Radar animation from Grand Forks, ND, on June 20-21, 2025, showing tornadic supercells being overtaken by fast-moving line of storms before entering Minnesota where the combined complex produced extensive damage. Not shown are the additional storms that formed ahead of this line, to the east of the radar range over north-central and northeastern Minnesota.
Radar loop courtesy of College of DuPage; data from NOAA/National Weather Service
Please note, damage surveys are still underway and the National Weather Service indicates it may be weeks before results are finalized.
Waves of extremely intense thunderstorms Friday night and early Saturday (June 20-21, 2025) produced very large hail, along with the strongest measured winds in Minnesota in almost 13 years, resulting in widespread and in some cases heavy damage, particularly in the Bemidji area.
Strong thunderstorms had been developing across the region since Thursday, as a warm humid air mass that ultimately would fuel an intense weekend heat wave, worked into Minnesota from the southwest. The incoming sultry air mass was replacing much cooler conditions, and in the transitional area between the two different types of weather, winds aloft were quite strong. This transitional area had access to deep and potent instability, along with the kinetic energy from the strong winds aloft to make already strong thunderstorms more intense, faster-moving, and longer-lasting. By Friday afternoon, a region from eastern Montana through northeastern Minnesota had become primed for an explosive outbreak of thunderstorms.
Thunderstorms developed in Montana and North Dakota long before they arrived in Minnesota. Whereas long journeys often cause thunderstorm complexes to weaken, especially after dark, this particular set-up allowed storms to maintain or even increase intensity hours after forming, and long after dark.
Almost countless thunderstorms seemed to form between Friday afternoon and Saturday morning, but there were really two separate storm complexes of interest. The first was a morphing band of severe thunderstorms that formed in central and eastern Montana around 3 PM and raced eastward, producing large hail and very strong winds along the way. The second was an area of isolated "supercell" thunderstorms that formed over central and eastern North Dakota, producing large hail and tornadoes while drifting eastward during the late afternoon and evening. These two complexes merged well after dark and entered Minnesota just before midnight. It was near the time of this merger that an intense tornado struck near Enderlin, ND, killing at least three people, and producing "at least EF-3" damage, though surveys had not been finalized as of June 24.
In Minnesota, the intense storm complex produced very strong winds, beginning with a gust to 81 mph near Waukon in Norman county around 1130 PM. Several other gusts between 65 and 85 mph were measured or observed over the next hour, but as one area of storms re-intensified, the major event of the evening for Minnesota unfolded. Wind gusts reached 92, and then 106 mph at the Bemidji airport just before 1 AM, followed by a massive power outage and reports of widespread and heavy damage. Nearly 60 thousand customers lost power in northwestern Minnesota, spread over nearly a dozen counties. As of Tuesday June 24, about 2,000 customers still had no power, mostly, but not entirely in the Bemidji area.
The extreme winds snapped and uprooted trees; peeled off roofs; knocked down power lines and transmission towers; flipped vehicles; and produced secondary damage to structures and vehicles throughout the area. The damage was so severe that Lake Bemidji State Park closed for multiple days, and nearby Lake Itasca State Park and La Salle Lake State Recreation Area both had to limit availability of some facilities and services. It is currently unclear if stronger winds will be estimated from the damage, but we do know the 106 mph gust at Bemidji was the strongest measured gust in Minnesota since August 3, 2012, when a 107 mph gust was recorded by a road-weather sensor in Rothsay.
Other severe storms erupted in northern and northeastern Minnesota in the late night and early morning hours, before also being overtaken by the main batch of severe thunderstorms racing eastward across the Northland. Prior to that second merger, these other thunderstorms produced very large hail, including some larger than baseballs in parts of Itasca County.
This article will be updated as information is finalized.
Posted June 24, 2025
KAB