

968 

WWUS20 KWNS 181909

SEL4

SPC WW 181909

OKZ000-TXZ000-190200-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 584

NWS STORM PREDICTION CENTER NORMAN OK

210 PM CDT SAT AUG 18 2012



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       FAR SOUTHWEST OKLAHOMA

       WESTERN AND NORTHWEST TEXAS



EFFECTIVE THIS SATURDAY AFTERNOON AND EVENING FROM 210 PM UNTIL

900 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 60

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 35 MILES WEST

SOUTHWEST OF PLAINVIEW TEXAS TO 45 MILES NORTHEAST OF MINERAL

WELLS 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...INCIPIENT TSTM DEVELOPMENT IS OCCURRING ALONG OUTFLOW

BOUNDARY FROM NW/N OF PVW TO SE OF CDS WHERE ENVIRONMENT HAS BECOME

UNCAPPED WITH MLCAPE OF 1000-1500 J/KG.  BOTH FORCING FOR ASCENT AND

DEEP-LAYER SHEAR ARE EXPECTED TO INCREASE THROUGH THE REMAINDER OF

THE AFTERNOON AS REGION IS GLANCED BY A VORTICITY MAXIMUM MOVING

ACROSS THE CNTRL PLAINS.  MULTICELL AND SOME SUPERCELL STRUCTURES

ARE POSSIBLE WITH THE PRIMARY HAZARDS BEING LARGE HAIL AND DAMAGING

WIND GUSTS.



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 35015.





...MEAD

