Subj : DAY2SVR: Enhanced Risk S To : All From : Mike Powell Date : Mon Apr 08 2024 08:22:00 ACUS02 KWNS 080554 SWODY2 SPC AC 080553 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1253 AM CDT Mon Apr 08 2024 Valid 091200Z - 101200Z ....THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS IN SOUTHEAST TX TO WEST LA... ....SUMMARY... Severe thunderstorms are expected from Tuesday into early morning Wednesday across most of Texas towards the Lower Mississippi River Valley. Several tornadoes, a couple of which should be strong, significant large hail, and damaging winds are likely. ....Synopsis... A shortwave trough centered near the AZ/NM/northwest Mexico border area at 12Z Tuesday will progress steadily eastward into west TX by early Wednesday. Two separate mid-level speed maxes, one curling through the base of the trough and another farther east closer to the northwest Gulf Coastal Plain will gradually translate eastward, likely phasing by 12Z Wednesday. As this occurs, multiple surface lows should consolidate into a primary cyclone in the southeast TX vicinity early Wednesday. ....TX/LA... Several rounds of deep convection are expected across a large portion of TX towards the Ark-La-Tex and Lower MS Valley vicinity during the period. A corridor of enhanced severe potential is evident across a part of southeast TX into west LA, where the environment should be most favorable for regenerative supercells and organized clustering. An MCS will likely be ongoing at 12Z Tuesday in the Ark-La-Tex to Ark-La-Miss vicinity with scattered to widespread convection trailing westward into west TX. An isolated supercell or two may be ongoing in the south-central TX area as well. Primary convective coverage during the day will be tied to the persistent low-level warm theta-e advection regime, with regenerative periods of convection expected across at least east TX to the Ark-La-Miss. Surface heating of a richly moist Gulf air mass to the south of the convective plume, coupled with steep mid-level lapse rates from 8-9 C/km should support a broad swath of moderate to large buoyancy by afternoon. This will yield an uptick in severe storms in a portion of southeast TX to west LA. Although convective mode should predominately consist of clusters, embedded supercells are expected within a favorable low-level hodograph and deep-layer shear, supporting all severe hazards. Farther west, isolated convective redevelopment should occur during the early evening along the trailing outflow boundary intersection with the dryline/surface trough in the central TX vicinity. Low-level shear should be substantially weaker relative to the Sabine Valley, but the favorable deep shear/thermodynamic environment should yield a threat for significant severe hail. An increase in storm coverage is expected Tuesday night across south-central TX to southwest LA. Overall tornado potential should be centered on the Sabine Valley, with potential for discrete warm-sector supercells merging into the residual large-scale outflow boundary. A couple strong tornadoes will be possible. Finally, in west TX, early-day large hail potential should subside for a time, before additional storms refire later into the afternoon near the mid-level trough. While surface winds should largely be northerly by this time, adequate buoyancy within the approaching mid-level cold pocket will yield a renewed threat for large hail. This should wane after dusk. ....Lower Great Lakes... The drifting mid/upper low over the Upper Great Lakes/northern Ontario will aid in scattered showers and lower-topped thunderstorms across the Lower Great Lakes vicinity on Tuesday afternoon. A plume of low-level moisture being advected northeast from the Lower MS Valley, coupled with differential boundary-layer heating south of the stratocu field attendant to the northwest Ontario surface cyclone, should yield a plume of MLCAPE around 500 J/kg. Adequate speed shear within the deep-layer southwesterly flow regime should support a threat for isolated severe hail and locally strong gusts. ...Grams.. 04/08/2024 $$ --- SBBSecho 3.20-Linux * Origin: ILink: CCO - capitolcityonline.net (454:3/105) .