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URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 194

NWS STORM PREDICTION CENTER NORMAN OK

1030 AM CDT THU MAY 20 2010



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       SOUTHEAST ARKANSAS

       NORTHERN LOUISIANA

       CENTRAL MISSISSIPPI

       PARTS OF EASTERN TEXAS



EFFECTIVE THIS THURSDAY MORNING AND EVENING FROM 1030 AM UNTIL

700 PM CDT.



HAIL TO 2.5 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70

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 30 MILES WEST

SOUTHWEST OF LONGVIEW TEXAS TO 25 MILES NORTHEAST OF MERIDIAN

MISSISSIPPI.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU4).



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.



DISCUSSION...TSTMS ARE EXPECTED TO INCREASE IN COVERAGE AND

INTENSITY TODAY ALONG AND AHEAD OF A CONVECTIVE OUTFLOW BOUNDARY

SHIFTING SEWD THROUGH THE REGION.  THE AMBIENT INFLOW AIR MASS IS

QUITE MOIST WITH DEW POINTS IN THE LOWER 70S.  WHEN COUPLED WITH

COOL MIDLEVEL TEMPERATURES...ENVIRONMENT IS EXPECTED TO BECOME

MODERATELY TO STRONGLY UNSTABLE BY AFTERNOON.  THIS INSTABILITY IN

CONJUNCTION WITH 40-45 KT OF DEEP WLY SHEAR WILL SUPPORT THE

DEVELOPMENT OF ORGANIZED SEVERE STORMS INCLUDING SUPERCELLS AND

BOWING LINE SEGMENTS.  WHILE A TORNADO IS POSSIBLE...LARGE HAIL AND

DAMAGING WIND GUSTS APPEAR TO BE THE PRIMARY SEVERE WEATHER HAZARDS.



AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT

TO 2.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60

KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM

MOTION VECTOR 27025.





...MEAD

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