Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue Apr 01 2025 19:45:50 ACUS01 KWNS 011945 SWODY1 SPC AC 011943 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0243 PM CDT Tue Apr 01 2025 Valid 012000Z - 021200Z ....THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS EVENING AND OVERNIGHT ACROSS PARTS OF OKLAHOMA AND KANSAS.... ....SUMMARY... Rapid, intense thunderstorm development should occur this evening over parts of the central/southern Plains. A few supercells with a risk for very large hail and strong tornadoes appear possible, particularly across central Oklahoma into eastern Kansas. A line of thunderstorms should also develop and pose a threat for severe/damaging winds across eastern Kansas into western Missouri tonight. No changes have been made to the ongoing convective outlook severe risk areas. Low-level moisture is streaming northward, roughly in line with model guidance. This will lead to a corridor of strong instability and only weak cap by late afternoon to the east of the surface dryline. Widely scattered intense supercells are expected to develop by early evening along the dryline from central KS into central OK. Very favorable thermodynamic and kinematic parameters suggest all severe hazards are possible with these storms, including very large hail and a strong tornado or two. Overnight, the primary upper trough and associated 100 knot mid-level jet max will move into the Plains states, leading to the development of another round thunderstorms over eastern KS/OK before 12z. These storms will also pose a risk of large hail and a few tornadoes. ...Hart.. 04/01/2025 ..PREV DISCUSSION... /ISSUED 1135 AM CDT Tue Apr 01 2025/ ....OK-TX... Visible-satellite imagery shows stratus and moisture streaming northward through TX into OK on strengthening southerly low-level flow. Increasingly rich moisture around 850 mb layer will mix downward beneath an initially strong capping inversion sampled on 12 UTC area observed soundings. Heating of an increasingly moist and destabilizing boundary layer will result in a very unstable airmass late this afternoon into the early evening. Models show lower 60s dewpoints reaching I-40 by early evening. Very strong and favorable wind profiles for supercells will support rapid supercell development if storms initiate (22-01 UTC). Models differ on the diurnal storm coverage casting considerable uncertainty---but some guidance has trended towards at least one to a few dryline discrete supercells across the southern Great Plains. Very large hail and tornadoes would be the primary hazards. Enlarged and elongated hodographs would support the potential for strong tornadoes provided a sustained supercell develops late this afternoon/evening. Later tonight, models show richer moisture with a very unstable airmass being maintained. Of particular note is forcing for ascent perturbing the airmass from north-central TX into OK near and ahead of the front. A nocturnal risk for renewed supercell development capable of all hazards would be strongly favored with any activity not undercut by the front---mainly during the 08-12 UTC period. ....Central Plains into Missouri... Not much change in thinking from the prior forecast. The cap is forecast to erode on the northern periphery of more appreciable moisture over the central High Plains by late afternoon or early evening. At least isolated thunderstorms are expected to develop near the triple point in the south-central KS/north-central OK vicinity, and subsequently spread quickly northeastward. Moderate to locally strong instability, coupled with 50-60 kt of effective bulk shear, will easily support supercells, with an associated threat for very large hail (up to 2-3 inches in diameter). As the southerly low-level jet markedly increases this evening, hodographs will enlarge and become elongated, with ample effective SRH to support tornadoes with any sustained supercells. Given the strength of the low-level flow expected (50-60+ kt southerly jet at 850 mb) and degree of low-level shear forecast, strong tornadoes appear possible. A line of convection should also erupt along the cold front in north-central to northeast KS tonight, and spread eastward into parts of western MO through early Wednesday morning. Even with the time of night, the overall environment appears quite favorable for severe/damaging winds, including the potential for isolated 75+ mph gusts. ....Central Valley of California... With cold air aloft associated with the upper trough over the western CONUS, weak instability could develop by peak afternoon heating to support isolated strong thunderstorms. These could pose a risk for small hail, gusty winds, and perhaps a brief tornado across portions of the Central Valley in CA. $$ = = = 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) .