Subj : MESO: Mesoscale Discussion 2037 To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Thu Aug 24 2023 19:47:31 ACUS11 KWNS 241947 SWOMCD SPC MCD 241946=20 ILZ000-WIZ000-242145- Mesoscale Discussion 2037 NWS Storm Prediction Center Norman OK 0246 PM CDT Thu Aug 24 2023 Areas affected...Southeast WI...Northeast IL Concerning...Severe potential...Watch unlikely=20 Valid 241946Z - 242145Z Probability of Watch Issuance...20 percent SUMMARY...Isolated strong to severe thunderstorm development is possible across southeast WI and northeast IL this afternoon. DISCUSSION...Recent surface analysis places a low near UNU in southeast WI, just ahead of a weak front moving southward/southeastward through southern WI. This front is demarcated better by the wind field, which shows a shift to more westerly/northwesterly winds, than temperature field, which shows little discontinuity. The air mass across the region is very warm and moist, with numerous observations reporting mid/upper 90s temperatures amid upper 70s and low 80s dewpoints. This warm and moist airmass sits beneath relatively steep mid-level lapse rates, contributing to strong to extreme buoyancy. Recent mesoanalysis estimates MLCAPE over 4000 J/kg across much of northern IL and southern WI. Cumulus has been increasing in the vicinity of this low, and it appears that convective initiation could take place within the next hour or two. Even if storms do initiate, updrafts will be battling significant dry-air entrainment. ECAPE values from forecast soundings are close to 1500-1700 J/kg, a reduction of more than half versus MLCAPE. This suggests many updrafts may not survive to maturity, somewhat limiting the overall severe potential. That being said, any updrafts that can mature could become robust enough to produce significant water loading, with an attendant threat for strong downbursts. Highest probability for thunderstorm development currently appears to be across southeast WI, to the south of the low but west of the lake breeze. Convective inhibition is higher south into northern IL, but a conditional risk for strong/severe storms exists here as well. Given the general uncertainties regarding development, and likely limited coverage, a watch is not anticipated. Convective trends will still be monitored closely. ...Mosier/Grams.. 08/24/2023 ....Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!-OKP28rCp7Gmt825LmICz7HkzBzqv571lHKZQOkrcJCw8ypSKzDqA9yaC6roJkZmMrdhYxt18= BEwtpNP5qCtxPy2syU$ for graphic product... ATTN...WFO...LOT...MKX... LAT...LON 42688945 43468877 43638817 43468800 42818797 41828780 41928919 42688945=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) .