Subj : DAY2SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Wed Aug 06 2025 17:29:53 ACUS02 KWNS 061729 SWODY2 SPC AC 061728 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1228 PM CDT Wed Aug 06 2025 Valid 071200Z - 081200Z ....THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS IN ND... ....SUMMARY... Scattered severe thunderstorms are expected from mid-afternoon into the night on Thursday. The most likely corridor is centered on North Dakota where a few tornadoes, very large hail, and significant severe gusts are possible. ....Northern Great Plains... Potential for intense supercells growing upscale into a severe MCS appears increasingly likely across ND, with a swath of scattered supercells possible across eastern MT. A shortwave trough will amplify across the Northwest and northern Rockies with a seasonably vigorous impulse rotating through the base. Downstream mid/upper ridging will shift east from the Dakotas to MN, coincident with expansion of a stout EML characterized by very steep lapse rates. This will overspread increasing boundary-layer moisture from evapotranspiration across the Corn Belt, and yield large to extreme buoyancy from southern ND to the Mid-MO Valley by late afternoon Thursday. A strengthening baroclinic zone along the northwest periphery of the MLCAPE plume should aid in increasing thunderstorm development towards mid-afternoon across western ND. Supercells capable of very large hail and a few tornadoes are possible. The initially zonal and moderate mid/upper flow regime will favor upscale growth. Numerous 12Z CAMs support this scenario with indications of a severe MCS spreading eastward, mainly across ND during the evening before gradually waning overnight in MN. Uncertainty does exist on how far south the MCS may build into SD and how far east the damaging wind threat will be maintained in MN amid nocturnally increasing MLCIN. Scattered thunderstorms will also develop across the higher terrain of southwest/south-central MT by late afternoon to early evening. Initial storms should generally pose a marginal severe threat until they impinge on the western periphery of the eastern MT buoyancy plume in the evening. Deep-layer shear profiles should support mainly discrete supercells with some clustering possible late. A mix of both scattered large hail and severe gusts are possible. The eastern extent of the threat overnight into western ND and far northwest SD should be modulated by the earlier round of supercells/MCS. ....IL to western Upper MI... Nebulous, low-probability severe wind/hail potential is evident along the northeast lobe of the expansive buoyancy plume over the central states on Thursday into Thursday night. Most guidance indicates potential for a minor MCV or two from remnants of late D1 convection, ahead of a mid-level ridge over the Dakotas to MN. These may focus mesoscale corridors of diurnal storm development from IL to western Upper MI, but latitudinal uncertainty is large. In addition, modest low-level warm theta-e advection northeast of the Lower MO Valley to IA jet could support a corridor or two of regenerative convection Thursday night. Amid moderate mid-level northwesterlies, sporadic strong storms are anticipated with a few severe storms possible. ...Grams.. 08/06/2025 $$ = = = 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 3.28-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .