Hail and Damaging Winds in Virginia, June 16, 2011

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
305 PM EDT THU JUN 16 2011

.SYNOPSIS...
IMPULSES WILL TRAVERSE THE REGION FROM THE NORTHWEST FRIDAY INTO
THE WEEKEND BRINGING PERIODIC SHOWERS AND THUNDERSTORMS.
TEMPERATURES WILL WARM 10 DEGREES OR MORE ABOVE NORMAL THROUGH
EARLY NEXT WEEK.

&&

.NEAR TERM /THROUGH FRIDAY/...
AN UPPER LEVEL LOW WILL TRACK FROM WESTERN PENNSYLVANIA THIS EVENING
TO THE DELMARVA COAST TOMORROW. MEANWHILE...AN UPPER LEVEL RIDGE WILL
BUILD ACROSS THE MID WEST. SHORT WAVES ROTATING BETWEEN THESE TWO
SYSTEMS WILL TRACK ACROSS THE OHIO VALLEY AND EVENTUALLY OVER RNK
CWA.

THE LEE SIDE TROUGH...THAT GENERATED CONVECTION THIS AFTERNOON WILL
ALLOWED A STRONG DRY SLOT TO ENCOMPASS THE AREA TONIGHT...AS IT
MOVES EAST. THIS DRY SLOT AND WEAK RIDGING ACROSS THE SOUTH SHOULD
KEEP MOST OF THE AREA RAIN FREE THROUGH AT LEAST TOMORROW MORNING.
SOME MODELS HINTING AT SHOWERS COMING ACROSS THE GREENBRIER
VALLEY/ALLEGHANY HIGHLAND OVERNIGHT AS THE UPPER LEVEL LOW MOVES TO
THE EAST COAST. THERE IS SOME VALIDITY WITH THIS SCENARIO BUT
CONFIDENCE IS LOW AS NOT ALL MODEL AGREE. WILL KEEP SOME LOW POPS
OVER THE NORTHWEST TONIGHT.

FOR TOMORROW...WILL HAVE POPS MAINLY IN THE AFTERNOON. THE UPPER
LEVEL LOW WILL BE CLOSE ENOUGH TO THE AREA THAT ANY ROTATING SHORT
WAVES WILL HELP GENERATE AFTERNOON CONVECTION. LEE TROUGH SHOULD BE
ALONG THE COAST AND WITH A WEST WIND...CONVECTION WILL BE SCATTERED.
WILL NEED TO KEEP AN EYE ON THE OHIO VALLEY. IF AN MESO-SCALE
COMPLEXES DO FORM...THEY WILL LIKELY BECOME THE DOMINATE FEATURE
AND BRING POTENTIAL FOR STRONG STORMS TO THE ENTIRE AREA DURING THE
AFTERNOON AND EVENING HOURS.

AFTERNOON TEMPERATURES A TOUGH CALL TOMORROW. TEMPERATURES COULD BE
INFLUENCED BY THE UPPER LEVEL LOW TO THE NORTH (NAM) OR INCREASING
HEIGHTS FROM THE UPPER LEVEL RIDGE IN THE MID WEST (GFS). THE COOLER
NAM HAS 85H TEMPERATURES +17C WHILE THE GFS HAS +20C. WITH THE
GROUND REMAINING DRY THE PAST COUPLE OF DAYS...WILL PLAY IN BETWEEN
GUIDANCE BUT LEAN A LITTLE TO THE MAV/GFS FOR AFTERNOON HIGHS.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
DURING THIS PORTION OF THE FORECAST...A CONVEYOR BELT WILL SET UP
FROM THE GREAT LAKES SOUTHEAST THROUGH OUR REGION OF DAILY SHOWERS
AND STORMS WITH THE POTENTIAL FOR AN MCS TO PROGRESS SOUTHEAST OUT
OF THE OHIO VALLEY INTO OR THROUGH OUR REGION. THIS PATTERN WILL
EMERGE FROM THE AREA BEING SANDWICHED BETWEEN A BUILDING UPPER RIDGE
OVER THE LOWER MISSISSIPPI VALLEY AND A PASSING AREA OF LOW PRESSURE
THROUGH SOUTHEAST CANADA. DURING THIS PERIOD...SUNDAY LOOKS TO BE
THE DAY WITH THE GREATEST COVERAGE OF CONVECTION AS THE MAIN TROUGH
AXIS OF THE CANADIAN LOW MOVES THROUGH THE REGION. TEMPERATURES
SHOULD EXPERIENCE A GRADUAL INCREASE THROUGH THE PERIOD.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
DURING THIS PORTION OF THE FORECAST...WE ANTICIPATE THE UPPER RIDGE
OVER THE LOWER MISSISSIPPI VALLEY WILL SLOWLY BUILD OVER...AND THEN
EAST OF OUR REGION. ANTICIPATE A FAIRLY ACTIVE WEATHER PATTERN
SUNDAY NIGHT THROUGH WEDNESDAY AS THUNDERSTORMS DEVELOP ALONG THE
INTERFACE BETWEEN THE MORE STABLE AIR OF THE RIDGE...AND THE LESS
STABLE AIR OUTSIDE THE INFLUENCE OF THE RIDGE. THIS BOUNDARY IS
EXPECTED TO BE ALONG AN ORIENTATION FROM INDIANA THROUGH VIRGINIA.
NOT ONLY WILL THE AREA HAVE THE POTENTIAL FOR DAILY SCATTERED
THUNDERSTORMS...WE WILL HAVE TO WATCH UPSTREAM TO IN/OH FOR
THUNDERSTORM COMPLEXES THAT WILL HAVE A GOOD CHANCE OF MOVING INTO
OR THROUGH THE REGION. WHILE TOO EARLY TO TELL...WE MAY GET INTO A
PATTERN WHERE THE SAME AREA IS RECEIVING THE POTENTIALLY HEAVY RAIN
ON A DAILY BASIS...AND THUS INCREASING THE FLOOR AND FLASH FLOOD
POTENTIAL FOR PARTS OF THE AREA. TEMPERATURES SHOULD TREND WARMER
THROUGH WEDNESDAY AS THE INFLUENCE OF SUBSIDENCE INCREASES AS THE
UPPER RIDGE APPROACHES AND 850 MB TEMPS INCREASE TO AROUND +20C.
EXPECT SLIGHTLY COOLER TEMPERATURES ON THURSDAY AS THE CENTER OF THE
UPPER RIDGE MOVES EAST OF THE AREA. ALSO...PRECIPITATION CHANCES
WILL LIKELY BE LOWER IN PART TO THE PREVAILING TRAJECTORIES WILL BE
MORE SOUTHWEST...AND THUS WE LOSE THE POTENTIAL FOR AN MCS MOVING
OUT OF THE MIDWEST INTO OUR REGION.

&&

.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
MVFR CEILINGS HOLDING STRONG ON WESTERN SLOPES AND HIGHER ELEVATIONS
THROUGH THIS MORNING. FORECAST SOUNDING INDICATING THESE LOW CEILING
WILL REMAIN THROUGH EARLY AFTERNOON (19Z THU). ELSEWHERE...VFR
SCT-BKN CEILINGS TO PREVAIL INTO THE AFTERNOON.

OCCLUDED FRONT WILL PUSH EAST INTO AREA WITH OPPORTUNITY FOR
ORGANIZED SHOWERS/THUNDERSTORMS ACROSS THE FCST AREA THIS
AFTERNOON. IT APPEARS THAT THE GREATEST POTENTIAL FOR STRONG
STORMS WILL BE IN THE PIEDMONT (LYH/DAN). THUS WENT AHEAD IN ADDED
IN VCTS/CB MENTION FROM THE BLUE RIDGE EAST TOWARD MID/LATE
AFTERNOON BUT LOW CONFIDENCE AT THIS POINT GIVEN SUCH SHALLOW
MOISTURE AND DOWNSLOPING WEST WIND.

ADDED PERIODIC BOUTS OF SHRA/TSRA ARE LIKELY FRIDAY THROUGH
SUNDAY AS IMPULSES TRAVERSE THE AREA FROM THE NW WITH BEST
COVERAGE DURING THE LATE AFTERNOON TO LATE NIGHT HOURS.
MAINLY VFR EXPECTED BY EARLY NEXT WEEK AS CONVECTIVE COVERAGE BECOMES
MORE ISOLATED AND OROGRAPHICALLY DRIVEN BY MONDAY AS THE UPPER
RIDGE STRENGTHENS AND MOISTURE DECREASES.

&&

.EQUIPMENT...
BCB AWOS IS INTERMITTENTLY TRANSMITTING OBSERVATIONS...THE RESULT
OF A LIGHTNING STRIKE SEVERAL DAYS AGO.

THE KFCX 88D RADAR WILL BE DOWN TODAY...AS MAINTENANCE WORK IS
DONE ON THE RADOME. IF STORMS THREATEN THE AREA LATER TODAY...THE
RADAR WILL BE UP SOONER.

&&

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

&&

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

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE BLACKSBURG VA
359 AM EDT THU JUN 16 2011

NCZ003>006-020-VAZ014-017>020-022>024-032>035-043>047-058-059-WVZ044-
045-170800-
SURRY-STOKES-ROCKINGHAM-CASWELL-YADKIN-MONTGOMERY-FLOYD-CRAIG-
ALLEGHANY VA-BATH-ROANOKE-BOTETOURT-ROCKBRIDGE-PATRICK-FRANKLIN-
BEDFORD-AMHERST-HENRY-PITTSYLVANIA-CAMPBELL-APPOMATTOX-BUCKINGHAM-
HALIFAX-CHARLOTTE-MONROE-GREENBRIER-
359 AM EDT THU JUN 16 2011

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.

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND
EVENING.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY.

A FEW STRONG TO SEVERE THUNDERSTORMS CONTAINING LARGE HAIL AND
DAMAGING WINDS WILL BE POSSIBLE AGAIN FRIDAY AFTERNOON AND
EVENING.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED LATER TODAY.

NCZ001-002-018-019-VAZ007-009>013-015-016-WVZ042-043-170800-
ASHE-ALLEGHANY NC-WATAUGA-WILKES-TAZEWELL-SMYTH-BLAND-GILES-WYTHE-
PULASKI-GRAYSON-CARROLL-MERCER-SUMMERS-
359 AM EDT THU JUN 16 2011

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

.DAY ONE...TODAY AND TONIGHT.

HAZARDOUS WEATHER IS NOT EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY.

A FEW STRONG TO SEVERE THUNDERSTORMS CONTAINING LARGE HAIL AND
DAMAGING WINDS WILL BE POSSIBLE FRIDAY AFTERNOON AND EVENING.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.