-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KRNK 180232
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
932 PM EST TUE DEC 17 2013

.SYNOPSIS...
LOW PRESSURE WILL MOVE OFF THE MIDDLE ATLANTIC COAST AS A COLD
FRONT CROSSES THE REGION TONIGHT. SURFACE HIGH PRESSURE GRADUALLY
MOVES OVER MUCH OF THE SOUTHEASTERN UNITED STATES LATE TOMORROW
AND INTO THURSDAY MORNING. WARM AIR AND MOISTURE SURGES EAST OF
THE MISSISSIPPI RIVER THIS WEEKEND AS A DEEP TROUGH ENTERS THE
NATION`S HEARTLAND.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
-- Changed Discussion --
AS OF 900 PM EST TUESDAY...

VIGOROUS SHORT WAVE PASSED RIGHT OVERHEAD THIS EVENING. REPORTS
RANGED FROM CHICKEN FEATHER SIZED SNOW FLAKES IN THE
MOUNTAINS...TO THUNDERSTORMS AND WIND GUSTS OF 40 MPH IN THE
FOOTHILLS AND PIEDMONT. HEAVIEST PRECIP HAS NOW EXITED THE
CWA...MOVING EAST BOUND INTO THE TIDEWATER OF VA. THIS AREA OF
PRECIP IS RUNNING JUST AHEAD OF THE SURFACE FRONT WHICH HAS ALMOST
CLEARED THE EASTERN CWA.

RAIN AND CLOUDS WILL EXIT THE FAR EASTERN CWA VCNTY OF
FARMVILLE...CHARLOTTE COURT HOUSE AND BUGGS ISLAND...BY MIDNIGHT.
RAIN HAS ALREADY ENDED IN LYNCHBURG...DANVILLE...WITH THE ONLY
LINGERING PRECIP NOW OCCURRING WEST OF THE ROANOKE VALLEY IN THE
FORM OF SNOW SHOWERS ACROSS THE MOUNTAINS. FOR THE
OVERNIGHT...SCATTERED SNOW SHOWERS AND FLURRIES WILL CONTINUE
WEST OF THE BLUE RIDGE...DIMINISHING IN COVERAGE AS WE TRANSITION
INTO THE DAY WEDNESDAY.

WITH THE EXCEPTION OF THE 40 MPH GUSTS THAT HAVE ALREADY BEEN
REPORTED THIS EVENING DIRECTLY ASSOCIATED WITH THE FRONTAL
PASSAGE...WINDS OVERNIGHT SHOULD REMAIN BELOW ADVISORY CRITERIA
(WHICH IS 40 KTS OR 46 MPH). STRONGEST WINDS FOR THE REMAINDER OF
THE OVERNIGHT WILL BE ACROSS THE MOUNTAINS...WITH RIDGE TOP GUSTS
OF 30 TO 35 MPH. GUSTS OF 40 MPH SHOULD BE LIMITED TO ELEVATIONS
ABOVE 3500 FEET.
-- End Changed Discussion --

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/...
AS OF 200 PM EST TUESDAY...

FORECAST THIS PERIOD SWINGS TOWARD MILDER WEATHER AS WE SEE A CLOSED
UPPER LOW FORMING ALONG THE WEST COAST THURSDAY WHICH BUCKLES THE
FLOW TOWARD SW ACROSS THE SRN TIER OF STATES INTO THE SOUTHEAST.

AT THE SFC HIGH PRESSURE SHIFTS OFF THE SOUTHEAST COAST THURSDAY
MORNING AND CONTINUES EWD TOWARD BERMUDA BY FRIDAY. MEANWHILE...A
SLOW MOVING FRONT WILL BE ADVANCING ACROSS THE UPPER MIDWEST TO
CENTRAL PLAINS TO NEW ENGLAND AND THE WESTERN OHIO VALLEY BY FRIDAY.
OVERALL LOOKING AT DRY WEATHER RIGHT UP UNTIL FRIDAY WHERE THE
FRONTAL PROXIMITY SEEMS CLOSE ENOUGH ALONG WITH SW FLOW ALOFT FROM
THE GULF TO INCREASE THE THREAT OF RAIN SHOWERS ACROSS THE MTNS OF
WV...INTO FAR SW VA. THE UPPER LOW SHOULD SWING SE TOWARD OLD MEXICO
BY FRIDAY NIGHT WHILE A NRN STREAM SHORTWAVE SLIDES EAST ALONG THE
CANADIAN/US BORDER INTO THE GREAT LAKES. MAIN FOCUS OF PRECIP
APPEARS TO STAY IN A CORRIDOR FROM TX TO THE OHIO VALLEY WITH SOME
SHOWER ACTIVITY ADVANCING TO THE MTNS...BUT SHOULD BE SLIGHT TO LOW
CHANCE...WHILE AREAS MAINLY EAST OF THE I-81 CORRIDOR FROM THE
SHENANDOAH TO THE NEW RIVER VALLEYS STAY DRY.

DESPITE THE DRY WX...THE UPPER FLOW FAVORS FROM TIME TO TIME A
SHIELD OF CIRRUS MOVING ACROSS AND THE 00Z ECMWF SHOWS THIS MORESO
FOR THURSDAY THAN THE OTHER MODELS BUT WE WILL LEAN TOWARD LESS
CLOUDS GIVEN THE DRY AIRMASS IN PLACE. WOULD NOT BE SURPRISED SOME
LIMITED SUNSHINE OCCURS. AS WE HEAD INTO FRIDAY AND FRIDAY NIGHT
MODELS AGREE THAT INCREASED SW FLOW WILL BRING MORE CLOUDS IN WHICH
SHOULD KEEP OVERNIGHT LOWS ON THE MILD SIDE.

&&

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

A MILD WEEKEND ANTICIPATED WITH COOL SEASONABLE WEATHER IN TIME FOR
CHRISTMAS. A COLD FRONT WITH SEVERAL WAVES OF LOW PRESSURE RIDING
ALONG IT WILL TRAVEL EAST AND ADVANCE THROUGH OUR REGION BY SUNDAY
NIGHT. THE BOUNDARY WILL PUSH INTO THE ATLANTIC OCEAN ON MONDAY. IN
ITS WAKE...HIGH PRESSURE WILL BUILD INTO OUR REGION ON TUESDAY.

SOUTHWEST FLOW WILL RESULT IN WARMER THAN NORMAL TEMPERATURES ON
SATURDAY AND SUNDAY. LEANED ISC GRIDS DURING THE MEDIUM RANGE
TOWARDS THE ECMWF SLOWER TIMING OF THE FRONT COMPARED TO THE FASTER
CANADIAN AND GFS SOLUTIONS.

A WAVE OF LOW PRESSURE RIDING NORTH ALONG THE BOUNDARY WILL PUSH THE
COLD FRONT CLOSER TO US ON SATURDAY. PLACED THE HIGHEST POPS IN THE
NORTHWEST ON SATURDAY.  UNSEASONABLY WARM TEMPERATURES EXPECTED FOR
SATURDAY WITH HIGHS RANGING FROM THE MID 50S IN THE MOUNTAINS TO
NEAR 70 DEGREES IN SOUTHEAST. THE WAVE THAT LIFTS NORTH ALONG THE
BOUNDARY SATURDAY NIGHT MAY SLOW ITS ADVANCE EAST SATURDAY NIGHT
INTO SUNDAY. KEPT LOW TEMPERATURES ON SATURDAY NIGHT ON THE MILD
SIDE WITH VALUES FROM THE UPPER 40S IN THE WEST TO UPPER 50S IN THE
EAST. SHOWERS ARE LIKELY ON SUNDAY INTO SUNDAY NIGHT AS THE COLD
FRONT ADVANCES THROUGH OUR AREA. FELT THERE WAS ENOUGH INSTABILITY
TO MENTION THUNDERSTORMS IN THE EAST. HIGHS ON SUNDAY WILL RANGE FROM
AROUND 60 DEGREES IN THE WEST TO AROUND 70 DEGREES IN THE EAST.
LEANED LOW ON SUNDAY NIGHT TOWARDS THE ENSEMBLE ECMWF FROM THE MID
30S IN THE NORTHWEST TO AROUND 50 DEGREES IN THE SOUTHEAST. ALLOWED
FOR HIGHER POPS IN THE SOUTHERN PORTION OF FORECAST AREA ON MONDAY
WITH RICHER MOISTURE. NORTHWEST FLOW WILL RESULT IN MORE SEASONABLE
HIGHS IN THE UPPER 30S IN THE MOUNTAINS TO THE MID 50S IN THE
PIEDMONT. A SHORTWAVE ROTATING THROUGH MONDAY NIGHT SUPPORT THE
MENTION OF CHANCE OF SHOWERS. HIGH PRESSURE BUILDS ACROSS THE REGION
ON TUESDAY WITH UPPER FLOW BECOMING MORE ZONAL. LOOK FOR HIGHS
TUESDAY FROM THE UPPER 30S IN THE WEST TO THE MID 40S IN THE EAST.

&&

.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
AS OF 640 PM EST TUESDAY...

COLD FRONT/UPPER LEVEL DISTURBANCE WILL TRAVEL EAST ACROSS THE
REGION THIS EVENING INTO TONIGHT. SCATTERED RAIN AND SNOW SHOWERS
WILL SPREAD EAST ACROSS THE AREA. A LIGHT SNOW ACCUMULATION IS
POSSIBLE AT LWB/BLF TONIGHT. IN THE WEST...EXPECTING A FEW HOURS
OF MVFR/IFR CONDITIONS AND ISOLATED LIFR WITH HEAVIER SHOWERS.

CLIPPER EXISTS PRETTY QUICKLY AND CIG SHOULD IMPROVE THROUGH THE
NIGHT WITH WINDS BECOMING WEAKER. IN EAST...VFR/MVFR CONDITIONS
WITH A FEW LIGHT RAIN/SNOW SHOWERS. WINDS WILL REMAIN GUSTY THIS
EVENING INTO TONIGHT WITH SOME 30KT GUSTS POSSIBLE. HIGH PRESSURE
AND VFR CONDITIONS WILL PREVAIL THURSDAY.

HIGH CONFIDENCE OF CEILINGS AND VISIBILITIES DURING THE TAF
PERIOD. MEDIUM CONFIDENCE OF WINDS DURING THE PERIOD.

THE WEATHER WILL BE DETERIORATING FOR THE WEEKEND AS NEXT LOW
PRESSURE SYSTEM MOVES IN FROM THE WEST WITH PRECIPITATION AND MVFR
OR LOWER CONDITIONS EXPECTED. A COLD FRONT WITH SEVERAL WAVES OF
LOW PRESSURE ALONG IT WILL TRAVEL EAST AND ADVANCE THROUGH OUR
REGION BY SUNDAY NIGHT. THE BOUNDARY WILL PUSH INTO THE ATLANTIC
OCEAN ON MONDAY. IN ITS WAKE...HIGH PRESSURE WILL BUILD INTO OUR
REGION ON TUESDAY.

&&

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

&&

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