Subj : DAY2SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Fri Sep 22 2023 17:26:29 ACUS02 KWNS 221726 SWODY2 SPC AC 221725 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1225 PM CDT Fri Sep 22 2023 Valid 231200Z - 241200Z ....THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS FAR SOUTHEAST KS...NORTHEAST OK...AND FAR SOUTHWEST MO... ....SUMMARY... Thunderstorms, associated with large to very large hail, wind damage, and tornadoes, will be possible on Saturday across eastern parts of the Great Plains, and in the Lower to Mid Missouri Valley. A couple of tornadoes are also be possible in parts of the Mid-Atlantic. ....Mid MO Valley southward into OK... A shortwave trough, accompanied by cold mid-level temperatures and enhanced mid-level flow, is expected to trend more negatively tilted as it progresses across NE and SD on Saturday. The strongest mid-level flow associated with this system is forecast to spread eastward from NE into the into IA and southern MN during the afternoon and evening, with modestly increasing mid-level flow anticipated farther south across much of KS and OK. Triple-point surface low associated with this shortwave will likely begin the period centered over central KS/NE border vicinity, before then progressing northeastward across eastern NE and western IA. Occluded front extending from this triple point is forecast to arc back westward to a deepening low over the eastern Dakotas. Cold front extending south from the triple point is forecast to progress steadily eastward across the central Plains during the day before then slowing its eastward progression Saturday evening into Saturday night. A warm front is expected to extend northeastward from the triple point as well, before then arcing more southeastward into IL. This complex surface structure will play a pivotal role in thunderstorm development across the region, with each of these boundaries provided the impetus for convective initiation in some way. Thunderstorms will likely be ongoing ahead of the primary surface low across NE and SD early Saturday morning, with a reservoir of mid 60s dewpoints ahead of the cold front from the Mid MO Valley into OK. Re-intensification (or new development) is anticipated during the early afternoon along the occluded front as it enters southern MN and western IA. Given limited heating, buoyancy is not expected to be overly strong. However, with ample low-level moisture and lower convective inhibition in place, thunderstorm development is expected to increase southward along the occluded front during the afternoon. Vertical shear is strong enough to support organized updrafts capable of large to very large hail and damaging gusts. These storms may trend towards a more elevated character with eastern extent, but there does appear to be a narrow corridor where surface-based storms are probable. Given the backed low-level flow and resultant low-level low hodographs, the environment could support tornado development. Additional thunderstorm development is anticipated during the afternoon along the cold front farther south into eastern KS and central/eastern OK. This area will be displace south of the strongest shear, but deep-layer shear should still be sufficient for initial supercells capable of large to very large hail. High cloud bases and steep low-level lapse rates should foster a trend towards outflow-dominant storms, and the potential for strong wind gusts. ....Mid-Atlantic... A tropical system is forecast by the National Hurricane Center to begin the period centered over the central NC coast, before then moving northward through eastern North Carolina in southeast VA on Saturday. Limited instability is forecast throughout the day to the east of the storm's center across eastern north Carolina into eastern Virginia. Strong low to mid-level wind fields will be in place, and a marginal tornado threat will exist within any deeper convective cores that develop throughout the day. ...Mosier.. 09/22/2023 $$ = = = 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) .