MESOSCALE DISCUSSION 1853
   NWS STORM PREDICTION CENTER NORMAN OK
   0104 PM CDT THU AUG 04 2011
   
   AREAS AFFECTED...ERN OK INTO CNTRL AR
   
   CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 
   
   VALID 041804Z - 041900Z
   
   TSTMS ARE EXPECTED TO INCREASE IN COVERAGE ACROSS THE WATCH AREA
   THIS AFTERNOON WITH ATTENDANT THREATS FOR LOCALLY DAMAGING WET
   MICROBURSTS.  A WATCH IS NOT CURRENTLY ANTICIPATED.
   
   VISIBLE SATELLITE IMAGERY SHOWS GRADUAL INCREASE IN CONVECTIVE
   DEVELOPMENT OVER SRN LEFLORE COUNTY OK TO NRN POLK COUNTY AR JUST S
   OF AN AGGREGATE SYNOPTIC FRONT-OUTFLOW BOUNDARY EXTENDING FROM CNTRL
   OK TO CNTRL AR.  AIR MASS SOUTH OF THIS BAROCLINIC ZONE HAS WARMED
   TO OVER 100 F...WHICH WHEN COUPLED WITH BOUNDARY LAYER DEWPOINTS IN
   THE 60S TO LOW/MID 70S IS RESULTING IN MLCAPE VALUES APPROACHING
   4000-4500 J/KG.  THOUGH LARGE-SCALE FORCING WILL REMAIN NEGLIGIBLE
   THROUGH THE REMAINDER OF THE DIURNAL HEATING CYCLE...CONVERGENCE
   ALONG FRONTAL ZONE SHOULD SUFFICIENTLY WEAKEN CAP TO ALLOW FOR AN
   INCREASE IN TSTM ACTIVITY.
   
   A VERY WEAK WIND FIELD INVOF UPPER-LEVEL ANTICYCLONE WILL LIMIT
   STORM ORGANIZATION.  BUT...GIVEN THE STRONG TO EXTREME INSTABILITY
   AND DCAPE OF 1500-1800 J/KG...THE POTENTIAL WILL EXIST FOR LOCALLY
   DAMAGING WET MICROBURSTS.  THOUGH A WATCH IS NOT CURRENTLY
   ANTICIPATED...CONVECTIVE TRENDS WILL BE MONITORED FOR THE MERGING OF
   STORMS INTO AN MCS WHICH COULD POSE A RISK FOR MORE ORGANIZED
   DAMAGING WINDS.
   
   ..MEAD.. 08/04/2011
   
   
   ATTN...WFO...MEG...LZK...SHV...TSA...OUN...
   
   LAT...LON   34009520 34169660 34899722 35509681 35529411 35529200
               35509097 34849061 33919134 33679253 34009520