ZCZC SPCSWOMCD ALL
ACUS11 KWNS 162042 
SPC MCD 162042 
INZ000-ILZ000-WIZ000-162245-

Mesoscale Discussion 1291
NWS Storm Prediction Center Norman OK
0342 PM CDT Sun Jun 16 2024

Areas affected...northern Illinois and adjacent southeastern
Wisconsin

Concerning...Severe Thunderstorm Watch 424...

Valid 162042Z - 162245Z

The severe weather threat for Severe Thunderstorm Watch 424
continues.

SUMMARY...There appears increasing risk for potentially damaging
wind gusts as an organizing cluster of storms accelerates into the
Greater Chicago and Milwaukee metro areas through 5-6 PM CDT.

DISCUSSION...Based on 20Z surface observations, the
convectively-generated cold pool remains modest in strength. 
However, a notable intensification of convection along its leading
edge appears underway, and this seems likely to be sustained
east-northeastward into the southern Lake Michigan vicinity through
22-23Z, aided by easterly low-level inflow of unstable air
characterized by CAPE in excess of 1500 J/kg.  Boundary-layer mixing
has lowered surface dew points into the 60s F, but lapse rates have
become rather steep with temperatures rising through the lower/mid
90s F.  With some further increase in temperature differential
across the gust front, and strengthening rear inflow, it appears
that the forward propagation of the organizing cluster may undergo
acceleration toward the Greater Chicago and, perhaps, Greater
Milwaukee metro areas through 22-23Z, accompanied by increasing risk
for potentially damaging wind gusts.

..Kerr.. 06/16/2024

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

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

LAT...LON   41478742 41018848 40978915 41038940 41418926 41958925
            42338947 42908868 42738758 42058689 41478742 

NNNN