-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KRNK 270056
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
756 PM EST THU FEB 26 2015

.SYNOPSIS...
A COLD FRONT WILL CROSS THE AREA OVERNIGHT. COLD HIGH PRESSURE
WILL BUILD IN BEHIND IT...AND BE ACROSS OUR AREA THROUGH SATURDAY.
SUNDAY THROUGH AT LEAST THE MIDDLE OF NEXT WEEK...A SERIES OF LOW
PRESSURE SYSTEMS HAVE THE POTENTIAL TO BRINGING MORE ROUNDS OF
PRECIPITATION TO OUR AREA...AND TEMPERATURES ON AVERAGE WILL BE
MILDER THAN THIS WEEK.

&&

.NEAR TERM /THROUGH FRIDAY/...
-- Changed Discussion --
AS OF 715 PM EST THURSDAY...

NOT SEEING ANYTHING ON RADAR IN OUR AREA NOR IN OBSERVATIONS.
MESOANALYSIS DEPICTS WEAK CONVERGENCE WITH THE SFC
TROUGH...THEREFORE LOWERED THREAT OF PRECIP THIS EVENING...THOUGH
FORECAST SOUNDINGS IN THE EAST SUGGEST POTENTIAL FOR A LITTLE
DZ/FZDZ. NEXT UPSTREAM SHORTWAVE WILL BE SHIFTING TOWARD THE WV
MTNS OVERNIGHT AND UPSLOPE SNOW SHOWERS STILL LOOK GOOD...THOUGH
THE OVERALL MOISTURE PROFILE STILL SUGGESTS LOW THREAT OF ANY
ACCUMULATION OVER 1-2 INCHES IN THE HIGHER TERRAIN OF WRN
GREENBRIER.

PREVIOUS VALID DISCUSSION...
A WINTER WEATHER ADVISORY REMAINS FOR BLACK ICE FOR OUR NORTH
CAROLINA COUNTIES VIA OUR WORKING POLICY WITH THAT STATE. FOR
SOUTHWEST VIRGINIA AND SOUTHEAST WEST VIRGINIA...A SPECIAL WEATHER
STATEMENT HIGHLIGHTING THE BLACK ICE WAS ISSUED.

EXPECT INCREASING NORTHWEST WINDS...THAT WILL BE FULLY REALIZED
DURING THE DAY FRIDAY AFTER THE BREAKING OF THE NOCTURNAL
INVERSION. COLDER AND LOWER DEW POINT AIR WILL WORK ITS WAY INTO
THE AREA OVERNIGHT.

A WEAK DISTURBANCE WILL RIDE PIGGY BACK WITH THE FRONT...AND BRING
THE POTENTIAL FOR SOME LIGHT PRECIPITATION TO AREAS EAST OF THE
CREST OF THE BLUE RIDGE...WHERE NORMAL THE IMPACT OF DOWNSLOPING
WIND WOULD LIMIT IF NOT COMPLETELY RULE OUT THE POTENTIAL FOR
PRECIPITATION. THIS DISTURBANCE IS EXPECTED TO BRING A SLIGHT CHANCE
OF PRECIPITATION TO AREAS NEAR THE NC/VA BORDER EAST OF THE
FOOTHILLS. THIS SATURATION WITHIN THIS AREA WILL BE LIMITED TO A
NARROW BAND BETWEEN 850 MB AND THE SURFACE. THE COLDEST TEMPERATURE
WITHIN THIS BAND WILL RANGE FROM ROUGHLY -8 TO -11 C. WITH VERY
LIMITED OPPORTUNITIES FOR DENDRITIC GROWTH...THE PRECIPITATION
FOR THIS PART OF THE FORECAST AREA IS MORE LIKELY TO BE FREEZING
RAIN...RATHER THAN SNOW. ALTHOUGH WITH -10 TO -11 C AS A COLD
LIMIT...WE CANNOT RULE OUT AT LEAST A LITTLE LIGHT SNOW WITHIN THE
MIX.

ON FRIDAY...NORTHWEST FLOW ALOFT AND INCREASING NORTHWEST SURFACE
WINDS WILL HAVE THE IMPACT OF A DOWNSLOPING COMPONENT THAT WILL
GRADUALLY ERODE THE CLOUD COVER EAST OF THE CREST OF THE BLUE RIDGE.
CLOUDS ACROSS THE MOUNTAINS WILL BE LESS LIKELY TO ERODE AS
FAST...AND UPSLOPE SNOW SHOWERS WILL CONTINUE...BUT TREND TOWARDS
DECREASING COVERAGE AND INTENSITY. HIGH TEMPERATURES TOMORROW WILL
RANGE FROM THE LOW TO MID 20S ACROSS THE MOUNTAINS WITH AROUND 30 TO
UPPER 30S ACROSS THE PIEDMONT.
-- End Changed Discussion --

&&

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

ZONAL PATTERN AT 500 MB THROUGH SUNDAY WITH NO SIGNIFICANT SHORT
WAVES THROUGH THE PERIOD. MID AND HIGH LEVEL CLOUDS MOVE IN FROM THE
WEST ON FRIDAY NIGHT AND SATURDAY. TRULY DEEP MOISTURE FILLS IN
ACROSS THE FORECAST AREA ON SATURDAY NIGHT AND SUNDAY. FRIDAY
NIGHT HAS THE POTENTIAL TO HAVE MINIMUM TEMPERATURES BELOW
GUIDANCE DUE TO SNOW COVER AND LIGHT WINDS. HOWEVER...CLOUD COVER
MAY COUNTERACT THAT COOLING. LEANED TOWARD BIAS CORRECTED ECMWF
GUIDANCE FOR LOWS ON FRIDAY NIGHT THEN MAV NUMBERS FOR SATURDAY
THROUGH SUNDAY.

HIGH PRESSURE THAT WILL BE CENTERED OVER THE OHIO VALLEY ON FRIDAY
NIGHT WILL MOVE EAST AND WEDGE DOWN THE EAST SIDE OF THE
APPALACHIANS ON SATURDAY AND SUNDAY. SFC AND LOW LEVEL WINDS WILL
HAVE AND EASTERLY COMPONENT BUT AT 850MB THE HIGH IS OFF THE
SOUTHEAST COAST AND FLOW AROUND THE HIGH BRINGS MOISTURE RIGHT
OUT OF THE GULF AND ADVECTS WARMER TEMPERATURES INTO THE REGION.
850MB TEMPERATURES RISE ABOVE ZERO ON SATURDAY NIGHT AND SUNDAY.
THE NAM IS MUCH FASTER THAN THE GFS/ECMWF BRINGING PRECIPITATION
BACK INTO THE COUNTY WARNING AREA ON SUNDAY. WILL KEEP BEST CHANCE
OF PRECIPITATION IN THE WESTERN COUNTY WARNING AREA LATE ON
SUNDAY.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 315 PM EST THURSDAY...

SHOWER ACTIVITY WILL INCREASE SUNDAY NIGHT AS ANOTHER COLD FRONT
APPROACHES THE REGION FROM THE WEST. INCREASED CLOUD COVER AND
SOUTHWESTERLY WINDS WILL MAINTAIN WARMER OVERNIGHT TEMPERATURES
COMPARED TO PREVIOUS NIGHTS...AND THEREFORE EXPECT MAINLY RAIN SOUTH
OF THE INTERSTATE 64 CORRIDOR...POSSIBLY BECOMING A WINTRY MIX
TOWARD SUNRISE MONDAY AS TEMPERATURES FALL NEAR FREEZING. ALONG AND
NORTH OF INTERSTATE 64...EXPECT POCKETS OF FREEZING RAIN OR SLEET TO
DEVELOP.

SOUTHWESTERLY WINDS WILL ALLOW FOR SIGNIFICANTLY WARMER TEMPERATURES
FOR MONDAY...WITH TEMPERATURES RANGING FROM THE MID 40S ACROSS
SOUTHEAST WEST VIRGINIA TO THE MID 50S ACROSS THE SOUTHSIDE. A COLD
FRONT WILL PASS ACROSS THE REGION DURING THE AFTERNOON...BRINGING A
NORTHWESTERLY WIND SHIFT AND AN INCREASE IN RAIN SHOWER ACTIVITY
ALONG THE BOUNDARY. SHOWERS WILL THEN DIMINISH IN COVERAGE DURING
THE EVENING IN THE DOWNSLOPE WINDFLOW...WITH A FEW SHOWERS LINGERING
ACROSS THE WESTERN SLOPES FROM WEST VIRGINIA INTO NORTHERN NORTH
CAROLINA.

HIGH PRESSURE WILL BUILD ACROSS THE SOUTHERN GREAT LAKES MONDAY
EVENING...EVENTUALLY CROSSING TO NEW ENGLAND...WHERE IT WILL THEN
BUILD SOUTHWARD ACROSS THE MID ATLANTIC BY TUESDAY MORNING. ANOTHER
DEEPER LOW PRESSURE SYSTEM WILL DEVELOP OVER THE PLAINS ON
TUESDAY...AND PUSH RAPIDLY NORTHEAST TOWARD THE GREAT LAKES. COLD
SURFACE TEMPERATURES PROVIDED BY HIGH PRESSURE COMBINED WITH THE
WARM AIR ALOFT AND DEEP MOISTURE AS PROVIDED BY THE LOW PRESSURE
SYSTEM TO OUR WEST WOULD MAKE FOR A CHANCE FOR FREEZING RAIN FROM
THE INTERSTATE 64 CORRIDOR...POSSIBLY AS FAR SOUTH AS THE NEW RIVER
VALLEY.

THE LOW PRESSURE SYSTEM WILL DRAG A COLD FRONT ACROSS OUR AREA ON
WEDNESDAY...POTENTIALLY BRINGING A ROUND OF LOCALLY HEAVY RAIN TO
THE MOUNTAINS. CHILLY ARCTIC AIR WILL BUILD INTO THE REGION BEHIND
THE COLD FRONT.

&&

.AVIATION /01Z FRIDAY THROUGH TUESDAY/...
AS OF 715 PM EST THURSDAY...

RADAR IS CLEAR THIS EVENING...HOWEVER A BLANKET OF LOW CLOUDS
REMAINS IN PLACE ACROSS THE REGION...WITH CEILINGS RANGING FROM
4KFT AND UP EAST OF THE BLUE RIDGE...TO BETWEEN 1KFT AND 3KFT
ACROSS THE MOUNTAINS.

OVERNIGHT...A WEAK COLD FRONT WILL CROSS THE AREA...WITH ANOTHER
ROUND OF COLD CANADIAN HIGH PRESSURE BUILDING IN ITS WAKE. MAY
SEE A REDEVELOPMENT OF SPOTTY LIGHT SNOW SHOWERS ACROSS THE RIDGES
OF SOUTHEAST WEST VIRGINIA BEHIND THE FRONT...AFFECTING KBLF/KLWB...
POSSIBLY KBCB WITH OCCASIONAL FLURRIES...BUT REDUCTIONS IN
VISIBILITY SHOULD NOT BE LONG LIVED. CEILINGS ACROSS THE AREA WILL
TREND TO IFR LEVELS.

ON FRIDAY...OCCASIONAL UPSLOPE SNOW SHOWERS WILL CONTINUE...BUT
TREND LESS IN COVERAGE AND INTENSITY. THE NORTHWEST FLOW WILL
START MIXING TO THE SURFACE SO THAT A PREVAILING 10 KT WIND WILL
BE COMMON ACROSS THE MOUNTAINS WITH 5 TO 10 KT COMMON ACROSS THE
PIEDMONT. THE DOWNSLOPING AFFECT WILL YIELD A TREND TOWARD
DECREASING CLOUDS ACROSS THE PIEDMONT BY MIDDAY.

FRIDAY AFTERNOON AND EVENING...MVFR CLOUDS ACROSS THE MOUNTAINS
WILL DECREASE IN COVERAGE AND SNOW SHOWERS WILL DWINDLE TO
FLURRIES.

VFR COLD HIGH PRESSURE WILL PREVAIL ON SATURDAY.

SUNDAY INTO MONDAY...OUR NEXT WEATHER SYSTEM WILL MOVE THROUGH THE
AREA. CONFIDENCE IS LOW CONCERNING THE EXACT DETAILS ON TIMING AND
PRECIP TYPE. HOWEVER...IT IS PROBABLE THAT THIS TIME PERIOD WILL
BE ONE WITH SUB-VFR CONDITIONS FOR MANY PARTS OF THE AREA.

ON THE HEELS OF THE SUNDAY/MONDAY SYSTEM WILL BE YET ANOTHER
POTENTIALLY POTENT SYSTEM THAT MAY IMPACT ALL OR PARTS OF THE
REGION LATE MONDAY NIGHT INTO AND THROUGH TUESDAY.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...WINTER WEATHER ADVISORY UNTIL NOON EST FRIDAY FOR NCZ001-002-
     018.
     WINTER WEATHER ADVISORY UNTIL NOON EST FRIDAY FOR NCZ003>006-
     019-020.
WV...NONE.

&&

$$
SYNOPSIS...DS
NEAR TERM...DS/WP
SHORT TERM...AMS
LONG TERM...NF
AVIATION...DS/NF