Subj : DAY2SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Wed Mar 15 2023 06:02:00 ACUS02 KWNS 150601 SWODY2 SPC AC 150600 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Wed Mar 15 2023 Valid 161200Z - 171200Z ....THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF NORTH-CENTRAL/NORTHEAST TEXAS...SOUTH-CENTRAL/SOUTHEAST OKLAHOMA...AND FAR SOUTHWEST ARKANSAS... ....SUMMARY... Scattered severe thunderstorms capable of producing large hail, damaging winds, and a few tornadoes appear likely Thursday into Thursday night across parts of the southern Plains, ArkLaTex, and lower Mississippi Valley. Some of the hail could be very large over south-central Oklahoma and north-central Texas. ....Southern Plains into the Lower Mississippi Valley... A southern-stream shortwave trough will eject eastward from northern Mexico and the Southwest across the southern Plains and lower MS Valley on Thursday. A lead low-amplitude shortwave trough is also forecast to advance quickly northeastward from the southern Plains to the MS Valley and Midwest through the day. A surface low initially centered over KS should develop northeastward towards the mid MS Valley by Thursday afternoon. A secondary surface low should form over western north TX and shift eastward along/near the Red River through Thursday evening. A cold front will sweep southeastward over much of the southern Plains into the lower MS Valley through the period. A dryline tied to the secondary surface low will mix eastward across central TX through late Thursday afternoon. Low-level moisture characterized by upper 50s to mid 60s surface dewpoints will continue to stream northward ahead of both the cold front and dryline. Some guidance suggests that convection may be ongoing at the start of the period Thursday morning across parts of TX/OK. This activity will be tied to strong lift/warm advection associated with a pronounced low-level jet. Even though they should have a tendency to remain elevated, some of these thunderstorms could pose an isolated threat for hail/wind through the early afternoon as the move quickly northeastward. Otherwise, daytime heating along/near the dryline, but west of any morning convection, should encourage the development of moderate instability across parts of north-central/northeast TX and far southern OK. With steepening lapse rates aloft also expected, MLCAPE of 1500-2500 J/kg seems probable by late Thursday afternoon across this region. Initial convective development near the triple point and southward along the dryline will likely be supercellular given 50+ kt of effective bulk shear forecast. These supercells will pose a threat for large hail, some of which could be 2+ inches in diameter. Somewhat weaker instability farther north in central/eastern OK and western AR should also support a large hail threat with any initially discrete development. Convection will grow upscale into an MCS along the front Thursday evening, with a greater threat for severe/damaging winds, especially across northeast TX/southeastern OK and vicinity. There are still some differences in guidance regarding the strength and placement of a south-southwesterly low-level jet Thursday evening across east TX into the ArkLaTex and lower MS Valley. Most guidance, with the 00Z NAM the notable exception, shows the low-level wind fields gradually weakening/veering with time along/ahead of the front. Regardless, ample low-level shear should be present from late Thursday afternoon through Thursday night to support a threat for a few tornadoes, both with supercells ahead of the front, and with circulations embedded within the line. Additional robust convection should develop across central/ south-central and coastal southeast TX Thursday night into early Friday morning, with a continued threat for mainly damaging winds given the linear mode expected. The eastern portion of the MCS will eventually encounter less instability over the lower MS Valley late in the period, which should result in a gradually lessening damaging wind threat with eastern extent. ...Gleason.. 03/15/2023 $$ = = = 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) .