Subj : MESO: Mesoscale Discussion 2007 To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Thu Aug 17 2023 01:24:38 ACUS11 KWNS 170124 SWOMCD SPC MCD 170123=20 MNZ000-WIZ000-IAZ000-170300- Mesoscale Discussion 2007 NWS Storm Prediction Center Norman OK 0823 PM CDT Wed Aug 16 2023 Areas affected...portions of southern Minnesota into far northern Iowa Concerning...Severe potential...Watch unlikely=20 Valid 170123Z - 170300Z Probability of Watch Issuance...20 percent SUMMARY...Thunderstorms may pose an isolated severe risk for hail and or a few strong wind gusts this evening. A WW is not anticipated. DISCUSSION...As of 0115 UTC, regional radar analysis showed isolated thunderstorm developing ahead of a southeastward moving cold front over parts of southern/southwestern MN. Ahead of the front, surface temperatures in the low 80s were supporting moderate buoyancy around 2000 J/kg of MLCAPE from the 00z MPX sounding. While unstable, low-level capping was also observed, suggesting storms may be elevated above the surface, or only realizing part of the thermodynamic profile. Regardless, shear profiles are quite strong, with 50-60 kt of effective shear sufficient for organized storms, including supercells. The strongest storms may be capable of isolated hail and a few strong/damaging outflow gusts for a couple of hours this evening. Confidence in the evolution of the severe risk is low, and related mainly to uncertainties about the thermodynamic environment. Thus far, storms have remained closely tied to the cold front, likely aided by frontal circulations in forcing ascent through the low-level stable layer. This trend appears likely to continue, with updrafts located along the advancing front. This would tend to favor undercutting and a transition to elevated convection with time. Farther east, cooler temperatures and higher inhibition are also less favorable for near-surface based convection. Thus, a small window (next 1-2 hours) may exist for isolated hail and perhaps a few damaging gusts if the more organized storms can remain along the front this evening. However, given the uncertainties and the relatively confined severe risk, a new watch appears unlikely. ...Lyons/Guyer.. 08/17/2023 ....Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!9Ip5jV8L8rqyiqTJlKrfIk2Nry2pDRK-IIy7ZPVLPrS8E1-VcETvTehwFbZyvoqbmC_PuwIhj= jXbf4T9YxOApf914r4$ for graphic product... ATTN...WFO...ARX...MPX...DMX...FSD... LAT...LON 44699241 44359224 43859242 43569270 43389325 43299374 43269419 43299462 43359497 43469522 43609543 43839552 44009519 44249452 44629396 45039338 44899282 44699241=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) .