Subj : DAY2SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue Aug 13 2024 17:22:36 ACUS02 KWNS 131722 SWODY2 SPC AC 131720 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1220 PM CDT Tue Aug 13 2024 Valid 141200Z - 151200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF EASTERN NE...WESTERN IA...NORTHEAST KS...NORTHWEST MO... ....SUMMARY... Isolated to scattered severe thunderstorms are possible Wednesday across parts of the northern/central Plains into the mid Missouri Valley, with greater potential for large hail, damaging winds, and a tornado or two across parts of northeast Kansas, eastern Nebraska, western Iowa, and northwest Missouri. ....Eastern NE/northeast KS into parts of IA/MO/southern MN... A mid/upper-level trough will move across the central/northern Great Plains towards the upper Midwest on Wednesday. Multiple vorticity maxima, and possibly one or more MCVs, will likely move through the larger-scale trough. The surface pattern will be similarly complex, with a general consensus for a consolidating surface low somewhere across central NE/KS by afternoon. Outflow and cloudiness from morning convection will influence the position of surface boundaries later in the day. One surface boundary that will serve as an effective warm front is forecast to move northward somewhere across northeast KS/northwest MO into eastern NE/western IA, though its position by afternoon/evening remains uncertain. A weak surface trough/cold front will move across parts of the Dakotas into central NE, with another surface trough potentially moving across KS/southeast NE and intersecting the warm front. Given the rather complex surface/upper-air pattern and influence of morning convection, storm evolution remains rather uncertain Wednesday afternoon and evening. From northeast KS/northwest MO into southeast NE/southwest IA, at least isolated storm development will be possible by late afternoon near the warm front and other surface boundaries. Modestly enhanced southwesterly flow aloft will support effective shear of 30-40 kt, and a couple of supercells could evolve from initial development, with a threat of large hail and damaging wind. Some tornado threat would also accompany any supercells near the warm front, especially into the evening when some increase in low-level flow and SRH is expected. With time, one or more upscale-growing clusters may develop, with an attendant threat of damaging gusts spreading eastward across parts of IA/MO. ....Dakotas into central NE... A few strong to locally severe storms will be possible across parts of the Dakotas into central NE. For the Dakotas, somewhat weaker instability and deep-layer shear is expected compared to areas to the south and east, but at least scattered storm development will be possible in conjunction with the mid/upper-level trough. Depending on the extent of heating/destabilization, isolated hail and strong/damaging gusts will be possible. Across central NE, instability and deep-layer shear may be somewhat stronger, though confidence regarding storm coverage decreases with southward extent. A conditional risk for hail and localized severe gusts will accompany any stronger storm in this area. ....Far eastern ID/UT into WY...northern/eastern CO...western KS...TX/OK Panhandles... Another round of relatively high-based convection appears possible Wednesday afternoon into the early evening from parts of eastern ID/UT into WY and northwest CO. Sufficient instability and modest westerly flow aloft could support a few stronger cells/clusters with strong to locally severe outflow winds. Isolated strong storms will also be possible from eastern CO into western KS, and potentially into the OK/TX Panhandle region. While this area will generally be displaced from stronger large-scale ascent, relatively strong heating, weak to moderate buoyancy, and modest deep-layer flow/shear could support a couple stronger cells/clusters capable of isolated strong/severe gusts and hail. ....Parts of New England... Isolated to widely scattered thunderstorms are possible Wednesday afternoon across parts of New England, along the western periphery of a midlevel low near the Canadian Maritimes. Deep-layer shear will generally be weak, but cold temperatures aloft and unidirectional northerly flow could support a few stronger southward-moving cells/clusters, with small hail and locally gusty winds. Confidence in a more organized severe threat is currently too low for probabilities. ...Dean.. 08/13/2024 $$ = = = 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) .