Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue Apr 01 2025 12:52:22 ACUS01 KWNS 011252 SWODY1 SPC AC 011250 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0750 AM CDT Tue Apr 01 2025 Valid 011300Z - 021200Z ....THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTHERN/CENTRAL PLAINS... ....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 north-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. ....Synopsis... Upper troughing over the western CONUS will undergo amplification today as multiple embedded mid-level shortwave troughs move east-northeastward across the Southwest and into the central/northern Plains. A pronounced southwesterly mid-level jet will also overspread the southern/central Plains this evening and overnight. Low-level moisture centered around 850 mb has been streaming northward this morning across TX in association with a strong southerly low-level jet. Surface dewpoints have also been increasing across the Rio Grande Valley into south-central TX. This trend is expected to continue through the day, as a surface low deepens as it develops from eastern CO into western KS through the afternoon. This low is forecast to further develop/reform across southwest KS into northwest OK as ascent associated with the mid-level jet overspreads the High Plains. A dryline will extend southward from this low across western OK into northwest TX. A cold front is expected to sweep east-southeastward over much of the central Plains and southern High Plains overnight, as the surface low develops northeastward towards eastern NE/western IA by early Wednesday morning. ....Central Plains into Missouri... It appears likely that the cap will erode 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. The Enhanced Risk has been expanded east-northeastward some across eastern KS into western MO to account for this scenario. ....Southern Plains... There is somewhat less confidence in convective initiation farther south into central/southern OK and western north TX late this afternoon and early evening. While low-level moisture will be greater across this area compared to locations farther north, with related stronger instability, large-scale ascent is forecast to be a bit weaker/delayed. Even so, a very favorable thermodynamic and kinematic environment will exist across this region, with MLCAPE ranging generally 2000-3000 J/kg by late afternoon, and 50+ kt of effective bulk shear present. Any supercell that initiates along the dryline, and which can be sustained into the early evening, would pose a risk for both very large hail and a strong tornado. While overall thunderstorm coverage may be more isolated with southward extent in OK, have opted to expand the Enhanced Risk southwestward along the I-44/I-35 corridors to account for an intense supercell or two which could form. Another round of severe convection may develop late tonight into early Wednesday morning as the cold front surges east-southeastward. Severe/damaging winds should be the main threat with this activity if it forms. But, given the strong low-level shear and ample MUCAPE forecast, tornadoes and perhaps large hail will also be a concern with any embedded supercells. ....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 or two across portions of the Central Valley in CA. ...Gleason/Leitman.. 04/01/2025 $$ = = = 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) .