MESOSCALE DISCUSSION 1291
   NWS STORM PREDICTION CENTER NORMAN OK
   0546 AM CDT SUN JUN 19 2011
   
   AREAS AFFECTED...FAR SERN IL...FAR SERN MO...SRN IND...AND
   WRN/CENTRAL KY
   
   CONCERNING...TORNADO WATCH 510...
   
   VALID 191046Z - 191145Z
   
   THE SEVERE WEATHER THREAT FOR TORNADO WATCH 510 CONTINUES.
   
   THREAT FOR DAMAGING WINDS AND A TORNADO OR TWO CONTINUES ACROSS WW
   510 ALONG AND AHEAD OF THE BOW ECHO...WHILE COUNTIES IN THE WAKE OF
   THIS SYSTEM CAN CONTINUE TO BE CANCELLED AS THE SEVERE WEATHER
   THREAT DIMINISHES WITH WWD EXTENT.
   
   REGIONAL RADAR IMAGERY CONTINUED TO SHOW A WELL ORGANIZED EWD MOVING
   BOW ECHO ACROSS THE LOWER OH VALLEY REGION /AFFECTING FAR SERN
   IL...FAR SERN MO INTO SRN IND AND WRN KY AT 1025Z/.  ALTHOUGH LATEST
   TRENDS INDICATED A RELATIVE SLOWER EWD MOVEMENT THAN OBSERVED ABOUT
   1 HOUR AGO /AROUND 930Z/...THE CURRENT 45+ KT FORWARD SPEED OF THE
   BOW INTO A MODERATELY UNSTABLE AIR MASS WILL CONTINUE TO POSE A
   THREAT FOR DAMAGING WINDS.  THE APEX OF THE BOW...NOW MOVING THROUGH
   FAR SWRN IND...SHOULD REACH THE ERN EXTENT OF WW 510 BY 13Z.
   
   MOST OF THE BOW REMAINS CONTAINED WITHIN WW 510.  HOWEVER...THE NRN
   EXTENT OF THIS LINE OF STORMS WAS MOVING ENEWD AT 40 KT AND AS OF
   1030Z BEGINNING TO AFFECT THE INDIANA COUNTIES JUST N OF THIS WATCH.
   IN THE SHORT TERM...MODERATE INSTABILITY RESIDING ACROSS SWRN INTO
   SOUTH CENTRAL IND SHOULD SUPPORT A CONTINUED THREAT FOR STRONG TO
   POSSIBLY SEVERE STORMS AS THIS NRN EXTENT OF THE LINE MOVES ALONG
   AND JUST N OF WW 510.  HOWEVER...OBJECTIVE ANALYSES INDICATED
   INSTABILITY IS MUCH WEAKER INTO SERN IND...WITH THE INSTABILITY
   GRADIENT EXTENDING FROM SWRN IND INTO CENTRAL KY.  THIS LATTER
   FACTOR WOULD SUGGEST AN EVENTUAL SEWD TURN OF THE ONGOING BOW ACROSS
   WRN/CENTRAL KY.  TRENDS WILL BE MONITORED FOR AN ADDITIONAL WW
   ISSUANCE ACROSS SRN IND...BUT CURRENT ANALYSIS AND FORECASTS SUGGEST
   THIS IS UNLIKELY.
   
   ..PETERS.. 06/19/2011
   
   
   ATTN...WFO...JKL...ILN...LMK...OHX...IND...PAH...ILX...
   
   LAT...LON   36518959 37058906 37328835 38298806 39108828 39238791
               39248680 39188558 38848523 38338492 37278485 36738493
               36598517 36518959