-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KRNK 040433
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
1133 PM EST TUE DEC 3 2013

.SYNOPSIS...
WEAK HIGH PRESSURE OFFSHORE WILL MAINTAIN AN INCREASINGLY MOIST
BUT MILD SOUTHERLY FLOW OF AIR ACROSS THE REGION INTO LATE WEEK.
WEAK DISTURBANCES PASSING ACROSS THE AREA MAY BRING A PERIOD OR
TWO OF RAINFALL...OTHERWISE DRY MAINLY DRY CONDITIONS ARE
EXPECTED UNTIL A STRONG COLD FRONT APPROACHES BY FRIDAY. THIS
FRONT WILL CROSS THE REGION FRIDAY NIGHT RESULTING IN MORE
WIDESPREAD RAINFALL ALONG WITH MUCH COLDER TEMPERATURES HEADING
INTO THE WEEKEND.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
-- Changed Discussion --
AS OF 1125 PM EST TUESDAY...

SHORT WAVE CROSSING THE AREA COMBINED WITH WEAK UPSLOPE SOUTHEAST
WINDS HAVE PRODUCE ENOUGH LIFT FOR SCATTERED LIGHT RAIN OVER THE
PIEDMONT. HAVE INCREASED PROBABILITY OF RAIN BETWEEN DANVILLE AND
LYNCHBURG. STILL EXPECTING SHORT WAVE TO BE EAST OF THE FORECAST
AREA BY 4AM. HAVE ADDED FOG IN FOR THE REST OF THE NIGHT WHERE
RAIN IS EXPECTED AND ACROSS THE MOUNTAINS WERE THE CLOUD BASE IS
LOW ENOUGH THAT RIDGES WILL BE IN THE CLOUDS.

KEPT LOW TEMPS CLOSER TO THE COLDER MAV MOS ALTHOUGH IF CLOUDS
END UP BLANKETING THE REGION SOONER THEN READINGS COULD BE HELD UP
IN THE 40S MOST SPOTS.

WEAK SHORTWAVE RIDGING BUILDING BACK IN WEDNESDAY AMIDST
INCREASING WARM ADVECTION ALOFT AHEAD OF THE STRONG FRONT TO THE
WEST. HOWEVER MODELS SUGGEST THAT LOW CLOUDS MAY BE SLOW TO GO
GIVEN CONTINUED WEAK THETA ADVECTION...AND ONLY LIGHT SOUTHERLY
FLOW INTO PERHAPS A FAINT LEFTOVER LOW LEVEL WEDGE OUT EAST. THIS
STILL NORTH OF A WEAK SURFACE WARM FRONT THAT WILL BE NEARING THE
AREA FROM THE SOUTH IN THE AFTERNOON. THUS HAVE GONE WITH MORE
CLOUDS AND PERHAPS SOME LEFTOVER -RA OR SPRINKLES ESPCLY SOUTH
DURING WEDNESDAY...WITH TEMPS ON THE COOLER SIDE OF MOS...MAINLY
50S TO AROUND 60 IN SPOTS.
-- End Changed Discussion --

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/...
AS OF 300 PM EST TUESDAY...

SYNOPTIC PATTERN IN THE MID TO LATE WEEK PERIOD CONTINUES TO
FEATURE A DEEP WESTERN TROUGH AND BUILDING SOUTHEASTERN U.S.
RIDGE WITH ARCTIC AIR DOMINATING MUCH OF THE WESTERN CONUS WHILE
SOUTHERLY FLOW BRINGS VERY MILD AIR NORTHWARD INTO THE EASTERN
STATES. PRIMARY AREA OF LOW PRESSURE TRACKS NORTHWARD THROUGH THE
MISSISSIPPI VALLEY ALONG THE BOUNDARY BETWEEN THESE TWO DISTINCT
AIR MASSES WITH A SLOW- MOVING COLD FRONT TRAILING BACK TO THE
GULF COAST. SEVERAL MORE WAVES OF LOW PRESSURE ARE LIKELY TO RIDE
NORTH ALONG THIS BOUNDARY AS IT SHIFTS SLOWLY EAST THROUGH EARLY
SATURDAY. TEMPERATURES THURSDAY MORNING MAY TEST RECORD HIGHS MINS
IN THE MORNING WITH LOW UPPER 40S TO MID 50S AND RUNNING CLOSE TO
20F ABOVE NORMAL. DEPENDING ON AMOUNT OF CLOUDS DURING THE DAY
COULD APPROACH RECORD HIGHS ON THURSDAY AS H85 TEMPS CLIMB INTO
+12 TO +14C RANGE AND WITH CURRENT GRIDS CARRYING MID-60S TO LOW
70S WHICH ARE IN THE BALLPARK OF RECORDS BUT GENERALLY 2 TO 4F
BELOW EXISTING RECORDS. A FEW WELL- PLACED HOURS OF SUN COULD
CAUSE BUST POTENTIAL ON UPSIDE. THE FRONT WILL SLOWLY OOZE
SOUTHEAST ACROSS THE AREA ON FRIDAY WITH INCREASING CHANCES FOR
PRECIP BEHIND IT AND A VERY SLOW COOLING TREND AS COOLER AIR
FIGHTS THE PERSISTENT SOUTHWEST FLOW ALOFT. H85 TEMPS START OUT
NEAR 15C IN THE EAST EARLY FRIDAY AND RECORD HIGH MINS ARE EVEN A
BETTER POSSIBILITY WITH LOW 60S OUT EAST POSSIBLE. SUB-ZERO H85
AIR FINALLY REACHES THE NW ZONES AROUND MIDNIGHT SATURDAY BUT MOST
OF AREA STILL WELL ABOVE WITH RAINFALL. QPF IN THE FORM OF
RAINFALL THROUGH EARLY SATURDAY WILL BE HIGHEST IN THE FAR WESTERN
SECTIONS WITH UP TO 1 INCH POSSIBLE BUT QUITE A BIT LESS..POSSIBLY
UNDER 0.25 INCHES IN THE FAR EAST.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 330 PM EST TUESDAY...

WILL START SATURDAY OFF WITH HIGH PRESSURE BUILDING ACROSS THE GREAT
LAKES...WHILE FRIDAY`S COLD FRONT BEGINS TO STALL ACROSS THE
CAROLINAS. AS THE CENTER OF THE HIGH SHIFTS EAST THROUGH THE
DAY...WILL SEE IT ALSO BEGIN TO BUILD SOUTHWARD ALONG THE EASTERN
FACE OF THE APPALACHIANS...BRINGING A CHILLY NORTHEASTERLY WIND
ACROSS THE PIEDMONTS THAT WILL SHIFT SOUTHEASTERLY UP THE BLUE RIDGE
INTO THE MOUNTAINS...AND WILL EXPECT TEMPERATURES TO FALL INTO THE
UPPER 20S AND LOW 30S FOR SATURDAY NIGHT LOWS.

AS THE HIGH BUILDS IN AT THE SURFACE SATURDAY NIGHT...WILL ALSO
SEE ANOTHER UPPER LEVEL TROUGH APPROACH FROM THE GREAT
PLAINS...BRINGING WARM GULF MOISTURE NORTHWARD ALONG THE
APPALACHIAN CHAIN. THE COMBINATION OF THESE TWO WEATHER FEATURES
WILL PROVIDE AN IDEAL FREEZING RAIN SETUP FOR PORTIONS OF THE
MOUNTAINS AND THE PIEDMONT NORTH OF INTERSTATE 81 SATURDAY NIGHT
INTO LATE SUNDAY MORNING. BY AFTERNOON...AREAS SOUTH OF INTERSTATE
81 ARE EXPECTED TO WARM ABOVE FREEZING...BUT DO NOT SEE THIS
OCCURRING FURTHER NORTH...WHERE AFTERNOON HIGHS ARE EXPECTED TO
REMAIN BELOW FREEZING...MEANING THAT WE MAY BE LOOKING AT A
PROLONGED FREEZING RAIN EVENT INTO EARLY MONDAY FOR AREAS FROM THE
GREENBRIER VALLEY THROUGH THE SHENANDOAH VALLEY.

BY LATE MONDAY MORNING...WILL SEE WINDS SHIFT MORE SOUTHWESTERLY
AS THE HIGH PRESSURE WEDGE FINALLY ERODES...JUST BEFORE OUR NEXT
COLD FRONT PUSHES THROUGH THE AREA. THE GFS MODEL IS SLIGHTLY
FASTER IN THE TIMING OF THE FRONT COMPARED TO THE ECMWF...BUT BOTH
MODELS AGREE THAT THE FRONT WILL SHIFT THROUGH EARLY IN THE DAY.
MAY SEE ANOTHER WAVE PASS ALONG THE FRONT MONDAY EVENING...BUT
HAVE LOW CONFIDENCE IN THAT AT THIS TIME.

&&

.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
-- Changed Discussion --
AS OF 1135 PM EST TUESDAY...

LATEST SURFACE OBSERVATIONS INDICATE HIGH PRESSURE OFF THE OUTER
BANKS THIS EVENING...WITH LOW PRESSURE TO OUR WEST...RESULTING IN
A LIGHT SOUTHEAST SURFACE AND LOW LEVEL WINDS. MOST CEILINGS WILL
CONTINUE TO LOWER OVERNIGHT AS MOISTURE CONTINUES TO FILTER INTO
THE REGION. HIGH CONFIDENCE OF IFR CEILINGS AT KBCB...KROA...KDAN
BETWEEN 06Z/1AM AND 12Z/7AM.

KEEPING CEILINGS MOSTLY MVFR INTO LATE MORNING...BEFORE AFTERNOON
HEATING ALLOWS FOR BREAKS IN THE LOWER CLOUD COVER. WITH THE
UPSLOPE FLOW.

EXTENDED AVIATION CONCERNS...A STRONG COLD FRONT WILL APPROACH
THE MID ATLANTIC REGION THURSDAY...CROSSING THE AREA LATE FRIDAY
AND SATURDAY. SOUTH WINDS WILL INCREASE AHEAD OF THIS FRONT
THURSDAY WITH A WIND SHIFT TO THE WEST FRIDAY...AND TRENDING
NORTH FOR THE WEEKEND. RAIN WILL ACCOMPANY THE FRONT FRIDAY AND
SATURDAY WITH MVFR/IFR CONDITIONS LIKELY.

NORTH WINDS SATURDAY WILL RESULT IN FALLING TEMPERATURES WITH
POTENTIAL FOR FREEZING RAIN AND ICING CONDITIONS SATURDAY NIGHT
AND SUNDAY...ESPCLY FOR TERMINALS NEAR AND WEST OF THE BLUE RIDGE.
-- End Changed Discussion --


&&

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

&&

$$
SYNOPSIS...JH/PM
NEAR TERM...AMS/JH
SHORT TERM...PC
LONG TERM...NF
AVIATION...JH/NF/AMS