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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KRNK 201949
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
349 PM EDT MON MAY 20 2013

.SYNOPSIS...
LOW PRESSURE ALOFT WILL MOVE ACROSS THE REGION INTO TONIGHT. A
LARGE LOW PRESSURE SYSTEM WILL TRACK FROM THE CENTRAL PLAINS INTO
THE GREAT LAKES BY THURSDAY. THIS SYSTEM WILL PUSH A COLD FRONT
THROUGH THE AREA THURSDAY...FOLLOWED BY HIGH PRESSURE ON FRIDAY.

&&

.NEAR TERM /THROUGH TUESDAY/...
-- Changed Discussion --
AS OF 330 PM EDT MONDAY...

UPPER LOW ACROSS SOUTHERN PORTION OF CWA THIS AFTERNOON WILL
CONTINUE TO MOVE EAST TONIGHT INTO TUESDAY. KFCX 88D LOOP SHOWED
AREAS OF SHOWERS AND THUNDERSTORMS IN THE WEST WEAKENING AS THEY
MOVE SOUTH AND CONVECTION FIRING UP ALONG AND EAST OF THE BLUE RIDGE
MOUNTAINS. WITH ANY SLOW MOVING OR TRAINING THUNDERSTORMS THIS
EVENING INTO TONIGHT...WE WILL HAVE TO WATCH FOR LOCAL FLOODING
PROBLEMS OVER A SATURATED GROUND. THE 06Z RNKWRFARW CAPTURED THE
EMPHASIS OF CONVECTION IN THE EAST BEST THIS AFTERNOON INTO TONIGHT.
SHAPED POPS TOWARDS THIS SOLUTION. ALL MODELS HAD THE BULK OF
PRECIPITATION OUT OF THE FORECAST AREA AROUND MIDNIGHT. PROBABILITY
OF PRECIPITATION LOWER FROM WEST TO EAST OVERNIGHT TO ACCOUNT FOR
THIS TREND. AREAS OF FOG WILL FORM OVERNIGHT INTO TUESDAY MORNING
ESPECIALLY WHERE RAIN HAS FALLEN THIS EVENING. PLAYED LOW
TEMPERATURES CLOSE TO ADJMAV WITH MILD READINGS FROM THE MID 50S IN
THE MOUNTAINS TO THE MID 60S IN THE SOUTHEAST.

SCATTERED SHOWERS AND THUNDERSTORMS WILL CONTINUE ON TUESDAY WITH A
FOCUS ACROSS THE HIGH TERRAIN. LEANED POPS TOWARDS GFS WITH BEST
CHANCE ALONG THE SOUTHERN BLUE RIDGE. KEPT HIGH TEMPERATURES CLOSE
TO WARMER ADJMAV WITH READINGS FROM THE UPPER 70S IN THE MOUNTAINS
TO NEAR 90 DEGREES IN THE SOUTHEAST.
-- End Changed Discussion --

&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
-- Changed Discussion --
AS OF 330 PM EDT MONDAY...

UNSETTLED WEATHER IS EXPECTED WEDNESDAY AND THURSDAY AS AN UPPER
LEVEL TROUGH MOVES FROM THE UPPER MIDWEST TUESDAY...TO THE EASTERN
GREAT LAKES BY LATE THURSDAY.  ASSOCIATED SURFACE FRONT IS EXPECTED
TO PASS THROUGH THE MID ATLANTIC REGION THURSDAY.

SUFFICIENT INSTABILITY FOR AIRMASS THUNDERSTORMS IS EXPECTED
WEDNESDAY WITH FRONTAL SHOWERS AND STORMS THURSDAY. H85 TEMPS OF +15
TO +17 DEG C ARE EXPECTED UP UNTIL THURSDAYS FROPA...SUPPORTING
DAYTIME HIGHS IN THE 80S AND NIGHT-TIME LOWS IN THE 50S/60S. AFTER
THE FRONTAL PASSAGE THURSDAY...TEMPS COOL DOWN THURSDAY NIGHT INTO
FRIDAY.
-- End Changed Discussion --

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
-- Changed Discussion --
AS OF 345 PM EDT MONDAY...

BOTH THE GFS AND ECMWF ARE DELIVERING A GOOD INTRUSION COOLER AIR BY
12Z FRIDAY WITH H85 TEMPS SLIPPING TO +5C.  THE UPPER TROUGH IS FCST
TO SLIDE ACROSS NEW ENGLAND ON FRIDAY WITH COOL NORTHWEST FLOW
PROGGED FROM THE GREAT LAKES TO THE MID ATLANTIC.

COOLER NORTHWESTERLY FLOW ALSO SUGGESTS THE AIR WILL BE DRY...THUS
HAVE REMOVED ALL MENTION OF PRECIP FOR THE WEEKEND.  THAT SAID...AS
HIGH PRESSURE PASSES OVHD SATURDAY AND ROLLS OFF THE EAST COAST
SUNDAY...MOISTURE COULD SNEAK BACK IN THE PICTURE AS EARLY AS SUNDAY
AFTERNOON.  ATTM...WILL GO WITH AN OPTIMISTIC FCST AND JUST
ADVERTISE INCREASING CLOUDS FOR SUNDAY...AND HOLD OFF ON NEXT
OPPORTUNITY FOR SHOWERS UNTIL MONDAY.

BOTH SATURDAY AND SUNDAY MORNINGS LOOK COOL WITH EARLY MORNING LOWS
IN THE 40S IN THE MOUNTAINS TO THE LOWER 50S IN THE PIEDMONT. IF
WINDS DECOUPLE AND SKIES REMAIN CLEAR...SOME OF THE SHELTERED
MOUNTAIN VALLEYS MAY SLIP INTO THE UPPER 30S.
-- End Changed Discussion --

&&

.AVIATION /20Z MONDAY THROUGH SATURDAY/...
AS OF 136 PM EDT MONDAY...

A SHORTWAVE WILL MOVE CROSS THE AREA THIS AFTERNOON INTO TONIGHT
WILL TRIGGER SHOWERS AND THUNDERSTORMS. ANY OF THE STRONGER STORMS
WILL HAVE VERY HEAVY RAIN...AS WELL AS IFR TO MVFR CEILINGS AND
VISIBILITIES. SHAPED FORECAST TOWARDS THE 06Z WRFARW ARW WHICH
CAPTURE CURRENT RADAR TRENDS THE BEST. KFCX 88D LOOP SHOWED
STORMS IN THE WEST LWB TO TNB MOVING SOUTH AND LINE NEAR DAN
INTO CENTRAL NORTH CAROLINA TRAVELING EAST. BELIEVE THAT
CONVECTION WILL WEAKEN WITH THE LOSS OF SOLAR HEATING TONIGHT.
EXPECTED AREAS OF MVFR/IFR FOG TO DEVELOP OVERNIGHT ESPECIALLY
WHERE RAIN HAS FALLEN.

THE REGION STAYS IN A WARM...MOIST AIRMASS THROUGH THURSDAY.
PATCHY FOG WITH MVFR VISIBILITIES IS LIKELY EACH NIGHT AND EACH
AFTERNOON AND EVENING THERE WILL BE SCATTERED THUNDERSTORMS.

NEXT FRONT APPROACHES ON THURSDAY WITH MORE SHOWERS/STORMS
DEVELOPING. HIGH PRESSURE AND BETTER FLYING CONDITIONS ARE
EXPECTED ON FRIDAY BEHIND THE FRONT.

&&

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

&&

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