Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue Jul 09 2024 05:50:15 ACUS01 KWNS 090550 SWODY1 SPC AC 090548 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1248 AM CDT Tue Jul 09 2024 Valid 091200Z - 101200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE LOWER OHIO VALLEY... ....SUMMARY... Tornadoes, in association with the remnants of Beryl, will be possible today from the mid Mississippi Valley northeastward through parts of the lower Ohio Valley. Marginally severe wind gusts and hail will also be possible in parts of New England. ....Lower Ohio Valley/Mid Mississippi Valley... The remnants of Beryl will move across the mid Mississippi and lower Ohio Valleys today. Ahead of the associated surface low, surface dewpoints will be in the lower to mid 70s F. In response to surface heating, pockets of moderate instability are expected to develop south of a warm front across parts of Kentucky by afternoon. Model forecasts are in generally good agreement that a broken line of storms will develop and move east-northeastward across the lower Ohio Valley. A 40 to 50 knot low-level speed max is forecast to move into the lower Ohio Valley during the afternoon. The storms will likely be located along the northeastern edge of this feature. RAP forecast soundings during the early to mid afternoon from Paducah to Louisville generally increase 0-3 km storm-relative helicity into the 200 to 250 m2/s2 range. This will be favorable for tornadoes with rotating cells that form in the remnant rainband of Beryl, especially with storms that interact with a warm front near the Ohio River. The tornado threat is expected to be greatest in the 18Z to 00Z temporal window. Compared to the previous day, the low-level jet for today is a bit weaker and further to the west relative to where the models are forecasting convective development. This introduces uncertainty concerning the magnitude of today's tornado potential. ....New England... A low-amplitude trough at mid-levels will move eastward across Quebec and New England today. Ahead of the trough, a moist and unstable airmass will be in place by afternoon from the Mid-Atlantic northeastward into New England. As surface temperatures warm, scattered thunderstorms are expected to develop in the higher terrain of New England early this afternoon. Some of this convection will move eastward into the lower elevations by late afternoon. RAP forecast soundings near the instability axis from southern Vermont into southern New Hampshire have MLCAPE peaking in the 1000 to 1500 J/kg range, with 0-3 km lapse rates approaching 8 C/km. This, combined with moderate deep-layer shear will be enough for an isolated wind-damage threat. A few rotating storms with hail potential will also be possible. ...Broyles/Thornton.. 07/09/2024 $$ = = = 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) .