MESOSCALE DISCUSSION 0838
   NWS STORM PREDICTION CENTER NORMAN OK
   0531 PM CDT FRI MAY 15 2009
   
   AREAS AFFECTED...PARTS OF ERN KS EWD TO CENTRAL INDIANA
   
   CONCERNING...SEVERE THUNDERSTORM WATCH 305...306...
   
   VALID 152231Z - 160030Z
   
   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH
   305...306...CONTINUES.
   
   STRONG STORMS CONTINUE ACROSS WW 305 AND 306...WHILE AND EWD-SPREAD
   OF THE SEVERE/TORNADO POTENTIAL WITH TIME INTO INDIANA COULD REQUIRE
   DOWNSTREAM WW ISSUANCE.
   
   LATEST SURFACE ANALYSIS REVEALS A GENERALLY W-E WARM FRONT EXTENDING
   FROM ROUGHLY THE KANSAS CITY METRO AREA EWD ACROSS NRN MO/CENTRAL IL
   TO NEAR INDIANAPOLIS.  MODERATE INSTABILITY INVOF THIS FRONT /2000
   TO 2500 J/KG MIXED-LAYER CAPE ALONG THE FRONT AND SWD INTO THE WARM
   SECTOR/ CONTINUES TO FUEL WIDESPREAD STRONG/SEVERE STORMS.  WHILE
   STORM MODE IS GENERALLY NOT PURELY CELLULAR...SEVERE UPDRAFTS
   EMBEDDED WITHIN LARGER STORM CLUSTERS/LINE SEGMENTS CONTINUE TO
   EXHIBIT ROTATION.  ADDITIONALLY...A FORWARD-PROPAGATING/BOWING
   SEGMENT CONTINUES MOVING EWD ACROSS PARTS OF NERN AND E CENTRAL MO
   -- AFFECTING ERN MONROE/WRN RALLS/AUDRAIN COUNTIES ATTM.  ALONG WITH
   THE LARGE HAIL THREAT...THE POTENTIAL FOR TORNADOES WILL CONTINUE
   WITH ROTATING STORMS...WHILE DAMAGING WIND POTENTIAL WILL BE
   MAXIMIZED NEAR LINEAR/BOWING STORM CLUSTERS.
   
   ALONG WITH THE SEVERE POTENTIAL...VERY HEAVY RAINFALL WILL CONTINUE
   ACROSS NRN /CENTRAL MO...WHERE A W-E BAND OF STRONG STORMS DRIFTS
   VERY SLOWLY SWD -- BUT INDIVIDUAL STORMS TRAIN EWD ALONG THE BAND
   RESULTING IN PERSISTENT/VERY HEAVY RAINFALL.  
   
   AS STORMS SPREAD EWD WITH TIME...THE SEVERE/TORNADO THREAT WILL
   SLOWLY INCREASE ACROSS INDIANA.  A FAIRLY PRONOUNCED DECREASE IN
   MID-LEVEL FLOW OCCURS SWD TOWARD THE OH RIVER.  HOWEVER...WITH
   FAVORABLE SHEAR ACROSS CENTRAL AND NRN INDIANA...AND FAVORABLE
   INSTABILITY ACROSS CENTRAL AND SRN AREAS...JUXTAPOSITION OF AMPLE
   INSTABILITY/SHEAR ACROSS THE CENTRAL THIRD OF THE STATE IMPLIES A
   ZONE OF INCREASING SEVERE POTENTIAL -- E OF WW 306 -- AS STORMS
   SPREAD/DEVELOP EWD WITH TIME.
   
   ..GOSS.. 05/15/2009
   
   
   ATTN...WFO...IWX...IND...PAH...LOT...ILX...LSX...DVN...SGF...
   EAX...
   
   LAT...LON   38589504 39469500 39659235 40339084 40868864 40878541
               39588558 38818768 38428889 38589504