Mesoscale Discussion 0627
   NWS Storm Prediction Center Norman OK
   1159 AM CDT Mon May 18 2020

   Areas affected...Parts of northeast into east-central Illinois

   Concerning...Severe potential...Watch unlikely 

   Valid 181659Z - 181830Z

   Probability of Watch Issuance...5 percent

   SUMMARY...A couple of funnels and perhaps a brief non-supercell
   tornado will be possible during the afternoon hours. A WW issuance
   is not expected.

   DISCUSSION...A sfc-300 mb stacked low continues to very gradually
   drift east-southeast across northern portions of IL, where some
   breaks in cloud cover have been noted. The cloud breaks, with
   temperatures reaching into the low 60s, with mid 50s dewpoints,
   promoted enough boundary layer heating and steepening low-level
   lapse rates to foster 100 J/kg 0-3km CAPE (per latest Mesoanalysis
   and RAP forecast soundings). While most convection within the
   low-center regime is expected to remain shallow, a few relatively
   deeper convective cells, aided by the available low-level buoyancy,
   may develop and stretch some of the ambient deep-layer, high
   magnitudes of vertically oriented vorticity. A few funnels have
   already been reported in Piatt and Putnam counties in central IL,
   with additional funnels and perhaps a brief non-supercell/landspout
   tornado remaining possible. 

   The best chance for a landspout tornado will be during the early to
   mid afternoon hours, when peak heating transpires. Given the brevity
   and isolated nature of the severe threat, a WW issuance is not
   anticipated.

   ..Squitieri/Guyer.. 05/18/2020

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

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

   LAT...LON   39928747 39828795 39708854 40048957 41008958 41678901
               41698820 41268777 40488747 39928747