Severe Thunderstorm Watch issued June 20 at 12:28AM CDT until June 20 at 4:00AM CDT by NWS Sioux Falls SD

SPC 1730Z Day 2 Outlook Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Fri Jun 20 2025 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE NORTHERN GREAT LAKES INTO NEW YORK AND NORTHERN PENNSYLVANIA... ...SUMMARY... Strong to locally severe storms are possible Saturday from the northern Great Plains into the Upper Midwest and Great Lakes. ...Synopsis... An amplifying pattern will occur on Saturday with a trough strengthening across the west with a ridge building across the eastern CONUS. Surface high pressure will be present across the eastern