Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue Jun 13 2023 20:01:48 ACUS01 KWNS 132001 SWODY1 SPC AC 132000 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Tue Jun 13 2023 Valid 132000Z - 141200Z ....THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS NORTH-CENTRAL TX... ....SUMMARY... Severe thunderstorms are still expected this afternoon into tonight from parts of the southern High Plains to the Southeast, with large hail and damaging winds possible. Highest severe thunderstorm coverage is expected over north Texas. ....20Z Update... ....Southern Plains into the Southeast today into tonight... Warm, moist, and strongly unstable air mass remain in place from the southern Plains through the Southeast. Numerous strong to severe thunderstorms are already ongoing, with 4 Severe Thunderstorm Watches (280, 281, and 282) currently in place. The stronger shear is expected to stay over western portions of the region, with mesoanalysis currently estimating effective bulk shear around 60 kt from north/central TX across LA. Recent VAD from FWS sampled 63 kt of effective bulk shear. Robust buoyancy exists over this region as well, and the overall environment appears favorable for splitting supercells. Very large hail will remain the primary severe risk through the evening. Farther east, thunderstorms have trended towards more linear structures across southern AL and southern GA. This trend is expected to continue, with some additional ascent provided by the convectively enhanced vorticity maximum moving through the region. As such, the severe threat is expected to continue across the region and into adjacent parts of the FL Panhandle/northern FL. ....Southern High Plains into Oklahoma this afternoon and evening... Thunderstorms are expected to continue maturing across southeast CO/northwest NM, eventually bringing these storms into the TX/OK Panhandle. Moderate buoyancy and shear will support some strong to severe storms, and Severe Thunderstorm Watch 283 was recently issued to cover this threat. These storms may persist into the evening hours, with some potential to remain strong to severe as far east as central OK by 06Z. These storms should gradually become elevated over time, trending towards mainly a hail risk. ...Mosier.. 06/13/2023 ..PREV DISCUSSION... /ISSUED 1135 AM CDT Tue Jun 13 2023/ ....Synopsis... Scattered to widespread thunderstorms are in progress along the immediate cool side of an west-to-east oriented baroclinic zone located across portions of central TX and extending eastward across parts of central MS/AL. These storms persist within a warm-air advection regime driven by a veering and gradually weakening low-level jet overspreading the Mid South. With time, the upper ridge across the southern Plains will subside to a degree, with mid-level westerly flow increasing in magnitude. During the mid to late afternoon hours, a mid-level impulse embedded in the broader westerly flow will eject from the southern Rockies, initiating newer rounds of strong to severe thunderstorms along the southern High Plains, and across central Texas. ....Arklatex into the Southeast today into tonight... Strong to potentially severe storms are ongoing within the warm-air advection regime. Surface temperatures warming into the 80s F amid near 70 F dewpoints will contribute to 3000 J/kg of thin MLCAPE (given mediocre mid-level lapse rates). The stronger mid-level flow overspreading the region will support elongated hodographs, with multicells and short line segments the expected storm modes. Large hail will be possible with the stronger cells and a few damaging gusts may also occur with storms on the warm side of the baroclinic zone, where steeper low-level lapse rates will reside. Later tonight, as the low-level jet increases in intensity, warm-air advection will encourage elevated thunderstorm development atop a stable boundary layer across the Arklatex into the Southeast. Large hail will be the main threat with these storms. ....Central into northeast Texas this afternoon and evening... In the wake of earlier storms, a warm/moist boundary layer is expected to develop through the afternoon. As mid-level flow intensifies over TX, steep mid-level lapse rates will overspread the deepening boundary layer, contributing to strong to extreme instability (i.e. 4000+ J/kg of wide CAPE, especially above 700 mb). Mainly straight but elongated hodographs will support splitting supercell structures later this afternoon. Given the depth of buoyancy above the freezing level and 50+ kts of effective bulk shear/elongated hodographs, very large hail is likely with the more established supercells. Later into the evening/overnight hours, elevated supercell structures should persist as they approach the Arklatex vicinity, with a continued threat for large hail. ....Southern High Plains into Oklahoma this afternoon and evening... Upslope flow and the passage of the aforementioned mid-level impulse will result in convective initiation along the lee of the southern Rockies. The eastward advection of 8-9 C/km lapse rates will support at least moderate instability amid elongated hodographs, supporting supercell structures capable of producing large hail (a couple stones of which may exceed 2 inches in diameter). These storms may persist into the evening hours, with some guidance member suggesting storms may remain strong to severe as far east as central OK by 06Z. By evening, these storms should gradually become elevated, producing large hail and perhaps a severe gust. $$ = = = 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) .