Storm Prediction Center Mesoscale Discussion 939

   Mesoscale Discussion 0939
   NWS Storm Prediction Center Norman OK
   0446 PM CDT Fri May 24 2024

   Areas affected...Northern Illinois into southeast Wisconsin

   Concerning...Severe potential...Watch unlikely 

   Valid 242146Z - 242345Z

   Probability of Watch Issuance...20 percent

   SUMMARY...Scattered thunderstorms will continue to spread northeast
   into northern Illinois and southeast Wisconsin through the evening
   hours. A few strong to severe storms are possible, but the overall
   threat should remain sufficiently limited to preclude watch
   issuance.

   DISCUSSION...Several thunderstorm clusters continue to move
   northeast from northwest IL/eastern IA towards northern IL/southern
   WI. GOES IR imagery has shown steadily cooling cloud top
   temperatures with this activity, suggesting some degree of
   intensification; however, MRMS vertically integrated ice (and other
   radar-based measures of convective intensity) show that most of the
   stronger updrafts/convective cores have been relatively short-lived.
   Some degree of air mass recovery has taken place across northern
   IL/southern WI with temperatures rebounding into the 70s, but cloud
   debris has limited overall destabilization, and RAP forecast
   soundings hint that low-level lapse rates are fairly marginal with
   some degree of lingering MLCIN. East/southeasterly low-level winds
   under 40 knot mid-level flow should continue to support transient
   storm organization with the deeper/stronger cells, but the marginal
   thermodynamic environment should modulate the overall severe threat.
   Sporadic damaging winds/hail, and perhaps a brief tornado, appear
   possible given the kinematic environment, but should be sufficiently
   isolated to preclude watch issuance.

   ..Moore/Thompson.. 05/24/2024

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

   ATTN...WFO...LOT...ILX...MKX...DVN...

   LAT...LON   40718878 41218955 41789006 42259016 42948995 43328953
               43568904 43578871 43318774 42808759 42178749 41898732
               41628731 41218744 40898773 40698811 40668840 40718878