MESOSCALE DISCUSSION 0055
   NWS STORM PREDICTION CENTER NORMAN OK
   0813 PM CST SAT JAN 13 2007
   
   AREAS AFFECTED...PORTIONS SE TX.
   
   CONCERNING...HEAVY RAINFALL 
   
   VALID 140213Z - 140445Z
   
   POTENTIAL FOR HEAVY RAINFALL -- COMPOUNDED BY TRAINING OF HEAVIEST
   PRECIP CORES -- WILL SHIFT EWD ACROSS LFK-HOU CORRIDOR THROUGH
   5Z...WITH LOCAL RAIN RATES BRIEFLY REACHING 2 INCHES/HOUR AND
   COMMONLY 1-1.5 INCH/HOUR IN TSTMS.
   
   SFC MESOANALYSIS AT 2Z SHOWS COLD FRONT BETWEEN ANGELINA-WRN
   HARRIS-NACOGDOCHES COUNTIES...MOVING SEWD APPROXIMATELY 15 KT.  RICH
   MOISTURE IN GULF AIR MASS -- CHARACTERIZED BY 1.75-2 INCH
   PW...MID-UPPER 60S F SFC DEW POINTS... AND 14-15 DEG C ESTIMATED 850
   MB DEW POINTS SHOULD PERSIST IN WARM SECTOR.  MOST ACTIVITY WILL
   OCCUR JUST BEHIND BOUNDARY AS FRONTAL AND ISENTROPIC LIFT FORCED
   PARCELS TO LFC.  WEAK MESOLOW --ANALYZED ALONG FRONT N HOU -- MAY
   LEAD TO ENHANCED LOW LEVEL CONVERGENCE TO ITS IMMEDIATE NE AS WELL. 
   DEEP-LAYER MEAN FLOW WILL REMAIN ALIGNED NEARLY PARALLEL TO ZONE OF
   STRONGEST CONVECTIVE FORCING...AS LATTER MOVES SLOWLY
   EWD...RESULTING IN REPEAT PASSAGE OF HEAVY CORES OVER SOME LOCALES.
   
   MODIFIED PROFILER/VWP/RUC SOUNDING DATA INDICATE SUFFICIENT VERTICAL
   SHEAR TO SUPPORT SUPERCELL POTENTIAL...AND CONTINUED PRESENCE OF
   SFC-BASED EFFECTIVE LAYER IN WARM SECTOR SOUNDINGS INDICATES
   POTENTIAL FOR BRIEF TORNADO CANNOT BE RULED OUT.  HOWEVER...LINEAR
   INCLINATION OF CONVECTIVE MODE...COMBINED WITH ANAFRONTAL REGIME
   KEEPING MOST ACTIVITY BEHIND COLD FRONT...WILL KEEP SVR POTENTIAL
   MRGL AT BEST.
   
   ..EDWARDS.. 01/14/2007
   
   
   ATTN...WFO...LCH...SHV...HGX...
   
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