Severe Thunderstorm Watch 438

Issued

Jun 29, 2012, 6:34 PM EDT (22:34 UTC)

Expired

Jun 30, 2012, 12:35 AM EDT

In force

6 hr

Issued by

the Storm Prediction Center

Largest hail expected

2 in

Strongest gust expected

70 kt

The Sterling radar (KLWX), 188 km from the middle of the area, began a volume at 22:36 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

Two or more tornadoes

20%

One or more EF2 to EF5 tornadoes

5%

Ten or more severe wind reports

95%

One or more gusts of 65 knots or more

70%

Ten or more severe hail reports

50%

One or more hailstones of 2 inches or more

20%

Six or more combined severe hail and wind reports

95%

• Mesoscale Discussion 1308Jun 29, 3:07 PM EDT
• Mesoscale Discussion 1310Jun 29, 4:22 PM EDT
• Mesoscale Discussion 1311Jun 29, 6:03 PM EDT
• Mesoscale Discussion 1314Jun 29, 7:51 PM EDT
• Mesoscale Discussion 1316Jun 29, 10:51 PM EDT

960 
WWUS20 KWNS 292234
SEL8
SPC WW 292234
DCZ000-KYZ000-MDZ000-PAZ000-VAZ000-WVZ000-CWZ000-300500-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 438
NWS STORM PREDICTION CENTER NORMAN OK
635 PM EDT FRI JUN 29 2012

THE NWS STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

       DISTRICT OF COLUMBIA
       EXTREME EASTERN KENTUCKY
       WESTERN MARYLAND
       SOUTHWEST PENNSYLVANIA
       MUCH OF VIRGINIA
       SOUTHERN AND EASTERN WEST VIRGINIA
       COASTAL WATERS

EFFECTIVE THIS FRIDAY NIGHT AND SATURDAY MORNING FROM 635 PM
UNTIL 100 AM EDT.

HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 80
MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 110
STATUTE MILES NORTH AND SOUTH OF A LINE FROM 35 MILES SOUTH OF
PARKERSBURG WEST VIRGINIA TO 45 MILES NORTH NORTHEAST OF RICHMOND
VIRGINIA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU8).

REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE
FAVORABLE FOR SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH
AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR
THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS
AND POSSIBLE WARNINGS. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY
DO PRODUCE TORNADOES.

OTHER WATCH INFORMATION...CONTINUE...WW 436...WW 437...

DISCUSSION...FAST MOVING AND DAMAGING DERECHO OVER OH HAS RESULTED
IN WIDESPREAD DAMAGING WINDS.  THIS SYSTEM WILL CONTINUE TO TRACK
EAST-SOUTHEASTWARD ACROSS THE WATCH AREA THIS EVENING.  STORMS MAY
LOSE SOME INTENSITY AS THEY MOVE ACROSS THE APPALACHIANS...BUT MOIST
AND VERY UNSTABLE AIR MASS OVER VA SUGGESTS THAT THREAT OF AT LEAST
SCATTERED SEVERE WIND GUSTS WILL CONTINUE.

AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 70
KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 550. MEAN STORM
MOTION VECTOR 30045.


...HART

Severe Thunderstorm Watches in Virginia, 2012Severe Thunderstorm Watches in West Virginia, 2012Severe Thunderstorm Watches in Maryland, 2012Every severe thunderstorm watch in 2012

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.