MESOSCALE DISCUSSION 1436
   NWS STORM PREDICTION CENTER NORMAN OK
   0720 PM CDT SAT JUL 04 2009
   
   AREAS AFFECTED...SERN OK AND WRN AR
   
   CONCERNING...SEVERE THUNDERSTORM WATCH 545...
   
   VALID 050020Z - 050045Z
   
   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 545
   CONTINUES.
   
   WRN PORTION OF WW 545 COULD BE EXTENDED IN TIME UNTIL 03Z TO SUPPORT
   AN ISOLATED SEVERE WEATHER THREAT.
   
   A FEW STORMS UNTIL ABOUT 03Z WILL HAVE THE POTENTIAL TO PRODUCE
   STRONG WIND GUSTS AND/OR MARGINALLY SEVERE HAIL.  IN ADDITION TO
   THIS MORE ISOLATED SEVERE THREAT...PWAT VALUES AROUND 1.75 INCHES
   AND GENERALLY SLOW MOVING STORMS SUGGEST HEAVY RAINFALL RATES UP TO
   2 INCHES AN HOUR WILL BE LIKELY.
   
   ALTHOUGH TSTMS WILL CONTINUE TO DEVELOP ACROSS ERN OK INTO WRN AR
   THIS EVENING WITH ADDITIONAL ONGOING STORMS SPREADING EWD FROM
   CENTRAL OK...OVERALL SEVERE WEATHER THREAT SHOULD WANE BY MID
   EVENING.  STRONG EFFECTIVE BULK SHEAR /UP TO 40-45 KT/ PRESENTLY
   LOCATED ACROSS THIS REGION COMBINED WITH MODERATE INSTABILITY WILL
   SUPPORT ADDITIONAL ORGANIZED STORMS.  HOWEVER...EFFECTIVE BULK SHEAR
   IS EXPECTED TO WEAKEN TOWARD MID EVENING PER 15Z NAMKF/21Z RUC OVER
   ERN OK/WRN AR AS SWRN EXTENT OF STRONG WNWLY MID LEVEL WINDS ACROSS
   THE LOWER OH/TN VALLEYS MOVE AWAY FROM THE WRN PORTION OF WW 545. 
   THIS SHOULD ALLOW STORMS TO BECOME LESS ORGANIZED WITH TIME.
   
   ..PETERS.. 07/05/2009
   
   
   ATTN...WFO...LZK...SHV...TSA...OUN...
   
   LAT...LON   34199572 34859605 35499606 35679447 35689379 35259364
               34739368 34409393 34249498 34199572