIOD MAINLY RAIN
BUT COULD BE SOME WINTRY WX AS WELL ESPECIALLY IN THE MOUNTAINS
WITH THE SUNDAY NIGHT/MONDAY EVENT. EXPECT POTENTIAL LOW LEVEL
WIND SHEAR AS WELL AND POOR FLYING WEATHER FOR EARLY NEXT WEEK.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...JH/RCS
NEAR TERM...JH
SHORT TERM...NF
LONG TERM...KK
AVIATION...JH/RCS/WP





000
FXUS61 KRNK 190927
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
427 AM EST FRI DEC 19 2014

.SYNOPSIS...
HIGH PRESSURE OVER THE UPPER MIDWEST WILL GRADUALLY BUILD SOUTHEAST
ACROSS THE AREA RESULTING IN OVERALL DRY WEATHER INTO TONIGHT. A
WEAK AREA OF LOW PRESSURE WILL DEVELOP ALONG THE GULF COAST
STATES LATE TONIGHT AND MOVE EAST OVER THE SOUTHEAST STATES ON
SATURDAY. THIS SYSTEM WILL BRING A PERIOD OF LIGHT WINTRY
PRECIPITATION TO MAINLY SOUTHERN AND WESTERN AREAS SATURDAY
MORNING BEFORE TAPERING OFF SATURDAY AFTERNOON.
&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 218 AM EST FRIDAY...

CLOUDS AGAIN THE MAIN CONCERN TODAY AS SHORTWAVE EXITS EARLY THIS
MORNING AND WEAK SUBSIDENCE FILLS IN BEFORE THE NEXT WAVE APPROACHES
FROM THE SW LATE TONIGHT. IR PICS SHOW A VARIETY OF MID DECK AS WELL AS
HIGH END STRATO-CU PASSING ACROSS WITH LINGERING LOW CLOUDS PINNED
ALONG THE NW SLOPES. GUIDANCE HANGS ON TO THIS SCENARIO INTO MID
MORNING BEFORE SHOWING PERHAPS ENOUGH DRYING ALOFT TO AID CLEARING BY
EARLY AFTERNOON AS BRIEF SHORTWAVE RIDGING BUILDS EAST. THIS SUPPORTS
GOING WITH MORE SUN BY THIS AFTERNOON BEFORE HIGH/MID CLOUDS
MAKE A RETURN OVER THE SW LATE. HIGH TEMPS REMAIN A BIT TRICKY GIVEN THE
WIDE RANGE OF VALUES TO INIT THIS MORNING AND TIMING OF CLOUD EXODUS
THIS AFTERNOON. OVERALL MOS A BIT COOLER THAN PREVIOUS SO LOWERED A
DEGREE OR TWO IN SPOTS BUT NOT AS COOL AS THE MET TODAY PER MORE
EXPECTED INSOLATION.

MID LEVEL WAVE CURRENTLY HEADING NE OUT OF NEW MEXICO WILL GIVE RISE TO
WEAK SURFACE LOW PRESSURE ALONG THE NORTHERN GULF LATE TONIGHT WITH
PLENTY OF SHEARED MOISTURE ZIPPING NE INTO THE REGION OVERNIGHT.
HOWEVER THE SYSTEM STILL LOOKS TO REMAIN WEAK GIVEN THE MAIN UPPER JET
WELL TO THE SOUTH AND DAMPENING OF THE MID LEVEL SHORTWAVE AS IT GETS
BOOTED EAST WITHOUT PHASING VIA A SEPARATE NORTHERN STREAM VORT. BEST
MOISTURE TRANSPORT WITH THE WEAK SURFACE LOW WILL STAY SOUTH WITH
PERHAPS A SECOND ZONE OF LIGHT PRECIP FARTHER NORTH DRIVEN BY THE COMBO
OF THE WAVE ALOFT AND WEAK ISENTROPIC LIFT INTO SW SECTIONS LATE.
MODELS CONTINUE TO ONLY SHOW VERY LIGHT QPF AND WOULDNT TAKE MUCH LIFT
TO THE SOUTH TO TOTALLY CUT OFF MOISTURE INTO THE CWA PER LATEST EURO.
HOWEVER WITH SOME SPOTTY QPF OF UP TO A TENTH OF AN INCH OFF THE NAM
OVER THE NW NC MOUNTAINS...BROUGHT IN LOW LIKELYS THERE BY DAYBREAK
WHILE SPREADING LOW CHANCES FARTHER NORTH ACROSS MOST OF THE
MOUNTAINS/FOOTHILLS UNDER THE WAVE AXIS. FORECAST SOUNDINGS SHOW MOST
OF THE REGION BELOW FREEZING ALOFT SO PTYPE MAINLY SNOW WITH PERHAPS
THE WARMER BOUNDARY LAYER IN SPOTS CAUSING A BIT MORE RAIN TO INIT
FOOTHILLS EAST. SOME SLEET ALSO POSSIBLE DURING THE CHANGE TO SNOW
AT THE ONSET IN THESE SPOTS AS WELL SO INCLUDED MENTION.

OVERALL SNOWFALL LOOKS TO BE LESS THAN A HALF INCH AT BEST BY
MORNING...THUS NO HEADLINES GIVEN LIGHT AMOUNTS AND POTENTIAL FOR JUST
MORE CLOUDS THAN SIGNIFICANT QPF AT THIS POINT. OTRW BECOMING CLOUDY
ALL SECTIONS WITH LOWS IN THE 20S TO LOW 30S...MAINLY THIS
EVENING...THEN STEADYING OR RISING LATE AS CLOUDS THICKEN.
&&

.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
AS OF 330 AM EST FRIDAY...

WEATHER FORECAST MODELS OVER THE PAST FEW RUNS ARE SETTLING ON A
MODEST UPPER LEVEL TROUGH PASSING ACROSS THE AREA ON SATURDAY...WITH
A WEAK LOW PRESSURE SYSTEM MOVING NORTHEAST ALONG THE ATLANTIC
COAST. THIS WILL BRING LIGHT SNOW ACROSS THE AREA DURING THE MORNING
AND AFTERNOON...WITH SPOTTY ACCUMULATIONS...MOSTLY LESS THAN AN
INCH...CONFINED TO THE HIGHER RIDGES...PARTICULARLY ALONG THE BLUE
RIDGE PARKWAY SOUTH OF ROANOKE INTO THE MOUNTAIN EMPIRE. ENERGY
ASSOCIATED WITH THE UPPER TROUGH WILL EXIT TO THE EAST DURING THE
AFTERNOON...LEAVING ONLY LIGHT SNOW SHOWERS ALONG THE WESTERN RIDGES
DURING THE EVENING. OTHERWISE...WILL BE LOOKING AT DRY WEATHER
THROUGH SATURDAY NIGHT...AS ANOTHER ROUND OF HIGH PRESSURE PASSES
ACROSS EASTERN CANADA...AND BUILDS SOUTHWARD ACROSS NEW ENGLAND AND
THE MID ATLANTIC TO WEDGE AGAINST THE EASTERN FACE OF THE
APPALACHIANS.

YET ANOTHER TROUGH WILL APPROACH FROM THE WEST ON SUNDAY...
SUPPORTING DEVELOPMENT OF LOW PRESSURE ALONG THE CENTRAL GULF COAST.
SOUTHERLY FLOW OFF THE SURFACE WILL PUSH WARM GULF AIR ALONG THE
CENTRAL APPALACHIANS TO OVERRUN THE COLD NORTHEASTERLY WIND FLOW
ASSOCIATED WITH THE HIGH PRESSURE WEDGE. AS SUCH...EXPECT TO SEE A
WINTRY MIX DEVELOP SUNDAY NIGHT AS PRECIPITATION ENTERS OUR AREA.
FORECAST MODEL SOUNDINGS INDICATE THAT THE COLD AIR ASSOCIATED WITH
THE WEDGE IS DEEP ENOUGH TO CAUSE MUCH OF THE PRECIPITATION ACROSS
THE MOUNTAINS TO FALL AS A MIXTURE OF SLEET AND RAIN NORTH OF
HIGHWAY 460...WITH TEMPERATURES TOWARD THE INTERSTATE 64 CORRIDOR
BECOMING COLD ENOUGH THAT SNOW WILL BECOME MORE OF A POSSIBILITY.
STILL A LITTLE EARLY TO DISCUSS ACCUMULATIONS...BUT AS OF THIS
MORNING...IT IS LOOKING MORE LIKE AN ADVISORY CRITERIA EVENT RATHER
THAN A WARNING EVENT...ALTHOUGH THIS CAN EASILY CHANGE OVER THE NEXT
DAY OR TWO.

TEMPERATURES WILL WARM ENOUGH BY EARLY MONDAY AFTERNOON TO ALLOW
PRECIPITATION TO CHANGE MAINLY TO RAIN...POSSIBLY WITH A FEW POCKETS
OF SLEET OR FREEZING RAIN REMAINING THROUGH THE DAY. THE MAIN ENERGY
ASSOCIATED WITH THE SYSTEM WILL PASS EAST DURING MONDAY
EVENING...LEAVING ONLY PATCHES OF LIGHT PRECIPITATION TO PASS ACROSS
THE AREA OVERNIGHT.
&&

.LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 230 PM EST THURSDAY...

A DEEP LONGITUDINAL TROUGH DEVELOPS SOUTH TO THE GULF OF MEXICO ON
TUESDAY WITH INCREASING SOUTHERLY LOW LEVEL FLOW ACROSS OUR
REGION...ACCOMPANIED BY INCREASING MOISTURE ADVECTION. TEMPERATURES
WILL TREND MILDER FOR HIGHS TUESDAY FROM THE MID 40S TO THE LOWER
50S.

BY TUESDAY NIGHT INTO WEDNESDAY...BOTH GFS AND ECWMF DEEPEN THE
UPPER LOW AND ASSOCIATED TROUGH AND NEGATIVELY TILT THE FEATURE SO
THAT THE TROUGH AXIS SHIFTS TO OFF THE NORTH CAROLINA COAST...
COINCIDENT TO THE POSITION OF THE ASSOCIATED SURFACE OCCLUDED
FRONT...WITH THE TRIPLE POINT PASSING SOMEWHERE NEAR OR JUST SOUTH
OF OUR REGION. AT THIS TIME...SPC DOES NOT HAVE ANY THUNDERSTORMS IN
ITS DAY 4-8 CONVECTIVE OUTLOOK. IT LOOKS LIKE...THERE IS THE
POTENTIAL FOR OUR REGION TO HAVE ACTIVE WEATHER LATE TUESDAY NIGHT
INTO WEDNESDAY WITH PLENTY OF SHOWERS...PERHAPS VERY GUSTY WINDS AND
A FEW THUNDERSTORMS.

COLD AIR PUSHES INTO THE REGION TUESDAY NIGHT INTO WEDNESDAY
MORNING...ALLOWING FOR SOME RAIN AND SNOW SHOWERS. IF ENOUGH COLD
AIR ARRIVES QUICKLY...THERE COULD BE SOME ACCUMULATING SNOW IN THE
WESTERN MOUNTAINS. KEPT THE HIGHEST POPS OF RAIN AND SNOW SHOWERS IN
THE WEST AS THE LOW CENTER MARCHES NORTHEAST PUSHES A COLD FRONT TO
THE COAST. IN THE WAKE OF THE COLD FRONT A COOLING TRENDS WILL
CONTINUE WEDNESDAY INTO THURSDAY...WITH WEST TO NORTHWEST FLOW
ALOFT. UPPER FLOW SHIFTS TO THE SOUTHWEST AS TROF CURVES OUT IN THE
CENTRAL US WITH SFC INFLECTION OF LOW PRESSURE DEVELOPS OVER THE
TENNESSEE VALLEY BY FRIDAY MORNING.
&&

.AVIATION /09Z FRIDAY THROUGH TUESDAY/...
AS OF 1045 PM EST THURSDAY...

NOT MUCH CHANGE TO THE AVIATION FORECAST...THOUGH CONFIDENCE IS
LESS THAT BLF WILL DROP BELOW 1KFT PER UPSTREAM OBS. STILL WILL
HAVE A TEMPO GROUP TOWARD 12Z FOR BLF DROPPING TO 9H FEET FOR A
COUPLE HOURS.

OTHERWISE BECOMING MVFR AT BLF/LWB OVERNIGHT THEN BACK TO VFR BY
MIDDAY FRIDAY...WHILE REST OF THE TAF SITES STAY VFR. COULD SEE
SOME SCT SUB 3KFT CLOUDS ACROSS BCB BUT CONFIDENCE HIGH THAT
THREAT OF BKN IS NOT GOING TO HAPPEN.

CLOUDS AHEAD OF THE NEXT SYSTEM WILL BE INCREASING OVERNIGHT
FRIDAY SO EXPECT MAINLY CIRROSTRATUS IN THE LATE EVENING ACROSS
THE REGION.

EXTENDED DISCUSSION...

THE SAT SYSTEM NOW HAS TRENDED WEAKER AND WILL SHIFT MOST OF THE
PRECIP ACROSS THE CAROLINAS...THOUGH STILL WILL SEE SOME WINTRY
MIX BUMP UP INTO THE SE WV/SW VA CORRIDOR INTO THE NC
MTNS...THOUGH TRENDS ARE SHOWING LESS. EXPECT SUB VFR THOUGH AT
TIMES SATURDAY INTO SAT NIGHT.

ON THE HEELS OF THIS  SYSTEM WILL BE ANOTHER SYSTEM TO
POTENTIALLY IMPACT MAINLY THE EASTERN PORTION OF THE REGION SUNDAY
NIGHT INTO MONDAY...WITH YET ANOTHER SYSTEM SLATED FOR LATE
TUESDAY INTO WEDNESDAY. THESE SYSTEMS ARE EXPECTED TO BRING A
PERIOD MAINLY RAIN BUT COULD BE SOME WINTRY WX AS WELL ESPECIALLY
IN THE MOUNTAINS. EXPECT POTENTIAL LOW LEVEL WIND SHEAR AS WELL
AND POOR FLYING WEATHER MONDAY.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...JH/RCS
NEAR TERM...JH
SHORT TERM...NF
LONG TERM...KK
AVIATION...JH/RCS/WP




000
FXUS61 KRNK 190927
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
427 AM EST FRI DEC 19 2014

.SYNOPSIS...
HIGH PRESSURE OVER THE UPPER MIDWEST WILL GRADUALLY BUILD SOUTHEAST
ACROSS THE AREA RESULTING IN OVERALL DRY WEATHER INTO TONIGHT. A
WEAK AREA OF LOW PRESSURE WILL DEVELOP ALONG THE GULF COAST
STATES LATE TONIGHT AND MOVE EAST OVER THE SOUTHEAST STATES ON
SATURDAY. THIS SYSTEM WILL BRING A PERIOD OF LIGHT WINTRY
PRECIPITATION TO MAINLY SOUTHERN AND WESTERN AREAS SATURDAY
MORNING BEFORE TAPERING OFF SATURDAY AFTERNOON.
&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 218 AM EST FRIDAY...

CLOUDS AGAIN THE MAIN CONCERN TODAY AS SHORTWAVE EXITS EARLY THIS
MORNING AND WEAK SUBSIDENCE FILLS IN BEFORE THE NEXT WAVE APPROACHES
FROM THE SW LATE TONIGHT. IR PICS SHOW A VARIETY OF MID DECK AS WELL AS
HIGH END STRATO-CU PASSING ACROSS WITH LINGERING LOW CLOUDS PINNED
ALONG THE NW SLOPES. GUIDANCE HANGS ON TO THIS SCENARIO INTO MID
MORNING BEFORE SHOWING PERHAPS ENOUGH DRYING ALOFT TO AID CLEARING BY
EARLY AFTERNOON AS BRIEF SHORTWAVE RIDGING BUILDS EAST. THIS SUPPORTS
GOING WITH MORE SUN BY THIS AFTERNOON BEFORE HIGH/MID CLOUDS
MAKE A RETURN OVER THE SW LATE. HIGH TEMPS REMAIN A BIT TRICKY GIVEN THE
WIDE RANGE OF VALUES TO INIT THIS MORNING AND TIMING OF CLOUD EXODUS
THIS AFTERNOON. OVERALL MOS A BIT COOLER THAN PREVIOUS SO LOWERED A
DEGREE OR TWO IN SPOTS BUT NOT AS COOL AS THE MET TODAY PER MORE
EXPECTED INSOLATION.

MID LEVEL WAVE CURRENTLY HEADING NE OUT OF NEW MEXICO WILL GIVE RISE TO
WEAK SURFACE LOW PRESSURE ALONG THE NORTHERN GULF LATE TONIGHT WITH
PLENTY OF SHEARED MOISTURE ZIPPING NE INTO THE REGION OVERNIGHT.
HOWEVER THE SYSTEM STILL LOOKS TO REMAIN WEAK GIVEN THE MAIN UPPER JET
WELL TO THE SOUTH AND DAMPENING OF THE MID LEVEL SHORTWAVE AS IT GETS
BOOTED EAST WITHOUT PHASING VIA A SEPARATE NORTHERN STREAM VORT. BEST
MOISTURE TRANSPORT WITH THE WEAK SURFACE LOW WILL STAY SOUTH WITH
PERHAPS A SECOND ZONE OF LIGHT PRECIP FARTHER NORTH DRIVEN BY THE COMBO
OF THE WAVE ALOFT AND WEAK ISENTROPIC LIFT INTO SW SECTIONS LATE.
MODELS CONTINUE TO ONLY SHOW VERY LIGHT QPF AND WOULDNT TAKE MUCH LIFT
TO THE SOUTH TO TOTALLY CUT OFF MOISTURE INTO THE CWA PER LATEST EURO.
HOWEVER WITH SOME SPOTTY QPF OF UP TO A TENTH OF AN INCH OFF THE NAM
OVER THE NW NC MOUNTAINS...BROUGHT IN LOW LIKELYS THERE BY DAYBREAK
WHILE SPREADING LOW CHANCES FARTHER NORTH ACROSS MOST OF THE
MOUNTAINS/FOOTHILLS UNDER THE WAVE AXIS. FORECAST SOUNDINGS SHOW MOST
OF THE REGION BELOW FREEZING ALOFT SO PTYPE MAINLY SNOW WITH PERHAPS
THE WARMER BOUNDARY LAYER IN SPOTS CAUSING A BIT MORE RAIN TO INIT
FOOTHILLS EAST. SOME SLEET ALSO POSSIBLE DURING THE CHANGE TO SNOW
AT THE ONSET IN THESE SPOTS AS WELL SO INCLUDED MENTION.

OVERALL SNOWFALL LOOKS TO BE LESS THAN A HALF INCH AT BEST BY
MORNING...THUS NO HEADLINES GIVEN LIGHT AMOUNTS AND POTENTIAL FOR JUST
MORE CLOUDS THAN SIGNIFICANT QPF AT THIS POINT. OTRW BECOMING CLOUDY
ALL SECTIONS WITH LOWS IN THE 20S TO LOW 30S...MAINLY THIS
EVENING...THEN STEADYING OR RISING LATE AS CLOUDS THICKEN.
&&

.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
AS OF 330 AM EST FRIDAY...

WEATHER FORECAST MODELS OVER THE PAST FEW RUNS ARE SETTLING ON A
MODEST UPPER LEVEL TROUGH PASSING ACROSS THE AREA ON SATURDAY...WITH
A WEAK LOW PRESSURE SYSTEM MOVING NORTHEAST ALONG THE ATLANTIC
COAST. THIS WILL BRING LIGHT SNOW ACROSS THE AREA DURING THE MORNING
AND AFTERNOON...WITH SPOTTY ACCUMULATIONS...MOSTLY LESS THAN AN
INCH...CONFINED TO THE HIGHER RIDGES...PARTICULARLY ALONG THE BLUE
RIDGE PARKWAY SOUTH OF ROANOKE INTO THE MOUNTAIN EMPIRE. ENERGY
ASSOCIATED WITH THE UPPER TROUGH WILL EXIT TO THE EAST DURING THE
AFTERNOON...LEAVING ONLY LIGHT SNOW SHOWERS ALONG THE WESTERN RIDGES
DURING THE EVENING. OTHERWISE...WILL BE LOOKING AT DRY WEATHER
THROUGH SATURDAY NIGHT...AS ANOTHER ROUND OF HIGH PRESSURE PASSES
ACROSS EASTERN CANADA...AND BUILDS SOUTHWARD ACROSS NEW ENGLAND AND
THE MID ATLANTIC TO WEDGE AGAINST THE EASTERN FACE OF THE
APPALACHIANS.

YET ANOTHER TROUGH WILL APPROACH FROM THE WEST ON SUNDAY...
SUPPORTING DEVELOPMENT OF LOW PRESSURE ALONG THE CENTRAL GULF COAST.
SOUTHERLY FLOW OFF THE SURFACE WILL PUSH WARM GULF AIR ALONG THE
CENTRAL APPALACHIANS TO OVERRUN THE COLD NORTHEASTERLY WIND FLOW
ASSOCIATED WITH THE HIGH PRESSURE WEDGE. AS SUCH...EXPECT TO SEE A
WINTRY MIX DEVELOP SUNDAY NIGHT AS PRECIPITATION ENTERS OUR AREA.
FORECAST MODEL SOUNDINGS INDICATE THAT THE COLD AIR ASSOCIATED WITH
THE WEDGE IS DEEP ENOUGH TO CAUSE MUCH OF THE PRECIPITATION ACROSS
THE MOUNTAINS TO FALL AS A MIXTURE OF SLEET AND RAIN NORTH OF
HIGHWAY 460...WITH TEMPERATURES TOWARD THE INTERSTATE 64 CORRIDOR
BECOMING COLD ENOUGH THAT SNOW WILL BECOME MORE OF A POSSIBILITY.
STILL A LITTLE EARLY TO DISCUSS ACCUMULATIONS...BUT AS OF THIS
MORNING...IT IS LOOKING MORE LIKE AN ADVISORY CRITERIA EVENT RATHER
THAN A WARNING EVENT...ALTHOUGH THIS CAN EASILY CHANGE OVER THE NEXT
DAY OR TWO.

TEMPERATURES WILL WARM ENOUGH BY EARLY MONDAY AFTERNOON TO ALLOW
PRECIPITATION TO CHANGE MAINLY TO RAIN...POSSIBLY WITH A FEW POCKETS
OF SLEET OR FREEZING RAIN REMAINING THROUGH THE DAY. THE MAIN ENERGY
ASSOCIATED WITH THE SYSTEM WILL PASS EAST DURING MONDAY
EVENING...LEAVING ONLY PATCHES OF LIGHT PRECIPITATION TO PASS ACROSS
THE AREA OVERNIGHT.
&&

.LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 230 PM EST THURSDAY...

A DEEP LONGITUDINAL TROUGH DEVELOPS SOUTH TO THE GULF OF MEXICO ON
TUESDAY WITH INCREASING SOUTHERLY LOW LEVEL FLOW ACROSS OUR
REGION...ACCOMPANIED BY INCREASING MOISTURE ADVECTION. TEMPERATURES
WILL TREND MILDER FOR HIGHS TUESDAY FROM THE MID 40S TO THE LOWER
50S.

BY TUESDAY NIGHT INTO WEDNESDAY...BOTH GFS AND ECWMF DEEPEN THE
UPPER LOW AND ASSOCIATED TROUGH AND NEGATIVELY TILT THE FEATURE SO
THAT THE TROUGH AXIS SHIFTS TO OFF THE NORTH CAROLINA COAST...
COINCIDENT TO THE POSITION OF THE ASSOCIATED SURFACE OCCLUDED
FRONT...WITH THE TRIPLE POINT PASSING SOMEWHERE NEAR OR JUST SOUTH
OF OUR REGION. AT THIS TIME...SPC DOES NOT HAVE ANY THUNDERSTORMS IN
ITS DAY 4-8 CONVECTIVE OUTLOOK. IT LOOKS LIKE...THERE IS THE
POTENTIAL FOR OUR REGION TO HAVE ACTIVE WEATHER LATE TUESDAY NIGHT
INTO WEDNESDAY WITH PLENTY OF SHOWERS...PERHAPS VERY GUSTY WINDS AND
A FEW THUNDERSTORMS.

COLD AIR PUSHES INTO THE REGION TUESDAY NIGHT INTO WEDNESDAY
MORNING...ALLOWING FOR SOME RAIN AND SNOW SHOWERS. IF ENOUGH COLD
AIR ARRIVES QUICKLY...THERE COULD BE SOME ACCUMULATING SNOW IN THE
WESTERN MOUNTAINS. KEPT THE HIGHEST POPS OF RAIN AND SNOW SHOWERS IN
THE WEST AS THE LOW CENTER MARCHES NORTHEAST PUSHES A COLD FRONT TO
THE COAST. IN THE WAKE OF THE COLD FRONT A COOLING TRENDS WILL
CONTINUE WEDNESDAY INTO THURSDAY...WITH WEST TO NORTHWEST FLOW
ALOFT. UPPER FLOW SHIFTS TO THE SOUTHWEST AS TROF CURVES OUT IN THE
CENTRAL US WITH SFC INFLECTION OF LOW PRESSURE DEVELOPS OVER THE
TENNESSEE VALLEY BY FRIDAY MORNING.
&&

.AVIATION /09Z FRIDAY THROUGH TUESDAY/...
AS OF 1045 PM EST THURSDAY...

NOT MUCH CHANGE TO THE AVIATION FORECAST...THOUGH CONFIDENCE IS
LESS THAT BLF WILL DROP BELOW 1KFT PER UPSTREAM OBS. STILL WILL
HAVE A TEMPO GROUP TOWARD 12Z FOR BLF DROPPING TO 9H FEET FOR A
COUPLE HOURS.

OTHERWISE BECOMING MVFR AT BLF/LWB OVERNIGHT THEN BACK TO VFR BY
MIDDAY FRIDAY...WHILE REST OF THE TAF SITES STAY VFR. COULD SEE
SOME SCT SUB 3KFT CLOUDS ACROSS BCB BUT CONFIDENCE HIGH THAT
THREAT OF BKN IS NOT GOING TO HAPPEN.

CLOUDS AHEAD OF THE NEXT SYSTEM WILL BE INCREASING OVERNIGHT
FRIDAY SO EXPECT MAINLY CIRROSTRATUS IN THE LATE EVENING ACROSS
THE REGION.

EXTENDED DISCUSSION...

THE SAT SYSTEM NOW HAS TRENDED WEAKER AND WILL SHIFT MOST OF THE
PRECIP ACROSS THE CAROLINAS...THOUGH STILL WILL SEE SOME WINTRY
MIX BUMP UP INTO THE SE WV/SW VA CORRIDOR INTO THE NC
MTNS...THOUGH TRENDS ARE SHOWING LESS. EXPECT SUB VFR THOUGH AT
TIMES SATURDAY INTO SAT NIGHT.

ON THE HEELS OF THIS  SYSTEM WILL BE ANOTHER SYSTEM TO
POTENTIALLY IMPACT MAINLY THE EASTERN PORTION OF THE REGION SUNDAY
NIGHT INTO MONDAY...WITH YET ANOTHER SYSTEM SLATED FOR LATE
TUESDAY INTO WEDNESDAY. THESE SYSTEMS ARE EXPECTED TO BRING A
PERIOD MAINLY RAIN BUT COULD BE SOME WINTRY WX AS WELL ESPECIALLY
IN THE MOUNTAINS. EXPECT POTENTIAL LOW LEVEL WIND SHEAR AS WELL
AND POOR FLYING WEATHER MONDAY.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...JH/RCS
NEAR TERM...JH
SHORT TERM...NF
LONG TERM...KK
AVIATION...JH/RCS/WP





000
FXUS61 KRNK 190400
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
1100 PM EST THU DEC 18 2014

.SYNOPSIS...
HIGH PRESSURE OVER THE UPPER MIDWEST WILL GRADUALLY BUILD EAST
ACROSS THE AREA RESULTING IN OVERALL DRY WEATHER THROUGH FRIDAY
EVENING. A WEAK AREA OF LOW PRESSURE WILL EVENTUALLY DEVELOP ALONG
THE GULF COAST STATES FRIDAY NIGHT AND MOVE EAST-NORTHEAST OVER
THE CAROLINAS ON SATURDAY. THIS SYSTEM WILL BRING A PERIOD OF
LIGHT WINTRY PRECIPITATION SATURDAY MORNING...CHANGING TO RAIN
OVER THE PIEDMONT IN THE AFTERNOON.

&&

.NEAR TERM /THROUGH FRIDAY/...
AS OF 1035 PM EST THURSDAY...

UPDATED FORECAST TO LOWER THREAT OF PRECIP IN THE NW. STILL COULD
SEE SOME FLURRIES ACROSS THE MTNS OF WRN GREENBRIER TOWARD DAWN.
OTHERWISE...LOOKING AT SKIES TURNING LESS CLOUDY OUT EAST AS ONE
SHORTWAVE EXITS EAST.

ADJUSTED TEMPS ESPECIALLY IN THE FOOTHILLS AND ROANOKE AS THEY ARE
RUNNING MILDER...BUT AS SKIES CLEAR AND WINDS FADE TEMPS WILL
STILL FALL INTO THE LOWER 30S. STILL LOOKING AT MID TO UPPER 20S
WEST.


PREVIOUS VALID DISCUSSION...

WAVE ALOFT PASSES EAST OVERNIGHT LEAVING WEAK SUBSIDENCE IN PLACE
AS HIGH PRESSURE TO THE NW NOSES BACK IN LATE.


FRIDAY LOOKS TO BE ON THE DRY SIDE AS HIGH PRESSURE STRETCHING
FROM THE GREAT LAKES THROUGH THE OHIO RIVER VALLEY REMAINS THE
MAIN FEATURE IN OUR WEATHER PATTERN. MOSTLY SUNNY SKIES AND LIGHT
NORTHWESTERLY DOWNSLOPE WINDS WILL ALLOW AFTERNOON TEMPERATURES TO
RANGE FROM THE MID 30S ALONG THE WESTERN RIDGES...TO AROUND 50
OVER THE SOUTHSIDE AND THE NORTH CAROLINA PIEDMONT.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
AS OF 250 PM EST THURSDAY...

MODELS HAVE BEEN TRENDING QUITE A BIT WEAKER WITH THE SHORT WAVE
COMING OUT OF ARIZONA AND REACHING THE MID ATLANTIC REGION ON
SATURDAY. ISENTROPIC LIFT AND VORTICITY ADVECTION COME THROUGH ON
SATURDAY AND WILL BE EAST OF THE FORECAST AREA ON SATURDAY NIGHT.
MOST SIGNIFICANT CHANGE IN THE GUIDANCE IS WITH THE AMOUNT OF
MOISTURE. 12Z GUIDANCE NOW KEEPS BULK OF THE DEEPER MOISTURE SOUTH
OF THE FORECAST AREA...ESPECIALLY THE 12Z NAM. WILL FOLLOW THIS
TREND AND LOWER PROBABILITY OF PRECIPITATION IN ALL BUT THE
SOUTHERN THIRD OF THE COUNTY WARNING AREA. WILL ALSO CUT BACK ON
AMOUNT OF PRECIPITATION.

SURFACE HIGH PRESSURE OVER THE UPPER MISSISSIPPI VALLEY WILL
GRADUALLY MOVE EAST AND WILL BE OVER THE OHIO VALLEY ON SATURDAY.
THE HIGH CONTINUES SLOW PROGRESS TO THE EAST SATURDAY NIGHT AND BY
LATE SUNDAY THE RIDGE AXIS WILL BE OFFSHORE. THIS WILL BEGIN TO
BRING SURFACE AND LOW LEVEL WINDS AROUND TO THE SOUTH LATE IN THE
DAY. SURFACE REFLECTION OF THE SHORT WAVE ON SATURDAY WILL BE AN
INVERTED TROF OVER THE SOUTHERN APPALACHIANS. EXPECT CLOUDS AND
PRECIPITATION WILL KEEP MAXIMUM TEMPERATURES ON SATURDAY COOLER
THAN GUIDANCE.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 230 PM EST THURSDAY...

A VERY ACTIVE WEATHER PATTERN EXPECTED DURING THE MEDIUM RANGE
WITH ENOUGH MODEL DIFFERENCES TO MAKE THE DETAILS OF THE SENSIBLE
WEATHER A GOOD CHALLENGE. AN AREA OF LOW PRESSURE SYSTEM WILL
DEVELOP ALONG THE GULF COAST SUNDAY NIGHT...PUSH MOISTURE
NORTHWARD AND INTRODUCING ANOTHER CHANCE OF RAIN...AND POTENTIALLY
FREEZING PRECIPITATION TO THE MOUNTAINS. UTILIZED THE TOPDOWN
APPROACH LEANING TOWARDS GFS FOR TEMPERATURE PROFILES. HELD LOW
TEMPERATURES A FEW DEGREES BELOW MOS WITH CLOUDS AND
PRECIPITATION. IN GENERAL...SUNDAY NIGHT LOWS WILL RANGE FROM THE
UPPER 20S IN THE MOUNTAINS TO THE LOWER 30S IN THE PIEDMONT.

FOR MONDAY...A WAVE OF LOW PRESSURE ALONG THE FRONTAL BOUNDARY
WILL BE LOCATED ALONG THE NORTH CAROLINA COAST WITH AXIS OF
MOISTURE/PRECIPITATION MOVING NORTH ASSOCIATED WITH INCREASING
WARM ADVECTION AHEAD OF THE DEVELOPING LONGWAVE TROUGH TO THE
WEST. HOW MUCH THE LOW CENTER DEEPENS...ITS ASSOCIATED
PRECIPITATION AND PTYPE REMAINS PROBLEMATIC FOR OUR REGION. EACH
MODEL HAS A DIFFERENT TAKE ON THE MAGNITUDE OF THE WARM NOSE OVER
OUR REGION. WILL MAINTAIN THE RAIN VERSUS FREEZING RAIN FORECAST
DURING MUCH OF MONDAY MORNING. THERMAL PROFILES SUGGEST SOME
POTENTIAL FOR LIGHT FREEZING RAIN OR SLEET ACROSS THE VIRGINIA
HIGHLANDS AND SOUTHERN SHENANDOAH VALLEY. FELT THAT THERE WAS
ENOUGH SUPPORT TO RAISE POPS FROM SLIGHT INTO THE CHANCE LEVEL
MONDAY. KEPT HIGHS MONDAY COOLER THAN GUIDANCE WITH READINGS FROM
THE MID 30S IN THE WEST TO THE MID 40S IN THE EAST.

BY MONDAY NIGHT...LOW PRESSURE MOVES INTO THE MIDWEST WITH
TRAILING FRONTAL BOUNDARY SOUTH INTO THE MISSISSIPPI VALLEY. A
DEEP LONGITUDINAL TROUGH DEVELOPS SOUTH TO THE GULF OF MEXICO BY
TUESDAY AFTERNOON WITH INCREASING SOUTHERLY LOW LEVEL FLOW ACROSS
OUR REGION...ACCOMPANIED BY INCREASING MOISTURE ADVECTION. USING
SUPERBLEND FOR LOW TEMPERATURES MONDAY NIGHT PRODUCED READINGS
GENERALLY IN THE UPPER 20S AND LOWER 30S. TEMPERATURES WILL TREND
MILDER FOR HIGHS TUESDAY FROM THE MID 40S TO THE LOWER 50S.

BY TUESDAY NIGHT INTO WEDNESDAY...BOTH GFS AND ECWMF DEEPEN THE
UPPER LOW AND ASSOCIATED TROUGH AND NEGATIVELY TILT THE FEATURE SO
THAT THE TROUGH AXIS SHIFTS TO OFF THE NORTH CAROLINA
COAST...COINCIDENT TO THE POSITION OF THE ASSOCIATED SURFACE
OCCLUDED FRONT...WITH THE TRIPLE POINT PASSING SOMEWHERE NEAR OR
JUST SOUTH OF OUR REGION. AT THIS TIME...SPC DOES NOT HAVE ANY
THUNDERSTORMS IN ITS DAY 4-8 CONVECTIVE OUTLOOK. IT LOOKS
LIKE...THERE IS THE POTENTIAL FOR OUR REGION TO HAVE ACTIVE
WEATHER LATE TUESDAY NIGHT INTO WEDNESDAY WITH PLENTY OF
SHOWERS...PERHAPS VERY GUSTY WINDS AND A FEW THUNDERSTORMS.

COLD AIR PUSHES INTO THE REGION TUESDAY NIGHT INTO WEDNESDAY
MORNING...ALLOWING FOR SOME RAIN AND SNOW SHOWERS. IF ENOUGH COLD
AIR ARRIVES QUICKLY...THERE COULD BE SOME ACCUMULATING SNOW IN THE
WESTERN MOUNTAINS. KEPT THE HIGHEST POPS OF RAIN AND SNOW SHOWERS
IN THE WEST AS THE LOW CENTER MARCHES NORTHEAST PUSHES A COLD
FRONT TO THE COAST. IN THE WAKE OF THE COLD FRONT A COOLING TRENDS
WILL CONTINUE WEDNESDAY INTO THURSDAY...WITH WEST TO NORTHWEST
FLOW ALOFT. UPPER FLOW SHIFTS TO THE SOUTHWEST AS TROF CURVES OUT
IN THE CENTRAL US WITH SFC INFLECTION OF LOW PRESSURE DEVELOPS
OVER THE TENNESSEE VALLEY BY FRIDAY MORNING.

&&

.AVIATION /04Z FRIDAY THROUGH TUESDAY/...
AS OF 1045 PM EST THURSDAY...

NOT MUCH CHANGE TO THE AVIATION FORECAST...THOUGH CONFIDENCE IS
LESS THAT BLF WILL DROP BELOW 1KFT PER UPSTREAM OBS. STILL WILL
HAVE A TEMPO GROUP TOWARD 12Z FOR BLF DROPPING TO 9H FEET FOR A
COUPLE HOURS.

OTHERWISE BECOMING MVFR AT BLF/LWB OVERNIGHT THEN BACK TO VFR BY
MIDDAY FRIDAY...WHILE REST OF THE TAF SITES STAY VFR. COULD SEE
SOME SCT SUB 3KFT CLOUDS ACROSS BCB BUT CONFIDENCE HIGH THAT
THREAT OF BKN IS NOT GOING TO HAPPEN.

CLOUDS AHEAD OF THE NEXT SYSTEM WILL BE INCREASING OVERNIGHT
FRIDAY SO EXPECT MAINLY CIRROSTRATUS IN THE LATE EVENING ACROSS
THE REGION.



EXTENDED DISCUSSION...

THE SAT SYSTEM NOW HAS TRENDED WEAKER AND WILL SHIFT MOST OF THE
PRECIP ACROSS THE CAROLINAS...THOUGH STILL WILL SEE SOME WINTRY
MIX BUMP UP INTO THE SE WV/SW VA CORRIDOR INTO THE NC
MTNS...THOUGH TRENDS ARE SHOWING LESS. EXPECT SUB VFR THOUGH AT
TIMES SATURDAY INTO SAT NIGHT.

ON THE HEELS OF THIS  SYSTEM WILL BE ANOTHER SYSTEM TO
POTENTIALLY IMPACT MAINLY THE EASTERN PORTION OF THE REGION SUNDAY
NIGHT INTO MONDAY...WITH YET ANOTHER SYSTEM SLATED FOR LATE
TUESDAY INTO WEDNESDAY. THESE SYSTEMS ARE EXPECTED TO BRING A
PERIOD MAINLY RAIN BUT COULD BE SOME WINTRY WX AS WELL ESPECIALLY
IN THE MOUNTAINS. EXPECT POTENTIAL LOW LEVEL WIND SHEAR AS WELL
AND POOR FLYING WEATHER MONDAY.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...RCS
NEAR TERM...RCS/WP
SHORT TERM...AMS
LONG TERM...KK
AVIATION...JH/RCS/WP





000
FXUS61 KRNK 190400
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
1100 PM EST THU DEC 18 2014

.SYNOPSIS...
HIGH PRESSURE OVER THE UPPER MIDWEST WILL GRADUALLY BUILD EAST
ACROSS THE AREA RESULTING IN OVERALL DRY WEATHER THROUGH FRIDAY
EVENING. A WEAK AREA OF LOW PRESSURE WILL EVENTUALLY DEVELOP ALONG
THE GULF COAST STATES FRIDAY NIGHT AND MOVE EAST-NORTHEAST OVER
THE CAROLINAS ON SATURDAY. THIS SYSTEM WILL BRING A PERIOD OF
LIGHT WINTRY PRECIPITATION SATURDAY MORNING...CHANGING TO RAIN
OVER THE PIEDMONT IN THE AFTERNOON.

&&

.NEAR TERM /THROUGH FRIDAY/...
AS OF 1035 PM EST THURSDAY...

UPDATED FORECAST TO LOWER THREAT OF PRECIP IN THE NW. STILL COULD
SEE SOME FLURRIES ACROSS THE MTNS OF WRN GREENBRIER TOWARD DAWN.
OTHERWISE...LOOKING AT SKIES TURNING LESS CLOUDY OUT EAST AS ONE
SHORTWAVE EXITS EAST.

ADJUSTED TEMPS ESPECIALLY IN THE FOOTHILLS AND ROANOKE AS THEY ARE
RUNNING MILDER...BUT AS SKIES CLEAR AND WINDS FADE TEMPS WILL
STILL FALL INTO THE LOWER 30S. STILL LOOKING AT MID TO UPPER 20S
WEST.


PREVIOUS VALID DISCUSSION...

WAVE ALOFT PASSES EAST OVERNIGHT LEAVING WEAK SUBSIDENCE IN PLACE
AS HIGH PRESSURE TO THE NW NOSES BACK IN LATE.


FRIDAY LOOKS TO BE ON THE DRY SIDE AS HIGH PRESSURE STRETCHING
FROM THE GREAT LAKES THROUGH THE OHIO RIVER VALLEY REMAINS THE
MAIN FEATURE IN OUR WEATHER PATTERN. MOSTLY SUNNY SKIES AND LIGHT
NORTHWESTERLY DOWNSLOPE WINDS WILL ALLOW AFTERNOON TEMPERATURES TO
RANGE FROM THE MID 30S ALONG THE WESTERN RIDGES...TO AROUND 50
OVER THE SOUTHSIDE AND THE NORTH CAROLINA PIEDMONT.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
AS OF 250 PM EST THURSDAY...

MODELS HAVE BEEN TRENDING QUITE A BIT WEAKER WITH THE SHORT WAVE
COMING OUT OF ARIZONA AND REACHING THE MID ATLANTIC REGION ON
SATURDAY. ISENTROPIC LIFT AND VORTICITY ADVECTION COME THROUGH ON
SATURDAY AND WILL BE EAST OF THE FORECAST AREA ON SATURDAY NIGHT.
MOST SIGNIFICANT CHANGE IN THE GUIDANCE IS WITH THE AMOUNT OF
MOISTURE. 12Z GUIDANCE NOW KEEPS BULK OF THE DEEPER MOISTURE SOUTH
OF THE FORECAST AREA...ESPECIALLY THE 12Z NAM. WILL FOLLOW THIS
TREND AND LOWER PROBABILITY OF PRECIPITATION IN ALL BUT THE
SOUTHERN THIRD OF THE COUNTY WARNING AREA. WILL ALSO CUT BACK ON
AMOUNT OF PRECIPITATION.

SURFACE HIGH PRESSURE OVER THE UPPER MISSISSIPPI VALLEY WILL
GRADUALLY MOVE EAST AND WILL BE OVER THE OHIO VALLEY ON SATURDAY.
THE HIGH CONTINUES SLOW PROGRESS TO THE EAST SATURDAY NIGHT AND BY
LATE SUNDAY THE RIDGE AXIS WILL BE OFFSHORE. THIS WILL BEGIN TO
BRING SURFACE AND LOW LEVEL WINDS AROUND TO THE SOUTH LATE IN THE
DAY. SURFACE REFLECTION OF THE SHORT WAVE ON SATURDAY WILL BE AN
INVERTED TROF OVER THE SOUTHERN APPALACHIANS. EXPECT CLOUDS AND
PRECIPITATION WILL KEEP MAXIMUM TEMPERATURES ON SATURDAY COOLER
THAN GUIDANCE.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 230 PM EST THURSDAY...

A VERY ACTIVE WEATHER PATTERN EXPECTED DURING THE MEDIUM RANGE
WITH ENOUGH MODEL DIFFERENCES TO MAKE THE DETAILS OF THE SENSIBLE
WEATHER A GOOD CHALLENGE. AN AREA OF LOW PRESSURE SYSTEM WILL
DEVELOP ALONG THE GULF COAST SUNDAY NIGHT...PUSH MOISTURE
NORTHWARD AND INTRODUCING ANOTHER CHANCE OF RAIN...AND POTENTIALLY
FREEZING PRECIPITATION TO THE MOUNTAINS. UTILIZED THE TOPDOWN
APPROACH LEANING TOWARDS GFS FOR TEMPERATURE PROFILES. HELD LOW
TEMPERATURES A FEW DEGREES BELOW MOS WITH CLOUDS AND
PRECIPITATION. IN GENERAL...SUNDAY NIGHT LOWS WILL RANGE FROM THE
UPPER 20S IN THE MOUNTAINS TO THE LOWER 30S IN THE PIEDMONT.

FOR MONDAY...A WAVE OF LOW PRESSURE ALONG THE FRONTAL BOUNDARY
WILL BE LOCATED ALONG THE NORTH CAROLINA COAST WITH AXIS OF
MOISTURE/PRECIPITATION MOVING NORTH ASSOCIATED WITH INCREASING
WARM ADVECTION AHEAD OF THE DEVELOPING LONGWAVE TROUGH TO THE
WEST. HOW MUCH THE LOW CENTER DEEPENS...ITS ASSOCIATED
PRECIPITATION AND PTYPE REMAINS PROBLEMATIC FOR OUR REGION. EACH
MODEL HAS A DIFFERENT TAKE ON THE MAGNITUDE OF THE WARM NOSE OVER
OUR REGION. WILL MAINTAIN THE RAIN VERSUS FREEZING RAIN FORECAST
DURING MUCH OF MONDAY MORNING. THERMAL PROFILES SUGGEST SOME
POTENTIAL FOR LIGHT FREEZING RAIN OR SLEET ACROSS THE VIRGINIA
HIGHLANDS AND SOUTHERN SHENANDOAH VALLEY. FELT THAT THERE WAS
ENOUGH SUPPORT TO RAISE POPS FROM SLIGHT INTO THE CHANCE LEVEL
MONDAY. KEPT HIGHS MONDAY COOLER THAN GUIDANCE WITH READINGS FROM
THE MID 30S IN THE WEST TO THE MID 40S IN THE EAST.

BY MONDAY NIGHT...LOW PRESSURE MOVES INTO THE MIDWEST WITH
TRAILING FRONTAL BOUNDARY SOUTH INTO THE MISSISSIPPI VALLEY. A
DEEP LONGITUDINAL TROUGH DEVELOPS SOUTH TO THE GULF OF MEXICO BY
TUESDAY AFTERNOON WITH INCREASING SOUTHERLY LOW LEVEL FLOW ACROSS
OUR REGION...ACCOMPANIED BY INCREASING MOISTURE ADVECTION. USING
SUPERBLEND FOR LOW TEMPERATURES MONDAY NIGHT PRODUCED READINGS
GENERALLY IN THE UPPER 20S AND LOWER 30S. TEMPERATURES WILL TREND
MILDER FOR HIGHS TUESDAY FROM THE MID 40S TO THE LOWER 50S.

BY TUESDAY NIGHT INTO WEDNESDAY...BOTH GFS AND ECWMF DEEPEN THE
UPPER LOW AND ASSOCIATED TROUGH AND NEGATIVELY TILT THE FEATURE SO
THAT THE TROUGH AXIS SHIFTS TO OFF THE NORTH CAROLINA
COAST...COINCIDENT TO THE POSITION OF THE ASSOCIATED SURFACE
OCCLUDED FRONT...WITH THE TRIPLE POINT PASSING SOMEWHERE NEAR OR
JUST SOUTH OF OUR REGION. AT THIS TIME...SPC DOES NOT HAVE ANY
THUNDERSTORMS IN ITS DAY 4-8 CONVECTIVE OUTLOOK. IT LOOKS
LIKE...THERE IS THE POTENTIAL FOR OUR REGION TO HAVE ACTIVE
WEATHER LATE TUESDAY NIGHT INTO WEDNESDAY WITH PLENTY OF
SHOWERS...PERHAPS VERY GUSTY WINDS AND A FEW THUNDERSTORMS.

COLD AIR PUSHES INTO THE REGION TUESDAY NIGHT INTO WEDNESDAY
MORNING...ALLOWING FOR SOME RAIN AND SNOW SHOWERS. IF ENOUGH COLD
AIR ARRIVES QUICKLY...THERE COULD BE SOME ACCUMULATING SNOW IN THE
WESTERN MOUNTAINS. KEPT THE HIGHEST POPS OF RAIN AND SNOW SHOWERS
IN THE WEST AS THE LOW CENTER MARCHES NORTHEAST PUSHES A COLD
FRONT TO THE COAST. IN THE WAKE OF THE COLD FRONT A COOLING TRENDS
WILL CONTINUE WEDNESDAY INTO THURSDAY...WITH WEST TO NORTHWEST
FLOW ALOFT. UPPER FLOW SHIFTS TO THE SOUTHWEST AS TROF CURVES OUT
IN THE CENTRAL US WITH SFC INFLECTION OF LOW PRESSURE DEVELOPS
OVER THE TENNESSEE VALLEY BY FRIDAY MORNING.

&&

.AVIATION /04Z FRIDAY THROUGH TUESDAY/...
AS OF 1045 PM EST THURSDAY...

NOT MUCH CHANGE TO THE AVIATION FORECAST...THOUGH CONFIDENCE IS
LESS THAT BLF WILL DROP BELOW 1KFT PER UPSTREAM OBS. STILL WILL
HAVE A TEMPO GROUP TOWARD 12Z FOR BLF DROPPING TO 9H FEET FOR A
COUPLE HOURS.

OTHERWISE BECOMING MVFR AT BLF/LWB OVERNIGHT THEN BACK TO VFR BY
MIDDAY FRIDAY...WHILE REST OF THE TAF SITES STAY VFR. COULD SEE
SOME SCT SUB 3KFT CLOUDS ACROSS BCB BUT CONFIDENCE HIGH THAT
THREAT OF BKN IS NOT GOING TO HAPPEN.

CLOUDS AHEAD OF THE NEXT SYSTEM WILL BE INCREASING OVERNIGHT
FRIDAY SO EXPECT MAINLY CIRROSTRATUS IN THE LATE EVENING ACROSS
THE REGION.



EXTENDED DISCUSSION...

THE SAT SYSTEM NOW HAS TRENDED WEAKER AND WILL SHIFT MOST OF THE
PRECIP ACROSS THE CAROLINAS...THOUGH STILL WILL SEE SOME WINTRY
MIX BUMP UP INTO THE SE WV/SW VA CORRIDOR INTO THE NC
MTNS...THOUGH TRENDS ARE SHOWING LESS. EXPECT SUB VFR THOUGH AT
TIMES SATURDAY INTO SAT NIGHT.

ON THE HEELS OF THIS  SYSTEM WILL BE ANOTHER SYSTEM TO
POTENTIALLY IMPACT MAINLY THE EASTERN PORTION OF THE REGION SUNDAY
NIGHT INTO MONDAY...WITH YET ANOTHER SYSTEM SLATED FOR LATE
TUESDAY INTO WEDNESDAY. THESE SYSTEMS ARE EXPECTED TO BRING A
PERIOD MAINLY RAIN BUT COULD BE SOME WINTRY WX AS WELL ESPECIALLY
IN THE MOUNTAINS. EXPECT POTENTIAL LOW LEVEL WIND SHEAR AS WELL
AND POOR FLYING WEATHER MONDAY.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...RCS
NEAR TERM...RCS/WP
SHORT TERM...AMS
LONG TERM...KK
AVIATION...JH/RCS/WP




000
FXUS61 KRNK 190400
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
1100 PM EST THU DEC 18 2014

.SYNOPSIS...
HIGH PRESSURE OVER THE UPPER MIDWEST WILL GRADUALLY BUILD EAST
ACROSS THE AREA RESULTING IN OVERALL DRY WEATHER THROUGH FRIDAY
EVENING. A WEAK AREA OF LOW PRESSURE WILL EVENTUALLY DEVELOP ALONG
THE GULF COAST STATES FRIDAY NIGHT AND MOVE EAST-NORTHEAST OVER
THE CAROLINAS ON SATURDAY. THIS SYSTEM WILL BRING A PERIOD OF
LIGHT WINTRY PRECIPITATION SATURDAY MORNING...CHANGING TO RAIN
OVER THE PIEDMONT IN THE AFTERNOON.

&&

.NEAR TERM /THROUGH FRIDAY/...
AS OF 1035 PM EST THURSDAY...

UPDATED FORECAST TO LOWER THREAT OF PRECIP IN THE NW. STILL COULD
SEE SOME FLURRIES ACROSS THE MTNS OF WRN GREENBRIER TOWARD DAWN.
OTHERWISE...LOOKING AT SKIES TURNING LESS CLOUDY OUT EAST AS ONE
SHORTWAVE EXITS EAST.

ADJUSTED TEMPS ESPECIALLY IN THE FOOTHILLS AND ROANOKE AS THEY ARE
RUNNING MILDER...BUT AS SKIES CLEAR AND WINDS FADE TEMPS WILL
STILL FALL INTO THE LOWER 30S. STILL LOOKING AT MID TO UPPER 20S
WEST.


PREVIOUS VALID DISCUSSION...

WAVE ALOFT PASSES EAST OVERNIGHT LEAVING WEAK SUBSIDENCE IN PLACE
AS HIGH PRESSURE TO THE NW NOSES BACK IN LATE.


FRIDAY LOOKS TO BE ON THE DRY SIDE AS HIGH PRESSURE STRETCHING
FROM THE GREAT LAKES THROUGH THE OHIO RIVER VALLEY REMAINS THE
MAIN FEATURE IN OUR WEATHER PATTERN. MOSTLY SUNNY SKIES AND LIGHT
NORTHWESTERLY DOWNSLOPE WINDS WILL ALLOW AFTERNOON TEMPERATURES TO
RANGE FROM THE MID 30S ALONG THE WESTERN RIDGES...TO AROUND 50
OVER THE SOUTHSIDE AND THE NORTH CAROLINA PIEDMONT.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
AS OF 250 PM EST THURSDAY...

MODELS HAVE BEEN TRENDING QUITE A BIT WEAKER WITH THE SHORT WAVE
COMING OUT OF ARIZONA AND REACHING THE MID ATLANTIC REGION ON
SATURDAY. ISENTROPIC LIFT AND VORTICITY ADVECTION COME THROUGH ON
SATURDAY AND WILL BE EAST OF THE FORECAST AREA ON SATURDAY NIGHT.
MOST SIGNIFICANT CHANGE IN THE GUIDANCE IS WITH THE AMOUNT OF
MOISTURE. 12Z GUIDANCE NOW KEEPS BULK OF THE DEEPER MOISTURE SOUTH
OF THE FORECAST AREA...ESPECIALLY THE 12Z NAM. WILL FOLLOW THIS
TREND AND LOWER PROBABILITY OF PRECIPITATION IN ALL BUT THE
SOUTHERN THIRD OF THE COUNTY WARNING AREA. WILL ALSO CUT BACK ON
AMOUNT OF PRECIPITATION.

SURFACE HIGH PRESSURE OVER THE UPPER MISSISSIPPI VALLEY WILL
GRADUALLY MOVE EAST AND WILL BE OVER THE OHIO VALLEY ON SATURDAY.
THE HIGH CONTINUES SLOW PROGRESS TO THE EAST SATURDAY NIGHT AND BY
LATE SUNDAY THE RIDGE AXIS WILL BE OFFSHORE. THIS WILL BEGIN TO
BRING SURFACE AND LOW LEVEL WINDS AROUND TO THE SOUTH LATE IN THE
DAY. SURFACE REFLECTION OF THE SHORT WAVE ON SATURDAY WILL BE AN
INVERTED TROF OVER THE SOUTHERN APPALACHIANS. EXPECT CLOUDS AND
PRECIPITATION WILL KEEP MAXIMUM TEMPERATURES ON SATURDAY COOLER
THAN GUIDANCE.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 230 PM EST THURSDAY...

A VERY ACTIVE WEATHER PATTERN EXPECTED DURING THE MEDIUM RANGE
WITH ENOUGH MODEL DIFFERENCES TO MAKE THE DETAILS OF THE SENSIBLE
WEATHER A GOOD CHALLENGE. AN AREA OF LOW PRESSURE SYSTEM WILL
DEVELOP ALONG THE GULF COAST SUNDAY NIGHT...PUSH MOISTURE
NORTHWARD AND INTRODUCING ANOTHER CHANCE OF RAIN...AND POTENTIALLY
FREEZING PRECIPITATION TO THE MOUNTAINS. UTILIZED THE TOPDOWN
APPROACH LEANING TOWARDS GFS FOR TEMPERATURE PROFILES. HELD LOW
TEMPERATURES A FEW DEGREES BELOW MOS WITH CLOUDS AND
PRECIPITATION. IN GENERAL...SUNDAY NIGHT LOWS WILL RANGE FROM THE
UPPER 20S IN THE MOUNTAINS TO THE LOWER 30S IN THE PIEDMONT.

FOR MONDAY...A WAVE OF LOW PRESSURE ALONG THE FRONTAL BOUNDARY
WILL BE LOCATED ALONG THE NORTH CAROLINA COAST WITH AXIS OF
MOISTURE/PRECIPITATION MOVING NORTH ASSOCIATED WITH INCREASING
WARM ADVECTION AHEAD OF THE DEVELOPING LONGWAVE TROUGH TO THE
WEST. HOW MUCH THE LOW CENTER DEEPENS...ITS ASSOCIATED
PRECIPITATION AND PTYPE REMAINS PROBLEMATIC FOR OUR REGION. EACH
MODEL HAS A DIFFERENT TAKE ON THE MAGNITUDE OF THE WARM NOSE OVER
OUR REGION. WILL MAINTAIN THE RAIN VERSUS FREEZING RAIN FORECAST
DURING MUCH OF MONDAY MORNING. THERMAL PROFILES SUGGEST SOME
POTENTIAL FOR LIGHT FREEZING RAIN OR SLEET ACROSS THE VIRGINIA
HIGHLANDS AND SOUTHERN SHENANDOAH VALLEY. FELT THAT THERE WAS
ENOUGH SUPPORT TO RAISE POPS FROM SLIGHT INTO THE CHANCE LEVEL
MONDAY. KEPT HIGHS MONDAY COOLER THAN GUIDANCE WITH READINGS FROM
THE MID 30S IN THE WEST TO THE MID 40S IN THE EAST.

BY MONDAY NIGHT...LOW PRESSURE MOVES INTO THE MIDWEST WITH
TRAILING FRONTAL BOUNDARY SOUTH INTO THE MISSISSIPPI VALLEY. A
DEEP LONGITUDINAL TROUGH DEVELOPS SOUTH TO THE GULF OF MEXICO BY
TUESDAY AFTERNOON WITH INCREASING SOUTHERLY LOW LEVEL FLOW ACROSS
OUR REGION...ACCOMPANIED BY INCREASING MOISTURE ADVECTION. USING
SUPERBLEND FOR LOW TEMPERATURES MONDAY NIGHT PRODUCED READINGS
GENERALLY IN THE UPPER 20S AND LOWER 30S. TEMPERATURES WILL TREND
MILDER FOR HIGHS TUESDAY FROM THE MID 40S TO THE LOWER 50S.

BY TUESDAY NIGHT INTO WEDNESDAY...BOTH GFS AND ECWMF DEEPEN THE
UPPER LOW AND ASSOCIATED TROUGH AND NEGATIVELY TILT THE FEATURE SO
THAT THE TROUGH AXIS SHIFTS TO OFF THE NORTH CAROLINA
COAST...COINCIDENT TO THE POSITION OF THE ASSOCIATED SURFACE
OCCLUDED FRONT...WITH THE TRIPLE POINT PASSING SOMEWHERE NEAR OR
JUST SOUTH OF OUR REGION. AT THIS TIME...SPC DOES NOT HAVE ANY
THUNDERSTORMS IN ITS DAY 4-8 CONVECTIVE OUTLOOK. IT LOOKS
LIKE...THERE IS THE POTENTIAL FOR OUR REGION TO HAVE ACTIVE
WEATHER LATE TUESDAY NIGHT INTO WEDNESDAY WITH PLENTY OF
SHOWERS...PERHAPS VERY GUSTY WINDS AND A FEW THUNDERSTORMS.

COLD AIR PUSHES INTO THE REGION TUESDAY NIGHT INTO WEDNESDAY
MORNING...ALLOWING FOR SOME RAIN AND SNOW SHOWERS. IF ENOUGH COLD
AIR ARRIVES QUICKLY...THERE COULD BE SOME ACCUMULATING SNOW IN THE
WESTERN MOUNTAINS. KEPT THE HIGHEST POPS OF RAIN AND SNOW SHOWERS
IN THE WEST AS THE LOW CENTER MARCHES NORTHEAST PUSHES A COLD
FRONT TO THE COAST. IN THE WAKE OF THE COLD FRONT A COOLING TRENDS
WILL CONTINUE WEDNESDAY INTO THURSDAY...WITH WEST TO NORTHWEST
FLOW ALOFT. UPPER FLOW SHIFTS TO THE SOUTHWEST AS TROF CURVES OUT
IN THE CENTRAL US WITH SFC INFLECTION OF LOW PRESSURE DEVELOPS
OVER THE TENNESSEE VALLEY BY FRIDAY MORNING.

&&

.AVIATION /04Z FRIDAY THROUGH TUESDAY/...
AS OF 1045 PM EST THURSDAY...

NOT MUCH CHANGE TO THE AVIATION FORECAST...THOUGH CONFIDENCE IS
LESS THAT BLF WILL DROP BELOW 1KFT PER UPSTREAM OBS. STILL WILL
HAVE A TEMPO GROUP TOWARD 12Z FOR BLF DROPPING TO 9H FEET FOR A
COUPLE HOURS.

OTHERWISE BECOMING MVFR AT BLF/LWB OVERNIGHT THEN BACK TO VFR BY
MIDDAY FRIDAY...WHILE REST OF THE TAF SITES STAY VFR. COULD SEE
SOME SCT SUB 3KFT CLOUDS ACROSS BCB BUT CONFIDENCE HIGH THAT
THREAT OF BKN IS NOT GOING TO HAPPEN.

CLOUDS AHEAD OF THE NEXT SYSTEM WILL BE INCREASING OVERNIGHT
FRIDAY SO EXPECT MAINLY CIRROSTRATUS IN THE LATE EVENING ACROSS
THE REGION.



EXTENDED DISCUSSION...

THE SAT SYSTEM NOW HAS TRENDED WEAKER AND WILL SHIFT MOST OF THE
PRECIP ACROSS THE CAROLINAS...THOUGH STILL WILL SEE SOME WINTRY
MIX BUMP UP INTO THE SE WV/SW VA CORRIDOR INTO THE NC
MTNS...THOUGH TRENDS ARE SHOWING LESS. EXPECT SUB VFR THOUGH AT
TIMES SATURDAY INTO SAT NIGHT.

ON THE HEELS OF THIS  SYSTEM WILL BE ANOTHER SYSTEM TO
POTENTIALLY IMPACT MAINLY THE EASTERN PORTION OF THE REGION SUNDAY
NIGHT INTO MONDAY...WITH YET ANOTHER SYSTEM SLATED FOR LATE
TUESDAY INTO WEDNESDAY. THESE SYSTEMS ARE EXPECTED TO BRING A
PERIOD MAINLY RAIN BUT COULD BE SOME WINTRY WX AS WELL ESPECIALLY
IN THE MOUNTAINS. EXPECT POTENTIAL LOW LEVEL WIND SHEAR AS WELL
AND POOR FLYING WEATHER MONDAY.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...RCS
NEAR TERM...RCS/WP
SHORT TERM...AMS
LONG TERM...KK
AVIATION...JH/RCS/WP





000
FXUS61 KRNK 190400
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
1100 PM EST THU DEC 18 2014

.SYNOPSIS...
HIGH PRESSURE OVER THE UPPER MIDWEST WILL GRADUALLY BUILD EAST
ACROSS THE AREA RESULTING IN OVERALL DRY WEATHER THROUGH FRIDAY
EVENING. A WEAK AREA OF LOW PRESSURE WILL EVENTUALLY DEVELOP ALONG
THE GULF COAST STATES FRIDAY NIGHT AND MOVE EAST-NORTHEAST OVER
THE CAROLINAS ON SATURDAY. THIS SYSTEM WILL BRING A PERIOD OF
LIGHT WINTRY PRECIPITATION SATURDAY MORNING...CHANGING TO RAIN
OVER THE PIEDMONT IN THE AFTERNOON.

&&

.NEAR TERM /THROUGH FRIDAY/...
AS OF 1035 PM EST THURSDAY...

UPDATED FORECAST TO LOWER THREAT OF PRECIP IN THE NW. STILL COULD
SEE SOME FLURRIES ACROSS THE MTNS OF WRN GREENBRIER TOWARD DAWN.
OTHERWISE...LOOKING AT SKIES TURNING LESS CLOUDY OUT EAST AS ONE
SHORTWAVE EXITS EAST.

ADJUSTED TEMPS ESPECIALLY IN THE FOOTHILLS AND ROANOKE AS THEY ARE
RUNNING MILDER...BUT AS SKIES CLEAR AND WINDS FADE TEMPS WILL
STILL FALL INTO THE LOWER 30S. STILL LOOKING AT MID TO UPPER 20S
WEST.


PREVIOUS VALID DISCUSSION...

WAVE ALOFT PASSES EAST OVERNIGHT LEAVING WEAK SUBSIDENCE IN PLACE
AS HIGH PRESSURE TO THE NW NOSES BACK IN LATE.


FRIDAY LOOKS TO BE ON THE DRY SIDE AS HIGH PRESSURE STRETCHING
FROM THE GREAT LAKES THROUGH THE OHIO RIVER VALLEY REMAINS THE
MAIN FEATURE IN OUR WEATHER PATTERN. MOSTLY SUNNY SKIES AND LIGHT
NORTHWESTERLY DOWNSLOPE WINDS WILL ALLOW AFTERNOON TEMPERATURES TO
RANGE FROM THE MID 30S ALONG THE WESTERN RIDGES...TO AROUND 50
OVER THE SOUTHSIDE AND THE NORTH CAROLINA PIEDMONT.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
AS OF 250 PM EST THURSDAY...

MODELS HAVE BEEN TRENDING QUITE A BIT WEAKER WITH THE SHORT WAVE
COMING OUT OF ARIZONA AND REACHING THE MID ATLANTIC REGION ON
SATURDAY. ISENTROPIC LIFT AND VORTICITY ADVECTION COME THROUGH ON
SATURDAY AND WILL BE EAST OF THE FORECAST AREA ON SATURDAY NIGHT.
MOST SIGNIFICANT CHANGE IN THE GUIDANCE IS WITH THE AMOUNT OF
MOISTURE. 12Z GUIDANCE NOW KEEPS BULK OF THE DEEPER MOISTURE SOUTH
OF THE FORECAST AREA...ESPECIALLY THE 12Z NAM. WILL FOLLOW THIS
TREND AND LOWER PROBABILITY OF PRECIPITATION IN ALL BUT THE
SOUTHERN THIRD OF THE COUNTY WARNING AREA. WILL ALSO CUT BACK ON
AMOUNT OF PRECIPITATION.

SURFACE HIGH PRESSURE OVER THE UPPER MISSISSIPPI VALLEY WILL
GRADUALLY MOVE EAST AND WILL BE OVER THE OHIO VALLEY ON SATURDAY.
THE HIGH CONTINUES SLOW PROGRESS TO THE EAST SATURDAY NIGHT AND BY
LATE SUNDAY THE RIDGE AXIS WILL BE OFFSHORE. THIS WILL BEGIN TO
BRING SURFACE AND LOW LEVEL WINDS AROUND TO THE SOUTH LATE IN THE
DAY. SURFACE REFLECTION OF THE SHORT WAVE ON SATURDAY WILL BE AN
INVERTED TROF OVER THE SOUTHERN APPALACHIANS. EXPECT CLOUDS AND
PRECIPITATION WILL KEEP MAXIMUM TEMPERATURES ON SATURDAY COOLER
THAN GUIDANCE.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 230 PM EST THURSDAY...

A VERY ACTIVE WEATHER PATTERN EXPECTED DURING THE MEDIUM RANGE
WITH ENOUGH MODEL DIFFERENCES TO MAKE THE DETAILS OF THE SENSIBLE
WEATHER A GOOD CHALLENGE. AN AREA OF LOW PRESSURE SYSTEM WILL
DEVELOP ALONG THE GULF COAST SUNDAY NIGHT...PUSH MOISTURE
NORTHWARD AND INTRODUCING ANOTHER CHANCE OF RAIN...AND POTENTIALLY
FREEZING PRECIPITATION TO THE MOUNTAINS. UTILIZED THE TOPDOWN
APPROACH LEANING TOWARDS GFS FOR TEMPERATURE PROFILES. HELD LOW
TEMPERATURES A FEW DEGREES BELOW MOS WITH CLOUDS AND
PRECIPITATION. IN GENERAL...SUNDAY NIGHT LOWS WILL RANGE FROM THE
UPPER 20S IN THE MOUNTAINS TO THE LOWER 30S IN THE PIEDMONT.

FOR MONDAY...A WAVE OF LOW PRESSURE ALONG THE FRONTAL BOUNDARY
WILL BE LOCATED ALONG THE NORTH CAROLINA COAST WITH AXIS OF
MOISTURE/PRECIPITATION MOVING NORTH ASSOCIATED WITH INCREASING
WARM ADVECTION AHEAD OF THE DEVELOPING LONGWAVE TROUGH TO THE
WEST. HOW MUCH THE LOW CENTER DEEPENS...ITS ASSOCIATED
PRECIPITATION AND PTYPE REMAINS PROBLEMATIC FOR OUR REGION. EACH
MODEL HAS A DIFFERENT TAKE ON THE MAGNITUDE OF THE WARM NOSE OVER
OUR REGION. WILL MAINTAIN THE RAIN VERSUS FREEZING RAIN FORECAST
DURING MUCH OF MONDAY MORNING. THERMAL PROFILES SUGGEST SOME
POTENTIAL FOR LIGHT FREEZING RAIN OR SLEET ACROSS THE VIRGINIA
HIGHLANDS AND SOUTHERN SHENANDOAH VALLEY. FELT THAT THERE WAS
ENOUGH SUPPORT TO RAISE POPS FROM SLIGHT INTO THE CHANCE LEVEL
MONDAY. KEPT HIGHS MONDAY COOLER THAN GUIDANCE WITH READINGS FROM
THE MID 30S IN THE WEST TO THE MID 40S IN THE EAST.

BY MONDAY NIGHT...LOW PRESSURE MOVES INTO THE MIDWEST WITH
TRAILING FRONTAL BOUNDARY SOUTH INTO THE MISSISSIPPI VALLEY. A
DEEP LONGITUDINAL TROUGH DEVELOPS SOUTH TO THE GULF OF MEXICO BY
TUESDAY AFTERNOON WITH INCREASING SOUTHERLY LOW LEVEL FLOW ACROSS
OUR REGION...ACCOMPANIED BY INCREASING MOISTURE ADVECTION. USING
SUPERBLEND FOR LOW TEMPERATURES MONDAY NIGHT PRODUCED READINGS
GENERALLY IN THE UPPER 20S AND LOWER 30S. TEMPERATURES WILL TREND
MILDER FOR HIGHS TUESDAY FROM THE MID 40S TO THE LOWER 50S.

BY TUESDAY NIGHT INTO WEDNESDAY...BOTH GFS AND ECWMF DEEPEN THE
UPPER LOW AND ASSOCIATED TROUGH AND NEGATIVELY TILT THE FEATURE SO
THAT THE TROUGH AXIS SHIFTS TO OFF THE NORTH CAROLINA
COAST...COINCIDENT TO THE POSITION OF THE ASSOCIATED SURFACE
OCCLUDED FRONT...WITH THE TRIPLE POINT PASSING SOMEWHERE NEAR OR
JUST SOUTH OF OUR REGION. AT THIS TIME...SPC DOES NOT HAVE ANY
THUNDERSTORMS IN ITS DAY 4-8 CONVECTIVE OUTLOOK. IT LOOKS
LIKE...THERE IS THE POTENTIAL FOR OUR REGION TO HAVE ACTIVE
WEATHER LATE TUESDAY NIGHT INTO WEDNESDAY WITH PLENTY OF
SHOWERS...PERHAPS VERY GUSTY WINDS AND A FEW THUNDERSTORMS.

COLD AIR PUSHES INTO THE REGION TUESDAY NIGHT INTO WEDNESDAY
MORNING...ALLOWING FOR SOME RAIN AND SNOW SHOWERS. IF ENOUGH COLD
AIR ARRIVES QUICKLY...THERE COULD BE SOME ACCUMULATING SNOW IN THE
WESTERN MOUNTAINS. KEPT THE HIGHEST POPS OF RAIN AND SNOW SHOWERS
IN THE WEST AS THE LOW CENTER MARCHES NORTHEAST PUSHES A COLD
FRONT TO THE COAST. IN THE WAKE OF THE COLD FRONT A COOLING TRENDS
WILL CONTINUE WEDNESDAY INTO THURSDAY...WITH WEST TO NORTHWEST
FLOW ALOFT. UPPER FLOW SHIFTS TO THE SOUTHWEST AS TROF CURVES OUT
IN THE CENTRAL US WITH SFC INFLECTION OF LOW PRESSURE DEVELOPS
OVER THE TENNESSEE VALLEY BY FRIDAY MORNING.

&&

.AVIATION /04Z FRIDAY THROUGH TUESDAY/...
AS OF 1045 PM EST THURSDAY...

NOT MUCH CHANGE TO THE AVIATION FORECAST...THOUGH CONFIDENCE IS
LESS THAT BLF WILL DROP BELOW 1KFT PER UPSTREAM OBS. STILL WILL
HAVE A TEMPO GROUP TOWARD 12Z FOR BLF DROPPING TO 9H FEET FOR A
COUPLE HOURS.

OTHERWISE BECOMING MVFR AT BLF/LWB OVERNIGHT THEN BACK TO VFR BY
MIDDAY FRIDAY...WHILE REST OF THE TAF SITES STAY VFR. COULD SEE
SOME SCT SUB 3KFT CLOUDS ACROSS BCB BUT CONFIDENCE HIGH THAT
THREAT OF BKN IS NOT GOING TO HAPPEN.

CLOUDS AHEAD OF THE NEXT SYSTEM WILL BE INCREASING OVERNIGHT
FRIDAY SO EXPECT MAINLY CIRROSTRATUS IN THE LATE EVENING ACROSS
THE REGION.



EXTENDED DISCUSSION...

THE SAT SYSTEM NOW HAS TRENDED WEAKER AND WILL SHIFT MOST OF THE
PRECIP ACROSS THE CAROLINAS...THOUGH STILL WILL SEE SOME WINTRY
MIX BUMP UP INTO THE SE WV/SW VA CORRIDOR INTO THE NC
MTNS...THOUGH TRENDS ARE SHOWING LESS. EXPECT SUB VFR THOUGH AT
TIMES SATURDAY INTO SAT NIGHT.

ON THE HEELS OF THIS  SYSTEM WILL BE ANOTHER SYSTEM TO
POTENTIALLY IMPACT MAINLY THE EASTERN PORTION OF THE REGION SUNDAY
NIGHT INTO MONDAY...WITH YET ANOTHER SYSTEM SLATED FOR LATE
TUESDAY INTO WEDNESDAY. THESE SYSTEMS ARE EXPECTED TO BRING A
PERIOD MAINLY RAIN BUT COULD BE SOME WINTRY WX AS WELL ESPECIALLY
IN THE MOUNTAINS. EXPECT POTENTIAL LOW LEVEL WIND SHEAR AS WELL
AND POOR FLYING WEATHER MONDAY.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...RCS
NEAR TERM...RCS/WP
SHORT TERM...AMS
LONG TERM...KK
AVIATION...JH/RCS/WP




000
FXUS61 KRNK 182333
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
633 PM EST THU DEC 18 2014

.SYNOPSIS...
HIGH PRESSURE OVER THE UPPER MIDWEST WILL GRADUALLY BUILD EAST
ACROSS THE AREA RESULTING IN OVERALL DRY WEATHER THROUGH FRIDAY
EVENING. A WEAK AREA OF LOW PRESSURE WILL EVENTUALLY DEVELOP ALONG
THE GULF COAST STATES FRIDAY NIGHT AND MOVE EAST-NORTHEAST OVER
THE CAROLINAS ON SATURDAY. THIS SYSTEM WILL BRING A PERIOD OF
LIGHT WINTRY PRECIPITATION SATURDAY MORNING...CHANGING TO RAIN
OVER THE PIEDMONT IN THE AFTERNOON.

&&

.NEAR TERM /THROUGH FRIDAY/...
AS OF 615 PM EST THURSDAY...

REALLY NOT MUCH TO UPDATE OVERALL IN THE FORECAST. SOME LIGHT
RETURNS ON RADAR OVER THE MTNS OF SE WV...MAY BRING A FLURRY/SNOW
SHOWERS...WITH LITTLE/NO ACCUMULATION THROUGH THIS EVENING.
OTHERWISE...CLOUDS WILL HANG TOUGH OVERNIGHT IN THE WEST AS FLOW
TURNS MORE NW...WHILE THE HIGHER CLOUDS OUT EAST THIN OUT.

PREVIOUS VALID DISCUSSION...

WAVE ALOFT PASSES EAST OVERNIGHT LEAVING WEAK SUBSIDENCE IN PLACE
AS HIGH PRESSURE TO THE NW NOSES BACK IN LATE.

CLOUDS THIS AFTERNOON KEPT TEMPERATURES COOL AND THIS SHOULD
TRANSLATE TO COOLER TEMPERATURES OVERNIGHT. WITH AFTERNOON DEW
POINTS MAINTAINING IN THE L/M 20S...ANY SUBSTANTIAL CLEARING WITH
LIGHT WINDS WILL ALLOW OVERNIGHT LOWS TO RADIATE DOWN COLDER THAN
FORECASTED. CURRENT THINKING IS TO HAVE SOME CLOUDS AND/OR MIXING
OVERNIGHT TO KEEP OVERNIGHT LOWS IN BETWEEN GFS AND NAM MOS.

FRIDAY LOOKS TO BE ON THE DRY SIDE AS HIGH PRESSURE STRETCHING
FROM THE GREAT LAKES THROUGH THE OHIO RIVER VALLEY REMAINS THE
MAIN FEATURE IN OUR WEATHER PATTERN. MOSTLY SUNNY SKIES AND LIGHT
NORTHWESTERLY DOWNSLOPE WINDS WILL ALLOW AFTERNOON TEMPERATURES TO
RANGE FROM THE MID 30S ALONG THE WESTERN RIDGES...TO AROUND 50
OVER THE SOUTHSIDE AND THE NORTH CAROLINA PIEDMONT.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
AS OF 250 PM EST THURSDAY...

MODELS HAVE BEEN TRENDING QUITE A BIT WEAKER WITH THE SHORT WAVE
COMING OUT OF ARIZONA AND REACHING THE MID ATLANTIC REGION ON
SATURDAY. ISENTROPIC LIFT AND VORTICITY ADVECTION COME THROUGH ON
SATURDAY AND WILL BE EAST OF THE FORECAST AREA ON SATURDAY NIGHT.
MOST SIGNIFICANT CHANGE IN THE GUIDANCE IS WITH THE AMOUNT OF
MOISTURE. 12Z GUIDANCE NOW KEEPS BULK OF THE DEEPER MOISTURE SOUTH
OF THE FORECAST AREA...ESPECIALLY THE 12Z NAM. WILL FOLLOW THIS
TREND AND LOWER PROBABILITY OF PRECIPITATION IN ALL BUT THE
SOUTHERN THIRD OF THE COUNTY WARNING AREA. WILL ALSO CUT BACK ON
AMOUNT OF PRECIPITATION.

SURFACE HIGH PRESSURE OVER THE UPPER MISSISSIPPI VALLEY WILL
GRADUALLY MOVE EAST AND WILL BE OVER THE OHIO VALLEY ON SATURDAY.
THE HIGH CONTINUES SLOW PROGRESS TO THE EAST SATURDAY NIGHT AND BY
LATE SUNDAY THE RIDGE AXIS WILL BE OFFSHORE. THIS WILL BEGIN TO
BRING SURFACE AND LOW LEVEL WINDS AROUND TO THE SOUTH LATE IN THE
DAY. SURFACE REFLECTION OF THE SHORT WAVE ON SATURDAY WILL BE AN
INVERTED TROF OVER THE SOUTHERN APPALACHIANS. EXPECT CLOUDS AND
PRECIPITATION WILL KEEP MAXIMUM TEMPERATURES ON SATURDAY COOLER
THAN GUIDANCE.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 230 PM EST THURSDAY...

A VERY ACTIVE WEATHER PATTERN EXPECTED DURING THE MEDIUM RANGE
WITH ENOUGH MODEL DIFFERENCES TO MAKE THE DETAILS OF THE SENSIBLE
WEATHER A GOOD CHALLENGE. AN AREA OF LOW PRESSURE SYSTEM WILL
DEVELOP ALONG THE GULF COAST SUNDAY NIGHT...PUSH MOISTURE
NORTHWARD AND INTRODUCING ANOTHER CHANCE OF RAIN...AND POTENTIALLY
FREEZING PRECIPITATION TO THE MOUNTAINS. UTILIZED THE TOPDOWN
APPROACH LEANING TOWARDS GFS FOR TEMPERATURE PROFILES. HELD LOW
TEMPERATURES A FEW DEGREES BELOW MOS WITH CLOUDS AND
PRECIPITATION. IN GENERAL...SUNDAY NIGHT LOWS WILL RANGE FROM THE
UPPER 20S IN THE MOUNTAINS TO THE LOWER 30S IN THE PIEDMONT.

FOR MONDAY...A WAVE OF LOW PRESSURE ALONG THE FRONTAL BOUNDARY
WILL BE LOCATED ALONG THE NORTH CAROLINA COAST WITH AXIS OF
MOISTURE/PRECIPITATION MOVING NORTH ASSOCIATED WITH INCREASING
WARM ADVECTION AHEAD OF THE DEVELOPING LONGWAVE TROUGH TO THE
WEST. HOW MUCH THE LOW CENTER DEEPENS...ITS ASSOCIATED
PRECIPITATION AND PTYPE REMAINS PROBLEMATIC FOR OUR REGION. EACH
MODEL HAS A DIFFERENT TAKE ON THE MAGNITUDE OF THE WARM NOSE OVER
OUR REGION. WILL MAINTAIN THE RAIN VERSUS FREEZING RAIN FORECAST
DURING MUCH OF MONDAY MORNING. THERMAL PROFILES SUGGEST SOME
POTENTIAL FOR LIGHT FREEZING RAIN OR SLEET ACROSS THE VIRGINIA
HIGHLANDS AND SOUTHERN SHENANDOAH VALLEY. FELT THAT THERE WAS
ENOUGH SUPPORT TO RAISE POPS FROM SLIGHT INTO THE CHANCE LEVEL
MONDAY. KEPT HIGHS MONDAY COOLER THAN GUIDANCE WITH READINGS FROM
THE MID 30S IN THE WEST TO THE MID 40S IN THE EAST.

BY MONDAY NIGHT...LOW PRESSURE MOVES INTO THE MIDWEST WITH
TRAILING FRONTAL BOUNDARY SOUTH INTO THE MISSISSIPPI VALLEY. A
DEEP LONGITUDINAL TROUGH DEVELOPS SOUTH TO THE GULF OF MEXICO BY
TUESDAY AFTERNOON WITH INCREASING SOUTHERLY LOW LEVEL FLOW ACROSS
OUR REGION...ACCOMPANIED BY INCREASING MOISTURE ADVECTION. USING
SUPERBLEND FOR LOW TEMPERATURES MONDAY NIGHT PRODUCED READINGS
GENERALLY IN THE UPPER 20S AND LOWER 30S. TEMPERATURES WILL TREND
MILDER FOR HIGHS TUESDAY FROM THE MID 40S TO THE LOWER 50S.

BY TUESDAY NIGHT INTO WEDNESDAY...BOTH GFS AND ECWMF DEEPEN THE
UPPER LOW AND ASSOCIATED TROUGH AND NEGATIVELY TILT THE FEATURE SO
THAT THE TROUGH AXIS SHIFTS TO OFF THE NORTH CAROLINA
COAST...COINCIDENT TO THE POSITION OF THE ASSOCIATED SURFACE
OCCLUDED FRONT...WITH THE TRIPLE POINT PASSING SOMEWHERE NEAR OR
JUST SOUTH OF OUR REGION. AT THIS TIME...SPC DOES NOT HAVE ANY
THUNDERSTORMS IN ITS DAY 4-8 CONVECTIVE OUTLOOK. IT LOOKS
LIKE...THERE IS THE POTENTIAL FOR OUR REGION TO HAVE ACTIVE
WEATHER LATE TUESDAY NIGHT INTO WEDNESDAY WITH PLENTY OF
SHOWERS...PERHAPS VERY GUSTY WINDS AND A FEW THUNDERSTORMS.

COLD AIR PUSHES INTO THE REGION TUESDAY NIGHT INTO WEDNESDAY
MORNING...ALLOWING FOR SOME RAIN AND SNOW SHOWERS. IF ENOUGH COLD
AIR ARRIVES QUICKLY...THERE COULD BE SOME ACCUMULATING SNOW IN THE
WESTERN MOUNTAINS. KEPT THE HIGHEST POPS OF RAIN AND SNOW SHOWERS
IN THE WEST AS THE LOW CENTER MARCHES NORTHEAST PUSHES A COLD
FRONT TO THE COAST. IN THE WAKE OF THE COLD FRONT A COOLING TRENDS
WILL CONTINUE WEDNESDAY INTO THURSDAY...WITH WEST TO NORTHWEST
FLOW ALOFT. UPPER FLOW SHIFTS TO THE SOUTHWEST AS TROF CURVES OUT
IN THE CENTRAL US WITH SFC INFLECTION OF LOW PRESSURE DEVELOPS
OVER THE TENNESSEE VALLEY BY FRIDAY MORNING.

&&

.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
AS OF 625 PM EST THURSDAY...

VFR CIGS AT 5-9KFT THIS EVENING WILL SCATTER OUT EAST OF THE BLUE
RIDGE TOWARD DAWN. MEANWHILE...NW FLOW BEHIND THE UPPER WAVE WILL
INTRODUCE LOWER CIGS TO LWB/BLF OVERNIGHT WITH MVFR AT LWB BY
05Z...AND MVFR TO IFR AT BLF IN THE 04-07Z TIME FRAME. BCB WILL
STAY OUTSIDE THE LOWER CIGS...AND SCATTER OUT BY 14Z FRIDAY.

MODELS HAVE LOWER CIGS IN THE WEST SCATTERING OUT BY LATE FRIDAY
MORNING WITH VFR ALL SITES OVER MUCH OF THE AREA DURING THE
AFTERNOON.

EXTENDED DISCUSSION...

THE FRI NIGHT-SAT SYSTEM NOW HAS TRENDED WEAKER BUT WILL STILL
NEED TO BE WATCHED AS IT WILL LIKELY BRING A PERIOD OF SUB VFR
WINTRY WEATHER ESPECIALLY FROM THE BLUE RIDGE WEST SAT.

ON THE HEELS OF THIS FRIDAY/SATURDAY SYSTEM WILL BE ANOTHER
SYSTEM TO POTENTIALLY IMPACT MAINLY THE EASTERN PORTION OF THE
REGION SUNDAY NIGHT INTO MONDAY...WITH YET ANOTHER SYSTEM SLATED
FOR LATE TUESDAY INTO WEDNESDAY. THESE SYSTEMS ARE EXPECTED TO
BRING A PERIOD MAINLY RAIN BUT COULD BE SOME WINTRY WX AS WELL
ESPECIALLY IN THE MOUNTAINS. EXPECT POTENTIAL LOW LEVEL WIND SHEAR
AS WELL AND POOR FLYING WEATHER MONDAY.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...RCS
NEAR TERM...RCS/WP
SHORT TERM...AMS
LONG TERM...KK
AVIATION...JH/RCS/WP




000
FXUS61 KRNK 182333
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
633 PM EST THU DEC 18 2014

.SYNOPSIS...
HIGH PRESSURE OVER THE UPPER MIDWEST WILL GRADUALLY BUILD EAST
ACROSS THE AREA RESULTING IN OVERALL DRY WEATHER THROUGH FRIDAY
EVENING. A WEAK AREA OF LOW PRESSURE WILL EVENTUALLY DEVELOP ALONG
THE GULF COAST STATES FRIDAY NIGHT AND MOVE EAST-NORTHEAST OVER
THE CAROLINAS ON SATURDAY. THIS SYSTEM WILL BRING A PERIOD OF
LIGHT WINTRY PRECIPITATION SATURDAY MORNING...CHANGING TO RAIN
OVER THE PIEDMONT IN THE AFTERNOON.

&&

.NEAR TERM /THROUGH FRIDAY/...
AS OF 615 PM EST THURSDAY...

REALLY NOT MUCH TO UPDATE OVERALL IN THE FORECAST. SOME LIGHT
RETURNS ON RADAR OVER THE MTNS OF SE WV...MAY BRING A FLURRY/SNOW
SHOWERS...WITH LITTLE/NO ACCUMULATION THROUGH THIS EVENING.
OTHERWISE...CLOUDS WILL HANG TOUGH OVERNIGHT IN THE WEST AS FLOW
TURNS MORE NW...WHILE THE HIGHER CLOUDS OUT EAST THIN OUT.

PREVIOUS VALID DISCUSSION...

WAVE ALOFT PASSES EAST OVERNIGHT LEAVING WEAK SUBSIDENCE IN PLACE
AS HIGH PRESSURE TO THE NW NOSES BACK IN LATE.

CLOUDS THIS AFTERNOON KEPT TEMPERATURES COOL AND THIS SHOULD
TRANSLATE TO COOLER TEMPERATURES OVERNIGHT. WITH AFTERNOON DEW
POINTS MAINTAINING IN THE L/M 20S...ANY SUBSTANTIAL CLEARING WITH
LIGHT WINDS WILL ALLOW OVERNIGHT LOWS TO RADIATE DOWN COLDER THAN
FORECASTED. CURRENT THINKING IS TO HAVE SOME CLOUDS AND/OR MIXING
OVERNIGHT TO KEEP OVERNIGHT LOWS IN BETWEEN GFS AND NAM MOS.

FRIDAY LOOKS TO BE ON THE DRY SIDE AS HIGH PRESSURE STRETCHING
FROM THE GREAT LAKES THROUGH THE OHIO RIVER VALLEY REMAINS THE
MAIN FEATURE IN OUR WEATHER PATTERN. MOSTLY SUNNY SKIES AND LIGHT
NORTHWESTERLY DOWNSLOPE WINDS WILL ALLOW AFTERNOON TEMPERATURES TO
RANGE FROM THE MID 30S ALONG THE WESTERN RIDGES...TO AROUND 50
OVER THE SOUTHSIDE AND THE NORTH CAROLINA PIEDMONT.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
AS OF 250 PM EST THURSDAY...

MODELS HAVE BEEN TRENDING QUITE A BIT WEAKER WITH THE SHORT WAVE
COMING OUT OF ARIZONA AND REACHING THE MID ATLANTIC REGION ON
SATURDAY. ISENTROPIC LIFT AND VORTICITY ADVECTION COME THROUGH ON
SATURDAY AND WILL BE EAST OF THE FORECAST AREA ON SATURDAY NIGHT.
MOST SIGNIFICANT CHANGE IN THE GUIDANCE IS WITH THE AMOUNT OF
MOISTURE. 12Z GUIDANCE NOW KEEPS BULK OF THE DEEPER MOISTURE SOUTH
OF THE FORECAST AREA...ESPECIALLY THE 12Z NAM. WILL FOLLOW THIS
TREND AND LOWER PROBABILITY OF PRECIPITATION IN ALL BUT THE
SOUTHERN THIRD OF THE COUNTY WARNING AREA. WILL ALSO CUT BACK ON
AMOUNT OF PRECIPITATION.

SURFACE HIGH PRESSURE OVER THE UPPER MISSISSIPPI VALLEY WILL
GRADUALLY MOVE EAST AND WILL BE OVER THE OHIO VALLEY ON SATURDAY.
THE HIGH CONTINUES SLOW PROGRESS TO THE EAST SATURDAY NIGHT AND BY
LATE SUNDAY THE RIDGE AXIS WILL BE OFFSHORE. THIS WILL BEGIN TO
BRING SURFACE AND LOW LEVEL WINDS AROUND TO THE SOUTH LATE IN THE
DAY. SURFACE REFLECTION OF THE SHORT WAVE ON SATURDAY WILL BE AN
INVERTED TROF OVER THE SOUTHERN APPALACHIANS. EXPECT CLOUDS AND
PRECIPITATION WILL KEEP MAXIMUM TEMPERATURES ON SATURDAY COOLER
THAN GUIDANCE.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 230 PM EST THURSDAY...

A VERY ACTIVE WEATHER PATTERN EXPECTED DURING THE MEDIUM RANGE
WITH ENOUGH MODEL DIFFERENCES TO MAKE THE DETAILS OF THE SENSIBLE
WEATHER A GOOD CHALLENGE. AN AREA OF LOW PRESSURE SYSTEM WILL
DEVELOP ALONG THE GULF COAST SUNDAY NIGHT...PUSH MOISTURE
NORTHWARD AND INTRODUCING ANOTHER CHANCE OF RAIN...AND POTENTIALLY
FREEZING PRECIPITATION TO THE MOUNTAINS. UTILIZED THE TOPDOWN
APPROACH LEANING TOWARDS GFS FOR TEMPERATURE PROFILES. HELD LOW
TEMPERATURES A FEW DEGREES BELOW MOS WITH CLOUDS AND
PRECIPITATION. IN GENERAL...SUNDAY NIGHT LOWS WILL RANGE FROM THE
UPPER 20S IN THE MOUNTAINS TO THE LOWER 30S IN THE PIEDMONT.

FOR MONDAY...A WAVE OF LOW PRESSURE ALONG THE FRONTAL BOUNDARY
WILL BE LOCATED ALONG THE NORTH CAROLINA COAST WITH AXIS OF
MOISTURE/PRECIPITATION MOVING NORTH ASSOCIATED WITH INCREASING
WARM ADVECTION AHEAD OF THE DEVELOPING LONGWAVE TROUGH TO THE
WEST. HOW MUCH THE LOW CENTER DEEPENS...ITS ASSOCIATED
PRECIPITATION AND PTYPE REMAINS PROBLEMATIC FOR OUR REGION. EACH
MODEL HAS A DIFFERENT TAKE ON THE MAGNITUDE OF THE WARM NOSE OVER
OUR REGION. WILL MAINTAIN THE RAIN VERSUS FREEZING RAIN FORECAST
DURING MUCH OF MONDAY MORNING. THERMAL PROFILES SUGGEST SOME
POTENTIAL FOR LIGHT FREEZING RAIN OR SLEET ACROSS THE VIRGINIA
HIGHLANDS AND SOUTHERN SHENANDOAH VALLEY. FELT THAT THERE WAS
ENOUGH SUPPORT TO RAISE POPS FROM SLIGHT INTO THE CHANCE LEVEL
MONDAY. KEPT HIGHS MONDAY COOLER THAN GUIDANCE WITH READINGS FROM
THE MID 30S IN THE WEST TO THE MID 40S IN THE EAST.

BY MONDAY NIGHT...LOW PRESSURE MOVES INTO THE MIDWEST WITH
TRAILING FRONTAL BOUNDARY SOUTH INTO THE MISSISSIPPI VALLEY. A
DEEP LONGITUDINAL TROUGH DEVELOPS SOUTH TO THE GULF OF MEXICO BY
TUESDAY AFTERNOON WITH INCREASING SOUTHERLY LOW LEVEL FLOW ACROSS
OUR REGION...ACCOMPANIED BY INCREASING MOISTURE ADVECTION. USING
SUPERBLEND FOR LOW TEMPERATURES MONDAY NIGHT PRODUCED READINGS
GENERALLY IN THE UPPER 20S AND LOWER 30S. TEMPERATURES WILL TREND
MILDER FOR HIGHS TUESDAY FROM THE MID 40S TO THE LOWER 50S.

BY TUESDAY NIGHT INTO WEDNESDAY...BOTH GFS AND ECWMF DEEPEN THE
UPPER LOW AND ASSOCIATED TROUGH AND NEGATIVELY TILT THE FEATURE SO
THAT THE TROUGH AXIS SHIFTS TO OFF THE NORTH CAROLINA
COAST...COINCIDENT TO THE POSITION OF THE ASSOCIATED SURFACE
OCCLUDED FRONT...WITH THE TRIPLE POINT PASSING SOMEWHERE NEAR OR
JUST SOUTH OF OUR REGION. AT THIS TIME...SPC DOES NOT HAVE ANY
THUNDERSTORMS IN ITS DAY 4-8 CONVECTIVE OUTLOOK. IT LOOKS
LIKE...THERE IS THE POTENTIAL FOR OUR REGION TO HAVE ACTIVE
WEATHER LATE TUESDAY NIGHT INTO WEDNESDAY WITH PLENTY OF
SHOWERS...PERHAPS VERY GUSTY WINDS AND A FEW THUNDERSTORMS.

COLD AIR PUSHES INTO THE REGION TUESDAY NIGHT INTO WEDNESDAY
MORNING...ALLOWING FOR SOME RAIN AND SNOW SHOWERS. IF ENOUGH COLD
AIR ARRIVES QUICKLY...THERE COULD BE SOME ACCUMULATING SNOW IN THE
WESTERN MOUNTAINS. KEPT THE HIGHEST POPS OF RAIN AND SNOW SHOWERS
IN THE WEST AS THE LOW CENTER MARCHES NORTHEAST PUSHES A COLD
FRONT TO THE COAST. IN THE WAKE OF THE COLD FRONT A COOLING TRENDS
WILL CONTINUE WEDNESDAY INTO THURSDAY...WITH WEST TO NORTHWEST
FLOW ALOFT. UPPER FLOW SHIFTS TO THE SOUTHWEST AS TROF CURVES OUT
IN THE CENTRAL US WITH SFC INFLECTION OF LOW PRESSURE DEVELOPS
OVER THE TENNESSEE VALLEY BY FRIDAY MORNING.

&&

.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
AS OF 625 PM EST THURSDAY...

VFR CIGS AT 5-9KFT THIS EVENING WILL SCATTER OUT EAST OF THE BLUE
RIDGE TOWARD DAWN. MEANWHILE...NW FLOW BEHIND THE UPPER WAVE WILL
INTRODUCE LOWER CIGS TO LWB/BLF OVERNIGHT WITH MVFR AT LWB BY
05Z...AND MVFR TO IFR AT BLF IN THE 04-07Z TIME FRAME. BCB WILL
STAY OUTSIDE THE LOWER CIGS...AND SCATTER OUT BY 14Z FRIDAY.

MODELS HAVE LOWER CIGS IN THE WEST SCATTERING OUT BY LATE FRIDAY
MORNING WITH VFR ALL SITES OVER MUCH OF THE AREA DURING THE
AFTERNOON.

EXTENDED DISCUSSION...

THE FRI NIGHT-SAT SYSTEM NOW HAS TRENDED WEAKER BUT WILL STILL
NEED TO BE WATCHED AS IT WILL LIKELY BRING A PERIOD OF SUB VFR
WINTRY WEATHER ESPECIALLY FROM THE BLUE RIDGE WEST SAT.

ON THE HEELS OF THIS FRIDAY/SATURDAY SYSTEM WILL BE ANOTHER
SYSTEM TO POTENTIALLY IMPACT MAINLY THE EASTERN PORTION OF THE
REGION SUNDAY NIGHT INTO MONDAY...WITH YET ANOTHER SYSTEM SLATED
FOR LATE TUESDAY INTO WEDNESDAY. THESE SYSTEMS ARE EXPECTED TO
BRING A PERIOD MAINLY RAIN BUT COULD BE SOME WINTRY WX AS WELL
ESPECIALLY IN THE MOUNTAINS. EXPECT POTENTIAL LOW LEVEL WIND SHEAR
AS WELL AND POOR FLYING WEATHER MONDAY.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...RCS
NEAR TERM...RCS/WP
SHORT TERM...AMS
LONG TERM...KK
AVIATION...JH/RCS/WP





000
FXUS61 KRNK 182005
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
305 PM EST THU DEC 18 2014

.SYNOPSIS...
HIGH PRESSURE OVER THE UPPER MIDWEST WILL GRADUALLY BUILD EAST
ACROSS THE AREA RESULTING IN OVERALL DRY WEATHER THROUGH FRIDAY
EVENING. A WEAK AREA OF LOW PRESSURE WILL EVENTUALLY DEVELOP ALONG
THE GULF COAST STATES FRIDAY NIGHT AND MOVE EAST-NORTHEAST OVER
THE CAROLINAS ON SATURDAY. THIS SYSTEM WILL BRING A PERIOD OF
LIGHT WINTRY PRECIPITATION SATURDAY MORNING...CHANGING TO RAIN
OVER THE PIEDMONT IN THE AFTERNOON.

&&

.NEAR TERM /THROUGH FRIDAY/...
AS OF 215 PM EST THURSDAY...

WAVE ALOFT PASSES EAST OVERNIGHT LEAVING WEAK SUBSIDENCE IN PLACE
AS HIGH PRESSURE TO THE NW NOSES BACK IN LATE. THIS WILL ALSO
INTRODUCE ANOTHER ROUND OF WEAK COLD ADVECTION ALLOWING UPSLOPE
CLOUDS TO REDEVELOP IN THE WEST...PERHAPS REACHING THE BLUE RIDGE
BY DAYBREAK. WITH ENOUGH MOISTURE...WESTERN GREENBRIER COULD EDGE
OUT A DUSTING TO A HALF OF AN INCH OF SNOW ABOVE 3000 FT. OTHER
SOUTHEASTERN WV COUNTIES SHOULD ONLY SEE FLURRIES OVERNIGHT.
COUNTIES ALONG THE BLUE RIDGE TO THE PIEDMONT WILL SEE SLOW
CLEARING OF THE MID/HIGH CLOUDS FROM WEST TO EAST AFTER MIDNIGHT.

CLOUDS THIS AFTERNOON KEPT TEMPERATURES COOL AND THIS SHOULD
TRANSLATE TO COOLER TEMPERATURES OVERNIGHT. WITH AFTERNOON DEW
POINTS MAINTAINING IN THE L/M 20S...ANY SUBSTANTIAL CLEARING WITH
LIGHT WINDS WILL ALLOW OVERNIGHT LOWS TO RADIATE DOWN COLDER THAN
FORECASTED. CURRENT THINKING IS TO HAVE SOME CLOUDS AND/OR MIXING
OVERNIGHT TO KEEP OVERNIGHT LOWS IN BETWEEN GFS AND NAM MOS.

FRIDAY LOOKS TO BE ON THE DRY SIDE AS HIGH PRESSURE STRETCHING
FROM THE GREAT LAKES THROUGH THE OHIO RIVER VALLEY REMAINS THE
MAIN FEATURE IN OUR WEATHER PATTERN. MOSTLY SUNNY SKIES AND LIGHT
NORTHWESTERLY DOWNSLOPE WINDS WILL ALLOW AFTERNOON TEMPERATURES TO
RANGE FROM THE MID 30S ALONG THE WESTERN RIDGES...TO AROUND 50
OVER THE SOUTHSIDE AND THE NORTH CAROLINA PIEDMONT.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
AS OF 250 PM EST THURSDAY...

MODELS HAVE BEEN TRENDING QUITE A BIT WEAKER WITH THE SHORT WAVE
COMING OUT OF ARIZONA AND REACHING THE MID ATLANTIC REGION ON
SATURDAY. ISENTROPIC LIFT AND VORTICITY ADVECTION COME THROUGH ON
SATURDAY AND WILL BE EAST OF THE FORECAST AREA ON SATURDAY NIGHT.
MOST SIGNIFICANT CHANGE IN THE GUIDANCE IS WITH THE AMOUNT OF
MOISTURE. 12Z GUIDANCE NOW KEEPS BULK OF THE DEEPER MOISTURE SOUTH
OF THE FORECAST AREA...ESPECIALLY THE 12Z NAM. WILL FOLLOW THIS
TREND AND LOWER PROBABILITY OF PRECIPITATION IN ALL BUT THE
SOUTHERN THIRD OF THE COUNTY WARNING AREA. WILL ALSO CUT BACK ON
AMOUNT OF PRECIPITATION.

SURFACE HIGH PRESSURE OVER THE UPPER MISSISSIPPI VALLEY WILL
GRADUALLY MOVE EAST AND WILL BE OVER THE OHIO VALLEY ON SATURDAY.
THE HIGH CONTINUES SLOW PROGRESS TO THE EAST SATURDAY NIGHT AND BY
LATE SUNDAY THE RIDGE AXIS WILL BE OFFSHORE. THIS WILL BEGIN TO
BRING SURFACE AND LOW LEVEL WINDS AROUND TO THE SOUTH LATE IN THE
DAY. SURFACE REFLECTION OF THE SHORT WAVE ON SATURDAY WILL BE AN
INVERTED TROF OVER THE SOUTHERN APPALACHIANS. EXPECT CLOUDS AND
PRECIPITATION WILL KEEP MAXIMUM TEMPERATURES ON SATURDAY COOLER
THAN GUIDANCE.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 230 PM EST THURSDAY...

A VERY ACTIVE WEATHER PATTERN EXPECTED DURING THE MEDIUM RANGE
WITH ENOUGH MODEL DIFFERENCES TO MAKE THE DETAILS OF THE SENSIBLE
WEATHER A GOOD CHALLENGE. AN AREA OF LOW PRESSURE SYSTEM WILL
DEVELOP ALONG THE GULF COAST SUNDAY NIGHT...PUSH MOISTURE
NORTHWARD AND INTRODUCING ANOTHER CHANCE OF RAIN...AND POTENTIALLY
FREEZING PRECIPITATION TO THE MOUNTAINS. UTILIZED THE TOPDOWN
APPROACH LEANING TOWARDS GFS FOR TEMPERATURE PROFILES. HELD LOW
TEMPERATURES A FEW DEGREES BELOW MOS WITH CLOUDS AND
PRECIPITATION. IN GENERAL...SUNDAY NIGHT LOWS WILL RANGE FROM THE
UPPER 20S IN THE MOUNTAINS TO THE LOWER 30S IN THE PIEDMONT.

FOR MONDAY...A WAVE OF LOW PRESSURE ALONG THE FRONTAL BOUNDARY
WILL BE LOCATED ALONG THE NORTH CAROLINA COAST WITH AXIS OF
MOISTURE/PRECIPITATION MOVING NORTH ASSOCIATED WITH INCREASING
WARM ADVECTION AHEAD OF THE DEVELOPING LONGWAVE TROUGH TO THE
WEST. HOW MUCH THE LOW CENTER DEEPENS...ITS ASSOCIATED
PRECIPITATION AND PTYPE REMAINS PROBLEMATIC FOR OUR REGION. EACH
MODEL HAS A DIFFERENT TAKE ON THE MAGNITUDE OF THE WARM NOSE OVER
OUR REGION. WILL MAINTAIN THE RAIN VERSUS FREEZING RAIN FORECAST
DURING MUCH OF MONDAY MORNING. THERMAL PROFILES SUGGEST SOME
POTENTIAL FOR LIGHT FREEZING RAIN OR SLEET ACROSS THE VIRGINIA
HIGHLANDS AND SOUTHERN SHENANDOAH VALLEY. FELT THAT THERE WAS
ENOUGH SUPPORT TO RAISE POPS FROM SLIGHT INTO THE CHANCE LEVEL
MONDAY. KEPT HIGHS MONDAY COOLER THAN GUIDANCE WITH READINGS FROM
THE MID 30S IN THE WEST TO THE MID 40S IN THE EAST.

BY MONDAY NIGHT...LOW PRESSURE MOVES INTO THE MIDWEST WITH
TRAILING FRONTAL BOUNDARY SOUTH INTO THE MISSISSIPPI VALLEY. A
DEEP LONGITUDINAL TROUGH DEVELOPS SOUTH TO THE GULF OF MEXICO BY
TUESDAY AFTERNOON WITH INCREASING SOUTHERLY LOW LEVEL FLOW ACROSS
OUR REGION...ACCOMPANIED BY INCREASING MOISTURE ADVECTION. USING
SUPERBLEND FOR LOW TEMPERATURES MONDAY NIGHT PRODUCED READINGS
GENERALLY IN THE UPPER 20S AND LOWER 30S. TEMPERATURES WILL TREND
MILDER FOR HIGHS TUESDAY FROM THE MID 40S TO THE LOWER 50S.

BY TUESDAY NIGHT INTO WEDNESDAY...BOTH GFS AND ECWMF DEEPEN THE
UPPER LOW AND ASSOCIATED TROUGH AND NEGATIVELY TILT THE FEATURE SO
THAT THE TROUGH AXIS SHIFTS TO OFF THE NORTH CAROLINA
COAST...COINCIDENT TO THE POSITION OF THE ASSOCIATED SURFACE
OCCLUDED FRONT...WITH THE TRIPLE POINT PASSING SOMEWHERE NEAR OR
JUST SOUTH OF OUR REGION. AT THIS TIME...SPC DOES NOT HAVE ANY
THUNDERSTORMS IN ITS DAY 4-8 CONVECTIVE OUTLOOK. IT LOOKS
LIKE...THERE IS THE POTENTIAL FOR OUR REGION TO HAVE ACTIVE
WEATHER LATE TUESDAY NIGHT INTO WEDNESDAY WITH PLENTY OF
SHOWERS...PERHAPS VERY GUSTY WINDS AND A FEW THUNDERSTORMS.

COLD AIR PUSHES INTO THE REGION TUESDAY NIGHT INTO WEDNESDAY
MORNING...ALLOWING FOR SOME RAIN AND SNOW SHOWERS. IF ENOUGH COLD
AIR ARRIVES QUICKLY...THERE COULD BE SOME ACCUMULATING SNOW IN THE
WESTERN MOUNTAINS. KEPT THE HIGHEST POPS OF RAIN AND SNOW SHOWERS
IN THE WEST AS THE LOW CENTER MARCHES NORTHEAST PUSHES A COLD
FRONT TO THE COAST. IN THE WAKE OF THE COLD FRONT A COOLING TRENDS
WILL CONTINUE WEDNESDAY INTO THURSDAY...WITH WEST TO NORTHWEST
FLOW ALOFT. UPPER FLOW SHIFTS TO THE SOUTHWEST AS TROF CURVES OUT
IN THE CENTRAL US WITH SFC INFLECTION OF LOW PRESSURE DEVELOPS
OVER THE TENNESSEE VALLEY BY FRIDAY MORNING.

&&

.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
AS OF 1250 PM EST THURSDAY...

MOST OF THE REGION WILL EXPERIENCE VFR CONDITIONS THROUGH THE
NEXT 24 HOURS WITH MAINLY INTERVALS OF MID AND HIGH CLOUDS PASSING
ACROSS. THE EXCEPTION WILL BE THE THOSE AREAS MAINLY ALONG AND
WEST OF A KBLF-KLWB LINE WHERE RETURNING LOW LEVEL MOISTURE WILL
MAKE FOR LOWER STRATO-CU CIGS OVERNIGHT INTO FRIDAY MORNING.

EXTENDED DISCUSSION...

THE FRI NIGHT-SAT SYSTEM NOW HAS TRENDED WEAKER BUT WILL STILL
NEED TO BE WATCHED AS IT WILL LIKELY BRING A PERIOD OF SUB VFR
WINTRY WEATHER ESPECIALLY FROM THE BLUE RIDGE WEST SAT.

AVIATION INTERESTS WILL NEED TO MONITOR THIS SITUATION AS LATER
FORECASTS BECOME AVAILABLE. THIS WILL LIKELY HAVE AN IMPACT ON AIR
TRAVEL OVER THE WEEKEND...FROM THE SOUTHERN APPALACHIANS AND
CAROLINAS NORTH TO THE MID ATLANTIC.

ON THE HEELS OF THIS FRIDAY/SATURDAY SYSTEM WILL BE ANOTHER
SYSTEM TO POTENTIALLY IMPACT MAINLY THE EASTERN PORTION OF THE
REGION MONDAY INTO TUESDAY. ANOTHER AREA OF LOW PRESSURE IS
EXPECTED TO HEAD NORTH ALONG THE EAST COAST WITH SCATTERED
PRECIPITATION ON ITS WESTERN FLANKS ENTERING THE REGION. AT THIS
POINT A WINTRY MIX IS POSSIBLE ALONG WITH LOCALIZED MVFR CIGS.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...RCS
NEAR TERM...RCS
SHORT TERM...AMS
LONG TERM...KK
AVIATION...JH/RCS




000
FXUS61 KRNK 182005
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
305 PM EST THU DEC 18 2014

.SYNOPSIS...
HIGH PRESSURE OVER THE UPPER MIDWEST WILL GRADUALLY BUILD EAST
ACROSS THE AREA RESULTING IN OVERALL DRY WEATHER THROUGH FRIDAY
EVENING. A WEAK AREA OF LOW PRESSURE WILL EVENTUALLY DEVELOP ALONG
THE GULF COAST STATES FRIDAY NIGHT AND MOVE EAST-NORTHEAST OVER
THE CAROLINAS ON SATURDAY. THIS SYSTEM WILL BRING A PERIOD OF
LIGHT WINTRY PRECIPITATION SATURDAY MORNING...CHANGING TO RAIN
OVER THE PIEDMONT IN THE AFTERNOON.

&&

.NEAR TERM /THROUGH FRIDAY/...
AS OF 215 PM EST THURSDAY...

WAVE ALOFT PASSES EAST OVERNIGHT LEAVING WEAK SUBSIDENCE IN PLACE
AS HIGH PRESSURE TO THE NW NOSES BACK IN LATE. THIS WILL ALSO
INTRODUCE ANOTHER ROUND OF WEAK COLD ADVECTION ALLOWING UPSLOPE
CLOUDS TO REDEVELOP IN THE WEST...PERHAPS REACHING THE BLUE RIDGE
BY DAYBREAK. WITH ENOUGH MOISTURE...WESTERN GREENBRIER COULD EDGE
OUT A DUSTING TO A HALF OF AN INCH OF SNOW ABOVE 3000 FT. OTHER
SOUTHEASTERN WV COUNTIES SHOULD ONLY SEE FLURRIES OVERNIGHT.
COUNTIES ALONG THE BLUE RIDGE TO THE PIEDMONT WILL SEE SLOW
CLEARING OF THE MID/HIGH CLOUDS FROM WEST TO EAST AFTER MIDNIGHT.

CLOUDS THIS AFTERNOON KEPT TEMPERATURES COOL AND THIS SHOULD
TRANSLATE TO COOLER TEMPERATURES OVERNIGHT. WITH AFTERNOON DEW
POINTS MAINTAINING IN THE L/M 20S...ANY SUBSTANTIAL CLEARING WITH
LIGHT WINDS WILL ALLOW OVERNIGHT LOWS TO RADIATE DOWN COLDER THAN
FORECASTED. CURRENT THINKING IS TO HAVE SOME CLOUDS AND/OR MIXING
OVERNIGHT TO KEEP OVERNIGHT LOWS IN BETWEEN GFS AND NAM MOS.

FRIDAY LOOKS TO BE ON THE DRY SIDE AS HIGH PRESSURE STRETCHING
FROM THE GREAT LAKES THROUGH THE OHIO RIVER VALLEY REMAINS THE
MAIN FEATURE IN OUR WEATHER PATTERN. MOSTLY SUNNY SKIES AND LIGHT
NORTHWESTERLY DOWNSLOPE WINDS WILL ALLOW AFTERNOON TEMPERATURES TO
RANGE FROM THE MID 30S ALONG THE WESTERN RIDGES...TO AROUND 50
OVER THE SOUTHSIDE AND THE NORTH CAROLINA PIEDMONT.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
AS OF 250 PM EST THURSDAY...

MODELS HAVE BEEN TRENDING QUITE A BIT WEAKER WITH THE SHORT WAVE
COMING OUT OF ARIZONA AND REACHING THE MID ATLANTIC REGION ON
SATURDAY. ISENTROPIC LIFT AND VORTICITY ADVECTION COME THROUGH ON
SATURDAY AND WILL BE EAST OF THE FORECAST AREA ON SATURDAY NIGHT.
MOST SIGNIFICANT CHANGE IN THE GUIDANCE IS WITH THE AMOUNT OF
MOISTURE. 12Z GUIDANCE NOW KEEPS BULK OF THE DEEPER MOISTURE SOUTH
OF THE FORECAST AREA...ESPECIALLY THE 12Z NAM. WILL FOLLOW THIS
TREND AND LOWER PROBABILITY OF PRECIPITATION IN ALL BUT THE
SOUTHERN THIRD OF THE COUNTY WARNING AREA. WILL ALSO CUT BACK ON
AMOUNT OF PRECIPITATION.

SURFACE HIGH PRESSURE OVER THE UPPER MISSISSIPPI VALLEY WILL
GRADUALLY MOVE EAST AND WILL BE OVER THE OHIO VALLEY ON SATURDAY.
THE HIGH CONTINUES SLOW PROGRESS TO THE EAST SATURDAY NIGHT AND BY
LATE SUNDAY THE RIDGE AXIS WILL BE OFFSHORE. THIS WILL BEGIN TO
BRING SURFACE AND LOW LEVEL WINDS AROUND TO THE SOUTH LATE IN THE
DAY. SURFACE REFLECTION OF THE SHORT WAVE ON SATURDAY WILL BE AN
INVERTED TROF OVER THE SOUTHERN APPALACHIANS. EXPECT CLOUDS AND
PRECIPITATION WILL KEEP MAXIMUM TEMPERATURES ON SATURDAY COOLER
THAN GUIDANCE.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 230 PM EST THURSDAY...

A VERY ACTIVE WEATHER PATTERN EXPECTED DURING THE MEDIUM RANGE
WITH ENOUGH MODEL DIFFERENCES TO MAKE THE DETAILS OF THE SENSIBLE
WEATHER A GOOD CHALLENGE. AN AREA OF LOW PRESSURE SYSTEM WILL
DEVELOP ALONG THE GULF COAST SUNDAY NIGHT...PUSH MOISTURE
NORTHWARD AND INTRODUCING ANOTHER CHANCE OF RAIN...AND POTENTIALLY
FREEZING PRECIPITATION TO THE MOUNTAINS. UTILIZED THE TOPDOWN
APPROACH LEANING TOWARDS GFS FOR TEMPERATURE PROFILES. HELD LOW
TEMPERATURES A FEW DEGREES BELOW MOS WITH CLOUDS AND
PRECIPITATION. IN GENERAL...SUNDAY NIGHT LOWS WILL RANGE FROM THE
UPPER 20S IN THE MOUNTAINS TO THE LOWER 30S IN THE PIEDMONT.

FOR MONDAY...A WAVE OF LOW PRESSURE ALONG THE FRONTAL BOUNDARY
WILL BE LOCATED ALONG THE NORTH CAROLINA COAST WITH AXIS OF
MOISTURE/PRECIPITATION MOVING NORTH ASSOCIATED WITH INCREASING
WARM ADVECTION AHEAD OF THE DEVELOPING LONGWAVE TROUGH TO THE
WEST. HOW MUCH THE LOW CENTER DEEPENS...ITS ASSOCIATED
PRECIPITATION AND PTYPE REMAINS PROBLEMATIC FOR OUR REGION. EACH
MODEL HAS A DIFFERENT TAKE ON THE MAGNITUDE OF THE WARM NOSE OVER
OUR REGION. WILL MAINTAIN THE RAIN VERSUS FREEZING RAIN FORECAST
DURING MUCH OF MONDAY MORNING. THERMAL PROFILES SUGGEST SOME
POTENTIAL FOR LIGHT FREEZING RAIN OR SLEET ACROSS THE VIRGINIA
HIGHLANDS AND SOUTHERN SHENANDOAH VALLEY. FELT THAT THERE WAS
ENOUGH SUPPORT TO RAISE POPS FROM SLIGHT INTO THE CHANCE LEVEL
MONDAY. KEPT HIGHS MONDAY COOLER THAN GUIDANCE WITH READINGS FROM
THE MID 30S IN THE WEST TO THE MID 40S IN THE EAST.

BY MONDAY NIGHT...LOW PRESSURE MOVES INTO THE MIDWEST WITH
TRAILING FRONTAL BOUNDARY SOUTH INTO THE MISSISSIPPI VALLEY. A
DEEP LONGITUDINAL TROUGH DEVELOPS SOUTH TO THE GULF OF MEXICO BY
TUESDAY AFTERNOON WITH INCREASING SOUTHERLY LOW LEVEL FLOW ACROSS
OUR REGION...ACCOMPANIED BY INCREASING MOISTURE ADVECTION. USING
SUPERBLEND FOR LOW TEMPERATURES MONDAY NIGHT PRODUCED READINGS
GENERALLY IN THE UPPER 20S AND LOWER 30S. TEMPERATURES WILL TREND
MILDER FOR HIGHS TUESDAY FROM THE MID 40S TO THE LOWER 50S.

BY TUESDAY NIGHT INTO WEDNESDAY...BOTH GFS AND ECWMF DEEPEN THE
UPPER LOW AND ASSOCIATED TROUGH AND NEGATIVELY TILT THE FEATURE SO
THAT THE TROUGH AXIS SHIFTS TO OFF THE NORTH CAROLINA
COAST...COINCIDENT TO THE POSITION OF THE ASSOCIATED SURFACE
OCCLUDED FRONT...WITH THE TRIPLE POINT PASSING SOMEWHERE NEAR OR
JUST SOUTH OF OUR REGION. AT THIS TIME...SPC DOES NOT HAVE ANY
THUNDERSTORMS IN ITS DAY 4-8 CONVECTIVE OUTLOOK. IT LOOKS
LIKE...THERE IS THE POTENTIAL FOR OUR REGION TO HAVE ACTIVE
WEATHER LATE TUESDAY NIGHT INTO WEDNESDAY WITH PLENTY OF
SHOWERS...PERHAPS VERY GUSTY WINDS AND A FEW THUNDERSTORMS.

COLD AIR PUSHES INTO THE REGION TUESDAY NIGHT INTO WEDNESDAY
MORNING...ALLOWING FOR SOME RAIN AND SNOW SHOWERS. IF ENOUGH COLD
AIR ARRIVES QUICKLY...THERE COULD BE SOME ACCUMULATING SNOW IN THE
WESTERN MOUNTAINS. KEPT THE HIGHEST POPS OF RAIN AND SNOW SHOWERS
IN THE WEST AS THE LOW CENTER MARCHES NORTHEAST PUSHES A COLD
FRONT TO THE COAST. IN THE WAKE OF THE COLD FRONT A COOLING TRENDS
WILL CONTINUE WEDNESDAY INTO THURSDAY...WITH WEST TO NORTHWEST
FLOW ALOFT. UPPER FLOW SHIFTS TO THE SOUTHWEST AS TROF CURVES OUT
IN THE CENTRAL US WITH SFC INFLECTION OF LOW PRESSURE DEVELOPS
OVER THE TENNESSEE VALLEY BY FRIDAY MORNING.

&&

.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
AS OF 1250 PM EST THURSDAY...

MOST OF THE REGION WILL EXPERIENCE VFR CONDITIONS THROUGH THE
NEXT 24 HOURS WITH MAINLY INTERVALS OF MID AND HIGH CLOUDS PASSING
ACROSS. THE EXCEPTION WILL BE THE THOSE AREAS MAINLY ALONG AND
WEST OF A KBLF-KLWB LINE WHERE RETURNING LOW LEVEL MOISTURE WILL
MAKE FOR LOWER STRATO-CU CIGS OVERNIGHT INTO FRIDAY MORNING.

EXTENDED DISCUSSION...

THE FRI NIGHT-SAT SYSTEM NOW HAS TRENDED WEAKER BUT WILL STILL
NEED TO BE WATCHED AS IT WILL LIKELY BRING A PERIOD OF SUB VFR
WINTRY WEATHER ESPECIALLY FROM THE BLUE RIDGE WEST SAT.

AVIATION INTERESTS WILL NEED TO MONITOR THIS SITUATION AS LATER
FORECASTS BECOME AVAILABLE. THIS WILL LIKELY HAVE AN IMPACT ON AIR
TRAVEL OVER THE WEEKEND...FROM THE SOUTHERN APPALACHIANS AND
CAROLINAS NORTH TO THE MID ATLANTIC.

ON THE HEELS OF THIS FRIDAY/SATURDAY SYSTEM WILL BE ANOTHER
SYSTEM TO POTENTIALLY IMPACT MAINLY THE EASTERN PORTION OF THE
REGION MONDAY INTO TUESDAY. ANOTHER AREA OF LOW PRESSURE IS
EXPECTED TO HEAD NORTH ALONG THE EAST COAST WITH SCATTERED
PRECIPITATION ON ITS WESTERN FLANKS ENTERING THE REGION. AT THIS
POINT A WINTRY MIX IS POSSIBLE ALONG WITH LOCALIZED MVFR CIGS.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...RCS
NEAR TERM...RCS
SHORT TERM...AMS
LONG TERM...KK
AVIATION...JH/RCS





000
FXUS61 KRNK 181759
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
1259 PM EST THU DEC 18 2014

.SYNOPSIS...
HIGH PRESSURE OVER THE UPPER MIDWEST WILL GRADUALLY BUILD EAST
ACROSS THE AREA RESULTING IN OVERALL DRY WEATHER THROUGH FRIDAY.
HOWEVER PASSING UPPER LEVEL DISTURBANCES WILL RESULT IN PERIODS OF
MID AND HIGH CLOUDINESS OVER THE NEXT COUPLE OF DAYS. A WEAK AREA
OF LOW PRESSURE WILL EVENTUALLY DEVELOP ALONG THE GULF COAST STATES
LATER FRIDAY AND MOVE EAST...PERHAPS BRINGING A PERIOD OF LIGHT
WINTRY PRECIPITATION ON SATURDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 1245 PM EST THURSDAY...

MOUNTAIN WAVE MID DECK THICK ENOUGH TO KEEP TEMPERATURES COOL
THROUGH EARLY THIS AFTERNOON. SHORT WAVE COMING ACROSS THE
SOUTHERN OHIO AND TENNESSEE VALLEYS WILL KICK THIS MOUNTAIN WAVE
ACTION EAST THROUGH THE AFTERNOON. COOLED TEMPERATURES A FEW
DEGREES ALONG THE BLUE RIDGE AND ACROSS THE FOOTHILLS DUE TO THESE
CLOUDS. MAINTAINED SPRINKLES FLURRIES THIS AFTERNOON AND INTO
TONIGHT AS SHORT WAVE SLIDE NORTH INTO THE OHIO VALLEY.


AS OF 215 AM EST THURSDAY...

OVERALL DRY WEATHER AND SEASONAL TEMPS TO CONTINUE OVER THE NEXT 24
HOURS WITH WEAK SURFACE RIDGING IN PLACE UNDER A FAST/CONFLUENT FLOW
ALOFT. HOWEVER THE DEGREE OF CLOUDS AND WHETHER OR NOT ANY
SPRINKLES/FLURRIES WILL OCCUR REMAINS IN QUESTION GIVEN THE APPROACH
OF DECENT MID LEVEL ENERGY FROM THE WEST TODAY OVERTOP VERY DRY AIR IN
PLACE. LATEST GUIDANCE SHOWING LITTLE IN THE WAY OF PRECIP...WITH THIS
WAVE NOW BACK OVER THE MIDWEST...MAKING IT ACROSS THE MOUNTAINS BUT DO
HAVE QUITE A BIT OF MID/HIGH CLOUDS PER RH SECTIONS. LATEST FORECAST
SOUNDINGS ALSO SHOW EXTENSIVE DRY AIR BENEATH THE MID DECK SO
DOUBTING MUCH IN THE WAY OF LIGHT PRECIP EXCEPT POSSIBLY THE FAR
WESTERN SLOPES. THUS TRIMMED BACK THE GOING COVERAGE OF SPRINKLES WITH
ONLY A BRIEF MENTION FAR WEST THIS AFTERNOON. OTRW LOOKING AT INTERVALS
OF SUN EARLY...OUTSIDE LINGERING UPSLOPE LOW CLOUDS WESTERN SLOPES...
WITH A PERIOD OF MORE MID DECK CLOUDS INTO THE AFTERNOON/EARLY EVENING.
BRIEF FLUX OF FAINT WARM ADVECTION AHEAD OF THE SHORTWAVE MAY PUSH
TEMPS OVER THE SE TO AROUND 50...WHILE MOST OTHER LOCATIONS
STRUGGLE IN THE UPPER 30S TO MID 40S ESPCLY IF CLOUDS ARE FASTER
TO ARRIVE WHICH COULD MEAN MORE 30S FOR HIGHS MOUNTAINS.

WAVE ALOFT PASSES EAST OVERNIGHT LEAVING WEAK SUBSIDENCE IN PLACE
AS HIGH PRESSURE TO THE NW NOSES BACK IN LATE. THIS WILL ALSO
INTRO ANOTHER ROUND OF WEAK COLD ADVECTION ALLOWING UPSLOPE CLOUDS TO
REDEVELOP FARTHER EAST...PERHAPS REACHING THE BLUE RIDGE BY DAYBREAK.
OTRW EXPECTING SLOW CLEARING OF THE MID/HIGH CLOUDS FROM WEST TO EAST
AFTER MIDNIGHT WITH INFILTRATION OF LOW DECK ACROSS THE FAR WEST LATE.
WENT CLOSER TO THE SLIGHTLY WARMER MET MOS AGAIN TONIGHT FOR TEMPS PER
LINGERING GRADIENT GIVEN THE PARENT HIGH TO THE NW AND SOME CLOUDS
PERSISTING AT TIMES.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY NIGHT/...
AS OF 300 AM EST THURSDAY...

FRIDAY LOOKS TO BE ON THE DRY SIDE AS HIGH PRESSURE STRETCHING FROM
THE GREAT LAKES THROUGH THE OHIO RIVER VALLEY REMAINS THE MAIN
FEATURE IN OUR WEATHER PATTERN. MOSTLY SUNNY SKIES AND LIGHT
NORTHWESTERLY DOWNSLOPE WINDS WILL ALLOW AFTERNOON TEMPERATURES TO
RANGE FROM THE UPPER 30S ALONG THE WESTERN RIDGES...TO AROUND 50
OVER THE SOUTHSIDE AND THE NORTH CAROLINA PIEDMONT. EXPECT TO SEE
HIGH CLOUDS INCREASING DURING THE EVENING...WITH WINDS BECOMING
INCREASINGLY NORTHEASTERLY AFTER MIDNIGHT...AS THE HIGH SHIFTS EAST
ACROSS THE GREAT LAKES AND BEGINS TO BUILD SOUTHWARD AGAINST THE
EASTERN FACE OF THE APPALACHIANS. COOL AIR FLOWING IN FROM THE NORTH
AND RADIATIONAL COOLING DESPITE THE HIGH CLOUDS WILL ALLOW OVERNIGHT
LOWS TO FALL INTO THE UPPER 20S TO LOW 30S.

18/00Z FORECAST MODELS CONTINUE TO TREND WEAKER AND SLOWER WITH THE
UPPER LEVEL TROUGH MOVING EAST OVER THE GREAT PLAINS AND ITS
ASSOCIATED SURFACE LOW DEVELOPING ALONG THE GULF COAST FRIDAY NIGHT.
MODELS ARE IN GENERAL AGREEMENT FOR PRECIPITATION TO ENTER THE NORTH
CAROLINA HIGHLANDS SHORTLY BEFORE DAWN ON SATURDAY. FOR THIS
MORNING`S FORECAST...STILL PRETTY CONFIDENT THAT MOST AREAS WILL SEE
MEASURABLE PRECIPITATION DESPITE MODELS TRENDING TOWARD A DRIER
SYSTEM...SO WILL MAINTAIN HIGH PRECIPITATION CHANCES. HOWEVER...HAVE
CUT DOWN ON PRECIPITATION AMOUNTS...WITH MOST LOCATIONS BELOW 0.25
INCHES OF LIQUID EQUIVALENT PRECIPITATION.

PRECIPITATION TYPE IS ALSO A CHALLENGE. THE ATMOSPHERE WILL START
THE NIGHT OUT DRY...WITH THE TEMPERATURE PROFILE IN THE LOWEST FEW
THOUSAND FEET OF THE ATMOSPHERE HOVERING WITHIN A FEW DEGREES OF
EITHER SIDE OF THE FREEZING MARK...DEPENDING ON LOCATION. IF HEAVIER
PRECIPITATION MOVES INTO THE AREA...IT WILL CAUSE THE ATMOSPHERE TO
MOISTEN AND THE TEMPERATURE PROFILE TO COOL...MAKING IT MORE LIKELY
TO START AS SLEET OR SNOW. LIGHT PRECIPITATION MAY MANAGE TO START
AS RAIN...ESPECIALLY ACROSS THE SLIGHTLY WARMER EASTERN HALF OF THE
AREA...BEFORE CHANGING OVER TO SLEET/SNOW TOWARD DAWN. ULTIMATELY
WENT ON THE PESSIMISTIC SIDE...TRENDING MORE TOWARDS FROZEN
PRECIPITATION TO START THE EVENT. BEST BET FOR ACCUMULATING SNOWFALL
WILL BE ON THE HIGHER RIDGES...WITH UP TO 2 INCHES POSSIBLE ALONG
THE BLUE RIDGE AND OTHER HIGHER RIDGELINES...AND LOCALLY HIGHER
AMOUNTS.

PRECIPITATION WILL PASS ACROSS THE AREA SATURDAY AND THE EARLY HALF
OF SATURDAY NIGHT. UNDERCUT MODEL GUIDANCE BY SEVERAL DEGREES FOR
FORECAST HIGHS CONSIDERING PRECIPITATION MOVING ACROSS THE AREA IN
EAST NORTHEASTERLY WIND FLOW. MOST PRECIPITATION WILL BE EAST OF THE
AREA AFTER MIDNIGHT SUNDAY...WITH YET ANOTHER HIGH PRESSURE WEDGE
BUILDING OVER THE MID ATLANTIC. ANOTHER LOW PRESSURE SYSTEM WILL
DEVELOP ALONG THE GULF COAST SUNDAY NIGHT...RADIATING MOISTURE
NORTHWARD AND INTRODUCING ANOTHER CHANCE OF RAIN...AND POTENTIALLY
FREEZING PRECIPITATION TO THE MOUNTAINS.

&&

.LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 400 AM EST THURSDAY...

THIS PORTION OF THE FORECAST HAS THE POTENTIAL TO BE AN ACTIVE
WEATHER PATTERN BASED UPON THE VARIOUS MODELS. HOWEVER...THESE SAME
MODELS OFFER ENOUGH DIFFERENCES TO MAKE THE DETAILS OF THE SENSIBLE
WEATHER ENOUGH OF CHALLENGE THAT CONFIDENCE IN THE SPECIFICS IS NOT
HIGH.

BY MONDAY...LATEST MODELS SHOW LOW PRESSURE ALONG THE NORTH
CAROLINA COAST WITH ANOTHER AXIS OF PRECIP MOVING NORTH ASSOCIATED
WITH INCREASING WARM ADVECTION AHEAD OF THE DEVELOPING LONGWAVE
TROUGH TO THE WEST. DEPENDING UPON HOW MUCH OR LITTLE THIS SYSTEM
DEEPENS WILL CORRELATE TO HOW LONG ANY ASSOCIATED PRECIPITATION
REMAINS OVER OUR REGION. THE PRECIPITATION TYPE ACROSS THE AREA IS
ALSO A QUESTION. EACH MODEL HAS A DIFFERENT TAKE ON THE MAGNITUDE
OF THE WARM NOSE OVER OUR REGION. THE ONLY CONSISTENT ELEMENT IS
THE EXISTENCE OF A WARM NOSE. GIVEN THIS...WILL OFFER RAIN VERSUS
FREEZING RAIN FORECAST DURING MUCH OF THE MONDAY PORTION OF THE
FORECAST. HOWEVER DESPITE QUITE A BIT OF WARMING ALOFT OFF THE
LATEST 00Z EC MODEL...THERMAL PROFILES SUGGEST SOME POTENTIAL FOR
LIGHT FREEZING RAIN OR SLEET ACROSS THE VIRGINIA HIGHLANDS AND
SOUTHERN SHENANDOAH VALLEY SECTIONS ESPCLY MONDAY MORNING.
PRECIPITATION CHANCES THOUGH WILL BE ON THE LOW SIDE...MAINLY
RANGING IN THE SLIGHT CHANCE CATEGORY FOR NOW WHICH MAY HAVE TO BE
RAMPED UP LATER TODAY.

BY MONDAY NIGHT...GUIDANCE IS IN FAIRLY GOOD AGREEMENT OF BRINGING A
CANADIAN LOW PRESSURE SYSTEM INTO THE NORTHERN MISSISSIPPI VALLEY.
FROM THAT POINT...A DEEP LONGITUDINAL TROUGH DEVELOPS SOUTH TO THE
GULF OF MEXICO BY TUESDAY AFTERNOON WITH INCREASING SOUTHERLY LOW
LEVEL FLOW ACROSS OUR REGION...ACCOMPANIED BY AN INCREASING MOISTURE
FETCH. BY TUESDAY NIGHT INTO EARLY WEDNESDAY...BOTH THE GFS AND
ECWMF CONTINUE TO DEEPEN THE UPPER LOW AND ASSOCIATED TROUGH AND
NEGATIVELY TILT THE FEATURE SO THAT THE TROUGH AXIS SHIFTS TO OFF
THE COAST OF THE CAROLINAS...COINCIDENT TO THE POSITION OF THE
ASSOCIATED SURFACE OCCLUDED FRONT....WITH THE TRIPLE POINT PASSING
SOMEWHERE NEAR OR JUST SOUTH OF OUR REGION. THIS PAINTS A PICTURE OF
VERY ACTIVE WEATHER ACROSS OUR REGION LATE TUESDAY NIGHT INTO
WEDNESDAY WITH PLENTY OF SHOWERS...VERY GUSTY...IF NOT DAMAGING...
WINDS...AND IF THE TRIPLE POINT PROGNOSTIC IS ACCURATE...SEVERE
WEATHER...OR AT LEAST A RUMBLE OR TWO OF THUNDER...OVER OR VERY
CLOSE TO OUR REGION OF THE COUNTRY. HOWEVER...THIS SCENARIO STILL IS
DAY 6 INTO DAY 7 OF THE FORECAST...AND THERE IS PLENTY OF TIME FOR
CHANGES IN THE OPERATIONAL MODELS TO TREND TOWARD A LESS AGGRESSIVE
SYSTEM. GIVEN THIS...WILL OFFER A FORECAST LATE MONDAY NIGHT INTO
TUESDAY THAT OFFERS INCREASING CHANCES OF LIGHT RAIN OR FREEZING RAIN
WITH LIGHT TO MODERATE RAIN ON TUESDAY...WITH MODERATE RAIN
SHOWERS TUESDAY NIGHT INTO EARLY WEDNESDAY ALONG WITH GUSTY WINDS.
TIMING OF THE PUSH OF COLDER AIR INTO THE REGION AS WELL AS THE
MAGNITUDE OF THAT COLDER AIR VARIES BETWEEN THE GFS AND ECWMF.
HOWEVER...THE FORECAST WILL ALLOW FOR THE POTENTIAL FOR COLD
ENOUGH AIR TO REACH WESTERN...HIGHER PARTS OF THE AREA LATE
TUESDAY NIGHT INTO WEDNESDAY FOR ACCUMULATING SNOW SHOWERS.

TEMPERATURES DURING THIS PORTION OF THE FORECAST WILL TREND MILDER
THROUGH AT LEAST TUESDAY. WEDNESDAY MAY BE A BIT MILDER IN THE
EAST...AND SLIGHTLY COOLER IN THE WEST AS COMPARED TO TUESDAY. ALL
DAYS OF THIS PORTION OF THE FORECAST ARE EXPECTED TO BE ABOVE NORMAL
FOR THIS TIME OF YEAR.

&&

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AS OF 1250 PM EST THURSDAY...

MOST OF THE REGION WILL EXPERIENCE VFR CONDITIONS THROUGH THE NEXT
24 HOURS WITH MAINLY INTERVALS OF MID AND HIGH CLOUDS PASSING
ACROSS. THE EXCEPTION WILL BE THE THOSE AREAS MAINLY ALONG AND
WEST OF A KBLF-KLWB LINE WHERE RETURNING LOW LEVEL MOISTURE WILL
MAKE FOR LOWER STRATO-CU CIGS OVERNIGHT INTO FRIDAY MORNING.

EXTENDED DISCUSSION...

THE FRI NIGHT-SAT SYSTEM NOW HAS TRENDED WEAKER BUT WILL STILL
NEED TO BE WATCHED AS IT WILL LIKELY BRING A PERIOD OF SUB VFR
WINTRY WEATHER ESPECIALLY FROM THE BLUE RIDGE WEST SAT.

AVIATION INTERESTS WILL NEED TO MONITOR THIS SITUATION AS LATER
FORECASTS BECOME AVAILABLE. THIS WILL LIKELY HAVE AN IMPACT ON AIR
TRAVEL OVER THE WEEKEND...FROM THE SOUTHERN APPALACHIANS AND
CAROLINAS NORTH TO THE MID ATLANTIC.

ON THE HEELS OF THIS FRIDAY/SATURDAY SYSTEM WILL BE ANOTHER SYSTEM
TO POTENTIALLY IMPACT MAINLY THE EASTERN PORTION OF THE REGION
MONDAY INTO TUESDAY. ANOTHER AREA OF LOW PRESSURE IS EXPECTED TO
HEAD NORTH ALONG THE EAST COAST WITH SCATTERED PRECIPITATION ON
ITS WESTERN FLANKS ENTERING THE REGION. AT THIS POINT A WINTRY MIX
IS POSSIBLE ALONG WITH LOCALIZED MVFR CIGS.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...JH
NEAR TERM...JH/RCS
SHORT TERM...NF
LONG TERM...DS/JH
AVIATION...JH/RCS




000
FXUS61 KRNK 181144
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
644 AM EST THU DEC 18 2014

.SYNOPSIS...
HIGH PRESSURE OVER THE UPPER MIDWEST WILL GRADUALLY BUILD EAST
ACROSS THE AREA RESULTING IN OVERALL DRY WEATHER THROUGH FRIDAY.
HOWEVER PASSING UPPER LEVEL DISTURBANCES WILL RESULT IN PERIODS OF
MID AND HIGH CLOUDINESS OVER THE NEXT COUPLE OF DAYS. A WEAK AREA
OF LOW PRESSURE WILL EVENTUALLY DEVELOP ALONG THE GULF COAST STATES
LATER FRIDAY AND MOVE EAST...PERHAPS BRINGING A PERIOD OF LIGHT
WINTRY PRECIPITATION ON SATURDAY.
&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 215 AM EST THURSDAY...

OVERALL DRY WEATHER AND SEASONAL TEMPS TO CONTINUE OVER THE NEXT 24
HOURS WITH WEAK SURFACE RIDGING IN PLACE UNDER A FAST/CONFLUENT FLOW
ALOFT. HOWEVER THE DEGREE OF CLOUDS AND WHETHER OR NOT ANY
SPRINKLES/FLURRIES WILL OCCUR REMAINS IN QUESTION GIVEN THE APPROACH
OF DECENT MID LEVEL ENERGY FROM THE WEST TODAY OVERTOP VERY DRY AIR IN
PLACE. LATEST GUIDANCE SHOWING LITTLE IN THE WAY OF PRECIP...WITH THIS
WAVE NOW BACK OVER THE MIDWEST...MAKING IT ACROSS THE MOUNTAINS BUT DO
HAVE QUITE A BIT OF MID/HIGH CLOUDS PER RH SECTIONS. LATEST FORECAST
SOUNDINGS ALSO SHOW EXTENSIVE DRY AIR BENEATH THE MID DECK SO
DOUBTING MUCH IN THE WAY OF LIGHT PRECIP EXCEPT POSSIBLY THE FAR
WESTERN SLOPES. THUS TRIMMED BACK THE GOING COVERAGE OF SPRINKLES WITH
ONLY A BRIEF MENTION FAR WEST THIS AFTERNOON. OTRW LOOKING AT INTERVALS
OF SUN EARLY...OUTSIDE LINGERING UPSLOPE LOW CLOUDS WESTERN SLOPES...
WITH A PERIOD OF MORE MID DECK CLOUDS INTO THE AFTERNOON/EARLY EVENING.
BRIEF FLUX OF FAINT WARM ADVECTION AHEAD OF THE SHORTWAVE MAY PUSH
TEMPS OVER THE SE TO AROUND 50...WHILE MOST OTHER LOCATIONS
STRUGGLE IN THE UPPER 30S TO MID 40S ESPCLY IF CLOUDS ARE FASTER
TO ARRIVE WHICH COULD MEAN MORE 30S FOR HIGHS MOUNTAINS.

WAVE ALOFT PASSES EAST OVERNIGHT LEAVING WEAK SUBSIDENCE IN PLACE
AS HIGH PRESSURE TO THE NW NOSES BACK IN LATE. THIS WILL ALSO
INTRO ANOTHER ROUND OF WEAK COLD ADVECTION ALLOWING UPSLOPE CLOUDS TO
REDEVELOP FARTHER EAST...PERHAPS REACHING THE BLUE RIDGE BY DAYBREAK.
OTRW EXPECTING SLOW CLEARING OF THE MID/HIGH CLOUDS FROM WEST TO EAST
AFTER MIDNIGHT WITH INFILTRATION OF LOW DECK ACROSS THE FAR WEST LATE.
WENT CLOSER TO THE SLIGHTLY WARMER MET MOS AGAIN TONIGHT FOR TEMPS PER
LINGERING GRADIENT GIVEN THE PARENT HIGH TO THE NW AND SOME CLOUDS
PERSISTING AT TIMES.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY NIGHT/...
AS OF 300 AM EST THURSDAY...

FRIDAY LOOKS TO BE ON THE DRY SIDE AS HIGH PRESSURE STRETCHING FROM
THE GREAT LAKES THROUGH THE OHIO RIVER VALLEY REMAINS THE MAIN
FEATURE IN OUR WEATHER PATTERN. MOSTLY SUNNY SKIES AND LIGHT
NORTHWESTERLY DOWNSLOPE WINDS WILL ALLOW AFTERNOON TEMPERATURES TO
RANGE FROM THE UPPER 30S ALONG THE WESTERN RIDGES...TO AROUND 50
OVER THE SOUTHSIDE AND THE NORTH CAROLINA PIEDMONT. EXPECT TO SEE
HIGH CLOUDS INCREASING DURING THE EVENING...WITH WINDS BECOMING
INCREASINGLY NORTHEASTERLY AFTER MIDNIGHT...AS THE HIGH SHIFTS EAST
ACROSS THE GREAT LAKES AND BEGINS TO BUILD SOUTHWARD AGAINST THE
EASTERN FACE OF THE APPALACHIANS. COOL AIR FLOWING IN FROM THE NORTH
AND RADIATIONAL COOLING DESPITE THE HIGH CLOUDS WILL ALLOW OVERNIGHT
LOWS TO FALL INTO THE UPPER 20S TO LOW 30S.

18/00Z FORECAST MODELS CONTINUE TO TREND WEAKER AND SLOWER WITH THE
UPPER LEVEL TROUGH MOVING EAST OVER THE GREAT PLAINS AND ITS
ASSOCIATED SURFACE LOW DEVELOPING ALONG THE GULF COAST FRIDAY NIGHT.
MODELS ARE IN GENERAL AGREEMENT FOR PRECIPITATION TO ENTER THE NORTH
CAROLINA HIGHLANDS SHORTLY BEFORE DAWN ON SATURDAY. FOR THIS
MORNING`S FORECAST...STILL PRETTY CONFIDENT THAT MOST AREAS WILL SEE
MEASURABLE PRECIPITATION DESPITE MODELS TRENDING TOWARD A DRIER
SYSTEM...SO WILL MAINTAIN HIGH PRECIPITATION CHANCES. HOWEVER...HAVE
CUT DOWN ON PRECIPITATION AMOUNTS...WITH MOST LOCATIONS BELOW 0.25
INCHES OF LIQUID EQUIVALENT PRECIPITATION.

PRECIPITATION TYPE IS ALSO A CHALLENGE. THE ATMOSPHERE WILL START
THE NIGHT OUT DRY...WITH THE TEMPERATURE PROFILE IN THE LOWEST FEW
THOUSAND FEET OF THE ATMOSPHERE HOVERING WITHIN A FEW DEGREES OF
EITHER SIDE OF THE FREEZING MARK...DEPENDING ON LOCATION. IF HEAVIER
PRECIPITATION MOVES INTO THE AREA...IT WILL CAUSE THE ATMOSPHERE TO
MOISTEN AND THE TEMPERATURE PROFILE TO COOL...MAKING IT MORE LIKELY
TO START AS SLEET OR SNOW. LIGHT PRECIPITATION MAY MANAGE TO START
AS RAIN...ESPECIALLY ACROSS THE SLIGHTLY WARMER EASTERN HALF OF THE
AREA...BEFORE CHANGING OVER TO SLEET/SNOW TOWARD DAWN. ULTIMATELY
WENT ON THE PESSIMISTIC SIDE...TRENDING MORE TOWARDS FROZEN
PRECIPITATION TO START THE EVENT. BEST BET FOR ACCUMULATING SNOWFALL
WILL BE ON THE HIGHER RIDGES...WITH UP TO 2 INCHES POSSIBLE ALONG
THE BLUE RIDGE AND OTHER HIGHER RIDGELINES...AND LOCALLY HIGHER
AMOUNTS.

PRECIPITATION WILL PASS ACROSS THE AREA SATURDAY AND THE EARLY HALF
OF SATURDAY NIGHT. UNDERCUT MODEL GUIDANCE BY SEVERAL DEGREES FOR
FORECAST HIGHS CONSIDERING PRECIPITATION MOVING ACROSS THE AREA IN
EAST NORTHEASTERLY WIND FLOW. MOST PRECIPITATION WILL BE EAST OF THE
AREA AFTER MIDNIGHT SUNDAY...WITH YET ANOTHER HIGH PRESSURE WEDGE
BUILDING OVER THE MID ATLANTIC. ANOTHER LOW PRESSURE SYSTEM WILL
DEVELOP ALONG THE GULF COAST SUNDAY NIGHT...RADIATING MOISTURE
NORTHWARD AND INTRODUCING ANOTHER CHANCE OF RAIN...AND POTENTIALLY
FREEZING PRECIPITATION TO THE MOUNTAINS.

&&

.LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 400 AM EST THURSDAY...

THIS PORTION OF THE FORECAST HAS THE POTENTIAL TO BE AN ACTIVE
WEATHER PATTERN BASED UPON THE VARIOUS MODELS. HOWEVER...THESE SAME
MODELS OFFER ENOUGH DIFFERENCES TO MAKE THE DETAILS OF THE SENSIBLE
WEATHER ENOUGH OF CHALLENGE THAT CONFIDENCE IN THE SPECIFICS IS NOT
HIGH.

BY MONDAY...LATEST MODELS SHOW LOW PRESSURE ALONG THE NORTH
CAROLINA COAST WITH ANOTHER AXIS OF PRECIP MOVING NORTH ASSOCIATED
WITH INCREASING WARM ADVECTION AHEAD OF THE DEVELOPING LONGWAVE
TROUGH TO THE WEST. DEPENDING UPON HOW MUCH OR LITTLE THIS SYSTEM
DEEPENS WILL CORRELATE TO HOW LONG ANY ASSOCIATED PRECIPITATION
REMAINS OVER OUR REGION. THE PRECIPITATION TYPE ACROSS THE AREA IS
ALSO A QUESTION. EACH MODEL HAS A DIFFERENT TAKE ON THE MAGNITUDE
OF THE WARM NOSE OVER OUR REGION. THE ONLY CONSISTENT ELEMENT IS
THE EXISTENCE OF A WARM NOSE. GIVEN THIS...WILL OFFER RAIN VERSUS
FREEZING RAIN FORECAST DURING MUCH OF THE MONDAY PORTION OF THE
FORECAST. HOWEVER DESPITE QUITE A BIT OF WARMING ALOFT OFF THE
LATEST 00Z EC MODEL...THERMAL PROFILES SUGGEST SOME POTENTIAL FOR
LIGHT FREEZING RAIN OR SLEET ACROSS THE VIRGINIA HIGHLANDS AND
SOUTHERN SHENANDOAH VALLEY SECTIONS ESPCLY MONDAY MORNING.
PRECIPITATION CHANCES THOUGH WILL BE ON THE LOW SIDE...MAINLY
RANGING IN THE SLIGHT CHANCE CATEGORY FOR NOW WHICH MAY HAVE TO BE
RAMPED UP LATER TODAY.

BY MONDAY NIGHT...GUIDANCE IS IN FAIRLY GOOD AGREEMENT OF BRINGING A
CANADIAN LOW PRESSURE SYSTEM INTO THE NORTHERN MISSISSIPPI VALLEY.
FROM THAT POINT...A DEEP LONGITUDINAL TROUGH DEVELOPS SOUTH TO THE
GULF OF MEXICO BY TUESDAY AFTERNOON WITH INCREASING SOUTHERLY LOW
LEVEL FLOW ACROSS OUR REGION...ACCOMPANIED BY AN INCREASING MOISTURE
FETCH. BY TUESDAY NIGHT INTO EARLY WEDNESDAY...BOTH THE GFS AND
ECWMF CONTINUE TO DEEPEN THE UPPER LOW AND ASSOCIATED TROUGH AND
NEGATIVELY TILT THE FEATURE SO THAT THE TROUGH AXIS SHIFTS TO OFF
THE COAST OF THE CAROLINAS...COINCIDENT TO THE POSITION OF THE
ASSOCIATED SURFACE OCCLUDED FRONT....WITH THE TRIPLE POINT PASSING
SOMEWHERE NEAR OR JUST SOUTH OF OUR REGION. THIS PAINTS A PICTURE OF
VERY ACTIVE WEATHER ACROSS OUR REGION LATE TUESDAY NIGHT INTO
WEDNESDAY WITH PLENTY OF SHOWERS...VERY GUSTY...IF NOT DAMAGING...
WINDS...AND IF THE TRIPLE POINT PROGNOSTIC IS ACCURATE...SEVERE
WEATHER...OR AT LEAST A RUMBLE OR TWO OF THUNDER...OVER OR VERY
CLOSE TO OUR REGION OF THE COUNTRY. HOWEVER...THIS SCENARIO STILL IS
DAY 6 INTO DAY 7 OF THE FORECAST...AND THERE IS PLENTY OF TIME FOR
CHANGES IN THE OPERATIONAL MODELS TO TREND TOWARD A LESS AGGRESSIVE
SYSTEM. GIVEN THIS...WILL OFFER A FORECAST LATE MONDAY NIGHT INTO
TUESDAY THAT OFFERS INCREASING CHANCES OF LIGHT RAIN OR FREEZING RAIN
WITH LIGHT TO MODERATE RAIN ON TUESDAY...WITH MODERATE RAIN
SHOWERS TUESDAY NIGHT INTO EARLY WEDNESDAY ALONG WITH GUSTY WINDS.
TIMING OF THE PUSH OF COLDER AIR INTO THE REGION AS WELL AS THE
MAGNITUDE OF THAT COLDER AIR VARIES BETWEEN THE GFS AND ECWMF.
HOWEVER...THE FORECAST WILL ALLOW FOR THE POTENTIAL FOR COLD
ENOUGH AIR TO REACH WESTERN...HIGHER PARTS OF THE AREA LATE
TUESDAY NIGHT INTO WEDNESDAY FOR ACCUMULATING SNOW SHOWERS.

TEMPERATURES DURING THIS PORTION OF THE FORECAST WILL TREND MILDER
THROUGH AT LEAST TUESDAY. WEDNESDAY MAY BE A BIT MILDER IN THE
EAST...AND SLIGHTLY COOLER IN THE WEST AS COMPARED TO TUESDAY. ALL
DAYS OF THIS PORTION OF THE FORECAST ARE EXPECTED TO BE ABOVE NORMAL
FOR THIS TIME OF YEAR.

&&

.AVIATION /11Z THURSDAY THROUGH MONDAY/...
AS OF 620 AM EST THURSDAY...

MOST OF THE REGION WILL EXPERIENCE VFR CONDITIONS THROUGH THE NEXT
24 HOURS WITH MAINLY INTERVALS OF MID AND HIGH CLOUDS PASSING
ACROSS. THE EXCEPTION WILL BE THE THOSE AREAS MAINLY ALONG AND
WEST OF A KBLF-KLWB LINE WHERE LINGERING LOW LEVEL MOISTURE WILL
MAKE FOR LOWER STRATO-CU CIGS THIS MORNING. HOWEVER MODELS FAVOR
KBLF LIFTING TO VFR AFTER 15Z/10AM SO KEPT SIMILAR TIMING TO
PREVIOUS ON LIFTING OUT THE LOW DECK. GUSTY NW WINDS WINDS THIS
MORNING WILL ALSO WEAKEN WITH SPEEDS MAINLY IN THE 8-15 KT RANGE
THIS AFTERNOON.

HIGH PRESSURE EXTENDING INTO THE AREA FROM THE NW WILL MAINTAIN
MAINLY VFR CONDITIONS OVERNIGHT INTO FRIDAY. HOWEVER LOW LEVEL
MOISTURE MAY AGAIN CAUSE UPSLOPE INDUCED MVFR CIGS ACROSS SE WEST
VA TO SPILL EAST TOWARD THE BLUE RIDGE LATE TONIGHT INTO FRIDAY
MORNING. SOME CHANCE FOR KBLF TO DROP INTO IFR LATE TONIGHT OTRW
KEEPING MVFR LEVELS MOSTLY AT KBLF/KLWB.

EXTENDED DISCUSSION...

THE FRI NIGHT-SAT SYSTEM NOW HAS TRENDED WEAKER BUT WILL STILL
NEED TO BE WATCHED AS IT WILL LIKELY BRING A PERIOD OF SUB VFR
WINTRY WEATHER ESPECIALLY FROM THE BLUE RIDGE WEST SAT.

AVIATION INTERESTS WILL NEED TO MONITOR THIS SITUATION AS LATER
FORECASTS BECOME AVAILABLE. THIS WILL LIKELY HAVE AN IMPACT ON AIR
TRAVEL OVER THE WEEKEND...FROM THE SOUTHERN APPALACHIANS AND
CAROLINAS NORTH TO THE MID ATLANTIC.

ON THE HEELS OF THIS FRIDAY/SATURDAY SYSTEM WILL BE ANOTHER SYSTEM
TO POTENTIALLY IMPACT MAINLY THE EASTERN PORTION OF THE REGION
MONDAY INTO TUESDAY. ANOTHER AREA OF LOW PRESSURE IS EXPECTED TO
HEAD NORTH ALONG THE EAST COAST WITH SCATTERED PRECIPITATION ON
ITS WESTERN FLANKS ENTERING THE REGION. AT THIS POINT A WINTRY MIX
IS POSSIBLE ALONG WITH LOCALIZED MVFR CIGS.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...JH
NEAR TERM...JH
SHORT TERM...NF
LONG TERM...DS/JH
AVIATION...DS/JH/PM/WP




000
FXUS61 KRNK 181144
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
644 AM EST THU DEC 18 2014

.SYNOPSIS...
HIGH PRESSURE OVER THE UPPER MIDWEST WILL GRADUALLY BUILD EAST
ACROSS THE AREA RESULTING IN OVERALL DRY WEATHER THROUGH FRIDAY.
HOWEVER PASSING UPPER LEVEL DISTURBANCES WILL RESULT IN PERIODS OF
MID AND HIGH CLOUDINESS OVER THE NEXT COUPLE OF DAYS. A WEAK AREA
OF LOW PRESSURE WILL EVENTUALLY DEVELOP ALONG THE GULF COAST STATES
LATER FRIDAY AND MOVE EAST...PERHAPS BRINGING A PERIOD OF LIGHT
WINTRY PRECIPITATION ON SATURDAY.
&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 215 AM EST THURSDAY...

OVERALL DRY WEATHER AND SEASONAL TEMPS TO CONTINUE OVER THE NEXT 24
HOURS WITH WEAK SURFACE RIDGING IN PLACE UNDER A FAST/CONFLUENT FLOW
ALOFT. HOWEVER THE DEGREE OF CLOUDS AND WHETHER OR NOT ANY
SPRINKLES/FLURRIES WILL OCCUR REMAINS IN QUESTION GIVEN THE APPROACH
OF DECENT MID LEVEL ENERGY FROM THE WEST TODAY OVERTOP VERY DRY AIR IN
PLACE. LATEST GUIDANCE SHOWING LITTLE IN THE WAY OF PRECIP...WITH THIS
WAVE NOW BACK OVER THE MIDWEST...MAKING IT ACROSS THE MOUNTAINS BUT DO
HAVE QUITE A BIT OF MID/HIGH CLOUDS PER RH SECTIONS. LATEST FORECAST
SOUNDINGS ALSO SHOW EXTENSIVE DRY AIR BENEATH THE MID DECK SO
DOUBTING MUCH IN THE WAY OF LIGHT PRECIP EXCEPT POSSIBLY THE FAR
WESTERN SLOPES. THUS TRIMMED BACK THE GOING COVERAGE OF SPRINKLES WITH
ONLY A BRIEF MENTION FAR WEST THIS AFTERNOON. OTRW LOOKING AT INTERVALS
OF SUN EARLY...OUTSIDE LINGERING UPSLOPE LOW CLOUDS WESTERN SLOPES...
WITH A PERIOD OF MORE MID DECK CLOUDS INTO THE AFTERNOON/EARLY EVENING.
BRIEF FLUX OF FAINT WARM ADVECTION AHEAD OF THE SHORTWAVE MAY PUSH
TEMPS OVER THE SE TO AROUND 50...WHILE MOST OTHER LOCATIONS
STRUGGLE IN THE UPPER 30S TO MID 40S ESPCLY IF CLOUDS ARE FASTER
TO ARRIVE WHICH COULD MEAN MORE 30S FOR HIGHS MOUNTAINS.

WAVE ALOFT PASSES EAST OVERNIGHT LEAVING WEAK SUBSIDENCE IN PLACE
AS HIGH PRESSURE TO THE NW NOSES BACK IN LATE. THIS WILL ALSO
INTRO ANOTHER ROUND OF WEAK COLD ADVECTION ALLOWING UPSLOPE CLOUDS TO
REDEVELOP FARTHER EAST...PERHAPS REACHING THE BLUE RIDGE BY DAYBREAK.
OTRW EXPECTING SLOW CLEARING OF THE MID/HIGH CLOUDS FROM WEST TO EAST
AFTER MIDNIGHT WITH INFILTRATION OF LOW DECK ACROSS THE FAR WEST LATE.
WENT CLOSER TO THE SLIGHTLY WARMER MET MOS AGAIN TONIGHT FOR TEMPS PER
LINGERING GRADIENT GIVEN THE PARENT HIGH TO THE NW AND SOME CLOUDS
PERSISTING AT TIMES.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY NIGHT/...
AS OF 300 AM EST THURSDAY...

FRIDAY LOOKS TO BE ON THE DRY SIDE AS HIGH PRESSURE STRETCHING FROM
THE GREAT LAKES THROUGH THE OHIO RIVER VALLEY REMAINS THE MAIN
FEATURE IN OUR WEATHER PATTERN. MOSTLY SUNNY SKIES AND LIGHT
NORTHWESTERLY DOWNSLOPE WINDS WILL ALLOW AFTERNOON TEMPERATURES TO
RANGE FROM THE UPPER 30S ALONG THE WESTERN RIDGES...TO AROUND 50
OVER THE SOUTHSIDE AND THE NORTH CAROLINA PIEDMONT. EXPECT TO SEE
HIGH CLOUDS INCREASING DURING THE EVENING...WITH WINDS BECOMING
INCREASINGLY NORTHEASTERLY AFTER MIDNIGHT...AS THE HIGH SHIFTS EAST
ACROSS THE GREAT LAKES AND BEGINS TO BUILD SOUTHWARD AGAINST THE
EASTERN FACE OF THE APPALACHIANS. COOL AIR FLOWING IN FROM THE NORTH
AND RADIATIONAL COOLING DESPITE THE HIGH CLOUDS WILL ALLOW OVERNIGHT
LOWS TO FALL INTO THE UPPER 20S TO LOW 30S.

18/00Z FORECAST MODELS CONTINUE TO TREND WEAKER AND SLOWER WITH THE
UPPER LEVEL TROUGH MOVING EAST OVER THE GREAT PLAINS AND ITS
ASSOCIATED SURFACE LOW DEVELOPING ALONG THE GULF COAST FRIDAY NIGHT.
MODELS ARE IN GENERAL AGREEMENT FOR PRECIPITATION TO ENTER THE NORTH
CAROLINA HIGHLANDS SHORTLY BEFORE DAWN ON SATURDAY. FOR THIS
MORNING`S FORECAST...STILL PRETTY CONFIDENT THAT MOST AREAS WILL SEE
MEASURABLE PRECIPITATION DESPITE MODELS TRENDING TOWARD A DRIER
SYSTEM...SO WILL MAINTAIN HIGH PRECIPITATION CHANCES. HOWEVER...HAVE
CUT DOWN ON PRECIPITATION AMOUNTS...WITH MOST LOCATIONS BELOW 0.25
INCHES OF LIQUID EQUIVALENT PRECIPITATION.

PRECIPITATION TYPE IS ALSO A CHALLENGE. THE ATMOSPHERE WILL START
THE NIGHT OUT DRY...WITH THE TEMPERATURE PROFILE IN THE LOWEST FEW
THOUSAND FEET OF THE ATMOSPHERE HOVERING WITHIN A FEW DEGREES OF
EITHER SIDE OF THE FREEZING MARK...DEPENDING ON LOCATION. IF HEAVIER
PRECIPITATION MOVES INTO THE AREA...IT WILL CAUSE THE ATMOSPHERE TO
MOISTEN AND THE TEMPERATURE PROFILE TO COOL...MAKING IT MORE LIKELY
TO START AS SLEET OR SNOW. LIGHT PRECIPITATION MAY MANAGE TO START
AS RAIN...ESPECIALLY ACROSS THE SLIGHTLY WARMER EASTERN HALF OF THE
AREA...BEFORE CHANGING OVER TO SLEET/SNOW TOWARD DAWN. ULTIMATELY
WENT ON THE PESSIMISTIC SIDE...TRENDING MORE TOWARDS FROZEN
PRECIPITATION TO START THE EVENT. BEST BET FOR ACCUMULATING SNOWFALL
WILL BE ON THE HIGHER RIDGES...WITH UP TO 2 INCHES POSSIBLE ALONG
THE BLUE RIDGE AND OTHER HIGHER RIDGELINES...AND LOCALLY HIGHER
AMOUNTS.

PRECIPITATION WILL PASS ACROSS THE AREA SATURDAY AND THE EARLY HALF
OF SATURDAY NIGHT. UNDERCUT MODEL GUIDANCE BY SEVERAL DEGREES FOR
FORECAST HIGHS CONSIDERING PRECIPITATION MOVING ACROSS THE AREA IN
EAST NORTHEASTERLY WIND FLOW. MOST PRECIPITATION WILL BE EAST OF THE
AREA AFTER MIDNIGHT SUNDAY...WITH YET ANOTHER HIGH PRESSURE WEDGE
BUILDING OVER THE MID ATLANTIC. ANOTHER LOW PRESSURE SYSTEM WILL
DEVELOP ALONG THE GULF COAST SUNDAY NIGHT...RADIATING MOISTURE
NORTHWARD AND INTRODUCING ANOTHER CHANCE OF RAIN...AND POTENTIALLY
FREEZING PRECIPITATION TO THE MOUNTAINS.

&&

.LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 400 AM EST THURSDAY...

THIS PORTION OF THE FORECAST HAS THE POTENTIAL TO BE AN ACTIVE
WEATHER PATTERN BASED UPON THE VARIOUS MODELS. HOWEVER...THESE SAME
MODELS OFFER ENOUGH DIFFERENCES TO MAKE THE DETAILS OF THE SENSIBLE
WEATHER ENOUGH OF CHALLENGE THAT CONFIDENCE IN THE SPECIFICS IS NOT
HIGH.

BY MONDAY...LATEST MODELS SHOW LOW PRESSURE ALONG THE NORTH
CAROLINA COAST WITH ANOTHER AXIS OF PRECIP MOVING NORTH ASSOCIATED
WITH INCREASING WARM ADVECTION AHEAD OF THE DEVELOPING LONGWAVE
TROUGH TO THE WEST. DEPENDING UPON HOW MUCH OR LITTLE THIS SYSTEM
DEEPENS WILL CORRELATE TO HOW LONG ANY ASSOCIATED PRECIPITATION
REMAINS OVER OUR REGION. THE PRECIPITATION TYPE ACROSS THE AREA IS
ALSO A QUESTION. EACH MODEL HAS A DIFFERENT TAKE ON THE MAGNITUDE
OF THE WARM NOSE OVER OUR REGION. THE ONLY CONSISTENT ELEMENT IS
THE EXISTENCE OF A WARM NOSE. GIVEN THIS...WILL OFFER RAIN VERSUS
FREEZING RAIN FORECAST DURING MUCH OF THE MONDAY PORTION OF THE
FORECAST. HOWEVER DESPITE QUITE A BIT OF WARMING ALOFT OFF THE
LATEST 00Z EC MODEL...THERMAL PROFILES SUGGEST SOME POTENTIAL FOR
LIGHT FREEZING RAIN OR SLEET ACROSS THE VIRGINIA HIGHLANDS AND
SOUTHERN SHENANDOAH VALLEY SECTIONS ESPCLY MONDAY MORNING.
PRECIPITATION CHANCES THOUGH WILL BE ON THE LOW SIDE...MAINLY
RANGING IN THE SLIGHT CHANCE CATEGORY FOR NOW WHICH MAY HAVE TO BE
RAMPED UP LATER TODAY.

BY MONDAY NIGHT...GUIDANCE IS IN FAIRLY GOOD AGREEMENT OF BRINGING A
CANADIAN LOW PRESSURE SYSTEM INTO THE NORTHERN MISSISSIPPI VALLEY.
FROM THAT POINT...A DEEP LONGITUDINAL TROUGH DEVELOPS SOUTH TO THE
GULF OF MEXICO BY TUESDAY AFTERNOON WITH INCREASING SOUTHERLY LOW
LEVEL FLOW ACROSS OUR REGION...ACCOMPANIED BY AN INCREASING MOISTURE
FETCH. BY TUESDAY NIGHT INTO EARLY WEDNESDAY...BOTH THE GFS AND
ECWMF CONTINUE TO DEEPEN THE UPPER LOW AND ASSOCIATED TROUGH AND
NEGATIVELY TILT THE FEATURE SO THAT THE TROUGH AXIS SHIFTS TO OFF
THE COAST OF THE CAROLINAS...COINCIDENT TO THE POSITION OF THE
ASSOCIATED SURFACE OCCLUDED FRONT....WITH THE TRIPLE POINT PASSING
SOMEWHERE NEAR OR JUST SOUTH OF OUR REGION. THIS PAINTS A PICTURE OF
VERY ACTIVE WEATHER ACROSS OUR REGION LATE TUESDAY NIGHT INTO
WEDNESDAY WITH PLENTY OF SHOWERS...VERY GUSTY...IF NOT DAMAGING...
WINDS...AND IF THE TRIPLE POINT PROGNOSTIC IS ACCURATE...SEVERE
WEATHER...OR AT LEAST A RUMBLE OR TWO OF THUNDER...OVER OR VERY
CLOSE TO OUR REGION OF THE COUNTRY. HOWEVER...THIS SCENARIO STILL IS
DAY 6 INTO DAY 7 OF THE FORECAST...AND THERE IS PLENTY OF TIME FOR
CHANGES IN THE OPERATIONAL MODELS TO TREND TOWARD A LESS AGGRESSIVE
SYSTEM. GIVEN THIS...WILL OFFER A FORECAST LATE MONDAY NIGHT INTO
TUESDAY THAT OFFERS INCREASING CHANCES OF LIGHT RAIN OR FREEZING RAIN
WITH LIGHT TO MODERATE RAIN ON TUESDAY...WITH MODERATE RAIN
SHOWERS TUESDAY NIGHT INTO EARLY WEDNESDAY ALONG WITH GUSTY WINDS.
TIMING OF THE PUSH OF COLDER AIR INTO THE REGION AS WELL AS THE
MAGNITUDE OF THAT COLDER AIR VARIES BETWEEN THE GFS AND ECWMF.
HOWEVER...THE FORECAST WILL ALLOW FOR THE POTENTIAL FOR COLD
ENOUGH AIR TO REACH WESTERN...HIGHER PARTS OF THE AREA LATE
TUESDAY NIGHT INTO WEDNESDAY FOR ACCUMULATING SNOW SHOWERS.

TEMPERATURES DURING THIS PORTION OF THE FORECAST WILL TREND MILDER
THROUGH AT LEAST TUESDAY. WEDNESDAY MAY BE A BIT MILDER IN THE
EAST...AND SLIGHTLY COOLER IN THE WEST AS COMPARED TO TUESDAY. ALL
DAYS OF THIS PORTION OF THE FORECAST ARE EXPECTED TO BE ABOVE NORMAL
FOR THIS TIME OF YEAR.

&&

.AVIATION /11Z THURSDAY THROUGH MONDAY/...
AS OF 620 AM EST THURSDAY...

MOST OF THE REGION WILL EXPERIENCE VFR CONDITIONS THROUGH THE NEXT
24 HOURS WITH MAINLY INTERVALS OF MID AND HIGH CLOUDS PASSING
ACROSS. THE EXCEPTION WILL BE THE THOSE AREAS MAINLY ALONG AND
WEST OF A KBLF-KLWB LINE WHERE LINGERING LOW LEVEL MOISTURE WILL
MAKE FOR LOWER STRATO-CU CIGS THIS MORNING. HOWEVER MODELS FAVOR
KBLF LIFTING TO VFR AFTER 15Z/10AM SO KEPT SIMILAR TIMING TO
PREVIOUS ON LIFTING OUT THE LOW DECK. GUSTY NW WINDS WINDS THIS
MORNING WILL ALSO WEAKEN WITH SPEEDS MAINLY IN THE 8-15 KT RANGE
THIS AFTERNOON.

HIGH PRESSURE EXTENDING INTO THE AREA FROM THE NW WILL MAINTAIN
MAINLY VFR CONDITIONS OVERNIGHT INTO FRIDAY. HOWEVER LOW LEVEL
MOISTURE MAY AGAIN CAUSE UPSLOPE INDUCED MVFR CIGS ACROSS SE WEST
VA TO SPILL EAST TOWARD THE BLUE RIDGE LATE TONIGHT INTO FRIDAY
MORNING. SOME CHANCE FOR KBLF TO DROP INTO IFR LATE TONIGHT OTRW
KEEPING MVFR LEVELS MOSTLY AT KBLF/KLWB.

EXTENDED DISCUSSION...

THE FRI NIGHT-SAT SYSTEM NOW HAS TRENDED WEAKER BUT WILL STILL
NEED TO BE WATCHED AS IT WILL LIKELY BRING A PERIOD OF SUB VFR
WINTRY WEATHER ESPECIALLY FROM THE BLUE RIDGE WEST SAT.

AVIATION INTERESTS WILL NEED TO MONITOR THIS SITUATION AS LATER
FORECASTS BECOME AVAILABLE. THIS WILL LIKELY HAVE AN IMPACT ON AIR
TRAVEL OVER THE WEEKEND...FROM THE SOUTHERN APPALACHIANS AND
CAROLINAS NORTH TO THE MID ATLANTIC.

ON THE HEELS OF THIS FRIDAY/SATURDAY SYSTEM WILL BE ANOTHER SYSTEM
TO POTENTIALLY IMPACT MAINLY THE EASTERN PORTION OF THE REGION
MONDAY INTO TUESDAY. ANOTHER AREA OF LOW PRESSURE IS EXPECTED TO
HEAD NORTH ALONG THE EAST COAST WITH SCATTERED PRECIPITATION ON
ITS WESTERN FLANKS ENTERING THE REGION. AT THIS POINT A WINTRY MIX
IS POSSIBLE ALONG WITH LOCALIZED MVFR CIGS.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...JH
NEAR TERM...JH
SHORT TERM...NF
LONG TERM...DS/JH
AVIATION...DS/JH/PM/WP





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