MESOSCALE DISCUSSION 1385
   NWS STORM PREDICTION CENTER NORMAN OK
   0259 PM CDT SAT JUN 25 2011
   
   AREAS AFFECTED...PORTIONS ERN MO...SRN IL...SWRN INDIANA...WRN
   KY...WRN-MIDDLE TN.
   
   CONCERNING...SEVERE THUNDERSTORM WATCH 549...
   
   VALID 251959Z - 252130Z
   
   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 549
   CONTINUES.
   
   CONTINUE WW.  IN ADDITION TO EXISTING CONVECTION AND POTENTIAL FOR
   SWD BACKBUILDING...TSTMS MAY MOVE INTO THIS REGION LATE IN WW VALID
   TIME FRAME FROM AREAS OF SERN KS OR SWRN MO.  AREAS S AND E OF WW
   WILL BE MONITORED FOR POSSIBILITY OF ADDITIONAL ISSUANCE AS TRENDS
   WARRANT.
   
   SFC MESOANALYSIS SHOWS SEVERAL POTENTIALLY IMPORTANT FEATURES...
   1. MAIN SFC WARM FRONT FROM ERN AL NWWD THROUGH HSV-FAM
   LINE...BLENDING WITH
   2. OUTFLOW BOUNDARY FROM EARLIER MCS THAT EXTENDS GENERALLY WWD
   ACROSS S-CENTRAL/SWRN MO INTO SERN KS AND AREA COVERED BY SPC
   MESOSCALE DISCUSSION 1383.  THIS MAY SUPPORT LATER
   DEVELOPMENT/MOTION OF CONVECTION INTO SRN MO.
   3. SECONDARY/NRN WARM FRONTAL ZONE FROM STL AREA SEWD ACROSS WRN
   KY...NEAR SWRN FRINGE OF PERSISTENT BAND OF ELEVATED CONVECTION THAT
   STILL MAY POST THREAT FOR ISOLATED/MRGL HAIL AND GUSTS.
   4. STG PRESSURE FALLS -- I.E. UP TO ABOUT 7 MB PER 2-HOUR
   WAKE-DEPRESSION OVER NERN MO THAT IS BECOMING INCREASINGLY REMOVED
   FROM MOST FAVORABLE LOW-LEVEL THERMODYNAMIC REGIME.  AMPLITUDE OF
   ISALLOBARIC WAVE ALSO IS NOT AS PRONOUNCED AS EARLIER TODAY...WITH
   MUCH WEAKER RISES.
   
   LATTER FACTOR APPEARS TO REDUCE -- BUT DEFINITELY NOT ELIMINATE --
   POTENTIAL FOR WELL-ORGANIZED DAMAGING WIND EVENT.  DEVELOPMENT OF
   HEAVY-PRECIP SUPERCELLS STILL MAY OCCUR WITH SOME RISK FOR UPSCALE
   GROWN AND DEVELOPMENT OF NEW COLD POOL S OF ORIGINAL ONE.  IN
   MEANTIME...ANY SUCH STORMS MAY PRODUCE DAMAGING DOWNDRAFT GUSTS AND
   LARGE HAIL...WITH TORNADO POTENTIAL MORE CONDITIONAL ON STORM-SCALE
   PROCESSES.  DEEP-LAYER SHEAR HAS INCREASED ACROSS WW AREA -- E.G.
   EFFECTIVE SHEAR MAGNITUDES 45-50 KT ESTIMATED FROM MODIFIED RUC
   SOUNDINGS -- PARTLY IN RESPONSE TO GRADIENT ENHANCEMENT ALOFT S OF
   IA MCV AND PARTLY DUE TO BACKING OF NEAR-SFC WINDS BETWEEN WARM
   FRONTAL SEGMENTS.  GIVEN STG DIFLUENCE ALOFT AND RELATED
   ANTICYCLONIC/SEWD SHIFT OF MID-UPPER FLOW ACROSS WRN KY AND WRN/MID
   TN...AND FAVORABLY BUOYANT/MOIST AIR MASS DOWNSHEAR...ANY COMPLEX
   THAT CAN DEVELOP OVER WW AREA SHOULD TURN MORE ESEWD/SEWD.
   
   ..EDWARDS.. 06/25/2011
   
   
   ATTN...WFO...LMK...OHX...PAH...MEG...LSX...
   
   LAT...LON   38309110 38909000 37688689 35378664 35128748 35338846
               35598909 36228988 36859079 38309110