MESOSCALE DISCUSSION 1638
   NWS STORM PREDICTION CENTER NORMAN OK
   0540 AM CDT TUE JUL 21 2009
   
   AREAS AFFECTED...OK...TX
   
   CONCERNING...SEVERE THUNDERSTORM WATCH 610...611...
   
   VALID 211040Z - 211115Z
   
   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH
   610...611...CONTINUES.
   
   EXCEPT FOR A FEW STRONGER AND MORE PERSISTENT STORM CORES WITH SOME
   POTENTIAL FOR GUSTY WINDS...OVERALL INTENSITY OF THE LARGE MCS
   EXTENDING FROM NRN TX TO THE OZARKS HAS BEEN ON THE DECLINE.
   WELL-FORMED AND COMPACT MCS CIRCULATION ACROSS SERN KS/NERN OK HAS
   RECENTLY PRODUCED A GUST TO 45KT. A PERSISTENT CELL HAS ALSO
   MAINTAINED INTENSITY AND A HIGH LIGHTNING FLASH RATE ON THE TRAILING
   PORTION OF MCS OUTFLOW OVER POTTAWATOMIE COUNTY OK. WITH THE OVERALL
   DOWNWARD TREND EVIDENT IN THE LARGE SCALE COMPLEX...AND GIVEN
   DIURNAL MINIMUM IN AVAILABLE SURFACE-BASED INSTABILITY...ADDITIONAL
   WATCHES ARE UNLIKELY AFTER 610 AND 611 EXPIRE AT THE TOP OF THE
   HOUR.
   
   ..CARBIN.. 07/21/2009
   
   
   ATTN...WFO...TSA...FWD...OUN...SJT...LUB...
   
   LAT...LON   33529781 33380000 34259996 35309789 35999659 35229592
               34749594 34869697 33859698 33789792 33529781