ZCZC SPCSWOMCD ALL ACUS11 KWNS 211815 SPC MCD 211815 WIZ000-211945- Mesoscale Discussion 0873 NWS Storm Prediction Center Norman OK 0115 PM CDT Tue May 21 2024 Areas affected...Southern WI Concerning...Severe potential...Watch possible Valid 211815Z - 211945Z Probability of Watch Issuance...40 percent SUMMARY...Isolated hail and/or damaging gusts are possible. Limited severe coverage will likely preclude the need for a watch in the short term. A greater severe risk is anticipated later this evening as the line of storms moving out of IA moves into the region. DISCUSSION...Surface observations reveal a warm front extends east-to-west across far southern WI, with temperatures in the upper 70s/low 80s south of the boundary and in the mid 60s to low 70s north of it. Dewpoints south of the boundary are in the upper 60s while remaining in the low to mid 60s north of it. Ongoing convective cluster moving across southwest WI has recently shown a strengthening trend, likely a result of increased warm-air advection across the warm front. Given the persistence of the strong low-level flow and increasing low-level moisture, this cluster is forecast to continue quickly northeastward, with some potential for isolated hail and/or damaging gusts as it does. A more isolated storm has developed east of this cluster in Dane County. This storm is very close to the warm front but still looks to be slightly elevated, although the more recent slow, more eastward storm motion may be indicating a trend toward more surface-based character. Recent MKX VAD sampled enough low-level curvature to support some tornado potential if the storm can become surface-based. Otherwise, the primary risk with this storm is large hail. Limited severe coverage will likely preclude the need for a watch, but convective trends are being monitored closely. A greater severe risk is anticipated later this evening as the line of storms moving out of IA moves into the region. ..Mosier/Guyer.. 05/21/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...GRB...MKX...ARX... LAT...LON 42718888 42989012 44149022 44618904 44148788 43108817 42718888 NNNN