MESOSCALE DISCUSSION 1228
   NWS STORM PREDICTION CENTER NORMAN OK
   0424 AM CDT WED JUN 15 2011
   
   AREAS AFFECTED...MO...IL..IND...KY
   
   CONCERNING...SEVERE THUNDERSTORM WATCH 477...
   
   VALID 150924Z - 151100Z
   
   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 477
   CONTINUES.
   
   STRONG TO OCCASIONALLY SEVERE STORMS WILL CONTINUE TO PLAGUE PARTS
   OF ERN MO...SRN IL...AND PORTIONS OF IND AND KY...THROUGH THIS
   MORNING. IN ADDITION TO HEAVY RAIN AND POSSIBLY SOME SMALL HAIL...A
   FEW WIND GUSTS TO NEAR SEVERE CRITERIA WILL BE POSSIBLE. A NEW WATCH
   DOWNSTREAM FROM WATCH 477 DOES NOT APPEAR WARRANTED AT THIS TIME.
   
   MID LEVEL SHORT WAVE TROUGH WILL CONTINUE TO TRANSLATE EAST TOWARD
   THE MIDDLE MS RIVER VALLEY EARLY TODAY. LIFT WITH THIS DISTURBANCE
   AND ITS ASSOCIATED STRENGTHENING SURFACE FEATURES WILL CONTINUE TO
   ACT ON MOIST AND MODERATELY AIR MASS TO RESULT IN WIDESPREAD
   CONVECTION. LIFT WITH THE SHORT WAVE IS MANIFESTING ITSELF IN
   SEVERAL DISTINCT AREAS.
   
   1) RECENT DEVELOPMENT ACROSS ECNTRL MO APPEARS TO BE TIED TO THE
   APPROACHING COLD FRONT AND OUTFLOW ASSOCIATED WITH EARLIER
   CONVECTION ACROSS SRN MO. THIS ACTIVITY HAS ERUPTED IN RELATIVELY
   UNPERTURBED AND UNSTABLE AIR MASS IN PROXIMITY TO GREATER DEEP LAYER
   SHEAR. THUS...SOME HAIL/WIND POTENTIAL SHOULD EXIST WITH THESE
   STORMS. ACTIVITY WILL SOON BE OVERTAKEN BY OUTFLOW SURGING SOUTH
   FROM MCS TO THE NORTH.
   
   2) MCS ACROSS NRN IL HAS BECOME PROGRESSIVE AS UPPER SYSTEM MOVES
   INTO THE AREA. LIFT ACROSS THE WARM FRONT...IN ADDITION TO LARGER
   SCALE ASCENT WITH THE UPPER TROUGH...IS LIKELY DRIVING ONGOING
   STORMS IN AN ARC AHEAD OF THE SYSTEM COLD POOL AS WELL AS MORE
   RECENT DEVELOPMENT ACROSS WRN IND AND THE OH RIVER. UPDRAFT SOURCE
   REGION FOR THESE STORMS LIES WELL ABOVE STABLE BOUNDARY LAYER AND
   ONLY MARGINAL HAIL/WIND POTENTIAL IS EXPECTED.
   
   3) VERY LITTLE REMAINS OF EARLIER CONVECTION ACROSS AR/SRN MO. ONE
   INTENSE CELL NEAR THE APEX OF THE SMALL MCS COLD POOL CONTINUES TO
   TRACK TOWARD THE BOOTHEEL AND WILL MOVE INTO AN AREA OF GREATER
   INSTABILITY NEAR THE CONFLUENCE OF MS/OH RIVERS. SHEAR AND
   STRENGTHENING MID LEVEL FLOW ACROSS THIS AREA MAY CONTRIBUTE TO A
   CONTINUING CHANCE FOR HAIL AND OR A DAMAGING WIND GUST OVER THE NEXT
   HOUR OR TWO.
   
   ..CARBIN.. 06/15/2011
   
   
   ATTN...WFO...LMK...IND...PAH...LOT...ILX...MEG...LSX...SGF...
   
   LAT...LON   39758914 40638774 38478651 37958665 37888685 36708940
               36139055 36959058 37269072 38009141 38009175 38479204
               39499111 39758914