Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Fri Mar 03 2023 01:01:27 ACUS01 KWNS 030101 SWODY1 SPC AC 030100 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0700 PM CST Thu Mar 02 2023 Valid 030100Z - 031200Z ....THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTHERN PLAINS...ARKLATEX...AND LOWER TO MID MISSISSIPPI VALLEY... ....SUMMARY... Severe thunderstorms with very large hail to the size of baseballs or larger, significant thunderstorm gusts to 75 mph, and tornadoes with a few strong tornadoes are likely from northeast Texas into the ArkLaTex this evening through tonight. ....Southern Plains/Arklatex/Lower to Mid Mississippi Valley... An upper-level trough is currently evident on water vapor extending from West Texas southward into northern Mexico. An associated 90 to 105 knot mid-level jet is located in the base of the trough. This feature will move northeastward into the lower to mid Mississippi Valley and accelerate substantially tonight. Ahead of the jet, a moist airmass is in place from central and east Texas into the lower Mississippi Valley. A line of severe thunderstorms is ongoing from near the Red River extending south-southwestward into the Texas Hill Country. MLCAPE ahead of the line is estimated by the RAP near 2000 J/kg. This combined with 0-6 km shear near 70 knots and 700-500 mb lapse rates near 8.0 C/km will be favorable for embedded supercells and bowing segments within the stronger parts of the line. Supercells will be capable of large hail and wind damage. Swaths of wind damage will be likely with bowing segments. Winds of greater than 70 knots will be possible along the stronger parts of the line. A tornado threat will also exist with the stronger supercells embedded in the line. Further to the east in the northeast Texas, southern Arkansas, and far northern Louisiana, isolated discrete rotating storms are ongoing. These supercells will be associated with threat for tornadoes, wind damage and hail. The tornado threat is expected to increase as the cells interact with a warm front extending west-to-east across southern Arkansas. Surface dewpoints near and to the south of the front are in the mid to upper 60s F. As the mid-level jet approaches later this evening, forecast soundings rapidly increase 0-3 km storm relative helicities into the 500 to 700 m2/s2 range. The magnitude of the low-level shear will be favorable for tornadoes. The first round of discrete cells will likely move northeastward into central Arkansas become elevated. A second round of discrete cells could form ahead of the squall line in northeast Texas and move across the ArkLaTex late this evening. If this were to occur, a substantial threat for tornadoes will be likely. A few strong tornadoes could develop across far northern Louisiana and southern Arkansas as the low and mid-level jets become coupled later this evening. The squall line will move across the ArkLaTex from late this evening into early tonight, approaching the Mississippi River around 09Z. After this time, a severe threat is expected to continue within the line, and with cells that form ahead of the line, from parts of central Mississippi northward into far western Tennessee. Wind damage, hail and a few tornadoes are expected late in the period. ...Broyles.. 03/03/2023 $$ = = = 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) .