Subj : DAY2SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sun Mar 24 2024 05:54:28 ACUS02 KWNS 240554 SWODY2 SPC AC 240552 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1252 AM CDT Sun Mar 24 2024 Valid 251200Z - 261200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF EAST TEXAS INTO THE LOWER MISSISSIPPI VALLEY... ....SUMMARY... Scattered severe thunderstorms with a threat for a few tornadoes and damaging winds should occur Monday through Monday night from parts of east Texas into the lower Mississippi Valley. ....Synopsis... A highly amplified upper trough will be present over much of the central CONUS into northern Mexico on Monday. Multiple embedded mid-level perturbations should exist within the larger upper trough. One such shortwave trough is forecast to move across the Upper Midwest through the day, and another over northern Mexico and the southern High Plains should eject towards the lower/mid MS Valley through the period. The primary surface low should be located over eastern NE/KS Monday morning, and it is forecast to develop east-northeastward across the Upper Midwest by Monday evening. A weak, secondary surface low may develop across the ArkLaTex and move towards the Mid-South through Monday night as strong ascent associated with the southern/basal portion of the upper trough overspreads the lower MS Valley. ....East Texas into the Lower Mississippi Valley... A line of generally sub-severe thunderstorms will likely be ongoing Monday morning from portions of central TX into eastern OK and the Ozarks. Strong low-level mass response associated with a southerly low-level jet is expected to aid in the northward transport of generally mid to upper 60s surface dewpoints across parts of the lower MS Valley ahead of the early-day convection. Even though mid-level lapse rates should remain rather poor, the increasing low-level moisture combined with modest daytime heating should support the development of weak instability by early Monday afternoon. A gradual uptick in convective coverage and intensity is anticipated Monday afternoon/evening across LA/southern AR and into MS as these thunderstorms encounter somewhat greater instability. Enhanced mid/upper-level flow attendant to the upper trough will easily support 45-60 kt of deep-layer shear and robust updraft organization. Scattered damaging winds should be the main threat with the line of intensifying convection as it moves eastward across the lower MS Valley, although low-level shear also appears strong enough to support line-embedded/QLCS tornadoes. The potential for pre-frontal supercells developing along a weak surface trough or confluence lines remains highly uncertain. Most high-resolution guidance suggests that the QLCS should maintain its intensity, and perhaps even strengthen Monday evening/night across MS as a southerly low-level jet increases to around 45-60 kt. A narrow corridor of greater severe/damaging-wind potential may exist across parts of northeastern LA/southeastern AR into central MS along and just south of the effective warm front. However, confidence in this scenario occurring is not high enough to include greater severe-wind probabilities at this time. A nocturnal tornado threat should continue with the organized QLCS as it moves across MS and towards western AL Monday night through early Tuesday morning, eventually weakening as it encounters a less unstable airmass with eastward extent. ....Western Iowa and Vicinity... Within the larger-scale upper trough over the central states, an embedded, cold-core mid-level shortwave trough will move quickly northeastward across the Upper Midwest Monday. Even though low-level moisture should remain quite limited, most guidance shows low 50s surface dewpoints present near a deep surface low across western IA and vicinity Monday afternoon. Just modest daytime heating will support weak destabilization given the cold mid-level temperatures, and deep-layer shear appears strong enough for somewhat organized thunderstorms. Isolated/marginally severe hail and strong/gusty winds may occur with any sustained low-topped convection. Based on latest guidance trends, the Marginal Risk has been adjusted westward in IA where a better signal for modest destabilization exists Monday afternoon. ...Gleason.. 03/24/2024 $$ = = = 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) .