MESOSCALE DISCUSSION 2293
   NWS STORM PREDICTION CENTER NORMAN OK
   0551 PM CST MON NOV 07 2011
   
   AREAS AFFECTED...NWRN TX THROUGH SWRN AND WCNTRL OK
   
   CONCERNING...TORNADO WATCH 870...
   
   VALID 072351Z - 080145Z
   
   THE SEVERE WEATHER THREAT FOR TORNADO WATCH 870 CONTINUES.
   
   THREAT FOR ISOLATED TORNADOES...LARGE HAIL AND DAMAGING WIND WILL
   PERSIST NEXT FEW HOURS. THOUGH SOME TORNADO THREAT SHOULD REMAIN THE
   REST OF THIS EVENING FROM SWRN TX INTO NWRN OK...THE GREATEST
   TORNADO THREAT WILL EXIST THROUGH MID EVENING. IN ADDITION...THE
   THREAT FOR PERSISTENT VERY HEAVY RAIN SHOULD INCREASE WITH TIME.
   
   EARLY THIS EVENING A COLD FRONT EXTENDS FROM A WEAK SURFACE LOW IN
   N-CNTRL OK SWWD THROUGH SWRN OK INTO THE TX PANHANDLE WHERE IT HAS
   BECOME STATIONARY. A DRYLINE STRETCHES FROM SWRN TX NWD INTO THE SRN
   TX PANHANDLE WHERE IT INTERSECTS THE FRONT. THE WARM SECTOR REMAINS
   MODERATELY UNSTABLE WITH 1000-1500 J/KG MLCAPE AND 7-7.5 C/KM MID
   LEVEL LAPSE RATES. STORMS CONTINUE DEVELOPING ALONG CLOUD STREETS
   WITHIN WARM ADVECTION REGIME FROM NWRN TX INTO SWRN AND W-CNTRL OK
   WHERE THE BOUNDARY LAYER HAS BEEN RENDERED UNSTABLE BY EARLIER
   DIABATIC WARMING. TORNADO AND LARGE HAIL THREAT WILL REMAIN GREATEST
   NEXT COUPLE HOURS FROM NWRN TX INTO SWRN OK...WHILE SOME OF THE
   STORMS ARE STILL DISCRETE AND AS THE LLJ STRENGTHENS.
   HOWEVER...TENDENCY FOR STORMS TO MERGE AND GROW UPSCALE...ALONG WITH
   A COOLING BOUNDARY LAYER SUGGEST AN INCREASING THREAT FOR VERY HEAVY
   RAIN AS STORMS TRAIN NEWD ALONG THE BOUNDARY. AS MODE TRANSITIONS TO
   DOMINANT LINEAR STRUCTURES...EFFECTIVE SHEAR OF 40+ KT WILL SUPPORT
   EMBEDDED LEWP/SUPERCELL STRUCTURES WITHIN THE MCS ALONG WITH A
   CONTINUED...BUT SOMEWHAT REDUCED THREAT FOR TORNADOES LATER THIS
   EVENING.
   
   ..DIAL.. 11/07/2011
   
   
   ATTN...WFO...TSA...OUN...SJT...LUB...AMA...
   
   LAT...LON   36959675 35909719 34939823 34179843 33529860 33350020
               33880065 35309966 36169823 36859748 36959675