MESOSCALE DISCUSSION 1719
   NWS STORM PREDICTION CENTER NORMAN OK
   0404 AM CDT THU JUL 30 2009
   
   AREAS AFFECTED...N CNTRL TX
   
   CONCERNING...SEVERE THUNDERSTORM WATCH 638...
   
   VALID 300904Z - 301030Z
   
   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 638
   CONTINUES.
   
   CURRENT TRENDS SUGGEST THAT A NEW WW MAY NOT BE NEEDED...BUT TRENDS
   WILL CONTINUE TO BE MONITORED FOR THAT POSSIBILITY...MAINLY ACROSS
   CENTRAL TEXAS...SOUTH OF CURRENT WW.
   
   CONVECTIVELY GENERATED OR ENHANCED CYCLONIC MID TROPOSPHERIC
   VORTICITY CENTERS CONTINUE TO MIGRATE EAST SOUTHEASTWARD WITHIN WEAK
   TO MODERATE WEST/NORTHWESTERLY FLOW...ACROSS PARTS OF SOUTH CENTRAL
   OKLAHOMA AND NORTHWEST TEXAS.  STRENGTHENING MID-LEVEL FLOW NEAR THE
   SOUTHERN FEATURE HAS ENHANCED VERTICAL SHEAR NEAR A 30 KT
   SOUTHWESTERLY 850 MB JET...MAINTAINING PERHAPS THE STRONGEST/MOST
   SIGNIFICANT CONVECTIVE DEVELOPMENT.  DESPITE RECENT WEAKENING
   TRENDS...THIS ACTIVITY MAY CONTINUE TO BE ACCOMPANIED BY GUSTY
   WINDS/SOME HAIL AND A PERIOD OF HEAVY RAINFALL AS IT OVERSPREADS THE
   DALLAS/FORT WORTH METROPLEX AND AREAS TO JUST TO THE SOUTHWEST
   DURING THE 09-11Z TIME FRAME.  
   
   IN THE WEAKER SHEAR REGIME FARTHER TO THE SOUTHWEST...CONVECTIVE
   OUTFLOW HAS SURGED IN ADVANCE /TO THE SOUTH AND EAST/ OF
   STRONG/SEVERE STORMS WHICH CONTINUE TO FORM IN RESPONSE TO STRONG
   WARM ADVECTION ABOVE THE COLD POOL.  THIS ACTIVITY MAY PERSIST AT
   LEAST ANOTHER COUPLE OF HOURS WITH A RISK FOR HAIL AND LOCALIZED
   STRONG DOWNBURSTS...NEAR/NORTH THROUGH EAST OF SAN ANGELO...BEFORE
   LIKELY DIMINISHING TOWARD DAYBREAK.
   
   ..KERR.. 07/30/2009
   
   
   ATTN...WFO...FWD...EWX...SJT...
   
   LAT...LON   33059726 33459649 33429622 32869593 32129595 31249705
               30979786 30979904 31100038 31590087 32050068 32009841
               32799771 33059726