

228 

WWUS20 KWNS 130342

SEL0

SPC WW 130342

OKZ000-TXZ000-131000-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 160

NWS STORM PREDICTION CENTER NORMAN OK

1040 PM CDT WED MAY 12 2010



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       SOUTHWEST OKLAHOMA

       WEST AND NORTHWEST TEXAS



EFFECTIVE THIS WEDNESDAY NIGHT AND THURSDAY MORNING FROM 1040 PM

UNTIL 500 AM 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 80

STATUTE MILES NORTH AND SOUTH OF A LINE FROM MIDLAND TEXAS TO 55

MILES SOUTH SOUTHEAST OF ALTUS OKLAHOMA.  FOR A COMPLETE

DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE UPDATE

(WOUS64 KWNS WOU0).



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 156. WATCH NUMBER 156 WILL NOT

BE IN EFFECT AFTER 1040 PM CDT. CONTINUE...WW 157...WW 158...WW

159...



DISCUSSION...STORM DEVELOPMENT ALONG RETREATING DRYLINE IS FORECAST

TO GRADUALLY EVOLVE INTO FORWARD PROPAGATING MCS THROUGH LATE

TONIGHT/EARLY THURSDAY. THIS PROCESS WILL BE AIDED AS DEEP-LAYER WSW

FLOW INCREASES ACROSS THE AREA AND LOW LEVEL JET MAINTAINS MASS AND

MOISTURE INFLOW INTO THE DEVELOPING CONVECTION. INITIAL THREAT WILL

BE FOR HAIL AND HEAVY RAIN WITH THE POTENTIAL FOR DAMAGING WINDS TO

EVOLVE AS COLD POOLS CONGEAL AND MAINTAIN STORM-SCALE/MESOSCALE

ASCENT EWD INTO VERY MOIST UNSTABLE REGIME ACROSS NW TX AND SW OK.



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 550. MEAN STORM

MOTION VECTOR 24035.





...CARBIN

