Severe Thunderstorm Warning 159, NWS Blacksburg, VA

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BLACKSBURG VA
118 PM EDT WED JUL 19 2006

.AVIATION...

OVERALL VFR CONDITIONS WILL PREVAIL THRU MUCH OF THE FORECAST
PERIOD. HOWEVER SCATTERED CONVECTION WILL MAKE FOR OCNL MVFR/IFR
AT TIMES ANYWHERE ACROSS THE REGION INTO TONIGHT. THUS PLAN TO INCLUDE
CB MENTION OR TEMPO GROUP MOST SPOTS INTO AT LEAST THIS EVENING.
ALSO FOG AGAIN LIKELY ESPCLY LWB WHERE VSBY AOB 1 MILE LIKELY WITH
MVFR CONDITIONS POSSIBLE LYH/DAN BY MORNING. ANY LOW CLOUDS/FOG
BREAK FOR VFR CONDITIONS UNDER LIGHT WINDS THU MORNING...WITH
MOST ADDED CONVECTION LIMITED TO THE MOUNTAINS IN THE AFTERNOON.
&&

.PREV DISCUSSION...
 (ISSUED 1016 AM EDT WED JUL 19 2006)

SHORT TERM /REST OF TODAY/...

OUTFLOW FROM OVERNIGHT CONVECTION HAS SLIPPED SOUTH INTO CENTRAL/SRN
VA WHILE ACTUAL WEAK BACKDOOR FRONT REMAINS JUST NORTH OF THE
AREA. MODIFIED 12Z RAOBS INDICATE PLENTY OF AFTERNOON INSTABILITY
WITH 3K CAPES IN SPOTS AND DEEPENING RH PER PWATS. APPEARS BEST
LOCATION FOR MORE ORGANIZED CONVECTION ACROSS THE NORTH/WEST
INITIALLY ALONG OLD SHEAR AXIS...AND THEN SOUTH AT LEAST ACROSS
THE VA PORTION OF THE CWA WHERE OUTFLOW SUPPORT EXISTS. ALSO LOOKS
LIKE TROPICAL SYSTEM FAR ENOUGH EAST TO LIMIT SUBSIDENCE AFFECTS
SO PLAN TO UP POPS ACROSS THE REGION FOR THE AFTERNOON. LATEST RUC
ALSO SHOWS GOOD COVERAGE NW WHERE WILL UP TO LIKELYS AND STAGGER
HIER CHANCE POPS SOUTH INTO NW NC. MORNING THICKNESS SHOWS
POTENTIAL FOR TEMPS TO GO ABOUT CAT WARMER ALONG/EAST OF THE BLUE
RIDGE PENDING CU/TSRA FORMATION.

PREV DISCUSSION...
 (ISSUED 640 AM EDT WED JUL 19 2006)

AVIATION...

MVFR TO IFR FOG AT BLF AND IN THE GREENBRIER VALLEY SHOULD MIX OUT
BY 13Z. TAF SITES WILL REACH CONVECTIVE TEMPERATURE AROUND 19Z
TODAY...BUT NOT A HIGH ENOUGH CHANCE AT EACH SITE EXCEPT ROA TO PUT
INTO THE BODY OF THE FCST. CHANCE OF RAIN MAY BEGIN SOONER AT LYH
IF OUTFLOW BOUNDARY FROM THE STORMS IN CENTRAL VIRIGNIA OVERNIGHT
TRIGGERS ANY THUNDERSTORMS.

PREV DISCUSSION...
 (ISSUED 312 AM EDT WED JUL 19 2006)

SHORT TERM /TODAY THROUGH FRIDAY NIGHT/...

06Z/19 SOUNDING NOW AVAILABLE.

SURFACE HIGH PRESSURE WILL BE MOVING EAST OUT OF NEW ENGLAND WHILE A
LOW MOVES ACROSS THE GREAT LAKES BY FRIDAY. A WEAK SURFACE BOUNDARY
WILL STALL OVER THE AREA TODAY...THEN THE GREAT LAKES LOW WILL PUSH
A STRONGER FRONT INTO THE MID ATLANTIC ON FRIDAY. THIS FRONT WILL
ALSO BECOME STATIONARY OVER THE FORECAST AREA WITH SEVERAL WAVES OF
LOW PRESSURE MOVING EAST ALONG IT DURING THE WEEKEND.

AS LONG AS THE FORECAST AREA IS SOUTH OF THE MAIN FRONT THERE WILL
BE IN AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS THROUGH
FRIDAY. WESTERN COUNTY WARNING AREA(CWA) WILL BE IN RIGHT REAR
QUADRANT OF UPPER JET THIS EVENING. MODELS AREA SHOWING BETTER LIFT
AND MOISTURE IN THE EASTERN CWA BY EARLY THIS AFTERNOON. THIS SHUD
BE AIDED BY SOUTHWARD MOVING OUTFLOW FROM ANY STORMS OVER NORTHERN
AND CENTRAL VIRGINIA AND WEAK FRONT SAGGING SOUTH INTO CENTRAL
VIRGINIA. THEN THE CHANCE WILL SPREAD WEST BY LATE IN THE DAY.

BEST UPWARD VERTICAL VELOCITY AT 850/700 MB AND BEST Q-VECTOR
FORCING IS AT THE 1000-850 AND 850-700 MB LAYERS IS ON FRIDAY AND
FRIDAY NIGHT. EXPECT THE MOST COVERAGE OF THE NEXT THREE DAYS ON
FRIDAY.

MAV GUIDANCE HAS BEEN TOO WARM PAST FEW DAYS. MOST OF THE CLOUDS
COVER TODAY WILL BE WITH THE SCATTERED THUNDERSTORMS EXPECTED THIS
AFTERNOON. MAXIMUM TEMPERATURES WILL BE A COUPLE OF DEGREES BELOW
THE MAV GUIDANCE.

LONG TERM /SATURDAY THROUGH TUESDAY/...

NO CHANGES AT THIS TIME.

AVIATION...

CONVECTION OVER SE WV/FAR SW VA DURING TUESDAY EVENING WILL PRIME
THE GROUND FOR FOG DEVELOPMENT...ONCE THE MID/HIGH CLOUD DECK
DISSIPATES. LEWISBURG SHOULD SEE MVFR VSBYS AROUND 09Z. WITH
POTENTIAL FOR HIGH CLOUDS TO LINGER...THINK LWB WILL NOT SEE AS
LOW VSBYS AS TUESDAY MORNING...ALTHOUGH COULD SEE IT GO DOWN TO
UNDER 1SM AT TIMES BEFORE DAWN.

LYNCHBURG/DANVILLE SHOULD ALSO SEE MVFR FOG...AND OCCASIONALLY IFR.

OTHERWISE...VFR CONDITIONS CAN BE EXPECT AGAIN TODAY. SCATTERED
THUNDERSTORMS WILL BE AROUND IN THE AFTERNOON ALMOST ANYWHERE...SO
KEPT JUST CB IN THE TAFS.

&&

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

JH

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE BLACKSBURG VA
1025 AM EDT WED JUL 19 2006

NCZ001>006-018>020-VAZ007-009>020-022>024-032>035-043>047-058-059-
WVZ042>045-201000-
ASHE-ALLEGHANY-SURRY-STOKES-ROCKINGHAM-CASWELL-WATAUGA-WILKES-
YADKIN-TAZEWELL-SMYTH-BLAND-GILES-WYTHE-PULASKI-MONTGOMERY-
GRAYSON-CARROLL-FLOYD-CRAIG-BATH-ROANOKE-BOTETOURT-ROCKBRIDGE-
PATRICK-FRANKLIN-BEDFORD-AMHERST-HENRY-PITTSYLVANIA-CAMPBELL-
APPOMATTOX-BUCKINGHAM-HALIFAX-CHARLOTTE-MERCER-SUMMERS-MONROE-
GREENBRIER-
1025 AM EDT WED JUL 19 2006

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

.DAY ONE...TODAY AND TONIGHT

SCATTERED SHOWERS AND THUNDERSTORMS WILL DEVELOP ACROSS THE AREA
THROUGH THIS EVENING. SOME OF THE STORMS MAY PRODUCE VERY HEAVY RAIN
AS WELL AS ISOLATED DAMAGING WINDS AND HAIL.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED LATER THIS AFTERNOON.

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BLACKSBURG VA
925 AM EDT WED JUL 19 2006

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

1055 PM     TSTM WND DMG     3 SE HINTON             37.64N 80.86W
07/18/2006                   SUMMERS            WV   DEPT OF HIGHWAYS

            SEVERAL LARGE TREES DOWN ALONG COUNTY ROAD 13.

&&

HYSELL