-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KRNK 110342
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
1142 PM EDT MON MAR 10 2014

.SYNOPSIS...
AN AREA OF HIGH PRESSURE...CENTERED ACROSS THE SOUTH...WILL
MAINTAIN CONTROL OF THE WEATHER ACROSS THE MID ATLANTIC REGION
THOUGH TUESDAY. MEANWHILE...AN UPPER LEVEL TROUGH WILL BE MOVING
ACROSS THE PLAINS...RESULTING IN THE DEVELOPMENT OF AN AREA OF LOW
PRESSURE MOVING INTO THE MIDWEST TUESDAY. THIS LOW PRESSURE
SYSTEM IS EXPECTED TO MOVE EAST...IMPACTING THE WEATHER ACROSS THE
EASTERN UNITED STATES ON WEDNESDAY. HIGH PRESSURE FOLLOWS THIS
SYSTEM FOR THE END OF THE WEEK.

&&

.NEAR TERM /THROUGH TUESDAY/...
-- Changed Discussion --
AS OF 1130 PM EDT MONDAY...

PLACEMENT OF CIRRUS PER SATELLITE SUGGESTS THE 00Z CMC HAS DECENT
HANDLE ON THIS...AND WILL SEE THE CIRRUS SHIFT NWD OVERNIGHT.
STILL ENOUGH MIXING OVERNIGHT TO KEEP TEMPS MILD ESPECIALLY IN THE
URBAN AREAS AND RIDGES. FORECAST EARLIER HAD A DECENT HANDLE ON
THIS BUT TRENDED WARMER ON THE RIDGES AND ROANOKE...WHERE VALLEYS
DROP INTO THE MID 30S...ROANOKE AND SOME HIGHER TERRAIN FALL TO
AROUND 50.

PREVIOUS VALID DISCUSSION...

ZONAL FLOW AND 85H TEMPERATURES NEAR +10C WILL BRING MID TO LATE
APRIL LIKE WEATHER TO THE AREA AGAIN ON TUESDAY. FORECASTED
TEMPERATURES WILL RANGE 65F-70F ACROSS THE MOUNTAINS TO 70F-75F IN
THE EAST. THESE TEMPERATURES ARE 15F-20F WARMER THAN NORMAL. DEW
POINTS TUESDAY WILL BE A LITTLE HIGHER WITH A LEE TROUGH IN THE
EAST. THERE MAY ALSO BE A FEW MORE HIGH CLOUDS BEING PUSHED INTO
THE AREA FROM A DISTURBANCE MOVING INTO THE MIDWEST AND OTHER
TRACKING ALONG THE GULF COAST. LOWEST DEW POINTS ACROSS THE
FORECAST AREA WILL BE ALONG THE FOOTHILLS WHICH COULD DIP DOWN
INTO THE MID 20S IN THE AFTERNOON.
-- End Changed Discussion --

&&

.SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/...
AS OF 300 PM EDT MONDAY...

WHAT IS LEFT OF THE UPPER LOW IN THE SOUTHERN STREAM CROSSES THE
SOUTHEAST UNITED STATES TUESDAY NIGHT. MORE AMPLIFIED LEAD SHORT
WAVE COMING THROUGH THE MIDWEST REACHES WESTERN SECTIONS OF THE
FORECAST AREA BY WEDNESDAY AFTERNOON. TROF AXIS EVENTUALLY PASSES
EAST OF THE AREA BY LATE THURSDAY. THIS TIMING IS SLIGHTLY SLOWER
THAN ON PREVIOUS MODEL RUNS. BEST PROBABILITY OF PRECIPITATION
WILL STILL BE FROM 12Z/8AM WED TO 00Z THUR/8PM WED.

COLDER AIR ALOFT COMING IN LATE WEDNESDAY WILL LEAD TO LARGER
LAPSE RATES. IN ADDITION...40 TO 50 KNOT SOUTHWEST 850 MB WINDS
AHEAD OF THE FRONT WILL RESULT IN A LARGE AMOUNT OF SHEAR. THE
SLOWER THE CLOUDS AND PRECIPITATION ARRIVE WEDNESDAY...THE BETTER
THE CHANCE FOR HEATING IN THE MORNING AND INSTABILITY AHEAD OF
THE FRONT IN THE AFTERNOON. CAPES MAY BE IN THE 400 TO 800 J/KG
RANGE AND SPC SREF WAS SHOWING THE POTENTIAL FOR AROUND 200 M2/S2
0-3KM HELICITY. MODELS ARE CLOSE WITH THE TIMING OF THE
FRONT...BRINGING IT ACROSS THE FORECAST AREA WEDNESDAY
AFTERNOON...BUT HAVE DIFFERING AMOUNTS OF MOISTURE AHEAD OF THE
BOUNDARY FOR TUESDAY NIGHT AND WEDNESDAY MORNING.

BEHIND THE FRONT...LARGE PRESSURE RISES OF 7 TO 17 MB/6HR AND
STRONG COLD AIR ADVECTION WILL COMBINE WITH THE 40 TO 50 KNOT
NORTHWEST LOW LEVEL JET TO PRODUCE VERY GUSTY SURFACE WINDS.
BUFKIT SHOWING POTENTIAL FOR 3O TO 45 KNOT WIND GUSTS WEDNESDAY
NIGHT AND THURSDAY MORNING.

UPSLOPE FLOW AND LOW LEVEL MOISTURE...ALONG WITH SOME WEAK UPPER
SUPPORT WITH BRING SNOW SHOWERS INTO FAVORED AREAS IN THE
MOUNTAINS. AIR MASS DRIES OUT EVEN AT LOW LEVELS THURSDAY
MORNING...ENDING THE SNOW SHOWERS.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 300 PM EDT MONDAY...

THURSDAY NIGHT SURFACE RIDGE AXIS WILL BE DIRECTLY OVER THE
FORECAST AREA. EXPECTING SURFACE WINDS TO DIMINISH WITH GOOD
RADIATIONAL COOLING CONDITIONS AND MINIMUM TEMPERATURES 10 TO 20
DEGREES BELOW NORMAL. THEN TEMPERATURES WILL MODERATE FRIDAY.

OVERALL UPPER TROF REMAINS OVER THE CENTRAL AND EASTERN UNITED
STATES THIS TIME FRAME. NEXT SYSTEM COMING THROUGH THE NORTHERN
STREAM STAYS NORTH OF THE FORECAST AREA. SURFACE LOW WITH THIS
SYSTEM WILL PUSH A COLD FRONT THROUGH THE REGION ON SATURDAY. ANY
THREAT OF PRECIPITATION WILL BE CONFINED TO THE NORTHWEST COUNTY
WARNING AREA.

LONG RANGE MODELS BECOME SIGNIFICANTLY DIFFERENT WITH THE UPPER
PATTERN ON SUNDAY AND MONDAY. WILL BE LEANING TOWARD THE SPLIT
FLOW OF THE ECMWF WHICH HOLDS AN UPPER TROF OVER THE GREAT LAKES
AND CLOSES OFF AN UPPER LOW OVER THE SOUTHERN PLAINS ON MONDAY.

BY DAY 7...MONDAY...THE ECMWF IS STARTING TO SUGGEST THE
POTENTIAL FOR A SURFACE LOW OFF THE CAROLINA COAST. IF THE LARGE
HIGH THAT THE MODEL HAS OVER THE GREAT LAKES IS ABLE TO WEDGE DOWN
THE EAST SIDE OF THE APPALACHIANS...THERE MAY BE A POTENTIAL FOR
WINTER PRECIPITATION MONDAY NIGHT.

&&

.AVIATION /04Z TUESDAY THROUGH SATURDAY/...
AS OF 745 PM EDT MONDAY...

VFR THROUGH TUESDAY. THE ONLY WEATHER CONCERN THE NEXT 24 HOURS
WILL BE THE PERSISTENT WESTERLY DOWNSLOPING WINDS OVER THE
MOUNTAINS. INVERSION SETS UP OVERNIGHT TO LIMIT HIGHER WINDS ALONG
THE HIGHER RIDGES. THIS INVERSION WILL BREAK TUESDAY MORNING FOR
ANOTHER ROUND OF BREEZY/GUSTY CONDITIONS. THESE WINDS WILL RELAX
IN THE AFTERNOON AS PRESSURE GRADIENT LOOSENS. SCT TO BKN MID
LEVEL CLOUDS MAY ARRIVE ACROSS KLWB TUESDAY AFTERNOON.

SUB-VFR CONDITIONS RETURN FROM SOUTHWEST TO NORTHEAST LATE
TUESDAY NIGHT THROUGH WEDNESDAY MORNING AS A WARM FRONT LIFTS
THROUGH THE AREA WITH ASSOCIATED RAINFALL. WEDNESDAY AFTERNOON AND
EVENING A STRONG COLD FRONT WILL CROSS THE AREA WITH STRONGER RAIN
SHOWERS AND PERHAPS A FEW THUNDERSTORMS ACROSS THE PIEDMONT.
WEDNESDAY NIGHT INTO THURSDAY...COLD AIR BEHIND THE COLD FRONT
WITH LINGERING MOISTURE WILL BRING SNOW SHOWERS TO THE
MOUNTAINS....KLWB AND KBLF. POTENTIAL BRIEF IFR CONDS WITH MVFR
PROBABLE. ALSO...STRONG WINDS ARE EXPECTED WEDNESDAY NIGHT INTO
THURSDAY BEHIND THE FRONT.

BY FRIDAY...HIGH PRESSURE WILL SETTLE OVER THE AREA AND BRING A
DECREASE IN WIND SPEED AND A RETURN TO VFR CONDITIONS FOR THE
ENTIRE AREA.

&&

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

&&

$$
SYNOPSIS...RCS
NEAR TERM...RCS/WP
SHORT TERM...AMS
LONG TERM...AMS
AVIATION...KM/PM/RCS