Subj : DAY2SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Wed Oct 11 2023 17:08:01 ACUS02 KWNS 111707 SWODY2 SPC AC 111706 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1206 PM CDT Wed Oct 11 2023 Valid 121200Z - 131200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE CENTRAL PLAINS...AND ACROSS NORTHERN/CENTRAL FLORIDA... ....SUMMARY... Isolated to scattered severe thunderstorms appear possible Thursday across parts of the central Plains, where large hail should be the main threat, but severe winds and a couple tornadoes may also occur. The threat for a few tornadoes should continue through at least Thursday morning across portions of north/central Florida. ....Central Plains vicinity... An upper low/trough will eject eastward across the Plain on Thursday. Ahead of the upper low, a 60-80 kt southwesterly midlevel jet will overspread portions of OK/KS/NE into MO/IA during the afternoon and overnight hours. At the surface, a low is forecast over southwest NE/northwest KS during the morning. The low will gradually spread east through the day, with a more rapid northeast progression during the evening as the upper system emerges over the Plains. A warm front will extend eastward from the low across northern NE into central IA, while a dryline extends southward from the low into central KS/western OK. A narrow corridor of upper 50s to low 60s F surface dewpoints will be present ahead of the dryline. Cooling aloft will result in steepening midlevel lapse rates, and in conjunction with modest boundary-layer moisture, modest destabilization (500-1250 J/kg SBCAPE) is anticipated from the triple point southward along the dryline. Capping with southward extent into OK should limit diurnal thunderstorm potential across the southern Plains. However, strong warm advection combined with increasing large-scale ascent should support initial thunderstorm development near the surface low and along the warm front by mid-afternoon across northern NE/southern SD. Convection may then increase along the dryline into portions of KS during the evening as a 40-50 kt southerly low-level jet increases. Effective shear magnitudes greater than 40 kt and favorable vertically veering wind profiles will support organized supercells posing a risk for large hail and sporadic strong/damaging gusts. Forecast soundings show a rather deeply mixed boundary-layer given stronger heating along the dryline. This, coupled with modest low-level moisture may limit tornado potential. However, low-level shear will become enhanced near the triple point where locally backed winds are expected. This would be the more favorable location for a couple of tornadoes as low-level hodographs become enlarged as the low-level jet increases, resulting in locally higher SRH values. Given latest trends in surface low and front locations, the Marginal (level 1 of 5) and Slight (level 2 of 5) risk areas have been expanded some to the north and west from the previous outlook. While guidance varies, some CAMs suggest a conditional risk of elevated convection is possible during the overnight period along the dryline into parts of north-central OK. If this activity develops, some potential for hail could accompany these storms. However, confidence is too low at this time to include marginal severe probabilities at this time. ....Florida... No changes have been made to this area from the previous outlook. A mid-level perturbation is forecast to move quickly off the Southeast Atlantic Coast Thursday morning. In its wake, strong low/mid-level winds across FL should tend to veer to a more unidirectional/west-southwesterly component by early Thursday afternoon. Still, enhanced low-level and deep-layer shear will probably persist through Thursday morning across parts of north/central FL along and south of a front. This shear, along with weak to moderate instability, should support some updraft organization and a continued threat for occasional strong/damaging winds and perhaps a few tornadoes with the more robust convection. ...Leitman.. 10/11/2023 $$ = = = 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) .