Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sun Jan 29 2023 19:48:05 ACUS01 KWNS 291948 SWODY1 SPC AC 291946 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0146 PM CST Sun Jan 29 2023 Valid 292000Z - 301200Z ....THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS THROUGH THIS EVENING FROM SOUTHEAST TX EASTWARD ALONG THE NORTHERN GULF COAST... ....SUMMARY... Isolated strong-severe storms are possible through this evening from southeast Texas eastward along the northern Gulf coast. ....Southeast TX to the northern Gulf coast through this evening... A marine warm front has drifted northward to near Houston, and extends eastward along the LA coast to the extreme northeast Gulf of Mexico. This boundary is unlikely to move much farther north, given continued reinforcement of the cool air north of the boundary by widespread rainfall. South of the boundary, surface dewpoints of 68-70 F characterize the warm sector, with temperatures in the low-mid 70s, which are contributing the MLCAPE of 500-1000 J/kg. Deep-layer vertical shear is sufficient for supercells, though hodographs are largely straight and low-level shear will remain relatively weak. The peak for thunderstorm coverage will occur this afternoon as a diffuse midlevel trough ejects east-northeastward over TX, with a gradual decrease expected this evening into tonight along the marine front inland from the northern Gulf coast. The severe threat will be on the lower margins for an outlook area, given poor midlevel lapse rates and relatively weak low-level shear. ...Thompson.. 01/29/2023 ..PREV DISCUSSION... /ISSUED 1028 AM CST Sun Jan 29 2023/ ....Gulf Coast including Southeast Texas to Florida Panhandle... Recent satellite imagery shows a low-amplitude shortwave trough entering TX Hill Country/South TX. This lead shortwave is expected to continue east-northeastward throughout the day, moving across central and east TX and into the Lower MS Valley. A broad area of low-level warm-air advection precedes this shortwave, supporting elevated showers and thunderstorms from southeast TX across much of the Lower MS Valley and into the central Gulf Coast. Recent surface analysis places the main frontal low near TYR in northeast TX, but another more subtle secondary low appears to be centered about 20 mi north of VCT. A warm front arcs northeastward and then eastward from this second low, delineating a more maritime air mass characterized by low/mid 70s temperatures and upper 60s dewpoints. This warm and moist air mass would be more supportive of surface-based storms with any storms to its north expected to remain elevated. Inland penetration of this more maritime air mass will be tempered by abundant cloud cover and continuing precipitation, likely confining the risk for surface-based storms to the middle and upper TX Coast, and perhaps the immediate coastal portions of southwest LA, this afternoon and into this evening. Damaging wind gusts associated with bowing line segments are the primary severe risk with these surface-based storms, but a brief tornado or two is also possible. The maritime air mass is expected to continue moving inland this evening father east across portions of the central Gulf Coast and the FL Panhandle. Warm-air advection will likely remain the primary forcing mechanism, keeping the majority of storms elevated north of more buoyant air mass. That being said, mesoscale ascent attendant to the eastward-progressing secondary low could still support a few surface-based storms. The environment is expected to remain favorable for bowing line segments capable of damaging wind gusts and perhaps a tornado or two. $$ = = = 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) .