MESOSCALE DISCUSSION 1908
   NWS STORM PREDICTION CENTER NORMAN OK
   0734 PM CDT MON AUG 08 2011
   
   AREAS AFFECTED...PORTIONS OK...SERN KS...SWRN MO...AR.
   
   CONCERNING...SEVERE THUNDERSTORM WATCH 748...
   
   VALID 090034Z - 090230Z
   
   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 748
   CONTINUES.
   
   SVR TSTMS WITH HISTORY OF DAMAGING WIND WILL PROCEED SEWD ACROSS NRN
   OK...WITH POTENTIAL TO EVOLVE INTO EXTENDED MCS OVER ERN OK AND
   PORTIONS AR.  ANOTHER WW IS LIKELY.
   
   NRN OK CONVECTION HAS PRODUCED MEASURED SVR GUSTS 61 KT AT END AND
   69 KT AT SWO SINCE 23Z...WITH INCREASINGLY WELL-DEVELOPED COLD POOL
   AND FORCED ASCENT IMPINGING UPON AIR MASS CONTAINING GREATER
   MOISTURE WITH EWD EXTENT.  INSTABILITY/THERMAL GRADIENT ACCOMPANYING
   OUTFLOW BOUNDARY...EXTENDING FROM CENTRAL AR CONVECTION WNWWD ACROSS
   FSM/TUL AREAS...SHOULD SERVE AS PRIMARY FOCUS FOR LIFT AHEAD OF NRN
   OK MCS AND FOR FORWARD PROPAGATION.  AIR MASS TO ITS S WILL REMAIN
   CHARACTERIZED BY CHANNEL OF RELATIVELY MINIMIZED MLCINH...AND DRY
   SUBCLOUD AIR THAT SHOULD MAINTAIN DCAPE ENOUGH TO ALLOW SVR
   DOWNDRAFT PENETRATION OF DIABATICALLY COOLING SKIN LAYER.  MEAN WIND
   IS ALIGNED NEARLY ORTHOGONAL TO THIS CONVECTION AS WELL...AND ALMOST
   PARALLEL TO FOCUSING BOUNDARY...FURTHER SUPPORTING POTENTIAL FOR
   WELL-ORGANIZED TSTM WIND EVENT TO CONTINUE INTO AR.  LONGEVITY OF
   SECONDARY CONVECTIVE SEGMENT OVER SWRN OK IS UNCERTAIN GIVEN WEAKER
   MLCAPE IN PROSPECTIVE INFLOW REGION...PER MODIFIED OUN
   RAOB...HOWEVER THIS ACTIVITY IS MOVING INTO HOT/DEEPLY-MIXED
   BOUNDARY LAYER IN SUPPORT OF DAMAGING GUST THREAT FOR ANOTHER COUPLE
   HOURS. 
   
   CONVECTION FARTHER N ACROSS SERN KS AND MO/AR BORDER REGION IS
   OCCURRING IN REGIME OF FAVORABLE ELEVATED BUOYANCY -- I.E. MUCAPE
   1500-3000 J/KG -- AND 40-45 KT EFFECTIVE SHEAR.  THIS BUOYANCY WILL
   DIMINISH SOMEWHAT WITH SEWD EXTENT...DEEPER OVER OUTFLOW AIR FROM
   EARLIER CONVECTION FARTHER S...HOWEVER WAA AND ISENTROPIC ASCENT TO
   LFC ALSO ARE POSSIBLE AS LLJ INCREASES ATOP THAT AIR MASS.  LARGE
   HAIL IS POSSIBLE...ALONG WITH OCNL STG-SVR GUSTS WHERE MOST INTENSE
   DOWNDRAFTS ACCELERATING THROUGH RELATIVELY DRY SUBCLOUD LAYER THEN
   CAN PENETRATE SHALLOW LAYER OF HIGH CINH NEAR SFC.  CONVECTION OVER
   CENTRAL AR ALSO MAY PRODUCE ISOLATED DAMAGING GUSTS AS ITS COLD POOL
   IMPINGES UPON FAVORABLE MOIST AIR MASS OVER DELTA REGION...ALTHOUGH
   DEEP-LAYER SHEAR IS RELATIVELY WEAK IN THAT AREA.
   
   ..EDWARDS.. 08/09/2011
   
   
   ATTN...WFO...MEG...LZK...SGF...SHV...TSA...ICT...OUN...
   
   LAT...LON   35119983 36199802 36649670 37649583 37639465 36449243
               34539065 33959376 34779574 34409758 34509881 35119983