MESOSCALE DISCUSSION 0875
   NWS STORM PREDICTION CENTER NORMAN OK
   0719 PM CDT TUE MAY 26 2009
   
   AREAS AFFECTED...PORTIONS W-CENTRAL THROUGH N-CENTRAL/NE
   TX...EXTREME S-CENTRAL OK.
   
   CONCERNING...SEVERE THUNDERSTORM WATCH 312...
   
   VALID 270019Z - 270145Z
   
   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 312
   CONTINUES.
   
   MOST ORGANIZED SVR POTENTIAL IN NEAR TERM SHOULD REMAIN OVER
   METROPLEX.  CLUSTER OF SVR TSTMS CONTINUES TO MOVE SLOWLY EWD OVER
   WRN PORTIONS METROPLEX INVOF SFC MESOLOW...WITH SEVERAL REPORTS OF
   SVR HAIL UP TO 1.75 INCH DIAMETER DURING PAST HOUR.  DAMAGING GUSTS
   ALSO ARE POSSIBLE GIVEN WELL-MIXED/INVERTED-V THERMODYNAMIC PROFILE
   EVIDENT IN FWD RAOB.
   
   OUTFLOW BOUNDARY HAS EXPANDED OUTWARD FROM MOST OF TARRANT/PARKER
   COUNTY ACTIVITY.  VISUAL OBSERVATION OF THIS ACTIVITY FROM HERE
   SHOWS INTERMITTENT/SPLASHING OVERSHOOTS...BUT ALSO SIGNIFICANT ANVIL
   GROWTH UPSHEAR...EVIDENCE OF RELATIVELY WEAK STORM-RELATIVE UPPER
   FLOW CONTRIBUTING TO PRECIP-LOADING AROUND UPDRAFTS.  ADDITIONAL
   DEVELOPMENT IS LIKELY ALONG NWWD-RETREATING LOW LEVEL BOUNDARY
   EVIDENT IN REFLECTIVITY ANIMATIONS FROM COLLIN COUNTY ACROSS NW
   DALLAS/SE DENTON/ERN TARRANT/ERN JOHNSON COUNTIES -- ESPECIALLY
   WHERE BOUNDARIES WILL COLLIDE ACROSS TARRANT AND PERHAPS NRN JOHNSON
   COUNTIES THROUGH 01Z.  MESOANALYSIS ALSO SHOWS SFC TROUGH EXTENDING
   NNEWD FROM FTW CLUSTER OVER LOVE COUNTY OK...E OF WHICH MLCAPE
   REMAIN IN 3000-4000 J/KG IN RELATIVELY MOIST AND UNMIXED AIR MASS
   ALONG/N OF OLDER MCS OUTFLOW BOUNDARY.  BUOYANCY AND LOW LEVEL SHEAR
   EACH APPEAR TO DECREASE SWD AND SWWD FROM METROPLEX...WHERE HOTTER
   AND MORE DEEPLY MIXED/DRIED AIR MASS COLLOCATE WITH LIGHT/SWLY SFC
   WINDS.
   
   LARGE/OUTFLOW-DOMINANT MULTICELL COMPLEX OVER W-CENTRAL TX CONTINUES
   TO SEND OUTFLOW BOUNDARY RADIALLY OUTWARD FROM CENTER POINT IN
   MITCHELL COUNTY.  ADDITIONAL DEVELOPMENT ALONG THIS BOUNDARY IS
   POSSIBLE AS IT MOVES TOWARD SWRN PORTIONS WW.  OCNL HAIL AND GUSTS
   NEAR SVR LEVELS ARE POSSIBLE...ESPECIALLY ALONG AND N OF SFC TROUGH
   EXTENDING SWWD FROM FTW AREA LOW...WHERE LOW LEVEL STORM-RELATIVE
   INFLOW WILL BE ENHANCED BY NLY/ELY SFC WIND COMPONENTS.
   
   ..EDWARDS.. 05/27/2009
   
   
   ATTN...WFO...SHV...FWD...OUN...SJT...LUB...MAF...
   
   LAT...LON   31400095 31610047 31890032 32370044 32630075 32730126
               33130003 33349896 34059703 34129598 33829599 33819529
               32949533 32959577 32059549 31819648 31829676 31729693
               31509684 31249733 31689774 31219858 31449897 31509975
               31400095