Area Forecast Discussion
Issued by NWS Blacksburg, VA

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000
FXUS61 KRNK 281133
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
733 AM EDT THU AUG 28 2014

.SYNOPSIS...
A WEAK COLD FRONT WILL MOVE SOUTH INTO THE REGION TODAY AND STALL
ACROSS NORTH CAROLINA TONIGHT. FRIDAY AND SATURDAY THE FRONT WILL
LIFT WELL NORTH OF THE AREA. BROAD HIGH PRESSURE CENTERED OFF THE
COAST WILL BE OVER THE REGION SUNDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 430 AM EDT THURSDAY...

COLD FRONT EXTEND FROM DELAWARE TO SOUTHERN KENTUCKY EARLY THIS
MORNING. MOISTURE WAS POOLED ALONG THE FRONT. SURFACE DEW POINTS
WERE IN THE MID TO UPPER 60S ALONG THE BOUNDARY AND THE
PRECIPITABLE WATER VALUE AT BLACKSBURG HAS CLIMBED TO NEAR 1.3
INCHES. NORTH OF THE FRONT DEW POINTS DROP OFF INTO THE 50S ACROSS
THE GREAT LAKES AND INTO PENNSYLVANIA.

THE FRONT MOVES SOUTH TODAY AND WILL STALL AROUND THE
VIRGINIA/NORTH CAROLINA BORDER THIS EVENING. THE BEST CHANCE OF
SHOWERS AND THUNDERSTORMS WILL BE ALONG AND SOUTH OF THE FRONT.
MODELS WERE NOT SHOWING MUCH CONVERGENCE ALONG THE FRONT. THERE
WILL BE ENOUGH SUN TODAY THAT CAPES MAY REACH 1500 J/KG IN THE
SOUTHERN COUNTY WARNING AREA. MOST LIKELY TIME FRAME FOR SCATTERED
THUNDERSTORMS WILL BE FROM 18Z/2PM TO 03Z/11PM.

SOME FOG MAY STILL DEVELOP IN THE NEW RIVER VALLEY...NEAR SMITH
MOUNTAIN LAKE AND THROUGH THE DAN RIVER BASIN THIS MORNING WHERE
THERE IS NOT AS MUCH CLOUD COVER. ANY FOG WILL MIX OUT BY MID
MORNING. CLOUD COVER WILL ALSO IMPACT MAXIMUM TEMPERATURES FOR
TODAY. STAYED CLOSE TO MAV GUIDANCE FOR HIGHS.

MAIN CORRIDOR OF HIGHER RELATIVE HUMIDITIES AND MOVES LITTLE
TONIGHT. CLOUDS AND MILDER DEW POINTS WILL HOLD TEMPERATURES
ACROSS THE SOUTH IN THE 60S. SREF AND LOCAL WRF HAD DEW POINTS IN
THE EXTREME NORTHERN COUNTY WARNING AREA DROPPING INTO THE 50S
TONIGHT. IF THIS AREA CLEARS OUT ENOUGH TEMPERATURES WILL DROP
INTO THE MID TO UPPER 50S.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 245 AM EDT THURSDAY...

FRIDAY START WITH AN AREA OF HIGH PRESSURE OVER NEW ENGLAND AND THE
MID ATLANTIC STATES. ALOFT...A RIDGE OF HIGH PRESSURE WILL BE
CENTERED OVER THE SOUTHEASTERN STATES STRETCHING NORTH OVER THE MID
ATLANTIC REGION. OVER THE FORECAST AREA...A STALL FRONTAL BOUNDARY
WILL BE IN THE VICINITY OF THE NC/VA BORDER. THROUGH FRIDAY
AFTERNOON AND NIGHT...BOTH HIGH PRESSURE SYSTEMS WILL DRIFT
EAST...WHILE THE FRONTAL BOUNDARY RETREATS NORTH AS A WARM FRONT.
WITH AN INCREASE IN MOISTURE AND AFTERNOON HEATING...THIS FRONTAL
BOUNDARY WILL BE THE FOCUS FOR AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS. TEMPERATURES FRIDAY WILL BE INFLUENCE MAINLY BY THE
UPPER LEVEL RIDGE OVER THE SOUTHEAST AND WILL WARM ABOVE NORMAL FOR
THE MAJORITY OF THE AREA. LOCATIONS FROM THE SOUTHERN SHENANDOAH
VALLEY TO THE VA PIEDMONT WILL REMAIN UNDER THE INFLUENCE OF THE
SURFACE HIGH THROUGH MUCH OF FRIDAY. AS LONG AS THIS AREA MAINTAINS
AN EASTERLY WIND...TEMPERATURES WILL REMAIN BELOW NORMAL. BY THE END
OF THE DAY...EXPECTING FRONTAL BOUNDARY TO BE NORTH OF THE FORECAST
AREA...ALLOWING NORTHERN COUNTIES TO HAVE A LATE DAY SURGE IN
TEMPERATURES. FRIDAY AFTERNOON TEMPERATURES WILL RANGE FROM THE L/M
80S WEST TO M/U 80S EAST.

THE NORTHERN AND SOUTHERN JET STREAMS ARE SPLIT ON SATURDAY. THE
NORTHERN STREAM FEATURES A LOW PRESSURE SYSTEM THAT WILL TRACK EAST
FROM THE GREAT LAKES TO NEW ENGLAND. THE UPPER LEVEL RIDGE OVER THE
SOUTHEASTERN STATES WILL BLOCK ANY SOUTHERN STREAM SYSTEMS FROM
ADVANCING EAST THROUGH THE PERIOD. THE OUTER RINGS OF THIS RIDGE
START AT THE TEXAS GULF COAST...TO THE TENNESSEE VALLEY...AND OVER
THE CENTRAL APPALACHIANS. SHORT WAVES WITH TROPICAL MOISTURE WILL
TRACK ON THESE OUTER RINGS...INCREASING THE CHANCES FOR SHOWERS AND
THUNDERSTORMS LATE SATURDAY INTO SATURDAY NIGHT. THE BEST CHANCE FOR
AREAWIDE RAIN LOOKS TO BE SUNDAY. WITH ONLY SCATTERED STORMS
EXPECTED SATURDAY AND MAINLY OVER THE MOUNTAINS...TEMPERATURES WILL
WARM INTO THE M/U 80S WITH THE PIEDMONT WARMING INTO THE L90S.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 345 PM EDT WEDNESDAY...

DEEP GULF MOISTURE FLOWING NORTH ALONG THE APPALACHIAN CHAIN WILL
MAINTAIN A CHANCE OF SHOWERS AND THUNDERSTORMS EACH DAY FOR THE
EARLY HALF OF NEXT WEEK.

FOR SUNDAY...RAINFALL IS LOOKING INCREASINGLY LIKELY AS AN
UPPER LEVEL TROUGH MOVES UP THE OHIO RIVER VALLEY. WITH
PERCEPTIBLE WATER VALUES IN THE BALLPARK OF 2 INCHES ACROSS OUR
AREA...BELIEVE THAT LOCALLY EXCESSIVE RAINFALL WILL BE POSSIBLE IN
SOME AREAS... ESPECIALLY IF STORMS BEGIN TO PASS REPEATEDLY OVER
THE SAME LOCATIONS.

ON MONDAY...UPPER LEVEL FLOW BEGINS TO TRANSITION TO A MORE WEST TO
EAST ORIENTATION...WITH NO STRONG DISTURBANCES EXPECTED. BELIEVE
SHOWER AND THUNDERSTORM ACTIVITY WILL BE MORE DRIVEN BY DAYTIME
HEATING THAN ANYTHING ELSE...MEANING RAINFALL WILL BE MORE OF THE
HIT AND MISS VARIETY.

LOOKING TO TUESDAY...EXPECT A SLIGHTLY BETTER CHANCE OF SHOWERS AND
THUNDERSTORMS AS A COLD FRONT APPROACHES OUR REGION FROM THE
NORTHWEST. BEST CHANCES FOR SHOWER AND THUNDERSTORM ACTIVITY WILL BE
DURING THE EVENING AS THE FRONT APPROACHES THE OHIO RIVER...HOWEVER
WITH NO REAL PUSH OF COLD AIR BEHIND THE FRONT...IT IS ENTIRELY
POSSIBLE THAT THE OHIO RIVER IS AS FAR SOUTH AS THE FRONT SINKS.

ABUNDANT GULF MOISTURE WILL MAKE FOR MUGGY AND WARM CONDITIONS FOR
THE EARLY HALF OF NEXT WEEK. LOOK FOR HIGHS TO RANGE FROM THE UPPER
70S/LOW 80S ACROSS THE MOUNTAINS...TO THE UPPER 80S ACROSS THE
PIEDMONT. OVERNIGHT LOWS WILL RANGE FROM THE MID 60S TO LOW 70S.

&&

.AVIATION /12Z THURSDAY THROUGH MONDAY/...
AS OF 730 AM EDT THURSDAY...

SATELLITE PICTURES SHOWERS STRATUS OVER A LARGE PART OF WEST
VIRGINIA THIS MORNING ALONG THE WESTERN SLOPES OF THE
APPALACHIANS. THE EDGE OF THIS IFR TO LIFR CLOUD COVER WAS NEAR
KBLF AND JUST WEST OF KLWB. EXPECT A SLOW IMPROVEMENT IN CEILINGS
UP TO VFR BY AFTERNOON.

WEAK SURFACE COLD FRONT STRETCHED ACROSS VIRGINIA AND KENTUCKY
THIS MORNING. THIS FRONT WILL BECOME STATIONARY ACROSS NORTH
CAROLINA TONIGHT. WINDS NORTH OF THE BOUNDARY WILL BECOME NORTH TO
NORTHEAST TODAY.

CONVERGENCE ALONG THE FRONT WILL TRIGGER SCATTERED SHOWERS AND
THUNDERSTORMS THIS AFTERNOON. STORMS WILL DEVELOP VCNTY OF THE
VA/NC BORDER THIS AFTERNOON...THEN DRIFT SOUTHEAST INTO NORTH
CAROLINA. FOR NOW HAVE LEFT ANY SHOWERS AND THUNDERSTORMS OUT OF
THE KDAN AND KBCB TAFS. HIGHER CONFIDENCE OF SHOWERS AND
THUNDERSTORMS FROM 18Z/2PM THROUGH 03Z/11PM SOUTH OF THESE
AIRPORTS.

EXTENDED DISCUSSION...
THE WEAK FRONT IS FORECAST TO RETURN NORTH AS A WARM FRONT
FRIDAY. WIDELY SCATTERED SHRA/TSRA ARE EXPECTED ALONG THIS
BOUNDARY FRIDAY AND SATURDAY...WITH THE GREATEST COVERAGE DURING
THE PEAK HEATING OF THE DAY. WHERE SHRA/TSRA OCCUR EXPECT BRIEF
PERIODS OF SUB VFR CONDITIONS.

AN AREA OF LOW PRESSURE IS FORECAST TO MOVE THROUGH THE GREAT
LAKES SATURDAY NIGHT AND SUNDAY...THE ASSOCIATED COLD FRONT
TRAILING SOUTH AND MOVING ACROSS THE OHIO/TN VALLEYS. SHOWERS AND
THUNDERSTORMS WILL LIKELY BE ASSOCIATED WITH THIS FRONT...THIS
ACTIVITY SPREADING EAST INTO THE CENTRAL APPALACHIANS SUNDAY AND
MONDAY. SHOWER COVERAGE SUNDAY/MONDAY IS EXPECTED TO BE MORE
WIDESPREAD AS COMPARED TO FRIDAY AND SATURDAY.

&&

.EQUIPMENT...
AS OF 730 AM EDT THURSDAY ...

THE VISIBILITY SENSOR AT KDAN...DANVILLE REGIONAL AIRPORT...REMAINS
OUT OF SERVICE. A PART HAS BEEN ORDERED. REPAIRS WILL BE DONE THIS FRIDAY.

&&

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

&&

$$
SYNOPSIS...AMS
NEAR TERM...AMS
SHORT TERM...RCS
LONG TERM...NF
AVIATION...AMS/PM
EQUIPMENT...AMS


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