Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sun Oct 06 2024 19:54:20 ACUS01 KWNS 061954 SWODY1 SPC AC 061952 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0252 PM CDT Sun Oct 06 2024 Valid 062000Z - 071200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF EASTERN OHIO...WESTERN NEW YORK/PENNSYLVANIA...AND NORTHERN WEST VIRGINIA... ....SUMMARY... Isolated to scattered severe thunderstorms are forecast later this afternoon into the evening from parts of eastern Ohio into western New York/Pennsylvania, West Virginia, and western Maryland. Damaging winds and large hail are the primary severe hazards. ....20Z Update... Minor changes were made to the 15% wind probabilities in western New York where the New York Mesonet indicated dewpoints reaching the upper 50s F. Elsewhere the outlook remains unchanged. See the previous discussion for additional information. ...Wendt.. 10/06/2024 ..PREV DISCUSSION... /ISSUED 1130 AM CDT Sun Oct 06 2024/ ....Upper Ohio Valley into the Lower Great Lakes and Central Appalachians... Midday water-vapor imagery shows a potent mid- to upper-level trough over Ontario and the Great Lakes. A speed max initially over northern WI/western U.P. of MI will quickly move east-southeast into the Lower Great Lakes through early evening. Strong, attendant forcing for ascent associated with this disturbance will overspread southwest Ontario into eastern OH by the mid-late afternoon. Coincidentally, a cold front over the Great Lakes will sweep eastward. A narrow plume of moisture will protrude northeastward through the Upper OH Valley with surface dewpoints generally in the mid to upper 50s. Mid-level cooling associated with the trough will act to steepen 700-500 mb lapse rates to around 7 deg C/km by mid-late afternoon immediately ahead of the cold front. Forecast soundings show generally 500-1000 J/kg of MLCAPE by mid afternoon and weakened convective inhibition. The nose of the cyclonically curved upper jet will nose into the region and contribute to effective shear 35-50 kt. The latest model guidance suggests convective initiation occurring over the northeast OH vicinity between 20-22z. This initial development will likely be supercellular given the strong deep-layer shear, with an associated threat for severe hail given favorable lapse rates aloft. A brief tornado or two may also occur. But, a transition to a convective band featuring a mix of cells and linear segments is anticipated given the linear forcing of the cold front. As this occurs, the threat for scattered damaging winds should quickly increase as convection moves east-southeastward from eastern OH across western NY/PA and into WV/western MD. Given the fairly narrow warm sector, this activity should weaken by mid evening with the loss of daytime heating, and as it encounters a much less unstable airmass in the central Appalachians. $$ = = = 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) .