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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KRNK 180449
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
1249 AM EDT TUE JUN 18 2013

.SYNOPSIS...
LOW PRESSURE OVER ARKANSAS WILL MOVE EAST ACROSS THE TENNESSEE
VALLEY TONIGHT AND OVER THE SOUTHERN APPALACHIANS ON TUESDAY.
THIS WILL BRING ADDITIONAL SHOWERS AND STORMS BACK TO THE REGION
TUESDAY INTO TUESDAY NIGHT. WEAK HIGH PRESSURE BUILDS ACROSS THE
AREA WEDNESDAY AND THURSDAY.
&&

.NEAR TERM /THROUGH TODAY/...
AS OF 1015 PM EDT MONDAY...

VERY MOIST AIR MASS IN PLACE TONIGHT. ISOLATED TO SCATTERED
SHOWERS AND THUNDERSTORMS WILL CONTINUE OVERNIGHT...ESPECIALLY
WEST OF THE BLUE RIDGE. COVERAGE OF PRECIPITATION WILL INCREASE
AFTER 4AM AS THE SHORT WAVE OVER THE MID MISSISSIPPI VALLEY
APPROACHES THE REGION.

WITH THE RAINFALL THIS AFTERNOON AND SURFACE DEWPOINTS IN THE
LOWER 60S TO LOWER 70S HAVE LEFT AREAS OF FOG IN THE FORECAST FOR
TONIGHT. HAVE RAISED MINIMUM TEMPERATURES BASED ON CURRENT
OBSERVATIONS AND THE LATEST GRIDDED LAMP GUIDANCE. NO CHANGE IN
AIR MASS EXPECTED TONIGHT SO TEMPERATURES WILL REMAIN MILD.

MAIN S/W TROUGH AND ASSOCIATED WEAK COLD FRONT ARE
EXPECTED TO DROP SOUTH ACROSS THE REGION TUESDAY. THE UNSETTLED
WEATHER WITH CONVECTION WILL CONTINUE TUESDAY WITH THE HIGHEST POPS
ACROSS THE SOUTHWEST PORTIONS OF FORECAST AREA. WITH RICH CLOUD
COVER AND PRECIPITATION PLAYED HIGH TEMPERATURES CLOSE TO COOL MOS
VALUES FROM THE UPPER 60S IN THE WEST TO THE LOWER 80S IN THE
SOUTHEAST.

&&

.SHORT TERM /TONIGHT THROUGH THURSDAY/...
AS OF 400 PM EDT MONDAY...

SHORT WAVE WHICH BRINGS PRECIP TO THE AREA TUESDAY WILL EXIT THE
REGION EARLY WED. DRIER AIR WILL WORK ITS WAY INTO THE
REGION...FIRST FROM THE NORTH TUESDAY NIGHT...AND THEN FROM THE
NORTHEAST WEDNESDAY...POPS WANING AS SUBSIDENCE INCREASES ACROSS THE
FORECAST AREA WEDNESDAY.  EASTERLY FLOW IS EXPECTED TO PERSIST INTO
THE DAY THURSDAY...GRADUALLY FADING AND BECOMING LIGHT AND VARIABLE
AS HIGH PRESSURE PASSES OVHD.  ANY PRECIP THREAT FOR THE LATER HALF
OF THE WEEK WILL BE MAINLY CONFINED TO THE MTNS WHERE ENOUGH
CONVERGENCE/DIFFERENTIAL HEATING MAY ALLOW FOR SOME WIDELY SCT
AFTN/EVE SHOWERS IN THE MTNS.  TEMPERATURES WILL REMAIN MOSTLY BELOW
SEASONAL NORMALS THROUGH WED...THEN BEGIN TO MODERATE AS HEIGHTS
BUILD FOR THURSDAY AND BEYOND.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 400 PM EDT MONDAY...

SUBTROPIAL RIDGE IS EXPECTED TO BUILD NORTH...FLOODING THE MID
ATLANTIC REGION WITH WARM TEMPERATURES AND INCREASING DEWPOINTS.
ATTM...NO REAL FOCUS FOR DEEP CONVECTION EXCEPT FOR CONVERGENCE OVER
THE MTNS...SO KEPT ANY PRECIP THREAT MAINLY DIURNAL WITH PRIMARY
TARGETED TO THE MTNS.  TRENDS SUGGEST TEMPS WILL CLIMB BACK ABOVE
NORMAL FOR THE WEEKEND...BUT NOTHING MAJOR...SHOULD NUDGE 90 FOR THE
URBAN AREAS.
&&

.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
-- Changed Discussion --
AS OF 1235 AM EDT TUESDAY...

WIDELY SCATTERED THUNDERSTORMS CONTINUE ALONG AN AXIS BETWEEN
KBLF AND KHSP WITH THE MOST WIDESPREAD COVERAGE JUST SOUTH OF
KLWB. EXPECT THESE TO PERSIST AND MEANDER ACROSS THE NW SECTIONS
INTO THE OVERNIGHT BEFORE FADING WITH OTHER ADDED SHRA MOVING UP
FROM THE SW. THUS WILL INCLUDE AN HOUR OR TWO OF MVFR IN TSRA OR
TEMPO MENTION AT KLWB PENDING RELEASE COVERAGE WHILE LEAVING OUT
CONVECTION ELSW GIVEN ISOLATED NATURE OVERNIGHT. FOG REMAINS QUITE
TRICKY GIVEN SOME SPOTS HAVING SEEN SHRA/TSRA NEARBY DURING THE
EVENING WHILE STILL HAVE QUITE A MID DECK CANOPY IN PLACE TO
NEGATE RADIATIONAL COOLING THROUGH DAYBREAK. THINK THIS WILL LIMIT
FOG MOST SPOTS EXCEPT KLWB WHERE MAY SEE ENOUGH BREAKS AFTER SHRA
TAPERS OVERNIGHT TO SEE AT LEAST MVFR IN FOG IF NOT A PERIOD OF
IFR AT DAYBREAK. BOTH KLYH/KBCB COULD ALSO EXPERIENCE SOME FOG BUT
LOOKS LESS THAN EARLIER UNLESS CLOUDS DIMINISH SOME.

FOR TUESDAY...A STALLED BOUNDARY WILL SERVE AS A FOCUSING
MECHANISM FOR SIGNIFICANT LIFT THAT WILL BEGIN IN EARNEST EARLY
TUESDAY. A STRONGER UPPER SHORTWAVE WILL APPROACH FROM THE
NORTHWEST RENEWING SHRA/TSRA ACTIVITY TO OUR SOUTH...WHICH WILL
SPREAD UP/OVER THE REGION TUESDAY...WITH WIDESPREAD SHOWERS AS A
RESULT. THIS IS NOT EXPECTED TO REACH OUR SOUTHERN CWA BORDER
UNTIL AFTER DAYBREAK TUE. OVERALL...WIND SPEEDS ON TUESDAY WILL
BE LIGHT WITH NORTHWEST TO WEST DIRECTION FAVORED IN THE
MOUNTAINS.

MEDIUM TO HIGH CONFIDENCE IN CIGS THROUGH TAF VALID PERIOD.
LOW TO MEDIUM CONFIDENCE IN VSBYS THROUGH TAF VALID PERIOD.
MEDIUM TO HIGH CONFIDENCE IN WIND SPD/DIR THROUGH TAF VALID
PERIOD.

EXTENDED AVIATION DISCUSSION...CLOUDS ALONG WITH A FEW SHOWERS
MAY LINGER INTO WEDNESDAY BEFORE DRIER AIR BRINGS A RETURN TO
OVERALL VFR THURSDAY INTO FRIDAY...WITH ONLY ISOLATED DIURNAL
MOUNTAIN CONVECTION. HIGH PRESSURE ALOFT BUILDS EAST SATURDAY WITH
CONTINUED OVERALL VFR OUTSIDE OF ISOLATED CONVECTION ALONG THE
MOUNTAINS.
-- End Changed Discussion --

&&

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

&&

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