MESOSCALE DISCUSSION 2556
   NWS STORM PREDICTION CENTER NORMAN OK
   0918 PM CST WED NOV 26 2003
   
   AREAS AFFECTED...ERN TX...SRN AR...LA  AND WCNTRL MS
   
   CONCERNING...SEVERE THUNDERSTORM POTENTIAL 
   
   VALID 270318Z - 270445Z
   
   LOW LEVEL FLOW ON THE PALESTINE PROFILER HAS VEERED SINCE 0100 UTC
   AS THE WEAK SHORTWAVE TROUGH MIGRATES ACROSS THE REGION.  STRONGEST
   LOW LEVEL THETA-E ADVECTION HAS BEEN SHIFTING NEWD INTO NRN LA AND
   SRN AR AND SHOULD SHIFT INTO THE REMAINDER OF LA INTO PARTS OF
   WCNTRL MS AFTER 0600 UTC.  THUS...THE CLUSTERS OF TSTMS WILL BE
   DEVELOPING/MOVING NEWD TOWARD THE MS RVR THE NEXT FEW HOURS. 
   
   DESPITE FAVORABLE DEEP LAYER SHEAR FOR ORGANIZED SEVERE STORMS...THE
   MAIN LIMITING FACTOR HAS BEEN THE LOW INSTABILITY IN PLACE.  00 UTC
   KSHV RAOB HAD ONLY 365 J/KG MLCAPE AND EVIDENCE OF RESIDUAL CAP AT
   H7.  THE STRONGER INSTABILITY EXISTS ACROSS EXTREME SERN TX AND SWRN
   LA AND OFFSHORE.  SEVERAL SUPERCELLS...POSSIBLY WITH WATERSPOUTS...
   HAVE BEEN MOVING ENEWD AT 30 KTS AROUND 30-60 NM OFFSHORE KGLS. 
   EXTRAPOLATION HAS THESE CELLS ONSHORE SCNTRL LA AROUND 06 UTC. 
   
   SINCE IT APPEARS THAT THE SHORTWAVE TROUGH AXIS HAS SHIFTED INTO ERN
   TX...WS 974 IS BEING TRIMMED FROM THE WEST.  THERE WILL BE AN ISOLD
   HAIL THREAT WITH THE STORMS THAT DEVELOP NEWD INTO SRN AR...NR LA
   AND WCNTRL MS...BUT ANOTHER WW MAY NOT BE REQUIRED. 
   OTHERWISE...WILL MONITOR SUPERCELLS OFF THE COAST AS THEY APPROACH
   SRN LA AND A NEW WW COULD BE NEEDED IF CELLS MAINTAIN INTENSITY AND
   CHARACTER.
   
   ..RACY.. 11/27/2003
   
   
   ATTN...WFO...JAN...LIX...LZK...LCH...SHV...HGX...FWD...
   
   29179522 32009577 33689406 33879173 33389027 31919028
   29599059 28639129 28029289 28119473