Subj : DAY2SVR: Marginal Risk To : All From : Mike Powell Date : Sun Mar 03 2024 08:46:00 ACUS02 KWNS 030702 SWODY2 SPC AC 030700 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CST Sun Mar 03 2024 Valid 041200Z - 051200Z ....THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PARTS OF CENTRAL/EAST TEXAS INTO THE LOWER/MID MISSISSIPPI VALLEY AND MIDWEST... ....SUMMARY... Isolated strong to severe thunderstorms will be possible Monday through Monday night from parts of central Texas into the lower Mississippi Valley, as well as the Ozarks into the Midwest. Large hail should be the main threat, but occasional strong/gusty winds may also occur. ....Synopsis... A split flow upper pattern will persist on Monday across the CONUS, with a southern-stream upper jet extending across northern Mexico and parts of the southern Plains through the day. Farther north, broad upper troughing will remain over much of the northwestern states into the northern/central Plains and Upper Midwest. A subtle mid-level shortwave trough moving eastward across TX and the lower MS Valley may encourage convective development through the period, while thunderstorm initiation from the Ozarks into the mid MS Valley/Midwest may be tied more to a southeastward-moving cold front Monday evening through early Tuesday morning. ....Central Texas into the ArkLaTex/Lower Mississippi Valley... A moist low-level airmass will be present along/east of a surface dryline across central TX Monday afternoon. The presence of steep mid-level lapse rates and diurnal heating of the moist airmass will support the development of weak to moderate instability from parts of central/east TX into the lower MS Valley/Mid-South. While mid-level flow is not forecast to be overly strong, it should still be enough to foster some updraft organization with around 25-35 kt of deep-layer shear. The main uncertainty is convective initiation through the day, as a lingering cap and generally weak forcing associated with the ejecting mid-level shortwave trough may keep overall thunderstorm coverage fairly isolated. Still, some guidance suggests that convection will gradually increase in intensity and coverage through Monday evening in a modest low-level warm advection regime. Additional thunderstorms may develop along/east of the dryline extending southward into central TX. Any convection that can initiate may pose an isolated threat for large hail and strong to locally damaging winds as it continues eastward through Monday night. The Marginal Risk has been expanded westward into parts of central TX to account for the possibility of isolated initiation along the dryline. But, confidence in a corridor of greater severe potential remains too low to include higher severe hail probabilities across this region. ....Ozarks into the mid Mississippi Valley and Midwest... Elevated thunderstorms may be ongoing Monday morning across parts of IA and vicinity, associated with a northeastward-ejecting shortwave trough embedded within the larger upper troughing present over the northern/central Plains. This activity is expected to remain elevated as it continues northeastward across the Upper Midwest through the day. At the surface, a weak low is forecast to develop northeastward from the central Plains to the Midwest along a southeastward-advancing cold front. Modest low-level moisture, with surface dewpoints generally in the mid to upper 50s, should advance northeastward through the period ahead of the front. Even with the quality of the low-level moisture remaining limited, somewhat steepened mid-level lapse rates should aid in at least weak MUCAPE developing by Monday evening. While the stronger mid/upper-level southwesterly flow will likely remain displaced to the cool side of the front, sufficient deep-layer shear to support updraft organization should be present over the warm sector extending from the Ozarks into the mid MS Valley/Midwest. Most guidance shows a convective precipitation signal along the front beginning Monday evening and continuing through early Tuesday morning. Isolated severe hail may occur with any of the stronger cells that can develop and remain at least semi-discrete. Occasional strong/gusty winds may also occur, even though low-level stability from nocturnal cooling of the boundary layer may mostly hinder convective downdrafts from reaching the surface. ...Gleason.. 03/03/2024 $$ --- SBBSecho 3.20-Linux * Origin: ILink: CCO - capitolcityonline.net (454:3/105) .