Subj : MESO: Mesoscale Discussion 0528 To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sat Apr 15 2023 20:22:00 ACUS11 KWNS 152021 SWOMCD SPC MCD 152021=20 ILZ000-KYZ000-MOZ000-ARZ000-152215- Mesoscale Discussion 0528 NWS Storm Prediction Center Norman OK 0321 PM CDT Sat Apr 15 2023 Areas affected...east-central/southeast Missouri and west-central/southwest Illinois Concerning...Severe potential...Watch likely=20 Valid 152021Z - 152215Z Probability of Watch Issuance...80 percent SUMMARY...Severe potential is expected to increase into late afternoon/early evening from east-central/southeast Missouri into west-central/southwest Illinois. A watch will likely be needed in the next couple hours. DISCUSSION...A broken line of severe supercells continues to develop and shift east/northeast across southwest into central MO and western AR across WW 138. East of the watch, airmass recovery has been slower due to earlier day convection. However, plenty of heating through the afternoon has allowed temperatures to warm into the mid/upper 70s with dewpoints increasing into the low 60s (mid/upper 60s further south toward the MS/OH River confluence/southeast MO vicinity). Combined with steep midlevel lapse rates, MLCAPE values have increased to around 1000-1500 J/kg late this afternoon, with some further destabilization expected.=20 The expectation is that the supercell clusters further west will develop upward into a bow/QLCS as convection approaches the MS River/southeast MO. While some hail potential will continue, this upscale development will support an increasing threat for swaths of damaging gusts. Current KLSX VWP data indicate larger than previously expected low-level hodographs, with forecast guidance also indicating a corridor of greater low-level SRH extending southward along the MS River vicinity through this evening. If backed low-level winds persist, this could indicated some greater potential for mesovortex tornadoes as the line of convection surges eastward this evening.=20 Timing is a bit uncertain as visible satellite indicated some attempts at convective development across central MO ahead of the ongoing supercells. If this activity develops further, a watch may be needed sooner downstream from WW 138. Regardless, a watch is expected across the MCD area in the next couple of hours. ...Leitman/Grams.. 04/15/2023 ....Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!6s8KCgkjoA8q0jtCOKOW2xdBNUBxZeE0m53V8el9kZdIXs06Fub2dYW0w_89EEhG81uSCbToX= JJJmPcoELQgVqAhKOM$ for graphic product... ATTN...WFO...PAH...ILX...MEG...LSX... LAT...LON 38999122 39159129 39339121 39419096 39519055 39569019 39328973 38978931 38628908 38028898 37608897 37188896 36848931 36608972 36479024 36589077 36979085 37689071 38479083 38839101 38999122=20 =3D =3D =3D To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM. --- SBBSecho 3.14-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .