MESOSCALE DISCUSSION 1721
   NWS STORM PREDICTION CENTER NORMAN OK
   0507 PM CDT MON SEP 19 2016

   AREAS AFFECTED...ERN IA...SRN WI...NRN IL

   CONCERNING...SEVERE THUNDERSTORM WATCH 483...

   VALID 192207Z - 200000Z

   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 483
   CONTINUES.

   SUMMARY...SCATTERED STRONG TO SEVERE THUNDERSTORMS WILL CONTINUE TO
   THREATEN PARTS OF SOUTHERN WI...EASTERN IA...AND NORTHERN IL THIS
   EVENING.  HOWEVER...A GENERAL WEAKENING TREND WITH TIME IS LIKELY.

   DISCUSSION...LATEST RADAR LOOPS SHOW MULTIPLE BROKEN LINES OF
   INTENSE THUNDERSTORMS.  ONE LINE IS AFFECTING PARTS OF
   SOUTHERN/SOUTHEASTERN WI AND WILL APPROACH THE MKE AREA WITHIN THE
   HOUR.  ANOTHER SHORT LINE OF STORMS IS OVER POWESHIEK/
   JASPER/MARION/LUCAS COUNTIES IA.  AND FINALLY...CONVECTION HAS
   RE-DEVELOPED WEST OF THE INITIAL STORMS ALONG A LINE FROM CENTRAL WI
   INTO EXTREME NORTHEAST IA.  ALL OF THIS ACTIVITY IS TRACKING
   EAST-SOUTHEASTWARD AT 30-35 KNOTS.  

   THE STORMS ARE IN A RELATIVELY NARROW INSTABILITY AXIS...WHICH
   SUGGESTS A SLOW WEAKENING TREND WILL OCCUR AS ACTIVITY MOVES INTO
   MORE STABLE AIR OVER NORTHERN IL.  NEVERTHELESS...THE STRONGEST
   CELLS WILL POSE A RISK OF DAMAGING WIND GUSTS AND LARGE HAIL. 

   OVER IA...FAVORABLE VERTICAL SHEAR AND STEEP MID LEVEL LAPSE RATES
   WILL MAINTAIN SOME RISK OF INTENSIFICATION OF ONGOING STORMS TO THE
   EAST OF DSM.  MORE PROMINENT SUPERCELL CHARACTERISTICS IN THESE
   STORMS SUGGEST SOME RISK OF AN ISOLATED TORNADO...ALONG WITH LARGE
   HAIL AND DAMAGING WINDS.

   ..HART/DIAL.. 09/19/2016


   ATTN...WFO...LOT...ILX...MKX...DVN...ARX...DMX...EAX...

   LAT...LON   41819368 43599098 43818743 42748712 42448866 42198936
               40819056 40359270 40299397 40669450 41819368