Subj : DAY2SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sun Jan 01 2023 06:56:52 ACUS02 KWNS 010656 SWODY2 SPC AC 010655 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1255 AM CST Sun Jan 01 2023 Valid 021200Z - 031200Z ....THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM SOUTHEAST OKLAHOMA AND NORTHEAST TEXAS INTO NORTHWEST LOUISIANA AND SOUTHERN/CENTRAL ARKANSAS... ....SUMMARY... Severe thunderstorms are expected Monday and Monday night from eastern Oklahoma and Texas into Louisiana and Arkansas and vicinity. Damaging gusts and tornadoes will be the main hazards with these storms. ....Eastern OK/TX to the Lower MS Valley Vicinity... A large-scale upper trough over the Rockies/Four Corners vicinity Monday morning will shift east across the Plains through the period. A closed low may develop over the central Plains, with the base of the trough becoming more negatively tilted as it pivots east/northeast over the southern Plains and Ozark Plateau. A belt of strong southwesterly deep-layer flow will overspread the region, with a 50+ kt south/southwesterly low-level jet oriented over the ArkLaTex vicinity into the Mid-MS Valley from late afternoon into the nighttime hours. At the surface, low pressure will deepen over the central High Plains and shift east/northeast toward IA through the period. A tight pressure gradient across the south-central U.S. will support strong southerly low-level flow. This will result in mid/upper 60s dewpoints advancing as far north as roughly the I-40 corridor from eastern OK through AR, and low 60s into northeast OK and southern MO. Cloud cover in a strong warm advection regime will limit heating, and thus instability. However, forecast guidance tends to have a cool bias in surface temperature during the cool season. Adjusting forecast soundings for this likely under-forecast in high temperatures, MLCAPE values from around 1000-1500 J/kg are expected from over the ArkLaTex vicinity, with decreasing values further north. A dryline/Pacific front is expected to extend north to south roughly along the I-35 corridor by afternoon from central OK into central TX. The boundary will shift east through the period, becoming positioned from central MO into southwest AR and then approaching the TX coast by Tuesday morning. Forecast guidance suggests a weak lead impulse may track over the region during the late morning/early afternoon before the main trough and surface front shift east during the evening/overnight. This may result in a couple of bands or multiple waves of storms. Storm mode is a bit uncertain, but a mix of supercells and line segments appears most likely. Vertical shear will support rotating convection, with enlarged and favorably curved low-level hodograph apparent in forecast soundings. Damaging gusts and several tornadoes (a couple potentially significant/EF2+) will be the main hazards Monday afternoon, into the nighttime hours. Isolated hail also is possible with supercells. A more marginal hail threat extends northward into southeast KS/central MO near the upper low within strong ascent and colder midlevel temperatures. ...Leitman.. 01/01/2023 $$ = = = 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) .