Another complex of thunderstorms developed the night of the 8th into the 9th across the Northern Plains and pushed eastward across the Northland during the morning hours. This round was not as intense as the round the previous morning, but did still produce some damaging winds and isolated flash flooding in parts of the Arrowhead as it moved through.
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Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS DLH wrote it up.
Another complex of thunderstorms developed the night of the 8th into the 9th across the Northern Plains and pushed eastward across the Northland during the morning hours. This round was not as intense as the round the previous morning, but did still produce some damaging winds and isolated flash flooding in parts of the Arrowhead as it moved through.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Duluth, MN wrote its last area forecast discussion before the first event at Aug 9, 5:39 AM CST, 15 minutes earlier. Its key messages:
Area Forecast Discussion National Weather Service Duluth MN 639 AM CDT Sat Aug 9 2025 .KEY MESSAGES... - Scattered severe thunderstorms are expected to continue to affect the area early this morning, with another round of storms possible for northwest Wisconsin this afternoon. All modes of severe weather are possible. - A drier airmass moves into the area today, producing more comfortable conditions for the weekend with highs closer to normal values. - Periodic shower and thunderstorm chances return for next week along with near normal temperatures. && .DISCUSSION... Issued at 400 AM CDT Sat Aug 9 2025 A trough axis ahead of a cold front advancing across Minnesota early this morning has generated clusters of showers and thunderstorms which are moving northeast across the Northland. Some of these storms have been strong to severe, with the potential for strong winds and hail. I expect this general pattern to continue for the next several hours as the boundaries progress slowly east early this morning. This initial wave of convection should move east by mid morning, though there may be some festering weaker convection that lingers longer. Another round of showers and storms may develop along the front that may push across the far eastern portions of the CWA this afternoon/early evening before the front finally exits the region to the east. The strongest storms will be the next several hours with the best MUCAPE and shear along and ahead of the front. If we can get some more sustained convection going, we may have a risk for training of storms which may lead to heavy rainfall and flash flooding concerns. However, this is going to dependent on getting those repeat storms over the same areas. Behind the front a much more comfortable airmass will move into the area. Upstream dewpoints dip down into the 50s, which will allow overnight lows to dip to near or below 60 for the first time in several days, with the coolest night Sunday night. While today will still be somewhat warm and humid with highs still in the 80s nearly everywhere, Sunday will be be cooler, only getting into the mid 70s to mid 80s. The main upper low which has been the main driver of this hot, humid and somewhat wet last few days pushes northeast of the region by late in the weekend, but leaves a broad upper level trough that lingers over the Northland through at least the middle part of this week. With it in the vicinity, we should have some small, mostly diurnally driven pops for Monday and Tuesday. The upper level trough shifts east allowing ridging to build in for the latter half of the week, allowing heat to begin building once again through the end of the work week. Precipitation chances return to the forecast for later in the week as well, though there is low confidence in the timing. && .AVIATION /12Z TAFS THROUGH 12Z SUNDAY/... Issued at 639 AM CDT Sat Aug 9 2025 A mixture of VFR and MVFR conditions as of issuance time as storms move across the region early this morning. Storms have now moved east of KINL, KHIB and KBRD, and no more storms are expected this morning for those sites. I have left another hour of VCTS for KDLH, and then it will be done there too. KHYR is the site which is currently being impacted by some post storm showers with MVFR visibilities and ceilings. Expect these lower conditions to linger another hour or two, then return to VFR, even with showers in the vicinity. Most sites will return to VFR by 14z and remain that way through the rest of the TAF period. There are good signals for fog to develop after 05z for KHYR tonight, and have put in deteriorating visibility values beginning around 05z, eventually lowering to IFR through 12z Sunday. && .MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/... Issued at 400 AM CDT Sat Aug 9 2025 The main concern the next 12 to 18 hours will be convection that should move off the land and out over the lake before either dissipating or moving off to the east. Wind gusts over 40 knots, hail and heavy rainfall will all be possible with these storms this morning. A cold front will follow the storms with winds becoming southwesterly by mid day today and continuing through at least Monday, mostly from 5 to 15 knots. A period of stronger winds to around 20 knots will develop along the North Shore north of Taconite Harbor, causing locally built up waves Sunday afternoon. A Small Craft Advisory may be needed. For the open water discussion, refer to the NWS Marquette Area Forecast Discussion at weather.gov/mqt. && .DLH WATCHES/WARNINGS/ADVISORIES... MN...None. WI...None. MARINE...None. && DISCUSSION...LE AVIATION...LE MARINE...LE
Hazardous Weather Outlook National Weather Service Duluth MN 417 AM CDT Sat Aug 9 2025 MNZ010>012-018>021-025-026-033>038-WIZ001>004-006>009-100930- Koochiching-North St. Louis-Northern Cook/Northern Lake- North Itasca-Central St. Louis-Southern Lake/North Shore- Southern Cook/North Shore-North Cass-South Itasca-South Cass- Crow Wing-Northern Aitkin-South Aitkin-Carlton/South St. Louis- Pine-Douglas-Bayfield-Ashland-Iron-Burnett-Washburn-Sawyer-Price- 417 AM CDT Sat Aug 9 2025 This Hazardous Weather Outlook is for portions of northeast Minnesota and northwest Wisconsin. .DAY ONE...Today and Tonight Strong to severe thunderstorms are expected across portions of northeast Minnesota and northwest Wisconsin this morning with damaging winds to 60 mph, heavy rainfall, large hail to quarter size, and dangerous lightning. This afternoon, thunderstorm chances will continue across northwest Wisconsin. A few storms could be strong to severe with gusty winds, large hail, locally heavy rain, and dangerous lightning .DAYS TWO THROUGH SEVEN...Sunday through Friday There is a 30 percent chance of thunderstorms across northeast Minnesota on Monday, and a 20 percent chance across northeast Minnesota and northwest Wisconsin on Thursday and Friday. .SPOTTER INFORMATION STATEMENT... Skywarn spotters may be needed today. LSZ121-140>148-150-100930- Bayfield to Oak Point WI-Grand Portage to Grand Marais MN- Grand Marais to Taconite Harbor MN- Taconite Harbor to Silver Bay Harbor MN- Silver Bay Harbor to Two Harbors MN-Two Harbors to Duluth MN- Duluth MN to Port Wing WI-Port Wing to Sand Island WI- Sand Island to Bayfield WI-Oak Point to Saxon Harbor WI- Outer Apostle Islands Beyond 5 NM from Mainland- 417 AM CDT Sat Aug 9 2025 This Hazardous Weather Outlook is for portions of Lake Superior and the Nearshore waters of western Lake Superior. .DAY ONE...Today and Tonight Scattered thunderstorms this morning, decreasing in coverage this afternoon. Wind gusts to 35 kts, dangerous cloud to water lightning and small hail are possible. .DAYS TWO THROUGH SEVEN...Sunday through Friday Gusty southwest winds on Sunday may produce hazardous conditions for small craft along the North Shore, north of Taconite Harbor. There is a 30 percent chance of thunderstorms on Monday, and a 20 percent chance on Thursday and Friday. PA More information may be obtained at the following web address: http://www.weather.gov/duluth
The Duluth radar (KDLH), 151 km away, was scanning. The volume nearest the first event began at 11:55 UTC.
1 thunderstorm wind, 1 flash flood. Local standard time, as filed.
One large tree was uprooted as well as a couple of cedar trees snapped in half.
Fast moving water was running over County Road 14 and scouring out the road.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Minnesota in 2025Every state in 2025This day in weather historyWarnings in Minnesota, August 2025
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 1290317, 1290316.