ZCZC SPCSWOMCD ALL ACUS11 KWNS 010038 SPC MCD 010038 INZ000-ILZ000-010245- Mesoscale Discussion 0318 NWS Storm Prediction Center Norman OK 0738 PM CDT Sun Mar 31 2024 Areas affected...portions of central Illinois into western Indiana Concerning...Severe potential...Watch unlikely Valid 010038Z - 010245Z Probability of Watch Issuance...20 percent SUMMARY...A long-lived supercell may persist for at least a few more hours across central and eastern IL into western IN with severe hail. The severe weather threat is expected to remain localized through evening. DISCUSSION...A long-lived supercell continues to traverse a diffuse warm-front over central IL, where upper 60s/mid 50s F surface temperatures/dewpoints are boosting MLCAPE/MUCAPE to 500 J/kg (per 00Z mesoanalysis). Though CAPE profiles are thin (based on the latest RAP forecast soundings and the 00Z observed ILX sounding), modestly curved low-level hodographs with mid/upper-level elongation suggest that vertical wind shear remains strong (i.e. 60+ kts of effective bulk shear). While the supercell will likely remain outflow dominant, efficient severe hail production should continue for at least a few more hours across central IL into western IN before the low-level jet veers, reducing convergence along the front and potentially supporting weakening convective potential later this evening. In the meantime, the severe threat may be constrained to this lone supercell. Convective trends will continue to be monitored for the need of a WW issuance, but current thinking is that the severe threat should remain localized over central IL/IN this evening. ..Squitieri/Guyer.. 04/01/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...IND...ILX... LAT...LON 39588894 39878942 40138937 40228902 40108806 39808662 39678615 39308599 38978631 39018688 39268815 39588894 NNNN