ZCZC SPCSWOMCD ALL ACUS11 KWNS 011735 SPC MCD 011735 ILZ000-MOZ000-IAZ000-011930- Mesoscale Discussion 0319 NWS Storm Prediction Center Norman OK 1235 PM CDT Mon Apr 01 2024 Areas affected...Portions of northern Missouri into central Illinois Concerning...Severe potential...Watch possible Valid 011735Z - 011930Z Probability of Watch Issuance...60 percent SUMMARY...An increase in storm coverage is expected along/north of a warm front this afternoon. Large to very large hail will be the initial threat. A greater tornado threat can be expected late afternoon/early evening with discrete storms near the boundary.On or more watches are possible this afternoon, but timing is not certain. DISCUSSION...The 12Z observed ILX sounding showed moderately steep mid-level lapse rates. As the warm front has lifted northward within the mid-Mississippi Valley, substantial low-level moistening has occurred in parts of central Illinois. With time, this boundary is expected to continue to lift northward. Initial weak, elevated convection has developed in northern Missouri and central Illinois. This activity should remain sub-severe in the short term. As destabilization continues into the afternoon, some of these storms may become surface based. Given the wind profiles and lapse rates, large hail would be possible. Very-large (2+ in.) hail could occur with the stronger supercells. Storms north of the warm front will remain elevated. Some increase in coverage and intensity appears possible as theta-e advection aloft increases as the 850 mb low deepens. There remains some uncertainty as to the exact timing of an increase in storm coverage. Several CAMs suggest coverage increases later in the afternoon as the upper trough moves farther east. The tornado threat will at least initially be low. However, low-level shear will increase late this afternoon/early evening. Storms ongoing near the warm front will consequently have a greater tornado potential at that time. On or more watches are possible this afternoon, but timing is not certain. ..Wendt/Thompson.. 04/01/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...PAH...ILX...LSX...DVN...SGF...EAX... LAT...LON 39109422 39629384 39939340 40399240 40429164 40438910 40298802 39758767 38728788 38228828 38039132 38049180 38619391 39109422 NNNN