MESOSCALE DISCUSSION 0585
   NWS STORM PREDICTION CENTER NORMAN OK
   0334 PM CDT SUN APR 26 2009
   
   AREAS AFFECTED...OK...NWRN TX...ERN PNHDL TX
   
   CONCERNING...TORNADO WATCH 190...192...
   
   VALID 262034Z - 262230Z
   
   THE SEVERE WEATHER THREAT FOR TORNADO WATCH 190...192...CONTINUES.
   
   SEVERE POTENTIAL WILL INCREASE...PARTICULARLY WITH RESPECT TO
   TORNADOES...THROUGH THIS EVENING FOR A LARGE PART OF CNTRL/WRN OK
   AND NWRN TX.  POTENTIAL FOR LONG-LIVED SUPERCELLS WITH STRONG
   TORNADOES AND GIANT HAIL WILL EXIST.
   
   RAPID INITIATION APPEARS TO BE TAKING PLACE NOW ALONG THE ERN TX
   PNHDL/OK BORDER ALONG THE DRYLINE WHERE THE AIR MASS HEATED IN WAKE
   OF EARLY DAY STORMS.  TSTMS WILL LIKELY BUILD SWWD INTO THE SERN TX
   PNHDL THROUGH LATE AFTN...WITH ACTIVITY MOVING OFF THE DRYLINE AND
   PROGRESSING NEWD INTO WCNTRL/NWRN OK.  MEANWHILE... TSTMS HAVE BEEN
   DEVELOPING OUT OF PRE-EXISTING MID-LVL CLOUD STREETS OVER NWRN
   TX...EFFECTIVELY ROOTING INTO THE VERY UNSTABLE BOUNDARY LAYER.
   
   AHEAD OF THE STORMS...PERSISTENT INFLUX OF RICH BOUNDARY LAYER
   MOISTURE AND SFC HEATING HAVE CONTRIBUTED TO MLCAPES OF 3000 J/KG
   ACROSS NWRN TX INTO WRN/CNTRL OK.  THUS...TSTMS SHOULD HAVE NO
   TROUBLE INTENSIFYING THROUGH EARLY EVENING.
   
   VERTICAL SHEAR CONTINUES TO IMPROVE PER AREA PROFILERS AS THE UPR
   LVL TROUGH OVER NM BEGINS TO SWING ENE.  45-50 KTS OF BULK SHEAR
   WILL SUPPORT SUPERCELLS WITH VERY LARGE HAIL AND DMGG WIND GUSTS.
   
   PRIMARY CONCERN IS FOR THE POTENTIAL FOR STRONG TORNADOES. 
   SIGNIFICANT TORNADO INGREDIENTS APPEAR IN PLACE FROM NWRN TX NWD
   INTO CNTRL/WRN OK WHERE LOW-LEVEL ENVIRONMENT WILL REMAIN RELATIVELY
   MOIST AND WHERE STORMS ARE APT TO STAY DISCRETE THE LONGEST.  0-1KM
   SRH VALUES WILL BE IN EXCESS OF 300 M2/S2.
   
   ..RACY.. 04/26/2009
   
   
   ATTN...WFO...OUN...LUB...AMA...
   
   LAT...LON   35270089 36799943 36659725 34919683 33799865 33500001
               33630114 35270089