MESOSCALE DISCUSSION 2240
   NWS STORM PREDICTION CENTER NORMAN OK
   1132 PM CDT SAT OCT 08 2011
   
   AREAS AFFECTED...MUCH OF CENTRAL TX/HILL COUNTRY
   
   CONCERNING...HEAVY RAINFALL 
   
   VALID 090432Z - 090700Z
   
   HEAVY RAINFALL...WITH PEAK HOURLY RAINFALL RATES OF 1-2 IN/HR...WILL
   CONTINUE TO OCCUR/SLOWLY DEVELOP GENERALLY EASTWARD OVERNIGHT ACROSS
   A LARGE PART OF CENTRAL TX/HILL COUNTRY. ADDITIONALLY...A LOCALIZED
   WIND DAMAGE THREAT CANNOT BE RULED OUT...BUT HEAVY RAINFALL WILL BE
   THE PRIMARY CONCERN.
   
   A CONVECTIVELY REINFORCED BOUNDARY/COLD POOL CONTINUES TO BE A FOCUS
   FOR A NORTHEAST-SOUTHWEST ORIENTED CORRIDOR OF HEAVY RAINFALL ACROSS
   A BROAD EXTENT OF CENTRAL TX...WITH THE BRUNT OF THE CONVECTIVE LINE
   GENERALLY CENTERED AROUND 25-75 MILES WEST OF I-35 IN AREAS FROM THE
   DFW METRO VICINITY TO SAN ANTONIO. COLD POOL/DIFFERENTIAL BOUNDARY
   LIFT ASIDE...SUSTAINED FORCING FOR ASCENT...ATTRIBUTABLE TO
   GRADUALLY STRENGTHENING WARM ADVECTION/UPPER JET ENTRANCE
   REGION...WILL CONTINUE TO YIELD HEAVY RAINFALL WITHIN A VERY
   MOIST/WEAKLY CAPPED AIRMASS. PW VALUES ARE ON THE ORDER OF 1.6-1.9
   INCHES AS PER 00Z OBSERVED SOUNDINGS FROM CORPUS CHRISTI AND FORT
   WORTH ALONG WITH MORE CONTEMPORARY GPS DERIVED DATA. WHILE
   INDIVIDUAL CONVECTIVE ELEMENTS WILL CONTINUE TO STEADILY SPREAD
   NORTH-NORTHEASTWARD...REGIONAL WIND PROFILERS/WSR-88D DERIVED WINDS
   SUGGEST SOME BACKING OF MID-LEVEL WINDS OVER THE PAST FEW HOURS
   WITHIN THIS MERIDIONAL LONGWAVE REGIME...SUCH THAT NET RESULT SHOULD
   BE A CONTINUED ONLY SLOW EASTWARD NET MOTION OF THE
   BROADER/COMPOSITE CONVECTIVE LINE. AS SUCH...EXPECTED HEAVY RAINFALL
   TO PERSIST OVERNIGHT...WITH RAINFALL RATES OF 1-2 IN/HR POSSIBLE
   WITH THE MORE INTENSE CONVECTIVE ELEMENTS. LASTLY...A LOCALIZED WIND
   DAMAGE THREAT CANNOT BE RULED OUT OVERNIGHT GIVEN WATER
   LOADING/SUFFICIENT LOW-MID LEVEL SHEAR AND STORM SCALE
   PROCESSES/PERHAPS EVENTUAL MCV DEVELOPMENT. HOWEVER...ANY SUCH
   THREAT IS EXPECTED TO BE LOCALIZED/MARGINAL IN NATURE.
   
   ..GUYER.. 10/09/2011
   
   
   ATTN...WFO...FWD...CRP...EWX...SJT...
   
   LAT...LON   28810050 30190044 33089782 32149711 30889796 28309937
               28810050