Subj : DAY3SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Mon Aug 19 2024 19:25:38 ACUS03 KWNS 191925 SWODY3 SPC AC 191924 Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0224 PM CDT Mon Aug 19 2024 Valid 211200Z - 221200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR THE MONTANA/NORTH DAKOTA BORDER VICINITY... ....SUMMARY... Widely scattered to potentially scattered storms will be possible on Wednesday across parts of the northern High Plains. Severe winds and large hail could occur. Marginally severe storms will be possible westward into central Montana and southward into the central High Plains. ....Synopsis... Broad cyclonic flow will continue across portions of the Western U.S. A mid-level shortwave trough is expected to lift northeastward through the northern Rockies into the northern High Plains late Wednesday afternoon into the evening. A surface low will deepen near the Montana/North Dakota border with a lee trough extending into the central High Plains. ....Montana into North Dakota... Convection is likely to form within the higher terrain of southwest Montana. Deep-layer shear will be strong, but buoyancy will be weak to modest. Strong/severe wind gusts and isolated large hail are possible. Greater uncertainty exists in the exact scenario for the Montana/North Dakota border vicinity. With the surface low deepening, a few storms could initiate during the mid/late-afternoon. These storms would have a greater chance at maintaining a supercellular mode. Severe wind gusts and large hail would be the main hazards with this scenario. However, mid-level heights will be mostly neutral through the day before modest falls occur by early evening and low-level forcing will be limited as well. A second possibility is for activity in Montana to move into the border region during early/mid-evening. Severe winds would be the primary hazard with what would likely be outflow-dominant storms. Given the late timing of these storms, it is not certain how much severe coverage there would be. The 15% severe probability area will be maintained this cycle with guidance hopefully providing more clarity in the coming days. ....Black Hills into central High Plains... Isolated to widely scattered storms are possible within the lee trough. Shear will be weaker with southern extent. A few severe gusts and marginally severe hail could occur with the strongest storms during the afternoon. ....Mid-Missouri Valley... Some convection may be ongoing in eastern South Dakota into southern Minnesota early in the period. Some outflow can be expected with this activity. With the MCV, flow aloft will be enhanced into eastern Nebraska. While a conditional threat for a strong/severe storm exists, low/mid-level forcing will be weak and storm initiation is far from certain. ...Wendt.. 08/19/2024 $$ = = = 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 3.20-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .