Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Wed Aug 23 2023 16:29:24 ACUS01 KWNS 231629 SWODY1 SPC AC 231628 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1128 AM CDT Wed Aug 23 2023 Valid 231630Z - 241200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS LOWER GREAT LAKES AND NORTHERN ND... ....SUMMARY... Scattered damaging winds and large hail, and a tornado or two will be possible across parts of the Lower Great Lakes and northern North Dakota, centered on this evening into tonight. ....Lower Great Lakes... A relatively low confidence but conditionally favorable environment for severe storms is expected through tonight with above-average spread in potential outcomes from minimal coverage to a mesoscale-focused swath of fairly numerous reports. Elevated convection is ongoing across eastern Lower MI to southern ON. This may not entirely decay during the afternoon, with a threat for isolated, marginally severe hail and strong wind gusts potentially persisting southeastward in eastern OH/western PA. To the west, a very unstable air mass will gradually advect east across much of southern Lower MI through western OH in tandem with an EML expanding from the Upper Midwest. A substantial baroclinic zone supported by pronounced differential boundary-layer heating will yield a sizable thermal gradient across the northwest to southeast-oriented warm front. The surface warm sector should remain capped but there are a few models, namely the 12Z ARW-NSSL and 00Z ECMWF which suggest convection should develop along the warm front and into the warm sector. The more probable scenario is for regenerative elevated convection to increase again after sunset. Forecast soundings suggest that deep-layer flow may remain relatively constant with height near the warm front which would limit cloud-bearing shear, with more favorable deep-layer shear farther east coincident with lesser instability. As such, a cluster convective mode will likely dominate with relatively equal threats for large hail and damaging winds. ....ND... An MCV over southeast SK will move east across southern MB into northwest ON tonight. While the bulk of convection attendant to this MCV may remain north of the international border, trailing development into ND will become increasingly likely towards early evening along the apex of a differential boundary-layer heating corridor centered over central ND. There should be favorable zone for a couple supercells across a portion of north-central to northeast ND within the MLCAPE/CIN gradient that should orient from northwest to southeast. Large hail, isolated severe wind gusts, and a tornado or two will be possible during the evening before convection tends to weaken overnight closer to the Red River Valley. ...Grams/Moore.. 08/23/2023 $$ = = = 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) .