Severe Thunderstorm Warning 401, NWS Blacksburg, VA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
1208 PM EDT SUN JUL 27 2008

.SYNOPSIS...
A WEAK FRONT WILL SLIDE THROUGH THE REGION TODAY. ISOLATED TO
SCATTERED SHOWERS AND THUNDERSTORMS WILL ACCOMPANY THE FRONT THROUGH
THIS EVENING. DRY AIR WILL FOLLOW IN THE WAKE OF THIS SYSTEM...THEN
A RETURN OF SHOWERS AND THUNDERSTORMS ARE EXPECTED BY MID WEEK.

&&

.NEAR TERM /UNTIL 9 PM THIS EVENING/...
WEAK COLD FRONT WAS APPROACHING THE WESTERN COUNTY WARNING AREA
THIS MORNING. A LEE TROF WILL BECOME BETTER DEFINED DURING THE
AFTERNOON WITH THE FRONT EVENTUALLY EXITING THE SOUTHEAST COUNTIES
OF THE FORECAST AREA BY 06Z.

LOCAL WRF CONTINUED TO SHOW THE BEST COVERAGE OF STORMS TODAY WILL
BE EAST OF THE BLUE RIDGE. MODIFIED 12Z SOUNDINGS FROM RNK AND GSO
HAD CAPES FROM 2500-3500 J/KG THIS AFTERNOON WITH DCAPES IN THE
EAST AROUND 1100J/KG. HAVE INCREASED CHANCE OF RAIN IN THE EAST
MAINLY FROM A LYH TO WILKESBORO LINE FROM 18-00Z AND FROM DAN TO
YADKIN COUNTY FROM 21-03Z. AFTER 03Z WITH LOSS OF HEATING AND WITH
THE FRONT ALMOST OUT OF THE FORECAST AREA CHANCE OF RAIN WILL DROP
OFF SHARPLY.

ONLY MINOR CHANGES TO MAXIMUM TEMPERATURES FOR THIS AFTERNOON.

&&

.SHORT TERM /9 PM THIS EVENING THROUGH TUESDAY/...
SURFACE HIGH PRESSURE WILL MOVE OVER THE AREA MONDAY WITH AN UPPER
LEVEL TROUGH OVERHEAD. FAIR WEATHER CUMULUS WILL FORM IN THE
AFTERNOON AND DISSIPATE DURING THE EVENING. AN ISOLATED SHOWER IS
POSSIBLE BUT MEASURABLE PRECIPITATION IS UNLIKELY...THEREFORE WILL
KEEP MONDAY AND MONDAY NIGHT POP FREE.

ON TUESDAY...THE HIGH WILL SHIFT EAST OF THE AREA ALLOWING FOR A
BETTER MOISTURE RETURN INTO THE REGION. MODELS ARE SHOWING AN
UPSTREAM NORTHWEST SHORTWAVE TROUGH HEADING TOWARDS THE AREA ON
TUESDAY. WITH UNCERTAINTY OF THIS FEATURE...WILL MAINTAIN CHANCE
POPS.

FOR TEMPERATURES...GUIDANCE IN MOST LOCATIONS AS OF LATE HAS BEEN
TOO COOL FOR THE LOWS...AND TOO WARM ON THE HIGHS.  WILL AIM FOR A
CONSENSUS FORECAST BETWEEN THE MAV AND MET MOS GUIDANCE AND MAKE
ADJUSTMENTS UP OR DOWN AS APPROPRIATE.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
TUESDAY NIGHT THROUGH THURSDAY...THE SCENARIO IS LOOKING SIMILAR TO
WHAT HAS BEEN ADVERTISED IN RECENT DAYS. A DOMINATE UPPER LOW WILL
REMAIN PARKED OVER SOUTHEASTERN CANADA WITH A PREVAILING MAINLY
NORTHWEST FLOW ALOFT ACROSS OUR AREA. A BAROCLINIC ZONE WILL
ESTABLISH ITSELF NEAR...OR NORTH OF THE AREA. DEPENDING UPON TIMING
AND TRACK OF ANY UPSTREAM SYSTEMS...OUR REGION WILL PROBABLY HAVE AT
LEAST ONE TWELVE HOUR PERIOD DURING THIS TIME SPAN WITH BETTER THAN
CHANCE POPS IN AT LEAST THE WESTERN OR NORTHERN PARTS OF THE AREA.
FOR NOW HOWEVER GIVEN THE CHALLENGE OF THIS TIMING...THE FORECAST
WILL CONTINUE TO MIRROR THAT OF HPC WITH A MIXTURE OF ISOLATED TO
SCATTERED SHOWERS AND STORMS ACROSS THE REGION. CURRENTLY...THE
FOCUS FOR THE BEST CHANCES IS ON WEDNESDAY INTO WEDNESDAY NIGHT WHEN
A COLD FRONT IS PROGGED TO SHIFT SOUTH INTO OUR AREA.

ON FRIDAY...THE FRONT MAY BE FAR ENOUGH SOUTH THAT THE FOCUS FOR
PRECIPITATION ALSO SHIFTS SOUTH OF THE REGION. WILL BE ONLY CARRYING
ISOLATED DAYTIME STORMS ACROSS SOUTHERN AND EASTERN PARTS OF THE
AREA. SATURDAY ALSO CURRENTLY LOOKS TO HAVE AT BEST ISOLATED DAYTIME
CONVECTION...BUT PERHAPS ACROSS MORE OF THE AREA.

HAVE FOLLOWED CLOSELY TO THE HPC NUMBERS FOR HIGHS AND LOWS DURING
THE TUESDAY NIGHT THROUGH SATURDAY PERIOD.

&&

.AVIATION /16Z SUNDAY THROUGH THURSDAY/...
SCATTERED SHOWERS WITH ISOLATED CONVECTION IS POSSIBLE THIS
MORNING ACROSS THE MOUNTAINS. THIS CONVECTION WILL MOVE INTO THE
PIEDMONT EARLY THIS AFTERNOON. WITH LIGHT WINDS AND LOW LEVEL
MOISTURE THIS MORNING...PATCHY MVFR FOG IS EXPECTED TO LINGER
THROUGH 14Z THEN MIX OUT AS WEST WINDS INCREASE.

THIS AFTERNOON...DRYING TREND WILL TAKE PLACE ACROSS THE MOUNTAINS.
SCATTERED CONVECTION INCREASES IN THE PIEDMONT AS A COLD FRONT AND
LEE TROUGH COMBINE. THESE STORMS WILL MOVE EAST OF THE AREA THROUGH
THE EVENING.

SHORT WAVE TROF AND ASSOCIATED FRONTAL BOUNDARIES WILL LIKELY BE
OSCILLATING THROUGH SOME PART OF THE MID ATLANTIC REGION FOR MUCH
OF THE FORECAST PERIOD. THEREFORE...FLIGHT INTERESTS SHOULD BE
PREPARED FOR SOME LOCALIZED FLIGHT RESTRICTIONS (TEMPORALLY OR
SPATIALLY) BY MID WEEK...ESPECIALLY SOUTH OF THE BLACKSBURG TERMINAL
FORECAST AREA.

&&

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

&&

SYNOPSIS...RCS
NEAR TERM...AMS
SHORT TERM...RCS
LONG TERM...DS
AVIATION...RCS

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE BLACKSBURG VA
107 PM EDT SUN JUL 27 2008

NCZ004>006-VAZ032>035-043>047-058-059-281000-
STOKES-ROCKINGHAM-CASWELL-PATRICK-FRANKLIN-BEDFORD-AMHERST-HENRY-
PITTSYLVANIA-CAMPBELL-APPOMATTOX-BUCKINGHAM-HALIFAX-CHARLOTTE-
107 PM EDT SUN JUL 27 2008

...SEVERE THUNDERSTORM WATCH 761 IN EFFECT UNTIL 8 PM EDT THIS
EVENING...

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

.DAY ONE...THIS AFTERNOON AND TONIGHT

PLEASE LISTEN TO NOAA WEATHER RADIO OR GO TO WEATHER.GOV ON THE
INTERNET FOR MORE INFORMATION ABOUT THE FOLLOWING HAZARDS.

   SEVERE THUNDERSTORM WATCH.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

NO HAZARDOUS WEATHER IS EXPECTED.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL LIKELY BE NEEDED.

NCZ001>003-018>020-VAZ007-009>020-022>024-WVZ042>045-281000-
ASHE-ALLEGHANY NC-SURRY-WATAUGA-WILKES-YADKIN-TAZEWELL-SMYTH-BLAND-
GILES-WYTHE-PULASKI-MONTGOMERY-GRAYSON-CARROLL-FLOYD-CRAIG-
ALLEGHANY VA-BATH-ROANOKE-BOTETOURT-ROCKBRIDGE-MERCER-SUMMERS-MONROE-
GREENBRIER-
107 PM EDT SUN JUL 27 2008

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

.DAY ONE...THIS AFTERNOON AND TONIGHT

NO HAZARDOUS WEATHER IS EXPECTED.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

NO HAZARDOUS WEATHER IS EXPECTED.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.