MESOSCALE DISCUSSION 0774
   NWS STORM PREDICTION CENTER NORMAN OK
   1119 PM CDT FRI MAY 08 2009
   
   AREAS AFFECTED...NORTH CENTRAL/NORTHEAST TX INTO ADJACENT SOUTHWEST
   AR/NORTHWEST LA
   
   CONCERNING...TORNADO WATCH 272...
   
   VALID 090419Z - 090545Z
   
   THE SEVERE WEATHER THREAT FOR TORNADO WATCH 272 CONTINUES.
   
   TORNADO WATCH 272 IS SCHEDULED TO EXPIRE AT 05Z...A NEW/REPLACEMENT
   TORNADO WATCH WILL LIKELY BE NEEDED SOON TO INCORPORATE MORE OF
   NORTH CENTRAL/NORTHEAST TX.
   
   IMPRESSIVE LONG-LIVED SUPERCELLS CONTINUE TO DEVELOP
   EAST-SOUTHEASTWARD ACROSS FAR NORTH CENTRAL TX...ROUGHLY CENTERED
   ALONG I-35 AS OF 0415Z. EVEN WITH A VERY MOIST AIRMASS IN PLACE
   /LOWER TO MIDDLE 70S F SURFACE DEWPOINTS/...SURFACE MODIFIED 00Z
   FORT WORTH SOUNDING SUGGESTS NEAR-SURFACE CINH CONTINUES TO
   GRADUALLY INCREASE. EVEN SO...LONG-LIVED NATURE OF THESE SUPERCELLS
   AND AMPLE SHEAR/LOW LEVEL SRH WILL CONTINUE TO SUPPORT AN ISOLATED
   TORNADO POTENTIAL. OTHERWISE...LARGE/POTENTIALLY SIGNIFICANT HAIL
   WILL REMAIN THE PRIMARY HAZARD GIVEN EXTREMELY STEEP MID LEVEL LAPSE
   RATES OF +9C/KM AND ROBUST INSTABILITY WITH 5000+ J/KG OF MUCAPE.
   AIDED BY A 35-40 KT LOW LEVEL JET AROUND 1 KM PER FORT WORTH WSR-88D
   VWP/PAT PROFILER...THESE QUASI-DISCRETE SUPERCELLS MAY CONTINUE TO
   GRADUALLY CONSOLIDATE WITH TIME...WITH POTENTIAL FOR UPSCALE MCS
   GROWTH AND AN INCREASING DAMAGING WIND RISK IF THESE TRENDS
   CONTINUE.
   
   ..GUYER.. 05/09/2009
   
   
   ATTN...WFO...SHV...FWD...OUN...
   
   LAT...LON   33879764 33849541 33479383 32229433 32309720 33879764