-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KRNK 140000
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
800 PM EDT THU MAR 13 2014

.SYNOPSIS...
HIGH PRESSURE WILL SHIFT ALONG THE GULF COAST THIS EVENING AND
TONIGHT...BRINGING A SOUTHWESTERLY WIND SHIFT TO THE MID ATLANTIC
AND WARMER CONDITIONS FOR FRIDAY. LOW PRESSURE PASSING ACROSS THE
GREAT LAKES WILL DRAG A COLD FRONT ACROSS THE AREA ON FRIDAY NIGHT
AND SATURDAY. A LARGER LOW PRESSURE SYSTEM WILL BRING WET
CONDITIONS FOR SUNDAY NIGHT AND MONDAY.

&&

.NEAR TERM /THROUGH FRIDAY/...
AS OF 345 PM EDT WEDNESDAY...

SATELLITE IMAGERY INDICATES NEARLY CLEAR SKIES ACROSS THE
FORECAST REGION THIS AFTERNOON...ASIDE FROM A FEW RESIDUAL CLOUDS
ACROSS SOUTHEAST WEST VIRGINIA AND THE MOUNTAIN EMPIRE. EXPECT
THESE CLOUDS TO DIMINISH DURING EARLY EVENING AS WELL...MAKING FOR
CLEAR SKIES DURING THE NIGHT. WIND SPEEDS HAVE ALSO COME DOWN
SIGNIFICANTLY SINCE EARLIER THIS MORNING...BUT CONTINUE TO GUST TO
30 MPH IN A FEW AREAS THIS AFTERNOON. THESE SPEEDS WILL CONTINUE
TO DIMINISH AS WE HEAD THROUGH THE EVENING AS HIGH PRESSURE ALONG
THE GULF COAST SHIFTS EAST...ALLOWING THE PRESSURE GRADIENT TO
RELAX. BY SUNSET...WINDS ARE EXPECTED TO WEAKEN TO LESS THAN 10
MPH...PERHAPS WITH HIGHER GUSTS ALONG THE RIDGES.

OVERNIGHT...THE COMBINATION OF CLEAR SKIES AND LIGHT WINDS WILL
ALLOW FOR STRONG RADIATIONAL COOLING...AND DESPITE THE DEPARTURE
OF THE UPPER LEVEL TROUGH THAT PROVIDED OUR SHOT OR ARCTIC
AIR...WILL STILL SEE TEMPERATURES OVERNIGHT FALL INTO THE LOW TO
MID 20S...PERHAPS THE UPPER TEENS ACROSS PORTIONS OF SOUTHEAST
WEST VIRGINIA AND THE ALLEGHANY HIGHLANDS.

BY SUNRISE FRIDAY...HIGH PRESSURE WILL SHIFT TO THE COAST OF THE
CAROLINAS...ALLOWING WINDS ACROSS OUR REGION TO SHIFT MORE
SOUTHWESTERLY. THESE SOUTHWESTERLY WINDS WILL DRAW SIGNIFICANTLY
WARMER AIR INTO THE AREA...ALLOWING AFTERNOON HIGHS TO REBOUND
SOME 20 TO 25 DEGREES OVER HIGHS ON THURSDAY. WIND SPEEDS WILL
ALSO BEGIN TO INCREASE DURING THE AFTERNOON AS A LOW PRESSURE
SYSTEM PASSES ACROSS THE GREAT LAKES. WILL START THE DAY OFF WITH
CLEAR SKIES...WITH HIGH CLOUDS INCREASING DURING THE AFTERNOON
FROM THE WEST.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
AS OF 330 PM EDT THURSDAY...

A SURFACE WAVE WILL TRACK FROM THE GREAT LAKES ACROSS
SOUTHEASTERN CANADA FRIDAY NIGHT AND SATURDAY. THIS WAVE WILL PUSH
A COLD FRONT ACROSS THE OHIO VALLEY FRIDAY NIGHT. THIS FRONT WILL
THEN MOVE OVER THE CENTRAL APPALACHIAN MOUNTAINS SATURDAY MORNING
AND STALL NEAR THE VA/NC BORDER SATURDAY AFTERNOON. WITH AVAILABLE
MOISTURE...LIGHT RAIN/SPRINKLES ARE POSSIBLE ACROSS THE WESTERN
SLOPES OF SE WV/SW VA SATURDAY MORNING. HIGH PRESSURE BUILDS IN
FROM THE NORTH SATURDAY AFTERNOON AND NIGHT. MOISTURE WILL BEGIN
TO ENTER FROM THE SOUTHWEST LATE SATURDAY NIGHT AS A WAVE OF LOW
PRESSURE TRACKS EAST OVER THE SOUTHERN MISSISSIPPI VALLEY. BOTH
THE NAM AND ECM KEEP THE AREA DRY OVERNIGHT WHILE THE GFS BRINGS
IN LIGHT PRECIPITATION IN AROUND MIDNIGHT. CONFIDENCE IS LOW FOR
MEASURABLE PRECIPITATION SATURDAY NIGHT...THEREFORE WILL ONLY HAVE
20-30 POPS IN RNK SW QUADRANT. SATURDAY HIGH TEMPERATURES WILL RUN
BETWEEN 50F-60F ACROSS THE MOUNTAINS AND 65F-70F IN THE EAST.
CLOUDS WILL INCREASE DURING THE EVENING...TRAPPING THIS
WARMTH...KEEPING SATURDAY NIGHT LOWS ABOVE FREEZING. PRECIPITATION
COMING IN BY SUNRISE WILL FALL AS RAIN.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 355 PM EDT THURSDAY...

AN UPPER LEVEL TROUGH WILL BE DIGGING ACROSS THE CENTRAL US SUNDAY
WITH A SURFACE LOW OVER THE SOUTHERN MISSISSIPPI VALLEY. WARM MOIST
AIR AHEAD OF THE SURFACE LOW WILL MOVE OVER THE AREA AND OVER A
SHALLOW WEDGE TO INCREASE THE CHANCES FOR RAIN ACROSS THE AREA
SUNDAY AFTERNOON AND NIGHT. THICKNESSES AND 85H TEMPERATURES COOL
THROUGH THE AFTERNOON BUT WILL REMAIN WARM ENOUGH FOR SUNDAY
PRECIPITATION TO FALL AS RAIN. OVERNIGHT SUNDAY INTO MONDAY...A
STRONGER AREA OF HIGH PRESSURE WILL WEDGE DOWN THE EAST COAST.
THERMAL PROFILES BEGIN TO COOL NORTH TO SOUTH WITH RAIN CHANGING TO
A WET SNOW. LOW LEVEL THICKNESSES SUGGEST WEDGE MAY BE SHALLOW TO
KEEP MOST FROZEN PRECIPITATION EAST OF THE BLUE RIDGE.
HOWEVER...WITH AN EASTERLY FLOW...AREAS ALONG THE BLUE RIDGE WILL
ALSO GET IN ON THIS SNOW ACTION. SNOWFALL AMOUNTS STILL IN QUESTION
AS BEST ISENTROPIC LIFT AND MOISTURE EXITS AS THE COLDER AIR DIVES
SOUTH MONDAY MORNING. WITH CONFIDENCE LOW ON TIMING COLD AIR WILL
KEEP HOURLY TEMPERATURES WITH A NORMAL DIURNAL CURVE AS HIGHS
APPROACH 40F. MODELS ARE SUGGESTING TEMPERATURES ALONG AND EAST OF
THE BLUE RIDGE WILL DROP OR REMAIN STEADY IN THE LOW TO MID 30S.
AREAS OUTSIDE OF THE WEDGE SHOULD WARM WITH A NORMAL DIURNAL CURVE
INTO THE LOW TO MID 40S WITH PRECIPITATION BEING MOSTLY RAIN.

THE AMOUNT OF PRECIPITATION MONDAY INTO TUESDAY WILL DEPEND ON THE
TRACK OF A CLOSED LOW OVER THE GULF STATES. THE 12Z ECM TRACKS THIS
LOW INLAND AND ACROSS THE SOUTHEASTERN US MONDAY INTO TUESDAY. THE
12Z GFS TRACKS THE CLOSED LOW JUST OFF THE GULF COAST THEN OFF THE
SOUTHEAST COAST TUESDAY MORNING. BOTH OF THESE MODELS KEEP BULK OF
PRECIPITATION ALONG THE SOUTHEAST COAST...LIMITING SNOW/RAIN AMOUNTS
OVER THE AREA MONDAY NIGHT INTO TUESDAY MORNING. DURING THE DAY
TUESDAY...WRAP-AROUND MOISTURE WITH THE CLOSED LOW MAY BRING AN
INCREASING CHANCE FOR RAIN AND/OR SNOW TO THE FOOTHILLS AND PIEDMONT
COUNTIES AS IT TRACKS OFF THE NC/VA COAST. FOR NOW...USED HPCGUIDE
WITH LESS THAN 20 POPS TUESDAY IN THE EAST. WE WILL REVISIT THIS
SCENARIO TOMORROW IF THE MODELS REMAIN CONSISTENT. WILL ALSO NEED TO
REVISIT TEMPERATURES FOLLOWING THE EXIT OF THIS LOW TUESDAY NIGHT
INTO THURSDAY. MODELS ARE HANGING ON TO WEDGE UNTIL THE NEXT FRONT
SWEEPS ACROSS THE REGION WEDNESDAY (GFS) OR THURSDAY (ECM).

&&

.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
-- Changed Discussion --
AS OF 745 PM EDT THURSDAY...

VFR CIGS/VSBYS EXPECTED THROUGH THE TAF VALID PERIOD. AN UPSTREAM
ALBERTA CLIPPER TYPE SYSTEM WILL BEGIN TO APPROACH THE AREA FROM
THE NORTHWEST BRINGING SCT-BKN HIGH CLOUDS TO THE NORTHERN
SECTIONS OF THE CWA BY OR AFT 18Z FRI. THE AIR MASS IS EXTREMELY
DRY WITH DEWPOINTS STILL NEAR ZERO OR EVEN BELOW...SO UNLIMITED
VSBYS EXPECTED THROUGH THE TAF VALID PERIOD. MAIN ISSUE THROUGH
THE TAF VALID PERIOD WILL BE WIND ONCE AGAIN. NW-W WINDS WILL
DIMINISH TO 5KTS OR LESS TONIGHT...BUT SFC HIGH PRESSURE WILL
SPREAD SOUTH OF THE REGION ACROSS THE SOUTHEAST STATES
FRI...BRINGING QUICK RETURN GUSTY SW WINDS TO THE AREA BY LATE
MORNING FRI WITH SUSTAINED 10-15KTS LIKELY WITH GUSTS
25-30KTS...POTENTIALLY EVEN TO SLIGHTLY OVER 30KTS ROA/BLF BY
AFTERNOON.

HIGH CONFIDENCE IN VFR CIGS/VSBYS THROUGH THE TAF VALID PERIOD.
HIGH CONFIDENCE IN WIND SPD/DIR THROUGH THE TAF VALID PERIOD.

.EXTENDED AVIATION DISCUSSION...

THE CLIPPER SYSTEM MENTIONED ABOVE WILL MOVE THROUGH THE REGION
FRI NIGHT/SAT WITH UPSLOPE CLOUDS AND POSSIBLE -SHSN EASTERN
WV...OTHERWISE MOSTLY VFR EXPECTED ELSEWHERE THROUGH SAT. A
SOUTHERN STREAM SYSTEM WILL PHASE WITH A NORTHERN STREAM SYSTEM
SUNDAY THROUGH MONDAY BRINGING WIDESPREAD RAIN TO THE AREA BY SUN
AFTERNOON ALONG WITH MVFR-IFR CIGS/VSBYS. AS COLD AIR SPREADS SWWD
DOWN THE EAST SIDE OF THE APPALACHIANS SUN NIGHT/MON...PCPN WILL
LIKELY CHANGE TO SNOW NORTH AND A WINTRY MIX SOUTH. ACCUMULATING
SNOW APPEARS POSSIBLE EARLY MON. WINDS WILL ALSO LIKELY BE STRONG
AND GUSTY IN ASSOCIATION WITH THIS WEATHER SYSTEM. IT COULD BE
TUE OR WED BEFORE CONDITIONS IMPROVE TO VFR.
-- End Changed Discussion --

&&

.FIRE WEATHER...
WIND SPEEDS CONTINUE TO WEAKEN THIS AFTERNOON...AND WITH
TEMPERATURES SOON TO BEGIN FALLING AS THE SUN SETS...RH VALUES
WILL BEGIN TO INCREASE FOR THE EVENING...DECREASING THE FIRE
WEATHER CONCERNS FOR THE REMAINDER OF THE DAY.

FIRE WEATHER CONCERNS WILL BE HIGH AGAIN ON FRIDAY. WINDS WILL
SHIFT SOUTHWESTERLY OVERNIGHT...ALLOWING WARMER AIR TO ENTER THE
REGION. WITH NO RETURN OF GULF/ATLANTIC MOISTURE EXPECTED...
AFTERNOON RH VALUES WILL AGAIN FALL BELOW CRITICAL LEVELS. THE
WARM AND DRY CONDITIONS...COMBINED WITH ABUNDANT SUNSHINE...WILL
ALLOW THE FINE FUELS TO CONTINUE TO DRY...FALLING AOB 8GM IN SOME
AREAS. WIND SPEEDS WILL INCREASE AGAIN DURING THE AFTERNOON AS
LOW PRESSURE PASSES ACROSS THE GREAT LAKES...BUT SOME QUESTION
REMAINS AS TO WHETHER SUSTAINED SPEEDS WILL REACH CRITICAL LEVELS.
CURRENTLY HAVE A FIRE WEATHER WATCH IN EFFECT FOR FRIDAY...AND
WILL REEXAMINE CONDITIONS THIS EVENING AND OVERNIGHT TO DETERMINE
IF A RED FLAG WARNING IS NEEDED OR IF A SPECIAL WEATHER STATEMENT
WILL BE SUFFICIENT.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
VA...FIRE WEATHER WATCH FROM FRIDAY MORNING THROUGH FRIDAY
     AFTERNOON FOR VAZ011>020-022>024-032>035-043>047-058-059.
NC...FIRE WEATHER WATCH FROM FRIDAY MORNING THROUGH FRIDAY
     AFTERNOON FOR NCZ002>006-019-020.
WV...NONE.
-- End Changed Discussion --

&&

$$
SYNOPSIS...NF
NEAR TERM...NF
SHORT TERM...RCS
LONG TERM...RCS
AVIATION...RAB
FIRE WEATHER...NF