Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Thu Jul 24 2025 05:58:46 ACUS01 KWNS 240558 SWODY1 SPC AC 240556 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1256 AM CDT Thu Jul 24 2025 Valid 241200Z - 251200Z ....THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF MICHIGAN AND THE LOWER GREAT LAKES INTO THE MIDWEST...CENTRAL/SOUTHERN PLAINS...AND HIGH PLAINS... ....SUMMARY... Locally damaging thunderstorm wind gusts will be possible from the Great Lakes to the central and southern Plains, mainly this afternoon and evening. Isolated severe storms will also pose a risk of large hail and severe wind gusts over the northern and central High Plains. ....Lower MI into the lower Great Lakes... The Marginal Risk has been maintained across lower MI and adjacent parts of the Great Lakes, though higher wind probabilities may eventually be needed, if confidence increases in a sufficient coverage of organized storm development later today into this evening. Multiple low-amplitude midlevel vorticity maxima (including potentially one or more MCVs) will move across parts of the Great Lakes region later today, within a broader large-scale upper-level trough. A cold front will move southeastward across parts of the upper Midwest and Great Lakes through the day into the evening. Diurnal heating of a richly moist airmass will result in the development of moderate buoyancy along/ahead of the front this afternoon. This destabilization will occur beneath moderate low/midlevel southwesterly flow (25-40 kt in the 850-700 mb layer). The resulting environment will be favorable for outflow-dominant storm clusters capable of wind damage. However, details of storm coverage and timing remain uncertain, due to weak frontal convergence and generally modest large-scale ascent, outside of the potential influence of any MCVs. There is some potential for development relatively early in the day across central/northern Lower MI, when somewhat steeper midlevel lapse rates may still be in place. This scenario may be the greatest relative threat for organized storms, though guidance varies regarding the coverage of storms through early afternoon. Otherwise, midlevel temperatures will tend to warm by later afternoon, though any stronger cells/clusters would still be capable of producing wind damage as low-level lapse rates steepen. Storms may spread into parts of western NY from Ontario late this evening. While a general weakening trend is expected by this time, strong to locally damaging gusts cannot be ruled out late tonight before convection subsides. ....Northern MO/IL/IN into central/eastern KS and northern OK... Scattered storm development is expected this afternoon and evening from central/eastern KS and northern OK into parts of northern MO/IL/IN, along and ahead of a cold front. Somewhat enhanced low/midlevel flow will be present across northern IL/IN early in the day, but gradual weakening of flow is generally forecast with time. Farther southwest, flow is forecast to remain rather weak into northern MO and the central/southern Plains. As a result, storm organization may tend to be limited, but moderate to strong buoyancy and large PW (potentially 2 inches or greater) will support a threat of localized downbursts. One or more small clusters could develop and pose a threat for more concentrated wind damage, but confidence in the details of this potential scenario remains low. ....High Plains... Moderate buoyancy is expected to develop across parts of the central and northern High Plains this afternoon. Large-scale ascent will generally be nebulous in the wake of a departing shortwave trough, but at least isolated storm development is possible near the adjacent higher terrain. Effective shear of 30-40 kt will support some storm organization. Initial discrete cells may pose a threat of hail, while some outflow amalgamation could eventually occur, with a threat of strong to locally severe gusts spreading eastward into the evening. Farther south, scattered to numerous thunderstorms are expected into parts of the southern High Plains. Deep-layer shear will be weak across this region, but localized strong to severe outflow gusts will be possible. ...Dean/Thornton.. 07/24/2025 $$ = = = 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 3.28-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .