Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue Jul 30 2024 06:09:43 ACUS01 KWNS 300609 SWODY1 SPC AC 300608 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0108 AM CDT Tue Jul 30 2024 Valid 301200Z - 311200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE CENTRAL PLAINS INTO PARTS OF THE MS/OH/TN VALLEYS...AND ALSO ACROSS THE NORTHERN PLAINS... ....SUMMARY... Severe storms are possible today into tonight across a broad area from eastern Nebraska and Iowa into parts of the Mississippi, Ohio, and Tennessee Valleys. There is some potential for a swath of severe/damaging winds within this corridor. A few severe storms are also possible across parts of the northern Plains. ....Synopsis... An upper-level ridge will remain in place across the southern Great Plains today. North of the ridge, multiple shortwave troughs and embedded MCVs will move eastward from the northern Rockies/Plains into the upper Midwest, Ohio Valley, and Northeast. The surface pattern will be complicated by the potential influence of overnight/morning convection, but in general, a broad surface low will remain in place across the central Plains, with a surface trough extending northward across the western Dakotas. Very rich low-level moisture will remain in place from the central Plains eastward into parts of the MS/OH Valleys. Farther east, a surface low is expected to move across the lower Great Lakes vicinity, as a trailing surface trough moves through parts of the Northeast and Mid Atlantic. ....Central Plains into parts of the upper Midwest...mid/upper MS Valley and OH/TN Valleys... Considerable uncertainty remains regarding storm evolution later today, but there is some potential for a swath of severe/damaging gusts from parts of NE/IA into parts of the MS/OH Valleys. At least one remnant or ongoing MCS may be ongoing across parts of the upper Midwest later this morning. Strong destabilization will be possible within a very moist environment from NE/IA into the mid MS Valley, though the effects of morning outflow on the instability reservoir remain somewhat uncertain. With modestly favorable deep-layer shear in place, a broad area will have conditional potential for organized severe storms. If the cold pool from an ongoing or developing MCS can be maintained or intensify later this morning into the afternoon (as suggested by some HREF members and recent HRRR runs), there is potential for a rather long-lived MCS to produce a swath of damaging wind gusts (potentially in excess of 75 mph) as it moves southeastward. A significant wind (hatched) area has been added to highlight this potential, and greater unconditional wind probabilities will be needed if confidence in this scenario increases. Even if a dominant MCS does not develop, more localized severe storm development will be possible by late afternoon, especially near any remnant outflow boundaries. Any discrete convection could evolve into a supercells with a conditional risk of all severe hazards, though a tendency toward storm clustering is expected with time, with some guidance suggesting multiple potentially severe storm clusters emanating out of the central Plains. Father southeast, some intensification of remnant overnight convection across the Ohio Valley could occur across parts of TN into the Southeast, within a modest northwesterly flow regime. Isolated to scattered damaging wind should be the primary threat. Any intense MCS that develops upstream could eventually approach this region from the northwest, potentially posing another round of damaging-wind potential. ....Northern Plains... Weak height falls amid moderate to strong instability may lead to widely scattered thunderstorm development along a surface trough/dryline across the Dakotas this afternoon. Moderate westerlies should support moderate deep-layer vertical shear around 30 to 35 kt from 0-6 km, sufficient a few organized storms capable of both large hail and damaging gusts. ....Northern NY into northern New England... Moderate buoyancy may develop this afternoon from northern NY into northern New England. While storm coverage remains somewhat uncertain, deep-layer shear and relatively cool temperatures aloft could support a couple modestly organized storms capable of locally damaging wind, and possibly some hail. ....Mid Atlantic vicinity... A mid/upper-level trough and possibly an MCV will move across the Mid Atlantic vicinity later today. Scattered thunderstorm development is expected by afternoon from northern VA into parts of PA. While there is some uncertainty regarding the extent of heating and destabilization, a couple stronger cells/clusters may become capable of producing isolated damaging wind. ...Dean/Weinman.. 07/30/2024 $$ = = = 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) .