

160 

WWUS20 KWNS 122211

SEL6

SPC WW 122211

TXZ000-130500-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 156

NWS STORM PREDICTION CENTER NORMAN OK

510 PM CDT WED MAY 12 2010



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       NORTHWEST TEXAS



EFFECTIVE THIS WEDNESDAY AFTERNOON FROM 510 PM UNTIL MIDNIGHT CDT.



HAIL TO 2.5 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 35

STATUTE MILES EITHER SIDE OF A LINE FROM 55 MILES NORTH NORTHWEST

OF CHILDRESS TEXAS TO 100 MILES SOUTH SOUTHWEST OF CHILDRESS

TEXAS.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED

WATCH OUTLINE UPDATE (WOUS64 KWNS WOU6).



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 154...WW 155...



DISCUSSION...COMPLEX SCENARIO UNFOLDING ACROSS SOUTHEAST TX PNHDL

AND SOUTH PLAINS AREA. STORM INITIATION NOW UNDERWAY ALONG

RETREATING DRYLINE FROM MOTLEY COUNTY TO WHEELER COUNTY. AIR MASS

FEEDING THIS DEVELOPMENT IS VERY UNSTABLE AND SHOULD CONTINUE TO

FUEL ROBUST STORMS INITIATING ALONG THE DRYLINE...AND PERHAPS NEAR

THE COLD FRONT DEVELOPING SOUTH ACROSS THE REGION LATER THIS

EVENING. IN ADDITION...LARGE SCALE FORCING FOR ASCENT SHOULD

CONTINUE TO STRENGTHEN AS UPPER SHORT WAVE TROUGH MOVES EAST FROM

NM. PRESENT QUASI-LINEAR DEVELOPMENT SUGGESTS THAT THE GREATEST

THREAT WILL BE VERY LARGE HAIL AND HIGH WIND GUSTS. STORMS MAY ALSO

BECOME UNDERCUT AS FRONT SPREAD SOUTH. IT IS POSSIBLE...BUT STILL

UNCERTAIN...THAT ISOLATED TORNADO POTENTIAL MAY INCREASE AS THE

SURFACE LOW REDEVELOPS EAST OF THE AREA THROUGH LATER TONIGHT AND

THIS SITUATION WILL NEED TO BE MONITORED CLOSELY. EXCESSIVE RAINFALL

WITH REPEAT/TRAINING CONVECTION APPEARS QUITE LIKELY IN PARTS OF THE

WATCH.



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

TO 2.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 70

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

MOTION VECTOR 22035.





...CARBIN

