Severe Thunderstorm Warning 66, NWS Blacksburg, VA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
133 PM EDT SUN MAY 23 2010

.SYNOPSIS...
AN UPPER LEVEL LOW PRESSURE SYSTEM WILL BE OVER CENTRAL VIRGINIA THIS
AFTERNOON...THEN OVER SOUTHEAST NORTH CAROLINA THIS EVENING. THIS
SYSTEM WILL THEN GET ABSORBED BY ANOTHER LOW WELL OFF THE
SOUTHEAST COAST MONDAY AND MEANDER OFFSHORE INTO THE MIDDLE OF
NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
VIS SAT SHOWING GOOD DEVELOPMENT OF CU FIELD FROM SE WV/NEW RIVER
VALLEY EAST INTO THE VA/NC PIEDMONT. SHOWERS/TSRA FORMING UNDER
THE UPPER LOW IN NRN VA...MOVING SWD INTO MY NRN CWA. BASED ON
LATEST WRF...AND MESOANALYSIS...THE BEST LOCATION FOR CONVECTION
THIS AFTN...WILL BE EAST OF THE BLUE RIDGE. HAVE MADE ADJUSTMENTS
TO UP POPS FROM NORTH OF LYH TO DANVILLE THIS
AFTERNOON...WITH LIKELY THERE...TO ISOLATED OR NONE TOWARD FAR SW
VA.

WILL HAVE TO WATCH FOR SVR POTENTIAL AS COOL AIR ALOFT COULD BRING
SOME HAIL...BUT CHANCES ARE VER LOW. PWATS ARE LOWER THIS MORNING
THAN YESTERDAY...ALTHOUGH STILL SEEING 1.0 TO 1.3 INCHES IN THE
EAST...SO RAINS COULD BE HEAVY OUT THERE THIS AFTERNOON.

FORECAST HIGHS WERE RAISED A FEW DEGREES...ESPECIALLY IN THE SW THINKING
WILL SEE MORE SUN.

WHILE MODELS DIFFER ON THE FORECAST LOCATION OF THE UPPER LOW BY
12Z MONDAY...WITH THE NAM FARTHER NORTH THAN THE GFS...12Z ECMWF
AND GEM...ALL OF THESE MODELS AGREE A DEEP EASTERLY FLOW FORMS
WHICH SHOULD KEEP SHOWERS GOING THROUGH SUNDAY NIGHT...ESPECIALLY
EAST OF THE BLUE RIDGE.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
UPPER LEVEL LOW MERGES WITH AN UPPER LOW OFF THE CAROLINAS COAST
MONDAY THEN LINGERS OVER THE WESTERN ATLANTIC THROUGH TUESDAY
NIGHT. THIS WILL AID IN KEEPING THE AREA IN A WEAK EAST TO
NORTHEASTERLY FLOW. HAVE LEANED TOWARD A BLEND OF THE 00Z GFS AND
THE 12Z ECMWF FOR THIS TIME PERIOD. ALTHOUGH A GOOD CHANCE ACROSS
THE ENTIRE COUNTY WARNING AREA...MODELS SUGGEST THE HIGHEST POPS
TO BE MAINLY ALONG THE BLUE RIDGE AND EAST MONDAY AFTERNOON. THE
POPS WILL THEN TAPER OFF FROM EAST TO WEST LATE MONDAY NIGHT AS
THE DEEP MOISTURE DIMINISHES. WITH SOME INSTABILITY PRESENT EXPECT
SOME DEVELOPMENT OF THUNDERSTORMS MONDAY AFTERNOON AND DECREASING
IN THE OVERNIGHT HOURS. PRECIP CHANCES CONTINUE TO DECREASE
THROUGH TUESDAY NIGHT AS HIGH PRESSURE AT THE SURFACE AND ALOFT
TRIES TO BUILD INTO THE REGION FROM THE NORTH.

MAX TEMPERATURES FOR MONDAY WILL BE BELOW NORMAL AND THEN RISING TO
NEAR SEASONAL NORMS MONDAY NIGHT THROUGH TUESDAY NIGHT.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
THE CLOSED UPPER HIGH WEAKENS AND RETROGRADES SOMEWHAT AS
TROUGHING ENTERS HUDSON BAY LATE WEEK. THIS ALLOWS A TROUGH TO
DEEPEN INTO NEW ENGLAND AND EVENTUALLY ATTRACTS THE SLOWLY OPENING
UPPER LOW JUST OFF THE SOUTHEAST COAST. AFTER A BACKDOOR FRONT
SNEAKS EAST OF THE APPLN MTNS THURSDAY...WINDS VEER BACK TO THE SW
AND WEST NEAR THE END OF THE LONG TERM. THUS...A WARMUP SOLIDLY
INTO THE 80S MAY ARRIVE FRIDAY AND SATURDAY WITH H85 TEMPS IN THE
UPPER TEENS. WIDELY SCATTERED SHWS/STORMS MAY DEVELOP MOSTLY ALONG
THE SOUTHERN CWA WITH THE BACKDOOR BOUNDARY THURSDAY...AND THEN
PERHAPS AGAIN FRI/SAT...IF ENOUGH COOL AIR REMAINS IN THE
MIDLEVELS...MITIGATING ANY CAP.

&&

.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
CONVECTION BREAKING OUT OVER THE SHENANDOAH VALLEY EAST TOWARD
LYH/CHO MOVING SLOWLY SOUTH. TERMINALS THAT HAVE THE GREATEST
CHANCE OF SEEING A SHOWER AND THUNDER IS LYH. FOR NOW WENT WITH
VCTS IN THE PREVAILING AND A PERIOD OF MODERATE SHOWERS AND IFR
VSBY BETWEEN 18-20Z. DANVILLE MAY ALSO SEE SOME CONVECTION THIS
AFTERNOON BUT ATTM...KEPT IT AS A CB IN TH CLOUD GROUPS WITH
A TEMP FOR IFR VSBY/MVFR CIGS.

FURTHER WEST THINK THE CHANCE OF PRECIP WILL BE LESS BUT CANNOT
RULE OUT A SHOWER NEAR LWB/ROA...BUT OVERALL VFR WX EXPECTED
THROUGH THIS EVENING.

THE MAIN THREAT OF SHRA/TSRA WILL BE EAST/SOUTHEAST OF LYH/DAN
THIS EVENING AND LOOKING AT NE-E FLOW BRINGING LOW CIGS...AND
MAYBE EVEN SUB MVFR VSBYS LATE TONIGHT.

BLF/ROA SHOULD SEE MVFR CIGS LATE TONIGHT...WHILE LWB DROPS TO
LIFR RANGE.

SUNDAY MORNING...CLOUDS WILL BE SLOW TO DISPERSE AND KEEPING MVFR
CIGS IN THROUGH THE PERIOD.

AS THIS UPPER LOW DROPS SOUTH THROUGH THE MID ATLANTIC REGION THE
POTENTIAL FOR PERSISTENT MVFR/IFR CONDITIONS WILL CONTINUE INTO
MONDAY AFTN. BY TUESDAY...A LOW OFF THE SOUTHEAST COAST STILL COULD
BE AFFECTING THE EASTERN SECTIONS OF THE AREA...FROM ROANOKE
EAST...WITH SHOWERS AND LOWER CIGS FOLLOWED BY ONLY A GRADUAL
IMPROVEMENT INTO MID WEEK.

&&

.EQUIPMENT...
THE KFCX 88D REMAINS DOWN. THE EARLIEST RETURN TO SERVICE WILL
BE MONDAY.

&&

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

&&

SYNOPSIS...PH/WP
NEAR TERM...PH/WP
SHORT TERM...REB
LONG TERM...KM
AVIATION...PH/WP
EQUIPMENT...

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE BLACKSBURG VA
1029 AM EDT SUN MAY 23 2010

NCZ001>003-018-019-VAZ007-009>020-022>024-032>035-WVZ042>045-241430-
ASHE-ALLEGHANY NC-SURRY-WATAUGA-WILKES-TAZEWELL-SMYTH-BLAND-GILES-
WYTHE-PULASKI-MONTGOMERY-GRAYSON-CARROLL-FLOYD-CRAIG-ALLEGHANY VA-
BATH-ROANOKE-BOTETOURT-ROCKBRIDGE-PATRICK-FRANKLIN-BEDFORD-AMHERST-
MERCER-SUMMERS-MONROE-GREENBRIER-
1029 AM EDT SUN MAY 23 2010

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.

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

NCZ004>006-020-VAZ043>047-058-059-241430-
STOKES-ROCKINGHAM-CASWELL-YADKIN-HENRY-PITTSYLVANIA-CAMPBELL-
APPOMATTOX-BUCKINGHAM-HALIFAX-CHARLOTTE-
1029 AM EDT SUN MAY 23 2010

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

.DAY ONE...TODAY AND TONIGHT.

A FEW THUNDERSTORMS THIS AFTERNOON COULD BRING LOCALIZED FLOODING
AS WELL AS LARGE HAIL AND DAMAGING WINDS.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE BLACKSBURG VA
102 PM EDT SUN MAY 23 2010

VAZ023-024-034-231745-
BEDFORD VA-BOTETOURT VA-ROCKBRIDGE VA-
102 PM EDT SUN MAY 23 2010

...A STRONG THUNDERSTORM WILL AFFECT BEDFORD...BOTETOURT AND
ROCKBRIDGE COUNTIES...

AT 100 PM EDT...A STRONG THUNDERSTORM WAS LOCATED 4 MILES SOUTHEAST
OF COLLIERSTOWN...MOVING SOUTH AT 15 MPH.

WIND GUSTS TO 40 MPH AND PEA-SIZED HAIL ARE POSSIBLE WITH THIS STORM.
VERY HEAVY RAIN WILL FALL FROM THIS STORM...AND WILL CAUSE WATER TO
POND ON ROADS AND QUICKLY FILL ROADSIDE DITCHES AND SMALL STREAMS.

THIS STORM WILL BE NEAR NATURAL BRIDGE AROUND 125 PM AND ARCADIA
AROUND 145 PM.

THE PUBLIC IS ENCOURAGED TO RELAY REPORTS OF STRONG WINDS...HAIL OR
FLOODING TO THE NATIONAL WEATHER SERVICE IN BLACKSBURG BY CALLING
1...8 6 6...2 1 5...4 3 2 4...WHEN YOU CAN DO SO SAFELY.

LAT...LON 3734 7962 3743 7992 3786 7959 3776 7940

WP

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BLACKSBURG VA
107 PM EDT SUN MAY 23 2010

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

0530 PM     TSTM WND DMG     ELMO                    36.67N 79.13W
05/22/2010                   HALIFAX            VA   EMERGENCY MNGR

            LARGE TREE DOWN. TIME ESTIMATED FROM RADAR.

&&

KM

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE BLACKSBURG VA
110 PM EDT SUN MAY 23 2010

VAZ035-045-046-231800-
AMHERST VA-APPOMATTOX VA-CAMPBELL VA-
110 PM EDT SUN MAY 23 2010

...A STRONG THUNDERSTORM WILL AFFECT AMHERST...APPOMATTOX AND
CAMPBELL COUNTIES...

AT 104 PM EDT...A STRONG THUNDERSTORM WAS LOCATED 6 MILES SOUTH OF
AMHERST...MOVING SOUTH AT 15 MPH.

WIND GUSTS TO 30 MPH AND PEA-SIZED HAIL ARE POSSIBLE WITH THIS STORM.
VERY HEAVY RAIN WILL FALL FROM THIS STORM...AND WILL CAUSE WATER TO
POND ON ROADS AND QUICKLY FILL ROADSIDE DITCHES AND SMALL STREAMS.

THIS STORM WILL BE NEAR MADISON HEIGHTS AROUND 125 PM...STONEWALL
AROUND 130 PM...BOCOCK AROUND 140 PM...CONCORD AROUND 150 PM AND
RUSTBURG AROUND 200 PM.

THE PUBLIC IS ENCOURAGED TO RELAY REPORTS OF STRONG WINDS...HAIL OR
FLOODING TO THE NATIONAL WEATHER SERVICE IN BLACKSBURG BY CALLING
1...8 6 6...2 1 5...4 3 2 4...WHEN YOU CAN DO SO SAFELY.

LAT...LON 3722 7886 3719 7917 3762 7918 3766 7896

WP