Subj : DAY2SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sun Jul 16 2023 17:31:32 ACUS02 KWNS 161731 SWODY2 SPC AC 161730 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Sun Jul 16 2023 Valid 171200Z - 181200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE BLACK HILLS SOUTHEASTWARD INTO NEBRASKA... ....SUMMARY... Severe storms producing damaging hail and wind gusts are most likely from the Black Hills area southeastward into northern Nebraska late Monday. Other strong wind gusts or marginal hail will be possible from parts of Kentucky and Tennessee northeastward into western Pennsylvania. ....Synopsis... A large upper trough will remain situated from Ontario into the Great Lakes, providing cool air aloft and a cyclonic flow regime from Mid and Upper MS Valley into the Northeast. To the west, a shortwave trough will affect parts of the Pacific Northwest and into MT, with strong westerly flow aloft. East of there, a northwest flow regime will exist over the northern and central Plains, with embedded waves developing from eastern WY/MT into SD/NE in association with areas of storms late. At the surface, dry air will exist behind a cold front which will extend from northern KS/MO into northern IL/IN, with a plume of mid to upper 60s dewpoints ahead of it. Westerly flow around 850 mb will maintain an unstable air mass from KY/TN into OH and western PA, beneath moderate mid to upper level flow. ....Northern Plains... Ahead of the upper wave and near a deepening surface trough, storms are likely to develop over southeast MT and northern WY during the afternoon, moving southeast across SD through late evening and continuing into east-central/northeast NE overnight. Initial activity is likely to produce large hail with long hodographs and steep lapse rates aloft, although some of the activity may be elevated. Even so, substantial, penetrating downdrafts may yield wind damage as well, especially as storm mode transitions to MCS overnight into NE. ....KY/TN into western PA... Areas of storms may be ongoing Monday morning over parts of western KY and TN, and these would move into a destabilizing air mass during the day. As such, a few damaging gusts may occur assuming stronger instability develops ahead this potential activity. Forecast soundings show modest deep-layer shear around 30 kt, but steep lapse rates and sufficient mean wind to produce mobile cold pools and locally damaging winds. In addition, sporadic marginal hail will be possible with the more cellular activity given cool air aloft. Farther east, additional activity is possible from WV into eastern OH and western PA where heating will steep low-level lapse rates, and colder air aloft will exist near the midlevel temperature gradient. Marginal hail and locally strong gusts will be possible. ...Jewell.. 07/16/2023 $$ = = = 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 3.14-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .