Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue Oct 03 2023 16:32:39 ACUS01 KWNS 031632 SWODY1 SPC AC 031630 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Tue Oct 03 2023 Valid 031630Z - 041200Z ....THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS PARTS OF WEST AND CENTRAL KS INTO SOUTH-CENTRAL NE... ....SUMMARY... Scattered severe thunderstorms capable of producing a few tornadoes, very large hail, and damaging wind gusts are most probable later this afternoon into this evening, centered on the central Great Plains. ....Central Great Plains... Multiple rounds of scattered to widespread thunderstorms are expected this afternoon and evening, yielding a messy, multifaceted severe weather scenario. Initial ascent along the leading edge of the High Plains buoyancy plume has supported persistent shower and isolated thunderstorms from the eastern OK Panhandle to the north-central KS/south-central NE border area. Most 12Z HREF guidance suggest intensifying thunderstorms will probably evolve in the immediate wake of this activity with the bulk of greater destabilization occurring to its west amid steepening mid-level lapse rates, with decreasing buoyancy ahead of it. Modest mid-level lapse rates and inverted-v low-level thermodynamic profiles downstream should support a threat for mostly isolated severe hail and wind along the leading edge. There will be potential for more intense supercell development along the southwest backside of this initial lobe, around the southwest to south-central KS vicinity, as a plume of MLCAPE from 2000-2500 J/kg impinges on this region from the eastern TX Panhandle and western OK. This could favor a threat for isolated very large hail up to baseball size during the late afternoon to early evening. The primary lobe of ascent attendant to the shortwave impulse ejecting onto the central High Plains from the Front Range should initiate scattered thunderstorms in a few hours as it impinges on the buoyancy plume. This activity should further intensify along the surface front across far northeast CO and northwest KS into central NE later this afternoon. A plume of upper 50s to low 60s surface dewpoints and steep mid-level lapse rates will support supercells conditionally capable of producing significant severe hail. However, consensus of CAM guidance suggests relatively quick upscale growth may occur given the strong forcing for ascent and deep-layer shear vector generally paralleling the surface front. In addition, the gap between these front-aided storms and those within the downstream warm-advection plume should shrink during the evening, further lowering confidence on sustaining discrete supercells. A mix of large hail and severe wind gusts should be the main threats, with convection weakening to the north and east given the expected sharpness of the instability gradient towards the Mid-MO Valley. ....Southern Great Plains... Isolated to scattered thunderstorms appear most probable along the trailing periphery of the KS convective plume into northwest OK, and separately near the dryline in the Permian Basin vicinity during the late afternoon and farther northeast into northwest TX this evening. Mid-level lapse rates with southern extent will be increasingly modest relative to typical severe weather setups along the dryline, suggesting that hail magnitudes may struggle beyond golf ball size. A more favorable wind profile/lapse rate combination for significant severe hail will exist in the eastern TX Panhandle and western OK vicinity, but storm coverage is more questionable here. Overall, there will be sufficient vertical shear/buoyancy for splitting supercells capable of producing large hail and localized severe wind gusts through late evening. ....South-central ND vicinity... A corridor of weak surface-based buoyancy should develop downstream of a shortwave impulse gradually shifting east from the MT/WY/Dakotas border area. Steep mid-level lapse rates and elongation to the hodograph within the upper portion of the buoyancy profile could support a few cells producing marginally severe hail during the late afternoon to early evening. ...Grams/Bentley.. 10/03/2023 $$ = = = 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) .