MESOSCALE DISCUSSION 1389
   NWS STORM PREDICTION CENTER NORMAN OK
   0719 AM CDT MON JUL 13 2015

   AREAS AFFECTED...NRN IL THROUGH NWRN IND

   CONCERNING...SEVERE THUNDERSTORM WATCH 408...

   VALID 131219Z - 131345Z

   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 408
   CONTINUES.

   SUMMARY...SQUALL LINE WILL CONTINUE TO POSE A THREAT FOR ISOLATED
   STRONG TO DAMAGING WIND NEXT 2-3 HOURS AS IT MOVES SSEWD THROUGH NRN
   IL INTO NWRN IND. THESE STORMS WILL BEGIN TO MOVE SOUTH OF WW 408
   AFTER 1230Z...AND ADDITIONAL COUNTIES CAN BE LOCALLY ADDED AS
   NECESSARY THROUGH THE REMAINDER OF CHICAGO CWA. ANOTHER WW WILL NEED
   TO BE CONSIDERED FOR PARTS OF ECNTRL IL THROUGH NRN IND A BIT LATER
   THIS MORNING.

   DISCUSSION...SQUALL LINE EXTENDING FROM NRN IL THROUGH SRN LAKE MI
   IS MOVING SEWD AT 30-40 KT. THE STORMS SHOULD PERSIST NEXT FEW HOURS
   THROUGH SWRN LOWER MI...NWRN IND AND ECNTRL IL ALONG INSTABILITY
   GRADIENT PROMOTED BY CONVERGENCE INDUCED BY A 30 KT WSWLY LLJ
   INTERACTING WITH THE CONVECTIVE OUTFLOW BOUNDARY. THE VWP FROM
   MILWAUKEE WI ALSO INDICATES 40-50 KT NWLY LOW-MID LEVEL WINDS IN
   POST SQUALL LINE REGIME THAT APPEARS TO BE IN PART CONVECTIVELY
   INDUCED. VISIBLE IMAGERY SHOWS MOSTLY CLEAR SKIES OVER CNTRL
   IL...BUT WITH ANVIL DEBRIS SPREADING INTO NRN IND. WHILE THE LINE
   HAS SHOWN AT LEAST A SLIGHT WEAKENING TREND...SOME REINTENSIFICATION
   IS PROBABLE LATER THIS MORNING AS THE BOUNDARY LAYER BEINGS TO WARM.

   ..DIAL.. 07/13/2015


   ATTN...WFO...IWX...LOT...ILX...

   LAT...LON   41568912 41748808 41948720 41718622 41298609 40638690
               40468822 41028909 41568912