Subj : DAY1SVR: Day 1 Convective Outlook Corr 1 To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sun Jun 22 2025 01:06:32 ACUS01 KWNS 220106 SWODY1 SPC AC 220104 Day 1 Convective Outlook CORR 1 NWS Storm Prediction Center Norman OK 0804 PM CDT Sat Jun 21 2025 Valid 220100Z - 221200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF NEW YORK AND NEW ENGLAND... CORRECTED FOR FLIPPED THUNDER LINE IN SOUTHEAST ....SUMMARY... Thunderstorms associated with severe wind gusts and hail will be possible tonight across New York and New England. Isolated severe storms will also be possible across parts of the Great Lakes and the central to northern Plains. ....Northeast/New York/Great Lakes... Latest water vapor imagery has a belt of strong anticyclonic flow located from the upper Mississippi Valley into the Great Lakes and Northeast. A ridge-riding mid-level shortwave trough is located over Ontario. At the surface, a moist airmass is in place from New York into western New England, where surface dewpoints are in the lower to mid 60s F. The low-level moisture will contribute to continued destabilization across the region, in the form of elevated instability, this evening into tonight. As the shortwave trough moves southeastward toward the Northeast, low-level flow will markedly strengthen. In response, convective coverage is expected to increase, and a line of thunderstorms appears likely to develop late this evening. This line is forecast to move southeastward across New York and western New England from late evening into the overnight period. Overnight, RAP forecast soundings ahead of the line in northern New York have a low-level temperature inversion, with MUCAPE in the 1500 to 2000 J/kg range. Effective shear is forecast to be around 40 knots. This should be favorable for a severe threat. Although much of the line could be elevated, isolated large hail and severe gusts will still be possible, mainly with the more intense component of the line. The line is expected to move through the western New England and the Hudson River Valley late tonight, approaching southern New England toward 12Z. ....Central Plains... Southwest mid-level flow is in place across much of the central Plains early this evening. At the surface, a moist airmass is located over much of the High Plains, with surface dewpoints mostly in the 60s F. In response to low-level warm advection, isolated to scattered thunderstorms will likely develop along the western edge of this moist airmass. This convection is expected to move northeastward across Nebraska and southeastern South Dakota this evening. In addition to moderate instability, mid-level lapse rates are very steep. This, combined with moderate deep-layer shear, will likely support a marginal severe threat. Hail and isolated severe gusts will be possible. ....Northern High Plains... A mid-level trough, evident on water vapor imagery, will move northeastward into the northern High Plains tonight. Ahead of the trough, a post-frontal airmass is in place with the western edge of a moist airmass located over the western Dakotas. As large-scale ascent increases across the northern High Plains later tonight, scattered thunderstorm development is expected. These storms will move northeastward across eastern Montana and western North Dakota, mainly after midnight. Weak to moderate instability, combined with steep lapse rates and moderate deep-layer shear should support a marginal severe threat. Hail and a few severe gusts will be possible. ...Broyles.. 06/22/2025 $$ = = = 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) .