Subj : DAY3SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sun Jun 29 2025 19:28:09 ACUS03 KWNS 291927 SWODY3 SPC AC 291926 Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0226 PM CDT Sun Jun 29 2025 Valid 011200Z - 021200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE MID-ATLANTIC... ....SUMMARY... Scattered strong to severe storms are possible across parts of the Mid-Atlantic into the Northeast on Tuesday afternoon/evening. An isolated severe storm may also occur over parts of the central High Plains. ....Synopsis... A mid-level trough will track across the Northeast as upper-ridging remains in place across the central CONUS, and an upper low meanders along the West Coast on Tuesday. At the surface, a cold front will sweep across the Northeast/Mid-Atlantic regions while a surface anticyclone overspreads much of the U.S. between the Rockies and Appalachians. Ahead of the surface cold front, ample moisture and instability, coinciding with modest deep-layer shear, will support scattered strong thunderstorms, a few of which may be severe. ....Northeast into the Mid-Atlantic... As the surface cold front advances east across the central/northern Appalachians, surface heating should support surface temperatures rising into the 80s to 90 F amid low to mid 70s F dewpoints, resulting in moderate buoyancy. The rich low-level moisture, overspread by mediocre lapse rates, will support 2500+ J/kg MLCAPE, constrained to tall/thin profiles. With the approach of the trough, enough strengthening with height of the 850-500 mb wind fields will encourage 25-40 kts of effective bulk shear and the subsequent development of multicells and short line segments. At least isolated damaging gusts are possible throughout the Northeast. However, a Category 2/Slight risk was added across parts of the Mid-Atlantic, where the latest guidance depicts relatively robust convective development, and where forecast buoyancy is strongest. Here, wind damage may occur on a more frequent basis. ....Central High Plains... Weak upslope low-level flow around the aforementioned surface anticyclone will encourage the northwestward advection of upper 50s to 60 F surface dewpoints into the Nebraska Panhandle and immediate adjacent areas by Tuesday afternoon. These dewpoints will be overspread by 7.5-8.5 C/km mid-level lapse rates, resulting in at least 1500 J/kg MLCAPE. Isolated thunderstorms are expected to develop off of the higher terrain as they progress eastward. Multicellular or perhaps transient supercellular storm modes are possible given lackluster vertical wind shear. Nonetheless, a stray severe thunderstorm is possible, accompanied by mainly a severe wind/hail threat. ...Squitieri.. 06/29/2025 $$ = = = 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 3.20-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .