Subj : DAY2SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sat Feb 25 2023 17:42:11 ACUS02 KWNS 251742 SWODY2 SPC AC 251740 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1140 AM CST Sat Feb 25 2023 Valid 261200Z - 271200Z ....THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS OVER WESTERN OKLAHOMA... ....SUMMARY... Significant damaging wind and a few tornadoes are expected from the eastern Texas Panhandle during the late afternoon across much of Oklahoma through the evening, with a wind threat persisting into Missouri overnight. Widespread wind damage is possible. ....Synopsis... A potent shortwave trough with midlevel speed max over 120 kt will move quickly across AZ and NM during day and into western TX, KS and OK during the late afternoon and evening. This wave will take on a negative tilt after 00Z as it continues across MO and into western IL by 12Z Monday. A tight midlevel temperature gradient will exist with this system, resulting in rapid height falls. At the surface, a low will develop from eastern CO into western KS during the afternoon, and will continue to deepen as it pivots into northern MO and southern IA through Monday morning. A cold front will extend south from the low and move rapidly east through the period, as southerly winds over the warm sector bring low-level moisture north. Extreme shear profiles coupled with returning moisture and strong lift will likely result in a corridor of particularly damaging winds. ....TX/OK/KS... Warm/moist advection will be underway on Sunday with a relatively cool/capped air mass in place early. As the system rapidly approaches, prolonged mixing with strong southerly winds should result in a corridor of SBCAPE of 500-1000 J/kg, from northwest TX into the TX Panhandle and western OK by 00Z. Heating over western areas will remove the cap, and late afternoon storms are expected over TX. These will likely be supercells capable of hail and a few tornadoes, with tornado strength dependent on degree of moisture return/potential for 60s F dewpoints. A strong tornado may occur prior to the expected upscale growth to a linear MCS along the cold front. As the line of storms develops into western OK, extreme shear should aid damaging wind potential, and a few tornadoes will remain possible within the line. Effective SRH value over 500 m2/s2 are likely, perhaps up to 750 m2/s2 during the evening as the low-level jet increases to over 70 kt. The most favorable corridor of damage is expected to be along and north of the tight midlevel temperature gradient, which will also travel along the northern portion of the warm sector/better moisture. Strong lift will easily remove the cap along the cold front, with winds behind this line becoming westerly. Further supporting significant wind damage potential will be the rare nocturnal boundary-layer mixing and 850 mb winds of 60 kt out of the west. ....MO/IL... A mature line of severe storms is expected to move coincident with the midlevel vort max as it moves out of OK and KS, and proceeds into the MO/Mid MS Valley overnight. Forecast soundings indicate weak instability, but extreme wind fields will exist. Further, an area of steep lapse rates will accompany this system, further increasing the probability of strong winds aloft mixing to the surface. As such, have expanded the Marginal and Slight Risk areas into MO and IL. ...Jewell.. 02/25/2023 $$ = = = 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) .