Severe Thunderstorm Watch 252

Issued

May 6, 2009, 5:29 AM CDT (10:29 UTC)

Expired

May 6, 2009, 1:00 PM CDT

In force

8 hr

Issued by

the Storm Prediction Center

Largest hail expected

1 in

Strongest gust expected

70 kt

The Dallas/Ft Worth radar (KFWS), 182 km from the middle of the area, began a volume at 10:29 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

10%

Ten or more severe wind reports

80%

One or more gusts of 65 knots or more

50%

Ten or more severe hail reports

20%

One or more hailstones of 2 inches or more

10%

Six or more combined severe hail and wind reports

90%

• Mesoscale Discussion 724May 6, 2:00 AM CDT
• Mesoscale Discussion 726May 6, 3:05 AM CDT
• Mesoscale Discussion 727May 6, 5:08 AM CDT
• Mesoscale Discussion 728May 6, 6:58 AM CDT

079 
WWUS20 KWNS 061033
SEL2  
SPC WW 061033
ARZ000-LAZ000-OKZ000-TXZ000-061800-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 252
NWS STORM PREDICTION CENTER NORMAN OK
530 AM CDT WED MAY 6 2009

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

       SOUTHWESTERN ARKANSAS
       NORTHWESTERN LOUISIANA
       SOUTHERN OKLAHOMA
       NORTH-CENTRAL...NORTHEASTERN AND EASTERN TEXAS

EFFECTIVE THIS WEDNESDAY MORNING AND AFTERNOON FROM 530 AM UNTIL
100 PM CDT.

HAIL TO 1 INCH 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 60
STATUTE MILES NORTH AND SOUTH OF A LINE FROM 55 MILES WEST
SOUTHWEST OF ARDMORE OKLAHOMA TO 60 MILES NORTHEAST OF
NATCHITOCHES LOUISIANA.  FOR A COMPLETE DEPICTION OF THE WATCH
SEE THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU2).

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...THIS SEVERE THUNDERSTORM WATCH REPLACES
SEVERE THUNDERSTORM WATCH NUMBER 249. WATCH NUMBER 249 WILL NOT
BE IN EFFECT AFTER 530 AM CDT. CONTINUE...WW 248...WW 251...

DISCUSSION...INCREASINGLY WELL-ORGANIZED BOW ECHO IN FORMER WW 249
IS BEGINNING TO PRODUCE SVR GUSTS ABOVE 50 KT AS IT MOVES OVER AND S
OF SFC WARM FRONT OUTLINED IN MESOSCALE DISCUSSION 727.  THIS MCS
SHOULD CONTINUE TO SURGE SEWD WITH POTENTIAL FOR SWATH OF DAMAGING
WIND...POSSIBLE DERECHO...OVER PORTIONS WW AREA.  COUNTY WW AREA
FANS OUTWARD WITH SEWD EXTENT TO ACCOUNT FOR POTENTIAL
SPREAD/EXPANSION OF DRIVING COLD POOL.

AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 1 INCH. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 70 KNOTS.
A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 600. MEAN STORM MOTION
VECTOR 30040.


...EDWARDS/EVANS

Severe Thunderstorm Watches in Texas, 2009Severe Thunderstorm Watches in Louisiana, 2009Severe Thunderstorm Watches in Oklahoma, 2009Every severe thunderstorm watch in 2009

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.