Severe Thunderstorm Warning 245, NWS Blacksburg, VA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
1156 AM EDT FRI JUN 27 2008

.SYNOPSIS...
WARM AND MOIST SOUTHWEST FLOW WILL CONTINUE INTO THE REGION TODAY
AND SATURDAY WITH HIGH PRESSURE FIRMLY ENTRENCHED OVER FLORIDA AND
THE GULF COAST. AFTERNOON HEATING WILL LEAD TO SCATTERED SHOWERS
AND THUNDERSTORMS THROUGH THE PERIOD. A BETTER CHANCE OF
THUNDERSTORMS ARRIVES WITH A COLD FRONT SUNDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
CLUSTER OF TSTMS HAS BEEN HOLDING TOGETHER...CROSSING SE WV AND
INTO THE VA HIGHLANDS. SFC WINDS ARE DIFFLUENT EAST OF THE
MTNS...SO NOT SURE IF THE ACTIVITY WILL PERSIST AS IT MOVES
DOWNSLOPE. TEMPS AND DEWPOINTS ARE CLIMBING EAST OF THE MTNS...SO
EVEN IF ACTIVITY WEAKENS...OUTFLOW SHOULD HELP TO INITIATE NEW
STORMS FOR THE AFTERNOON.

MODIFIED RNK SOUNDING FOR A HIGH TEMP OF 87 AND IT YEILDED SBCAPES
OF AROUND 1600 AND AN LI OF M5. A DCAPE OF 558 SUGGESTS POTENTIAL
FOR STRONG DOWNDRAFTS. 55 DBZ CORES ABOVE 23K ARE NEEDED FOR
LARGE HAIL. UNLIKE YESTERDAY WHERE SVR STORMS WERE ENTIRELY PULSE
DRIVEN...TODAYS ACTIVITY MAY BE AIDED BY SOME MID LEVEL
CONVERGENCE DUE REMNANTS OF PASSING MESOSCALE CONVECTIVE VORT TO
OUR NORTH. THIS CONVERGENCE BAND CURRENTLY TRAILS SOUTH FROM THE
MCV (CENTERED OVR PA) ALONG THE WRN SLOPES OF THE
APPALACHIANS...IN THE VCNTY OF CURRENT TSTM CLUSTER ACTIVITY.
THIS MID LEVEL CONVERGENCE IS RESULTING IN A 25-30KT SPEED MAX
THROUGH WV. ALL CONSIDERED...THIS SPEED MAX WILL AID TSTM
DEVELOPMENT THIS AFTERNOON...STORMS POTENTIALLY BECOMING MORE
ORGANIZED THAT YOUR TYPICAL PULSE THUNDERSTORM. ATTM...STILL
ANTICIPATE PULSE STORMS...BUT THINK THUNDERSTORM CLUSTERS WILL
BECOME MORE FAVORED OVER OUR NRN CWA IN THE VICINITY OF THE
MORNING THUNDERSTORM OUTFLOW AND MID LEVEL SPEED MAX.

FOR TONIGHT...WAS SLOW TO REMOVE POPS. SHOULD SEE A GRADUAL
DECLINE ON CONVECTION OVERNIGHT BUT WITH THE BUILDUP OF HEAT OVER
THE PAST FEW DAYS...WOULD NOT BE SURPRISED TO SEE SOME CELLS
CONTINUING WELL PAST MIDNIGHT.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY/...
STRONG WAVE DROPPING OUT OF SOUTHERN CANADA FRIDAY NIGHT WILL END
UP PUSHING HEIGHTS DOWN A BIT OVER THE OHIO VALLEY FOR
SATURDAY...INCREASING MOISTURE SOUTHWEST FLOW...AND PROVIDING
BETTER SUPPORT FOR STORMS. BY SUNDAY...THE FAVORED 00Z ECMWF TAKES
THE CLOSED LOW INTO THE GREAT LAKES...AND KEEPS THE MAIN FRONT
OVER THE OHIO VALLEY WITH LEE TROUGH IN THE PIEDMONT. SUNDAY
SHOULD BE SIMILAR TO SATURDAY IN TERMS OF THUNDERSTORM
COVERAGE...BUT MAY HAVE MORE CLOUDS KEEPING HIGHS DOWN A COUPLE
DEGREES FROM SAT. BETTER UPPER SUPPORT THROUGH THE PERIOD WILL
LEAD TO SOMEWHAT BETTER STORM ORGANIZATION.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
THE FRONT SHOULD BE SOUTHEAST OF THE FORECAST AREA MONDAY WITH
UPPER SHORTWAVES ROTATING AROUND THE LOW OVER ONTARIO...KEEPING
THREAT OF MAINLY AFTERNOON/EVENING CONVECTION GOING INTO TUESDAY.
BY WED...HIGH PRESSURE SHOULD BE INTO THE OHIO/TN VALLEYS WITH
DEEP MOISTURE WELL OFF THE COAST...SO DRIER AND LESS HUMID WX
EXPECTED FOR MIDWEEK.

&&

.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
MOISTURE WILL STEADILY INCREASE INTO THE AREA THE NEXT SEVERAL
DAYS. EARLY MORNING PATCHY FOG AND AFTN AND EVENING TSTMS WILL BE
THE ONLY EXCEPTION TO THE VFR CONDITIONS EXPECTED THROUGH
SATURDAY.

PRECIPITATION CHANCES WILL INCREASE ACROSS THE ENTIRE AREA
SUNDAY AS A COLD FRONT APPROACHES...AND THEN PASSES ACROSS THE
AREA. A DRYING TREND WILL BEGIN MONDAY WITH BENIGN WEATHER
EXPECTED FOR MUCH OF NEXT WEEK.

&&

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

&&

SYNOPSIS...WP
NEAR TERM...JS/PM
SHORT TERM...JS/WP
LONG TERM...WP
AVIATION...JS/RCS

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE BLACKSBURG VA
403 AM EDT FRI JUN 27 2008

NCZ001>006-018>020-VAZ007-009>020-022>024-032>035-043>047-058-059-
WVZ042>045-280815-
ASHE-ALLEGHANY NC-SURRY-STOKES-ROCKINGHAM-CASWELL-WATAUGA-WILKES-
YADKIN-TAZEWELL-SMYTH-BLAND-GILES-WYTHE-PULASKI-MONTGOMERY-GRAYSON-
CARROLL-FLOYD-CRAIG-ALLEGHANY VA-BATH-ROANOKE-BOTETOURT-ROCKBRIDGE-
PATRICK-FRANKLIN-BEDFORD-AMHERST-HENRY-PITTSYLVANIA-CAMPBELL-
APPOMATTOX-BUCKINGHAM-HALIFAX-CHARLOTTE-MERCER-SUMMERS-MONROE-
GREENBRIER-
403 AM EDT FRI JUN 27 2008

THIS HAZARDOUS WEATHER OUTLOOK IS FOR 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

A FEW SEVERE THUNDERSTORMS MAY DEVELOP ACROSS THE REGION
TODAY...PRODUCING ISOLATED INSTANCES OF LARGE HAIL AND DAMAGING
WINDS. OTHERWISE NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

AN APPROACHING COLD FRONT WILL BRING THE THREAT OF STRONG TO SEVERE
THUNDERSTORMS TO THE AREA SATURDAY AND SUNDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED THIS WEEKEND.

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BLACKSBURG VA
1101 AM EDT FRI JUN 27 2008

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

0253 PM     HAIL             2 NW ELKVILLE           36.09N 81.42W
06/26/2008  E0.75 INCH       WILKES             NC   PUBLIC

&&

WHP

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BLACKSBURG VA
1119 AM EDT FRI JUN 27 2008

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

0800 PM     TSTM WND DMG     4 NW CLOVER             36.87N 78.79W
06/26/2008                   HALIFAX            VA   PUBLIC

            TREE DOWN IN MOUNT LAUREL

&&

AMS