Subj : DAY2SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sat Jan 28 2023 06:47:25 ACUS02 KWNS 280647 SWODY2 SPC AC 280645 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1245 AM CST Sat Jan 28 2023 Valid 291200Z - 301200Z ....THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PARTS OF THE UPPER TEXAS COAST/EAST TEXAS INTO THE CENTRAL GULF COAST STATES... ....SUMMARY... Isolated strong to severe thunderstorms appear possible Sunday across parts of the upper Texas Coast/east Texas into the central Gulf Coast states. Some hail may occur with thunderstorms in east Texas. Otherwise, occasional damaging winds and a couple of tornadoes should be the main threats. ....Upper Texas Coast/East Texas into the Central Gulf Coast States... Mainly elevated thunderstorms will probably be ongoing Sunday morning from parts of the upper Texas Coast into the lower MS Valley. This activity will largely be tied to modest warm advection associated with a 25-35 kt southwesterly low-level jet, and it may pose an isolated threat for marginally severe hail as MUCAPE gradually increases through the morning. A lead impulse embedded within broadly cyclonic mid-level flow is forecast to develop northeastward from the MS Valley towards the East Coast through the day. A southern-stream shortwave trough should advance from TX across the lower MS Valley and Southeast through the period. In response to these developments, a broad and somewhat unfocused area of modestly enhanced southwesterly low-level winds will overspread parts of the central Gulf Coast states by Sunday evening. A surface cold front should advance slowly southeastward over central/east TX through Sunday night. Latest guidance suggests that mid to upper 60s surface dewpoints will attempt to spread northward in tandem with a marine warm front across parts of LA, coastal/southern MS/AL, and the FL Panhandle. Even though instability will likely remain weak owing to poor mid-level lapse rates and limited diurnal heating, around 500-750 J/kg of MLCAPE should be sufficient to support a threat for surface-based thunderstorms. 40-50 kt of deep-layer shear will easily support convective organization, and around 100-200 m2/s2 of 0-1 km SRH should also foster some low-level updraft rotation. The morning convection associated with the low-level jet should spread eastward across LA/MS/AL through the day. Much of this activity will remain elevated to the north of the surface warm front. But, there is a chance for surface-based thunderstorms to occur across parts of southern LA into coastal/southern MS/AL and the FL Panhandle, especially where surface dewpoints can reach into the upper 60s as some guidance suggests. Occasional damaging winds and a couple of tornadoes should be the main threats as convection moves eastward Sunday afternoon through Sunday night. Additional thunderstorms may develop Sunday afternoon along/near the cold front in east TX. Somewhat steepened mid-level lapse rates emanating from northern Mexico should overspread this region. With a broad mid-level southwesterly jet persisting over much of TX into the lower MS Valley, strong deep-layer shear combined with 500-1000 J/kg MLCAPE (locally stronger) should support an isolated threat for severe hail with any discrete cells that can develop. Occasional damaging winds may also occur as these thunderstorms move into the upper TX Coast and southwestern LA through early Sunday evening. Large-scale forcing aloft will be somewhat nebulous across this region in the wake of the southern-stream shortwave trough and as the low-level jet shifts eastward through the day. Still, isolated thunderstorms appear possible as low-level convergence increases along the cold front by late Sunday afternoon. ...Gleason.. 01/28/2023 $$ = = = 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) .