Subj : DAY2SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sat Sep 30 2023 17:10:22 ACUS02 KWNS 301710 SWODY2 SPC AC 301708 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1208 PM CDT Sat Sep 30 2023 Valid 011200Z - 021200Z ....THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE SOUTHERN HIGH PLAINS AND THE NORTHERN HIGH PLAINS.... ....SUMMARY... Scattered storms capable of isolated large hail and severe wind gusts will be possible in the southern High Plains on Sunday. In addition, a few severe storms capable of hail or gusty winds may develop late Sunday over the northern High Plains. ....Synopsis... A large mid-level trough across the western CONUS will progress slowly eastward through the day on Sunday. A mid-level impulse over Arizona now, will move through the western Dakotas Sunday morning. Despite eastward movement of the larger scale trough, amplification of the ridge across the eastern CONUS will limit height falls across the High Plains until after 00Z. At the surface, lee troughing is anticipated across the central/northern High Plains. Eventually, a low pressure center will develop and move into the northern Plains. A cold front will extend from this surface low and down the High Plains. ....Southern High Plains... A relatively moist airmass (dewpoints in the low 60s) is expected to advect into eastern New Mexico by Sunday morning. Given this high moisture content at elevation, temperatures in the low to mid 70s will erode inhibition by early afternoon. During the afternoon, mid-level flow will start to strengthen with effective shear increasing from around 20 knots to 30 knots. This may support more sustained updrafts and even a few supercell structures by later in the afternoon. Isolated large hail and severe wind gusts will be the primary threat. ....Northern High Plains... Subsidence is expected across the northern High Plains for the first half of the day Sunday in the wake of the passing mid-level shortwave trough. Some upper-level diffluence will overspread the region by the evening which may support some isolated thunderstorm development. The boundary layer is expected to deeply mix across the northern High Plains during the day and thus, instability is forecast by most guidance to remain limited (<500 J/kg) near the front/surface low in eastern Wyoming, except for the NAM, which has a known moist bias. Therefore, storms may struggle during the afternoon/early evening. During the late evening, the low-level jet is expected to intensify to at or above 50 knots with some increase in low-to-mid level instability. This may provide ample support for a few elevated thunderstorms. Steep mid-level lapse rates and strengthening mid-level flow may be sufficient for some large hail or severe wind gusts from this activity. ...Bentley.. 09/30/2023 $$ = = = 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) .