Subj : DAY1SVR: Day 1 Convective Outlook Corr 1 To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Wed Oct 30 2024 06:17:09 ACUS01 KWNS 300617 SWODY1 SPC AC 300615 Day 1 Convective Outlook CORR 1 NWS Storm Prediction Center Norman OK 0115 AM CDT Wed Oct 30 2024 Valid 301200Z - 311200Z ....THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF EASTERN KANSAS INTO FAR NORTHEASTERN OKLAHOMA AND NORTHWESTERN MISSOURI... CORRECTED FOR NDFD GRAPHIC ....SUMMARY... Strong/severe thunderstorms, capable of producing large hail, damaging wind gusts, and a few tornadoes, are expected today into early tonight, particularly from the middle Missouri Valley area into the southern Plains. ....Synopsis... A pronounced mid-level trough will traverse the Plains and become negatively tilted as it impinges on the Upper MS Valley today. Surface lee-troughing will remain in place across the Plains, resulting in the northward transport of an appreciably moist low-level airmass. A surface low will develop along the KS/OK border this afternoon and track toward the MS Valley this evening. A cold front will be draped across the MS Valley into KS while a dryline, extending from the low, is poised to sweep eastward across OK and northern TX through the day. Deep-layer ascent along and ahead of the cold front and dryline will support at least scattered thunderstorm initiation by late afternoon across the Plains. These storms will progress eastward amid a buoyant and highly sheared airmass. Severe storms are likely ahead of the cold front and dryline, with all hazards possible. ....Upper MS Valley into the southern Plains... Thunderstorms are expected to first initiate along the cold front over northern KS into western IA by mid to late afternoon as stronger upper-level support from the impinging mid-level trough overspreads the terminus of a 50+ kt southerly low-level jet. 7+ C/km mid-level lapse rates, overspreading rich low-level moisture (including mid-60s F surface dewpoints), should yield at least 1500 J/kg SBCAPE. Strong southwesterly 500 mb flow overspreading the low-level jet will contribute to 50+ kts of effective bulk shear, but with vectors aligned roughly parallel with the front. Initial semi-discrete storm modes, capable of mainly severe wind/hail, will quickly merge to form a QLCS with embedded bowing segments and perhaps a few mesovortices. This initial band of storms should approach the MS Valley region by sunset, accompanied by mainly damaging gusts and perhaps an isolated tornado threat. Farther south into central KS/northern OK, more discrete thunderstorm development is expected by early evening. Surface temperatures in the upper 70s F, combined with mid to perhaps upper 60s F dewpoints, will contribute to 1500-2000 J/kg MLCAPE just before sunset. Storms that can mature in this environment may benefit from over 50 kts of effective bulk shear, as well as an increase in low-level shear upon approaching the western periphery of the low-level jet. Forecast soundings depict overall curved low-level hodographs with mid-level elongation and 250-350 m2/s2 effective SRH. As such, supercells should be the initial storm mode before storm mergers result in squall line development. While many forecast soundings depict a weakness in the 800-600 mb layer, the overall strength of the low-level shear suggests at least a few tornadoes are possible, and a strong tornado or two may occur, mainly after dark. The severe threat may transition to more of a damaging gust threat after the squall line forms, though line-embedded QLCS tornadoes remain possible. ...Squitieri/Lyons.. 10/30/2024 $$ = = = 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 3.20-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .