ZCZC SPCSWOMCD ALL ACUS11 KWNS 241344 SPC MCD 241344 ILZ000-WIZ000-IAZ000-241545- Mesoscale Discussion 0927 NWS Storm Prediction Center Norman OK 0844 AM CDT Fri May 24 2024 Areas affected...far southern WI...northern IL Concerning...Severe Thunderstorm Watch 301... Valid 241344Z - 241545Z The severe weather threat for Severe Thunderstorm Watch 301 continues. SUMMARY...A severe bow echo will continue moving east at 40 mph across far southern WI and northern IL through 1030 am CDT. Severe gusts 60-75 mph are likely with the more intense bowing segments of the squall line and a couple of mesovortex tornadoes are possible. DISCUSSION...A long-lived bow echo is currently moving across the MS River this morning. The airmass downstream of the squall line continues to destabilize despite an anvil-level cloud shield spreading east. Surface analysis indicates a warm front is advancing northward from north-central IN through far northeast IL and into southern WI. South of the boundary, surface dewpoints are rising into the lower to mid 60s deg F and temperatures are in the upper 60s. Further heating will likely result in temperatures rising into the mid-upper 60s over far southern WI and into the low-mid 70s across northern IL prior to squall line passage. Water-vapor imagery shows a progressive negatively tilted mid-level shortwave trough/mid-level low over the Upper Midwest. The very mature character of the Rear Inflow Jet sampled via the Des Moines and Davenport WSR-88Ds VADs suggest the strongly dynamic nature of the squall line and destabilizing boundary layer ahead of it, will combine to support a likely continuation of severe-gust risk into the greater Chicago metro during the 1030am to 1200pm timeframe. Severe gusts primarily in the 60-75 mph are likely in the next 1-2 hours as this activity moves east across northern IL/far southern WI. A couple of mesovortices capable of severe gusts and/or brief tornadoes are possible. ..Smith.. 05/24/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LOT...ILX...MKX...DVN... LAT...LON 42689028 42848860 42218837 41538832 41158851 41158935 41189010 41659008 41989014 42099036 42359024 42689028 NNNN