MESOSCALE DISCUSSION 0430
   NWS STORM PREDICTION CENTER NORMAN OK
   0942 AM CDT MON APR 07 2003
   
   AREAS AFFECTED...S-CENTRAL/SWRN LA...EXTREME SERN TX
   
   CONCERNING...SEVERE THUNDERSTORM POTENTIAL 
   
   VALID 071442Z - 071715Z
   
   WIDELY SCATTERED TSTMS POSSIBLE PRIMARILY SE OF A LINE FROM GLS
   BAY REGION ENEWD TO 60 NW BTR...WITH ACTIVITY BOTH DEVELOPING
   OVER LAND AND MOVING NEWD OFF GULF.  EXPECT COVERAGE/INTENSITY TO
   INCREASE STEADILY NEXT 2-3 HOURS.  SUPERCELLS WITH LARGE HAIL AND
   DAMAGING GUSTS ARE POSSIBLE.  SOME TORNADO POTENTIAL ALSO MAY
   DEVELOP WITH STORM-SCALE AND BOUNDARY INTERACTIONS.  WW MAY BE
   REQUIRED WITHIN NEXT 1-2 HOURS.
   
   SURFACE MESOANALYSIS INDICATES PREFRONTAL CONFLUENCE LINE AND
   WEAK SFC TROUGH NEAR HOU-HEZ LINE...NEAR AND S OF WHICH MOST
   ACTIVITY AHOLD BE FOCUSED.  MOISTURE CHANNEL IMAGERY AND RAOB
   ANALYSES INDICATE LOW-AMPLITUDE SHORTWAVE PERTURBATION NOW MOVING
   NEWD ACROSS TX COASTAL BEND REGION TOWARD DISCUSSION AREA. 
   EXPECT INCREASING MID/UPPER LEVEL ASCENT/DESTABILIZATION ACROSS
   REGION AHEAD OF THIS FEATURE...ENHANCING LAPSE RATES ALOFT.  8-9
   DEG C/KM MIDLEVEL LAPSE RATES SHOWN IN UPSTREAM CRP RAOB.  EXPECT
   INCREASING CAPE IN TANDEM WITH SURFACE DIABATIC WARMING...WHICH
   SHOULD OVERCOME LOW LEVEL CINH EVIDENT IN MORNING RAOB DATA AND
   RUC SOUNDINGS.	ONCE CONVECTION BECOMES NEARLY SURFACE BASED --
   AS APPEARS TO BE OCCURRING WITH ACTIVITY OVER GULF AND AS SHOULD
   OCCUR OVER LAND BY ABOUT 16Z -- MLCAPE 1500-2500 J/KG IS
   POSSIBLE.  VERTICAL SHEAR PROFILE APPEARS AT LEAST MARGINAL ON
   MESOSCALE WITH 40-50 KT 0-6 KM SHEAR AND BACKED LOW LEVEL FLOW
   ENHANCING SR SFC INFLOW.  HOWEVER...LOW-MID LEVEL SR FLOW
   WEAKNESSES ABOVE SFC WILL LIMIT HODOGRAPH SIZE...KEEPING 0-3 KM
   SRH LARGELY IN 100-200 J/KG RANGE.
   
   ..EDWARDS.. 04/07/2003
   
   
   ATTN...WFO...LIX...LCH...HGX...
   
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