Subj : DAY3SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sat Jul 19 2025 07:29:29 ACUS03 KWNS 190729 SWODY3 SPC AC 190728 Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0228 AM CDT Sat Jul 19 2025 Valid 211200Z - 221200Z ....THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS MONDAY INTO MONDAY NIGHT ACROSS PARTS OF THE NORTHERN GREAT PLAINS AND THE TENNESSEE VALLEY INTO SOUTH ATLANTIC SEABOARD... ....SUMMARY... Strong thunderstorm development may pose at least some risk for severe wind and perhaps hail across parts of the northern Great Plains and parts of the Tennessee Valley into southern Atlantic Seaboard Monday through Monday night. ....Discussion... Models indicate at least some shearing of mid-level troughing near the Pacific coast during this period, between fairly prominent and persistent lower latitude ridging encompassing much of the interior U.S. and stronger higher latitude ridging centered over the northeastern Pacific. The interior U.S. ridging may tend to build a bit further northeastward through the Upper Midwest/Great Lakes vicinity, in the wake of significant mid-level troughing progressing offshore of the northern U.S. and Canadian Atlantic coast. In lower levels, a cold front is forecast to progress southward along the Atlantic Seaboard, to the lee of the southern Appalachians, while its western flank retreats northeastward and eastward across the northern Great Plains, Upper Midwest and lower Ohio Valleys. ....Dakotas into Minnesota... Beneath a plume of warm and capping elevated mixed-layer air, models indicate that a seasonably moist boundary layer will again become characterized by moderate to large potential instability with daytime heating across the mid Missouri Valley toward Upper Midwest. Forcing for ascent to support convective development remains unclear, but guidance is suggestive that one or two subtle perturbations progressing around the northern periphery of the stronger mid-level ridging may support the initiation of storms near the North and South Dakota state border vicinity by late Monday afternoon. Although deep-layer shear may be modest, this evolution may include a supercell or two before activity tends to grow upscale into an east/southeastward propagating cluster capable of producing strong to severe surface gusts. ....Tennessee Valley into southern Atlantic Seaboard... With the cold front generally advancing south of the westerlies, the extent of severe weather potential remains unclear. Convection allowing models and other guidance suggest that it might not be out of the question that a remnant cluster of storms, emerging from the lower Ohio Valley early Monday, may persist or re-intensify during the day, while propagating southeastward along the front toward the southern Appalachians, aided by inflow of moderately unstable air. Otherwise, destabilization in advance of the progressive portion of the front, across the Carolinas, may contribute to strong storms posing a risk for potentially damaging wind gusts. ...Kerr.. 07/19/2025 $$ = = = 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) .