Special Weather Statement, NWS Blacksburg, VA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
806 PM EDT TUE AUG 6 2013

.SYNOPSIS...
HIGH PRESSURE MOVES OFF THE COAST TONIGHT. A FRONTAL BOUNDARY AND
UPPER DISTURBANCES AFFECT OUR WEATHER FROM WEDNESDAY THROUGH THE
END OF THE WEEKEND.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
AS 325 PM EDT TUESDAY...

LIMITED HEATING ALONG WITH LOW LEVEL CONVERGENCE MAY CREATE ISOLATED
TO SCATTERED SHOWERS AND THUNDERSTORM THIS AFTERNOON INTO TONIGHT.
THE BEST OF CHANCE OF CONVECTION IS ALONG AND EAST OF THE BLUE RIDGE
UNTIL SUNSET. THE WESTERLY WIND AND AMPLE CLOUD COVER ARE HINDERING
CONVECTION DEVELOPMENT.

THIS EVENING INTO TONIGHT...ANY SHOWERS AND THUNDERSTORMS FADE
THOUGH SE TO SOUTH FLOW ALONG WITH PLENTY OF LOW LEVEL MOISTURE MAY
KEEP THE SLIGHT CHANCE OF SHOWERS AROUND ALL NIGHT...WITH CHANCES
INCREASING OVER THE WEST LATE AS NEXT UPSTREAM SHORTWAVE MOVES
TOWARD THE MOUNTAINS. PLAYED LOW TEMPERATURES TONIGHT CLOSE TO
WARMER MET GUID WITH READINGS FROM THE LOWER 60S IN THE MOUNTAINS TO
AROUND 70 DEGREES IN THE SOUTHEAST.

GFS...NAM AND ECMWF ARE CONTINUING THE SLOWER ONSET TREND WITH
MIDLEVEL WAVES WEDNESDAY...AND THUS TRIMMED POPS AND SLOWED THE
ADVANCE OF CONVECTION. RICH MOISTURE ARRIVES WEDNESDAY BEHIND A WEAK
WARM FRONT...AS A COLD FRONT APPROACHES FROM THE NORTHWEST. KEPT THE
HIGHEST POPS IN THE WEST WEDNESDAY AND ALLOWED THE MENTION OF HEAVY
RAIN WITH STORMS BECAUSE SOME OF THE SHOWERS AND THUNDERSTORMS COULD
BE EFFICIENT RAIN PRODUCERS GIVEN THE HIGHER PWAT. AT THIS
TIME...NOT EXPECTING ANY WIDESPREAD FLOODING PROBLEMS. WITH RECENT
DRIER CONDITIONS... 1 HOUR RFC FFG HAVE CLIMB TO 1.7 TO 3 INCHES.
THE SEVERE THREAT REMAINS TO THE NORTH OF THE OHIO RIVER WHERE SPC
HAS SLIGHT RISK ON DAY TWO CONVECTIVE OUTLOOK WITH BEST DYNAMICS.
WENT WITH COOLER MOS HIGHS ON WEDNESDAY FROM THE LOWER 70S IN THE
MOUNTAINS TO THE LOWER 80S IN THE SOUTHEAST.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/...
AS OF 300 PM EDT MONDAY...

WILL MAINTAIN HIGHER LIKELY POPS ACROSS THE NW INTO WED EVENING WITH
MOSTLY CHANCE COVERAGE ELSW AS THE EARLIER DAMPENING VORT LOBE
PASSES ACROSS FROM THE WEST. OTRW PC AND MUGGY WED NIGHT WITH ANY
LEFTOVER SHRA FADING IN ALL EXCEPT THE MOUNTAINS BY MORNING. 5H
HEIGHTS THEN LOOK TO BUILD A BIT ON THU IN RESPONSE TO BACKING FLOW
ALOFT AHEAD OF THE NEXT SHORTWAVE APPROACHING FROM THE NW. HOWEVER
MAIN LIFT WITH THIS FEATURE LIKELY TO STAY TO THE WEST/NW CLOSER TO
THE UPPER TROF AND ASSOCIATED COLD FRONT ALONG A RIBBON OF DEEPER
MOISTURE FROM THE SRN MIDWEST INTO THE OHIO VALLEY. SOME OF THIS
SHRA/TSRA WITHIN THIS CORRIDOR MAY SPILL SE AFFECTING MAINLY THE FAR
NW SECTIONS THU AND MORESO WESTERN HALF FRIDAY AS A BETTER DEFINED
PRE-FRONTAL BAND DEVELOPS. WEAK IMPULSES WITHIN THIS HIGHER PWAT
BAND TO THE NW COULD ALSO CAUSE MCS COMPLEXES AS WELL WHICH MAY
INTERRUPT THE OVERALL CHAIN OF SHRA/TSRA MAKING EASTWARD EXTENT
OF POPS IFFY AS SEEN IN DIFFERENCES BETWEEN THE WETTER GFS AND
OTHER LAGGING SOLUTIONS WHICH HOLD MOST ORGANIZED SHRA TO THE
NORTH/WEST. OTRW LOOKING AT BETTER SW FLOW TO POSSIBLY CAUSE SOME
INCREASE IN TSRA ALONG THE BLUE RIDGE THU...AND IN A WIDER
CORRIDOR MOUNTAINS FRI SO KEPT LIKELY POPS THERE INTO THE WESTERN
SLOPES AND CHANCE ELSW. HEAVY RAIN AGAIN POSSIBLE BUT KEPT OUT
MENTION GIVEN SLOWER MODEL TRENDS IN HAVING WIDESPREAD COVERAGE OF
LATE.

WITH POTENTIAL IN SEEING MORE INSOLATION ESPCLY EAST GIVEN SLOWER
SOLUTIONS...BUMPED UP HIGHS A CAT OR SO MOST SPOTS WHICH WILL PUSH
TEMPS CLOSE TO 90ISH PIEDMONT...AND INTO THE 80S ELSW OUTSIDE OF THE
HIGHER ELEVATIONS.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 1140 AM EDT TUESDAY...

LOTS OF UNCERTAINTY REMAINS IN THE EXTENDED IN REGARDS TO TIMING OF
THE COLD FRONT DROPPING IN FROM THE NORTH THIS WEEKEND AND JUST HOW
FAR SOUTH THE BOUNDARY GETS EARLY NEXT WEEK. LATEST MODELS HAVE
GOTTEN SLOWER WITH THE EVOLUTION OF THE HUDSON BAY UPPER LOW IN TURN
KEEPING A STRONGER/ZONAL 5H TRAJECTORY ACROSS THE MID ATLANTIC A BIT
LONGER. THIS COMBINED WITH RIPPLES OF ENERGY SLIDING EAST AND
PARALLEL WESTERLY FLOW TO THE FRONT...MAY KEEP THE BOUNDARY STUCK
CLOSER TO THE OHIO RIVER EARLY SATURDAY BEFORE CONVECTION...
INCLUDING A PASSING WAVE FORCE IT SOUTH OF THE AREA LATER IN THE
WEEKEND. THIS WOULD PUT THE AXIS OF DEEPER MOISTURE AND BEST PRE-
FRONTAL LIFT ACROSS THE AREA SAT AFTERNOON/EVENING AND MAINLY OVER
THE SOUTHERN/EASTERN SECTIONS SUNDAY AT THIS POINT. THUS WILL GO
CLOSER TO THE HIGHER WPC LIKELY POPS LATER SATURDAY WITH A
SCATTERING OF CONVECTION SUNDAY AFTERNOON. GIVEN TRENDS OF A SLOWER
FRONTAL ARRIVAL...EXPECT MUCH WARMER TEMPS SAT PER WEAK COMPRESSION
AND MORE HEATING WITH 80S MOST SPOTS AND LOWER 90S SE.

FRONT SHOULD DRIFT TO THE SOUTH AND DISSIPATE EARLY NEXT WEEK WITH
POTENTIAL FOR ANOTHER WAVE ALOFT TO DROP SE AND LIFT MOISTURE BACK
NORTH BY LATER MONDAY INTO TUESDAY. HOWEVER THIS QUITE LOW
CONFIDENCE ESPCLY GIVEN DRIER EC SOLNS WHICH SPILLS WEAK RIDGING IN
FROM THE NORTH EARLY ON WITH ANY SECONDARY SURFACE LOW WELL
OFFSHORE. THEREFORE WILL GO WITH LOW CHANCE POPS MAINLY SOUTH/WEST
BOTH DAYS...WITH MORE SUN POSSIBLE BUT TEMPS CLOSER TO NORMAL BEHIND
THE BOUNDARY AND UNDER CLOUDS/NE FLOW.

&&

.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
...AS OF 730 PM EDT TUESDAY...

EXPECTING CURRENT CONVECTION SEEN ON RADAR TO GRADUALLY DIMINISH
AFTE SUNSET...THOUGH MODELS AND KEYING ON A WEAK SHORT WAVE MOVING
THROUGH OVERNIGHT WHICH MAY KEEP SHOWERS GOING GOING. WILL GO WITH
SHRA AT KLWB SINCE THEY WILL BE CLOSEST TO THE CENTER OF THE SHORT
WAVE BUT WILL PLAY THE DIURNAL TREND FOR OTHER SITES AND GO DRY
AFTER ABOUT 03Z. EXPECTING MOIST FLOW TO RESULT IN STRATUS BLOOM
OVERNIGHT WITH SOME FOG AS WELL. BEST BET FOR REAL SOUPY
CONDITIONS WILL BE AT KLWB WITH MAINLY MVFR AT OTHER SITES.

LINGERING FOG/STRATUS SHOULD TRANSFORM TO A VFR CU DECK BY LATE
MORNING. ANOTHER SHORT SHORT WAVE APPROACHING FROM THE WEST LOOKS
TO GENERATE MORE AFTERNOON CONVECTION...ESPECIALLY ALONG AND WEST
OF THE BLUE RIDGE. CURRENT THINKING IS THAT KDAN MAY BE ABLE TO
AVOID CONVECTION THROUGH THE TAF PERIOD TOMORROW. WILL COVER THE
SITUATION WITH VCTS AT ALL OTHER SITES.

.AVIATION EXTENDED...

THE PATTERN WILL BE ACTIVE WED-SUN WITH A FRONT SAGGING SE TOWARD
THE AREA BY THURSDAY-FRIDAY. WILL SEE OFF AND ON SHOWERS AND
STORMS MAINLY IN THE AFTERNOON/EVENING WED...WITH OVERNIGHT
POSSIBILITIES INCREASING WITH THE FRONT THU-SUN. AT THIS TIME
ASIDE FROM AIRPORTS BEING AFFECTED BY STORMS OR FOG...VFR WEATHER
EXPECTED.

&&

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

&&

SYNOPSIS...KK/WP
NEAR TERM...KK
SHORT TERM...JH
LONG TERM...JH
AVIATION...KK/MBS

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE BLACKSBURG VA
327 PM EDT TUE AUG 6 2013

VAZ007-010-011-018>020-WVZ042>045-071930-
TAZEWELL-BLAND-GILES-CRAIG-ALLEGHANY VA-BATH-MERCER-SUMMERS-MONROE-
GREENBRIER-
327 PM EDT TUE AUG 6 2013

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHWEST VIRGINIA...WEST
CENTRAL VIRGINIA AND SOUTHEAST WEST VIRGINIA.

.DAY ONE...THIS AFTERNOON AND TONIGHT.

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER LOW AT THIS TIME.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY.

PERIODIC ROUNDS OF AFTERNOON SHOWERS AND THUNDERSTORMS WILL OCCUR
INTO THE WEEKEND...WITH THE BEST COVERAGE THURSDAY INTO SATURDAY
AHEAD OF A SLOW MOVING COLD FRONT. HEAVY RAINFALL MAY RESULT IN
AN INCREASING THREAT FOR FLASH FLOODING OVER THE NEXT FEW DAYS
ALONG WITH ISOLATED SEVERE STORMS.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

NCZ001-002-018-VAZ009-012>017-022>024-071930-
ASHE-ALLEGHANY NC-WATAUGA-SMYTH-WYTHE-PULASKI-MONTGOMERY-GRAYSON-
CARROLL-FLOYD-ROANOKE-BOTETOURT-ROCKBRIDGE-
327 PM EDT TUE AUG 6 2013

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHWEST NORTH
CAROLINA...SOUTHWEST VIRGINIA AND WEST CENTRAL VIRGINIA.

.DAY ONE...THIS AFTERNOON AND TONIGHT.

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER LOW AT THIS TIME.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY.

SCATTERED SHOWERS AND THUNDERSTORMS WILL BECOME MORE WIDESPREAD BY
THE WEEKEND. THESE STORMS COULD PRODUCE LOCALLY HEAVY RAINFALL
RESULTING IN AN INCREASING FLASH FLOOD THREAT BY LATE WEEK. ISOLATED
SEVERE THUNDERSTORMS MAY ALSO OCCUR.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

NCZ003>006-019-020-VAZ032>035-043>047-058-059-071930-
SURRY-STOKES-ROCKINGHAM-CASWELL-WILKES-YADKIN-PATRICK-FRANKLIN-
BEDFORD-AMHERST-HENRY-PITTSYLVANIA-CAMPBELL-APPOMATTOX-BUCKINGHAM-
HALIFAX-CHARLOTTE-
327 PM EDT TUE AUG 6 2013

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTH CENTRAL NORTH
CAROLINA...NORTHWEST NORTH CAROLINA...CENTRAL VIRGINIA...SOUTH
CENTRAL VIRGINIA...SOUTHWEST VIRGINIA AND WEST CENTRAL VIRGINIA.

.DAY ONE...THIS AFTERNOON AND TONIGHT.

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER LOW AT THIS TIME.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY.

SHOWERS AND THUNDERSTORMS WILL BECOME MORE WIDESPREAD FRIDAY INTO
SATURDAY. LOCALLY HEAVY RAINFALL AND ISOLATED SEVERE STORMS WILL
BE POSSIBLE.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE BLACKSBURG VA
634 PM EDT TUE AUG 6 2013

VAZ045-062300-
CAMPBELL VA-
634 PM EDT TUE AUG 6 2013

THE NATIONAL WEATHER SERVICE IN BLACKSBURG HAS ISSUED A

* SPECIAL WEATHER STATEMENT FOR...
  SOUTH CENTRAL CAMPBELL COUNTY IN CENTRAL VIRGINIA...

* UNTIL 700 PM EDT

* AT 631 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING
  A STRONG THUNDERSTORM NEAR LONG ISLAND...MOVING TO THE SOUTH AT 10
  MPH.

* WIND GUSTS UP TO 30 MPH ARE EXPECTED WITH THIS STORM. VERY HEAVY
  RAIN IS FALLING...AND WILL CAUSE WATER TO POND ON ROADWAYS AND
  QUICKLY FILL ROADSIDE DITCHES AND SMALL STREAMS.

* LOCATIONS IMPACTED INCLUDE...
  LONG ISLAND.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

PROLONGED HEAVY RAINFALL MAY CAUSE WATER TO FLOW OVER THE ROADWAY. DO
NOT DRIVE YOUR VEHICLE WHERE THE ROAD HAS BECOME FLOODED.

&&

LAT...LON 3704 7902 3704 7905 3706 7910 3709 7912
      3707 7914 3716 7916 3717 7909 3704 7899
TIME...MOT...LOC 2231Z 342DEG 8KT 3711 7911

DS

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE BLACKSBURG VA
635 PM EDT TUE AUG 6 2013

VAZ046-062300-
APPOMATTOX VA-
635 PM EDT TUE AUG 6 2013

THE NATIONAL WEATHER SERVICE IN BLACKSBURG HAS ISSUED A

* SPECIAL WEATHER STATEMENT FOR...
  NORTHERN APPOMATTOX COUNTY IN CENTRAL VIRGINIA...

* UNTIL 700 PM EDT

* AT 631 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING
  STRONG THUNDERSTORMS ALONG A LINE EXTENDING FROM TOWER HILL TO
  RIVERVILLE...MOVING TO THE SOUTHEAST AT 10 MPH.

* VERY HEAVY RAIN IS FALLING...AND WILL CAUSE WATER TO POND ON
  ROADWAYS AND QUICKLY FILL ROADSIDE DITCHES AND SMALL STREAMS.

* LOCATIONS IMPACTED INCLUDE...
  BENT CREEK...
  TOWER HILL...
  AND OAKVILLE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

PROLONGED HEAVY RAINFALL MAY CAUSE WATER TO FLOW OVER THE ROADWAY. DO
NOT DRIVE YOUR VEHICLE WHERE THE ROAD HAS BECOME FLOODED.

&&

LAT...LON 3742 7869 3742 7893 3750 7893 3752 7889
      3753 7890 3754 7887 3754 7881 3748 7873
TIME...MOT...LOC 2231Z 332DEG 8KT 3750 7879 3750 7891

DS

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE BLACKSBURG VA
701 PM EDT TUE AUG 6 2013

VAZ046-062330-
APPOMATTOX VA-
701 PM EDT TUE AUG 6 2013

THE NATIONAL WEATHER SERVICE IN BLACKSBURG HAS ISSUED A

* SPECIAL WEATHER STATEMENT FOR...
  NORTHERN APPOMATTOX COUNTY IN CENTRAL VIRGINIA...

* UNTIL 730 PM EDT

* AT 700 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING
  A STRONG THUNDERSTORM NEAR TOWER HILL...MOVING TO THE SOUTHEAST AT
  5 MPH.

* VERY HEAVY RAIN IS FALLING...AND WILL CAUSE WATER TO POND ON
  ROADWAYS AND QUICKLY FILL ROADSIDE DITCHES AND SMALL STREAMS.

* THIS STORM WILL REMAIN OVER MAINLY RURAL AREAS OF
  NORTHERN APPOMATTOX COUNTY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

PROLONGED HEAVY RAINFALL MAY CAUSE WATER TO FLOW OVER THE ROADWAY. DO
NOT DRIVE YOUR VEHICLE WHERE THE ROAD HAS BECOME FLOODED.

&&

LAT...LON 3749 7889 3752 7883 3745 7871 3738 7883
TIME...MOT...LOC 2300Z 318DEG 6KT 3748 7882

DS

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE BLACKSBURG VA
737 PM EDT TUE AUG 6 2013

VAZ046-070000-
APPOMATTOX VA-
737 PM EDT TUE AUG 6 2013

THE NATIONAL WEATHER SERVICE IN BLACKSBURG HAS ISSUED A

* SPECIAL WEATHER STATEMENT FOR...
  NORTHERN APPOMATTOX COUNTY IN CENTRAL VIRGINIA...

* UNTIL 800 PM EDT

* AT 730 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING
  A STRONG THUNDERSTORM NEAR TOWER HILL...MOVING TO THE EAST AT 5
  MPH.

* VERY HEAVY RAIN IS FALLING...AND WILL CAUSE WATER TO POND ON
  ROADWAYS AND QUICKLY FILL ROADSIDE DITCHES AND SMALL STREAMS.

* THIS STORM WILL REMAIN OVER MAINLY RURAL AREAS OF
  NORTHERN APPOMATTOX COUNTY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

PROLONGED HEAVY RAINFALL MAY CAUSE WATER TO FLOW OVER THE ROADWAY. DO
NOT DRIVE YOUR VEHICLE WHERE THE ROAD HAS BECOME FLOODED.

&&

LAT...LON 3746 7884 3750 7879 3744 7869 3740 7879
TIME...MOT...LOC 2330Z 291DEG 6KT 3745 7878

DS

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BLACKSBURG VA
800 PM EDT TUE AUG 06 2013

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0745 PM     FLASH FLOOD      4 ENE ROANOKE           37.29N 79.89W
08/06/2013                   CITY OF ROANOKE    VA   911 CALL CENTER

            FLOODING NEAR KING STREET AND BERKLEY STREET.

&&

AMS

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE BLACKSBURG VA
913 PM EDT TUE AUG 6 2013

VAZ047-070145-
BUCKINGHAM VA-
913 PM EDT TUE AUG 6 2013

THE NATIONAL WEATHER SERVICE IN BLACKSBURG HAS ISSUED A

* SPECIAL WEATHER STATEMENT FOR...
  CENTRAL BUCKINGHAM COUNTY IN CENTRAL VIRGINIA...

* UNTIL 945 PM EDT

* AT 909 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING
  A STRONG THUNDERSTORM NEAR DILLWYN...MOVING TO THE EAST AT 10 MPH.

* VERY HEAVY RAIN IS FALLING...AND WILL CAUSE WATER TO POND ON
  ROADWAYS AND QUICKLY FILL ROADSIDE DITCHES AND SMALL STREAMS.

* LOCATIONS IMPACTED INCLUDE...
  DILLWYN.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

PROLONGED HEAVY RAINFALL MAY CAUSE WATER TO FLOW OVER THE ROADWAY. DO
NOT DRIVE YOUR VEHICLE WHERE THE ROAD HAS BECOME FLOODED.

&&

LAT...LON 3743 7840 3742 7849 3753 7851 3758 7834
      3752 7833
TIME...MOT...LOC 0109Z 260DEG 10KT 3749 7845

DS