Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sun Dec 24 2023 12:32:00 ACUS01 KWNS 241231 SWODY1 SPC AC 241230 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0630 AM CST Sun Dec 24 2023 Valid 241300Z - 251200Z ....NO SEVERE THUNDERSTORM AREAS FORECAST... ....SUMMARY... Severe thunderstorms are not forecast through tonight across the contiguous United States. ....Synopsis/Discussion... In mid/upper levels, a series of shortwave troughs will reinforce mean troughing over the central CONUS through the period, with these being the main influences: 1. A northern-stream perturbation -- apparent in moisture-channel imagery across eastern/southern SK, west-central MT, to near Star Valley in westernmost WY. The southern part of this perturbation should move eastward then break south-southeastward from the main northern-stream belt, and intensify considerably tonight. The net result by 12Z should be a deepening, closed cyclone centered over the BFF/SNY vicinity. The resulting large, synoptic cyclone will be a dominant pattern feature over the central/eastern CONUS for several more days. 2. A southern-stream trough now located near a CAO-CVS-PRS axis and over northeastern Chihuahua. This feature should move eastward and become negatively tilted today, reaching near a LBL-LTS-CLL axis by 00Z. As heights fall and synoptic gradients strengthen in advance of the northern Plains cyclogenesis, this trough will pivot to near a SLN-FYV-GLH axis by 12Z tomorrow. At the surface, 11Z analysis showed a low over west-central KS, along an Arctic front extending from a separate low near FSD to northeastern NM. A Pacific front was drawn from the KS low across extreme western OK, northwest TX, to the Big Bend region and west-central MX. By 00Z, the Arctic front should extend from central MN to south-central OK and the Permian Basin region of west TX and southeastern NM. The Pacific front should be moving more slowly eastward over southern OK, central TX and the middle TX Coast, with a wind shift and some surface veering ahead of the front in east TX. The strongest convective forcing should continue to occur over prefrontal (both fronts) areas with diurnal heating substantially restricted by clouds/precip, minimal to no surface-based buoyancy, marginal elevated instability to support thunder, and mostly messy convective modes. Areal/organized severe-thunderstorm potential should remain (and shift eastward) over the open waters of the northwestern and north-central Gulf, under the left-exit region of a subtropical-jet segment. There, vertical shear will be favorable, and sea-air fluxes should contribute to relatively maximized theta-e and buoyancy in the storm environment. Over land, however, severe potential appears to low for an unconditional outlook. ...Edwards/Broyles.. 12/24/2023 $$ = = = 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) .