Mesoscale Discussion 1274
   NWS Storm Prediction Center Norman OK
   1012 AM CDT Sun Jul 19 2020

   Areas affected...northern Illinois/northwestern Indiana

   Concerning...Severe potential...Watch possible 

   Valid 191512Z - 191645Z

   Probability of Watch Issuance...40 percent

   SUMMARY...A cluster of ongoing storms continues to surge
   east-northeastward across north-central Illinois.  Continuation of
   locally severe wind gusts over the next hour or so could warrant WW
   issuance.

   DISCUSSION...Latest radar loop shows a cluster of thunderstorms
   bowing/surging east-northeastward across north-central Illinois at
   50 kt at this time.  The storms are ongoing near/just ahead of the
   surface cold front lying northeast to southwest across the area, and
   it appears that the local convective enhancement is associated with
   a remnant MCV.

   Downstream from this bowing cluster, persistent rainfall/convection
   has been occurring across parts of northeast Illinois and into
   northwestern Indiana, which -- along with relatively dense cloud
   cover hindering heating -- suggests that severe-caliber wind gust
   potential may remain tempered/local as convection gradually
   approaches the Chicago metro area.  However, with latest objective
   analyses maintaining an axis of 2000 J/kg mixed-layer CAPE, and
   moderate/unidirectional westerly in the 30 to 40 kt range,
   convection appears likely to remain organized in the short term. 
   While current thinking is that wind risk may remain limited over the
   next 1 to 2 hours, continuation of severe-caliber gusts into regions
   that have been rain-cooled could prompt WW consideration.

   ..Goss/Hart.. 07/19/2020

   ...Please see www.spc.noaa.gov for graphic product...

   ATTN...WFO...IWX...IND...LOT...ILX...DVN...

   LAT...LON   41038961 41598979 42478811 41838626 40588669 40499012
               41038961