897 ACUS03 KWNS 060730 SWODY3 SPC AC 060729 Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 AM CDT Sun Jul 06 2025 Valid 081200Z - 091200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE SOUTHERN PLAINS INTO THE MIDDLE MISSISSIPPI VALLEY...AND PORTIONS OF THE CAROLINAS INTO SOUTHERN NEW ENGLAND... ...SUMMARY... A few strong storms, capable of producing isolated damaging to severe gusts, are possible across the Southern Plains into the Mid-Mississippi Valley and the Carolinas into the Northeast on Tuesday. ...Synopsis... A mid-level trough will progress across the Midwest while an upper ridge persists across the Southwest, and another upper trough meanders along the California Coastline on Tuesday. Weak surface troughs will be positioned over the central U.S. and along the East Coast by afternoon, serving as a focus for scattered to widespread thunderstorm development. Given the presence of at least moderate instability, isolated severe storms will be possible over portions of the central and eastern CONUS. ...Carolinas into southern New England... Scattered thunderstorm development is expected ahead of the surface trough by late morning/early afternoon. Surface temperatures should approach the upper 80s F amid 70+ F dewpoints, yielding up to 3000 J/kg of tall/thin MLCAPE (given poor mid-level lapse rates). Relatively weak flow below 500 mb should result in mediocre vertical wind shear. Pulse cellular storms and perhaps a few multicells are likely, with the stronger cores supporting wet downbursts and isolated damaging gust potential. ...Mid-Mississippi Valley into the southern Plains... Scattered thunderstorms should develop ahead of the surface trough, and along preexisting boundaries from preceding storms during the afternoon hours. These storms will develop within a northwesterly upper flow regime as the mid-level trough departs the Mid-MS Valley region and are poised to move/propagate south-southeastward into the evening hours. Ahead of the storms, surface temperatures should warm into the 90s F amid upper 60s/lower 70s F dewpoints. With mid-level lapse rates generally in the 6.5-7.5 C/km range, MLCAPE should peak around or just over 2500 J/kg. Given modest vertical wind shear (i.e. 30 kts of effective bulk shear), multicells are expected. The stronger storms may produce isolated severe gusts, though an instance of hail cannot be ruled out. Should storms merge into one or more MCSs, a slightly denser swath of strong to severe gusts may be realized. Higher severe wind probabilities may be needed if confidence increases in MCS development, and if the location/timing of the MCS can be better ascertained. ..Squitieri.. 07/06/2025 $$