Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sat Aug 31 2024 06:03:00 ACUS01 KWNS 310602 SWODY1 SPC AC 310601 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0101 AM CDT Sat Aug 31 2024 Valid 311200Z - 011200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL APPALACHIANS AND UPPER OHIO VALLEY... ....SUMMARY... Severe thunderstorms, associated with severe wind gusts and hail, will be possible today from parts of the central Appalachians into the Ohio and Tennessee Valleys. Isolated severe wind gusts will be possible in parts of the northern Great Lakes. ....Central Appalachians/Ohio and Tennessee Valleys... An upper-level trough will move through the Great Lakes region, with the southern end of the trough located in the mid Mississippi Valley. An associated cold front will advance southeastward through the mid Mississippi Valley and southern Great Lakes. Ahead of the front, a moist airmass will be in place with surface dewpoints in the upper 60s and lower 70s F. Moderate instability is expected to develop by midday ahead of much of the front. Further to the east, a pre-frontal trough will be located from western New York and western Pennsylvania southwestward into eastern Kentucky. Scattered thunderstorms will form from near the front eastward to near the pre-frontal trough. By early to mid afternoon, RAP forecast soundings have MLCAPE peaking in the 1500 to 2000 J/kg range from western New York southwestward into West Virginia. Along this portion of the instability corridor, 0-6 km shear is forecast to be in the 20 to 30 knot range. This, along with 0-3 km lapse rates near 7.5 C/km will support severe wind gusts with the more organized bowing line segments. Hail will also be possible. Further to the southwest into parts of the lower Ohio and Tennessee Valleys, the models suggest that deep-layer shear will generally be below 20 knots. Although steep low-level lapse rates could be enough for a marginal wind-damage threat, the weakness in shear should keep any threat isolated. ....Northern Great Lakes... A cyclonic mid-level flow pattern will be in place today across much of southern Canada and over the Great Lakes. Within this flow, a shortwave trough and an associated cold front is forecast to move southeastward toward the northern Great Lakes. Ahead of the front, surface dewpoints in the 50s F will contribute to weak destabilization by afternoon. Thunderstorms are expected to form along and ahead of the front as instability peaks during the mid to late afternoon. In spite of the weak instability, large-scale ascent and strong deep-layer shear, associated with the shortwave trough, could be enough for isolated severe wind gusts. ...Broyles/Moore.. 08/31/2024 $$ = = = 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) .