Subj : DAY3SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Fri Jun 20 2025 18:57:33 ACUS03 KWNS 201856 SWODY3 SPC AC 201855 Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0155 PM CDT Fri Jun 20 2025 Valid 221200Z - 231200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM CENTRAL NEBRASKA INTO THE UPPER MIDWEST... ....SUMMARY... Severe thunderstorms may develop on Sunday from parts of the central and northern Plains into the upper Midwest. ....Synopsis... A strong mid-level ridge will amplify further across the eastern CONUS on Sunday with a weak mid-level shortwave trough traversing the northeast. A trough across the west will start to weaken and move into the northern Plains during the period. At the surface, troughing will extend along a frontal zone from northern Minnesota to the central High Plains on Sunday. ....Great Plains into the Upper Midwest... Very strong to extreme instability is forecast to develop across the central and northern Plains on Sunday. However, very warm low-mid level temperatures should keep the warm sector mostly capped for much of the day. Therefore, thunderstorm development should be mostly confined to the front. However, even along the frontal zone, storm coverage may be mostly isolated given that forcing from the mid-level trough may remain mostly northwest of the frontal zone. In addition, the strong mid-level flow is forecast to remain mostly post-frontal which may limit storm organization across Nebraska and South Dakota. Given the somewhat decoupled upper-level and low-level pattern, the severe storm threat is more conditional across eastern South Dakota, Nebraska, and southwest Minnesota with the higher probability storm threat across eastern North Dakota and northern Minnesota where cooler temperatures aloft, stronger shear, and stronger forcing should be present. Severe wind gusts would be the most likely threat from this activity. ....Parts of the Northeast... Storms may be ongoing at the beginning of the period across the Northeast as a mid-level shortwave trough shifts southeast. These storms could be marginally severe with some damaging wind threat. In the wake of this convection, very strong to extreme instability is expected to build into the Northeast, but very warm lower tropospheric temperatures and building heights aloft should suppress additional afternoon thunderstorms. ...Bentley.. 06/20/2025 $$ = = = 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) .