MESOSCALE DISCUSSION 0021
   NWS STORM PREDICTION CENTER NORMAN OK
   0400 PM CST SAT JAN 17 2004
   
   AREAS AFFECTED...CENTRAL/ERN TX
   
   CONCERNING...SEVERE THUNDERSTORM POTENTIAL 
   
   VALID 172200Z - 180000Z
   
   ISOLATED SEVERE THUNDERSTORMS...WITH THE MAIN THREAT BEING LARGE
   HAIL SHOULD CONTINUE TO DEVELOP OVER PORTIONS OF CENTRAL TX IN THE
   NEXT 1-2 HOURS...BEFORE MOVING INTO ACROSS ERN TX.
   
   LATEST MESOANALYSIS INDICATES BETWEEN 500-1000 J/KG OVER ERN
   TX...WITH THE GREATEST INSTABILITY FROM HOU NWD TO NEAR GGG ALONG
   LOW LEVEL MOISTURE AXIS. ADDITIONAL CONVECTIVE DEVELOPMENT
   /STRENGTHENING IS ANTICIPATED ALONG A SFC TROUGH FROM A LOW JUST NE
   OF DFW SWD ALONG THE I-35 CORRIDOR AS WEAK SFC CONVERGENCE IMPINGES
   ON AFOREMENTIONED INSTABILITY. DESPITE MARGINAL/VEERED LOW-MID LEVEL
   SHEAR PROFILES...STEEP MID LEVEL LAPSE RATES IN EXCESS OF 7.5 DEG
   C/KM WILL SUPPORT ISOLATED SEVERE HAIL. OVERALL THREAT FOR SEVERE
   WILL BE MITIGATED BY DIURNAL COOLING/STABILIZATION BETWEEN 18/00Z
   AND 18/03Z. MARGINAL NATURE OF THE SEVERE THREAT ALONG WITH SHORT
   DURATION SHOULD PRECLUDE THE NEED FOR A WATCH.
   
   ..CROSBIE.. 01/17/2004
   
   
   ATTN...WFO...LCH...SHV...HGX...FWD...EWX...
   
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