Area Forecast Discussion
Issued by NWS Blacksburg, VA

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000
FXUS61 KRNK 020137
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
937 PM EDT MON SEP 1 2014

.SYNOPSIS...
WEAK HIGH PRESSURE WILL REMAIN OVER THE REGION TONIGHT INTO MUCH
OF TUESDAY. A WEAK COLD FRONT TRACKS SOUTHEAST INTO OUR AREA BY
TUESDAY EVENING...BEFORE STALLING ACROSS THE CAROLINAS AND WASHING
OUT ON WEDNESDAY. HIGH PRESSURE SETS BACK UP OVER THE EAST BY
FRIDAY WITH YET ANOTHER COLD FRONT MOVING TOWARD US THIS WEEKEND.
&&

.NEAR TERM /THROUGH TUESDAY/...
AS OF 850 PM EDT MONDAY...

OTHER FOR ISOLATED SHRA/TSRA PASSING ACROSS THE FAR
NORTH...CONVECTION REMAINS LIMITED THIS EVENING AS SOUNDINGS SHOW
WEAK CAPPING ALOFT WITHIN A DEEP WESTERLY FLOW REGIME. THIS ALONG
WITH LACK OF DEEP INSTABILITY SHOULD KEEP THINGS MAINLY QUIET
OVERNIGHT WITH JUST SOME PATCHY FOG IN THE VALLEYS AND PERHAPS OUT
EAST. HOWEVER WITH THE LATEST HRRR TRACKING THE CURRENT ISOLATED
COVERAGE OVER GREENBRIER EAST TOWARD THE SOUTHERN SHENANDOAH
VALLEY...WILL LEAVE IN SOME LOW POPS ACROSS THE EXTREME NORTH SINCE
HEADING INTO SOME DECENT LEFTOVER CAPE DESPITE LOSS OF HEATING.
WILL ALSO CONTINUE SOME LOW CHANCES FAR NW LATE FOR ACTIVITY
COMING IN AHEAD OF THE UPSTREAM FRONT AROUND DAYBREAK. OTRW FEW
CHANGES OTHER THAN TO INCLUDE A BIT OF FOG AND BUMP UP TEMPS IN
SPOTS GIVEN SUCH A MUGGY OVERNIGHT.

ANOTHER SHORTWAVE AHEAD OF A FRONT SHIFTING SE INTO THE OHIO VALLEY
PASSES ACROSS TUESDAY MORNING. FOR NOW IT LOOKS LIKE THE WESTERN CWA
WILL SEE A CHANCE OF SHOWERS/ISOLATED TSRA DURING THE MORNING BUT
AGAIN EAST OF THE BLUE RIDGE LOOKS FEEBLE. THERE IS GOOD SUBSIDENCE
BEHIND THIS FEATURE BY 18Z TUESDAY BUT ANOTHER WAVE AND THE FRONT
ITSELF WILL EDGE CLOSER TOWARD TUE EVENING...WHICH WILL BRING A
BETTER THREAT OF SHOWERS AND STORMS TO THE MOUNTAINS WITH ISOLATED
TO WIDELY SCATTERED COVERAGE OVER THE FOOTHILLS AND PIEDMONT.

TUESDAY WILL BE HOT...WITH ENOUGH SUN TO SEND TEMPS INTO THE LOWER
TO MID 90S EAST...AND LOWER TO MID 80S WEST.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
AS OF 224 PM EDT MONDAY...

A WEAK COLD FRONT SLIDES ACROSS THE REGION TUESDAY NIGHT...PUSHING
PRECIPITATION TO THE EAST COAST. HIGH PRESSURE BUILDS IN FROM THE
WEST THROUGH WEDNESDAY. THE ASSOCIATED DEW POINT FRONT AND DRIER AIR
IS LAGGING WAY BEHIND AND DOES NOT ENTER THE FORECAST AREA UNTIL
LATE WEDNESDAY MORNING. THIS DEW POINT FRONT MAY MAKE IT AS FAR AS
THE VA/NC BORDER WEDNESDAY AFTERNOON...THEN BEGINS TO RETREAT TO THE
NORTH WEDNESDAY NIGHT AND THURSDAY. SURFACE HIGH PRESSURE WILL KEEP
MOST OF THE AREA DRY BUT COULD SEE ISOLATED DIURNAL SHOWERS SOUTH OF
THE DEW POINT FRONT WEDNESDAY AFTERNOON/EVENING. AS THIS SURFACE
RIDGE DRIFTS OFF THE MID ATLANTIC COAST THURSDAY...SOUTHEAST FLOW
AND ATLANTIC MOISTURE WILL INCREASE THE CHANCE FOR SHOWERS FOR AREAS
ALONG AND EAST OF THE BLUE RIDGE...ESPECIALLY THE NORTH CAROLINA
HIGH COUNTY THURSDAY AFTERNOON. EVEN THOUGH FLOW IS WEAK
ALOFT...WARM SOUTHWEST FLOW WILL OVERRUN THIS RIDGE/INSITU WEDGE TO
PRODUCE A LOW STRATUS DECK AND A CHANCE FOR LIGHT RAIN/DRIZZLE FOR
AREAS EAST OF THE BLUE RIDGE OVERNIGHT THURSDAY.

TEMPERATURES WILL RANGE FROM THE UPPER 70S TO LOWER 80S ACROSS THE
MOUNTAINS AND UPPER 80S TO LOWER 90S EAST WEDNESDAY AFTERNOON.
EASTERLY FLOW THURSDAY WILL PRODUCE UNIFORM TEMPERATURES IN THE 80S.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 248 PM EDT MONDAY...

HIGH PRESSURE EXITS THE MID ATLANTIC COAST ON FRIDAY AND WILL BE
REPLACED BY A LEE TROUGH. WITH AN UPPER LEVEL RIDGE ACROSS THE GULF
STATE TO THE SOUTHEAST COAST...NEARLY ZONAL FLOW MAY BRING A SHORT
WAVE OVER THE REGION FRIDAY. THIS SHORT WAVE WILL HELP SPARK
CONVECTION THROUGH THE AFTERNOON AND EVENING HOURS. IF THIS SHORT
WAVE DOES NOT MATERIALIZE...DIURNAL CONVECTION IS STILL POSSIBLE
WITH ABUNDANT MOISTURE...AFTERNOON HEATING AND A LEE TROUGH. FOR THE
WEEKEND...A COLD FRONT IS EXPECTED TO PASS OVER THE REGION SATURDAY
(GFS) OR SUNDAY (ECM). WITH A STUBBORN UPPER LEVEL RIDGE TO THE
SOUTH...FAVORING THE SLOWER ECM RUN. PREFRONTAL OR DIURNAL
CONVECTION IS POSSIBLE SATURDAY BUT WILL KEEP THE HIGHEST POPS WITH
THE FRONTAL PASSAGE SUNDAY. NOT QUITE SURE IF THE FRONT WILL
COMPLETE CLEAR THE FORECAST AREA AS THE UPPER LEVEL RIDGE CONTINUES
TO HANG ACROSS THE SOUTHERN STATES.

TEMPERATURES WILL REMAIN WARMER THAN NORMAL UNTIL THE FRONT CLEARS
THE AREA. ONCE THE FRONT PASSES...TEMPERATURES WILL RUN COOLER THAN
NORMAL WITH HIGHS IN THE 70S.

&&

.AVIATION /01Z TUESDAY THROUGH SATURDAY/...
AS OF 640 PM EDT MONDAY...

OVERALL VFR SHOULD PREVAIL OVERNIGHT UNDER DIMINISHING WINDS AND
MOSTLY CLEAR SKIES THIS EVENING. A FEW SHOWERS MAY MAKE A RUN AT
KLWB OVER THE NEXT COUPLE OF HOURS BUT LIKELY TO DISSIPATE
CROSSING THE RIDGES SO LEAVING OUT MENTION WITH JUST A FEW MORE
CLOUDS AROUND. WELL MIXED LOW LEVELS FROM THIS AFTERNOON LIKELY TO
INHIBIT MUCH FOG DEVELOPMENT EXCEPT FOR SOME BRIEF MVFR AT
KLYH/KDAN THAT SHOULD STAY EAST OF ANY UPSTREAM MID DECK THAT MAY
ARRIVE OVER THE WEST TOWARD DAWN. CANT TOTALLY RULE OUT SOME BRIEF
VALLEY FOG AT KLWB/KBCB JUST AFTER MIDNIGHT BEFORE ANY ADDED
CLOUDS PUSH EAST. THUS WENT WITH A BRIEF MVFR TEMPO GROUP AT
KLWB/KBCB FOR FOG ALTHOUGH FORECAST FOG STABILITY VALUES SHOW ONLY
SPOTTY COVERAGE AT BEST.

UPPER TROUGH AND ITS ASSOCIATED COLD FRONT WILL APPROACH FROM THE
NORTHWEST TUESDAY WITH MOSTLY ISOLATED MOUNTAIN SHOWERS/STORMS
EXPECTED DURING THE DAY AHEAD OF THE BOUNDARY. HOWEVER MAY SEE A
MORE ORGANIZED BAND DROP IN FROM THE NW WITH THE LEADING PRE-
FRONTAL CONVERGENCE...SO INCLUDING A VCTS MENTION ACROSS THE
SOUTHEAST WEST VA SITES AROUND MID AFTERNOON AND LATE AT KBCB.
OTRW EXPECTING MOSTLY VFR AFTER EARLY MID DECK ERODES AND
SCATTERED-BROKEN CU FIELDS BETWEEN 4-6K FT TAKE SHAPE WITH
HEATING.

EXTENDED AVIATION DISCUSSION...

FRONT SETTLES CLOSER TUESDAY NIGHT INTO WEDNESDAY...WHEN BETTER
COVERAGE OF SHRA/TSRA IS EXPECTED. HOWEVER LOW CONFIDENCE ON THE
TIMING AND SOUTHWARD POSITION OF THE BOUNDARY ON WEDNESDAY AT THIS
POINT PENDING PRE-FRONTAL COVERAGE FROM TUESDAY NIGHT. FOR NOW APPEARS
MAINLY VFR OUTSIDE OF EARLY MORNING FOG WEDNESDAY...THEN PERIODS
OF MVFR WEDNESDAY AFTERNOON ESPCLY SOUTHERN SECTIONS...AND MAINLY
ACROSS THE SOUTH/SOUTHWEST THURSDAY AFTERNOON FOR MORE
ISOLATED NATURE COVERAGE. FRONT WASHES OUT TO THE SOUTH OF THE
AREA FRIDAY WITH MORE WIDELY SCATTERED DIURNAL NATURE SHOWERS AND
STORMS...THEN PERHAPS BECOMING MORE WIDESPREAD SATURDAY WITH
PERIODIC MVFR IN MORE ORGANIZED COVERAGE AHEAD OF ANOTHER COLD
FRONT ARRIVING FROM THE NORTHWEST LATE. OTRW WILL SEE A DAILY
TREND OF EARLY MVFR/IFR IN FOG...FOLLOWED BY BRIEF VFR...THEN
INCREASING AFTERNOON/EVENING CONVECTION WHEN MVFR TO LOCAL IFR
WILL BE POSSIBLE.

&&

.EQUIPMENT...
AS OF 730 AM EDT FRIDAY ...

THE VISIBILITY SENSOR AT KDAN...DANVILLE REGIONAL AIRPORT...WILL
BE OUT OF SERVICE UNTIL FURTHER NOTICE. A PART HAS BEEN BACK-ORDERED.

&&

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

&&

$$
SYNOPSIS...JH/WP
NEAR TERM...JH/WP
SHORT TERM...RCS
LONG TERM...RCS
AVIATION...JH/RAB/WP
EQUIPMENT...RAB



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