Severe Thunderstorm Watch 204

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 204
NWS STORM PREDICTION CENTER NORMAN OK
300 PM CDT THU APR 17 2008
THE NWS STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF
CENTRAL OKLAHOMA
NORTH CENTRAL TEXAS
EFFECTIVE THIS THURSDAY AFTERNOON AND EVENING FROM 300 PM UNTIL
1000 PM CDT.
HAIL TO 2 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 50
STATUTE MILES EAST AND WEST OF A LINE FROM 35 MILES NORTH
NORTHEAST OF CHANDLER OKLAHOMA TO 30 MILES SOUTHWEST OF FORT
WORTH TEXAS. 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...THUNDERSTORMS WILL LIKELY DEVELOP ALONG THE COLD FRONT
FROM CENTRAL OK INTO N TX DURING THE NEXT FEW HOURS AS THE CAP
WEAKENS WITH DAYTIME HEATING AND THE APPROACH OF A MID LEVEL TROUGH
FROM THE W. SURFACE TEMPERATURES IN THE LOW-MID 70S AND DEWPOINTS
OF 56-60 F...ALONG WITH REMNANTS OF THE ELEVATED MIXED LAYER...WILL
CONTRIBUTE TO MLCAPE VALUES OF 500-1000 J/KG IN ADVANCE OF THE
FRONT. VERTICAL SHEAR WILL BE SUFFICIENT FOR ORGANIZED SEVERE
STORMS...INCLUDING SUPERCELLS/BOW ECHOES...THOUGH EXPECTED LINEAR
ORGANIZATION OF THE CONVECTION WILL TEND TO FAVOR LARGE HAIL AND
DAMAGING WINDS AS THE MAIN SEVERE THREATS THROUGH THE EVENING.
AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60
KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM
MOTION VECTOR 24035.
...THOMPSON