Mesoscale Discussion 1922
   NWS Storm Prediction Center Norman OK
   0354 PM CDT Tue Sep 03 2019

   Areas affected...Northern/Central IL...Northwest/Central IN

   Concerning...Severe potential...Watch possible 

   Valid 032054Z - 032300Z

   Probability of Watch Issuance...40 percent

   SUMMARY...Increased thunderstorm activity is anticipated across the
   region over the next few hours. Some severe storms are possible.

   DISCUSSION...Recent surface analysis reveals a somewhat complex
   pattern across northern/central IL and northwest/north-central IN.
   Two outflow boundaries are apparent. One of these boundaries extends
   from about 35 mi north-northeast of LAF southeastward to the central
   IN/OH border. The other extends from near PPQ (in far west-central
   IL) northeastward into northwest IN, where it intersects the first
   outflow boundary mentioned. Air mass in the vicinity of these
   boundaries has not fully destabilized, with at least minimal
   convective inhibition still in place. Even so, increasing forcing
   for ascent is anticipated as a strong shortwave trough approaches.
   This strong forcing is apparent in the banded structure of the cloud
   features and recent radar signatures across northeast IL as well as
   storm development across west-central IN. 

   Expectation is for the increased forcing for ascent, both attendant
   to the shortwave trough and along the cold front (which remains
   farther west from southern WI southwestward across IA), to
   eventually result in thunderstorm development across
   northern/central IL. Given the favorable environment, some severe
   storms are possible. 

   The ongoing elevated activity is expected to persist across central
   IN before then moving into the more stable air mass to the north of
   the outflow boundary across northeast IN/northwest OH. Isolated hail
   and/or a strong wind gusts are possible with this storm.

   ..Mosier/Guyer.. 09/03/2019

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

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

   LAT...LON   42308957 42438807 41678759 41458635 40728543 39498611
               39398905 40329036 42308957