Two separate rounds of storms moved through Grant County on August 10th bringing both heavy rain and flash flooding along with them. The first round of storms moved through during the early morning hours bringing widespread flooding issues to northern portions of the county.
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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 ARX wrote it up.
Two separate rounds of storms moved through Grant County on August 10th bringing both heavy rain and flash flooding along with them. The first round of storms moved through during the early morning hours bringing widespread flooding issues to northern portions of the county. The worst of the flash flooding was in the town of Bagley where a debris blockage resulted in storm water inundating residences in the town. Later in the afternoon, a secondary round of storms moved through the area which brought additional instances of flooding.
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 La Crosse, WI wrote its last area forecast discussion before the first event at Aug 10, 5:28 AM CST, 11 minutes earlier. Its key messages:
Area Forecast Discussion National Weather Service La Crosse WI 628 AM CDT Sun Aug 10 2025 .KEY MESSAGES... - Heavy rainfall and flooding possible across southwest Wisconsin and adjacent northeast Iowa through the day (20% chance of over 3"). A Flood Watch remains in effect there, but now ends earlier (7pm) as the heavy rain threat will shift east of the area tonight. - Rain chances were increased (50-areawide today as a weather system tracks from southwest to northeast across the area this afternoon. - A tranquil pattern is setting up for the next week with low rain chances and temperatures near seasonal normals. Some warm up possible late week. && .DISCUSSION... Issued at 343 AM CDT Sun Aug 10 2025 Todays Heavy Rainfall Threat, Early Ending to Flood Watch Current 3 am radar depicts an axis of storms from southwest WI back to southwest Iowa associated with an increasing low-level jet and moisture transport axis. A bit troubling is the linear band to the storms parallel to the flow - this sets up a training situation. That axis and air mass is still the potent rain maker with near-record precipitable water (Davenport IA sounding at 7pm Sat - 1.91") and deep warm cloud depths over 4 km. Some of that materialized north of La Cross through Rochester with a 5" band of rain Saturday. Over 9 inches of rain fell in the Milwaukee area tonight from that air mass in repeat storms. SPC mesoa shows MUCAPE of about 3000 J/Kg over IA/IL, decreasing northward to about 1k on I-90, so plenty of instability. Eyes are also on the convective swirling complex in southeast Neb which has begun to lift northeast toward the area. Rainfall observations show 1.46"/hr in Lincoln Neb in the last hour. Predictability remains fair to okay with this pattern but the model guidance has clear disagreements between the global and CAM solutions with the evolution of the rainfall axis and very potent rainfall axis. The global models, which have a north bias (toward stable air) to heavy rain, continue to show these differences through Monday while CAM solutions agree that the heavy rainfall threat ends today. Tend to give the nod to the CAMS when convectively driven evolution is important....like today. Storms will continue to develop and repeat this morning south of I-90 mainly, with the potent rain axis across southwest WI and adjacent northeast IA. At the same time, the Nebraska convectively-enhanced vortex will track toward the area, arriving in northeast IA by mid/late morning and causing a showery Sunday with isolated storms for much of the afternoon across the area. This convective vort max will also provide a progression to the weather, and an end to any repeat storm activity in the Flood Watch in SW WI and NE IA, and overall clear the weather east of the area by early evening. Thus, have increased rain chances quite a bit across the forecast area as the vort max transits today per HRRR guidance - which has been very consistent run-to-run and the radar is supporting its good handle on the forecast. Flooding risk is mainly this morning before the vort max disrupts the training setting up. Rain amounts today across the Flood Watch look to be in the 1-3" range depending on the amount of repeat storms occur. Should any repeat/anchored storm pattern setup, rainfall rates of 1"/hr will quickly add up. The 10.00Z HREF suggests 20% probabilities of 3" in the Flood Watch. Tonight and Monday, those probabilities shift southeast of the area and drastically lower /20% chance of 1"/. Today, the HREF QPF max is 6-7" which is always unsettling as a ceiling and the local prob matched mean, a better measure of realistic amounts vs the mean, is 4-5". This reinforces the Flood Watch is valid today and we need to watch rainfall totals through the morning in this training regime that has developed now on radar. Since this area saw very little rain Saturday, the soils can take 3" without much problem, thus flooding risk has decreased overall. Without a second heavy expected tonight, have changed the expiration time on the Flood Watch to 7 pm today. Seasonable August Weather Next Week A zonal flow pattern will take over for much of the week with weak impulses moving through causing low rain chances. A bit stronger shortwave trough and front in northwest flow sweeps through Tuesday to bring in some lower dewpoint air for a couple days before ridge and heat building probabilities increase for late week /highs in the 90s/. The Tuesday front may bring some showers with it. && .AVIATION /12Z TAFS THROUGH 12Z MONDAY/... Issued at 625 AM CDT Sun Aug 10 2025 Low clouds and fog have overspread much of the area creating MVFR to LIFR CIGs and visibilities at the terminals. The fog is expected to gradually burn off over the coming hours with CIGs improving between mid morning and early afternoon. A large swath of training showers and storms are moving northeast through portions of NE Iowa and SW Wisconsin creating MVFR to IFR CIGs and visibilities. These will spread further north into the terminals through the morning. Further refinements may be needed for the timing of showers and storms going forward but have based timing off of latest radar trends. Precipitation chances generally decrease through the afternoon hours, coming to an end after 00Z. Fog/mist is expected to build in again overnight tonight. Have introduced MVFR/IFR visibilities for this time period at the terminals with consistent indications from guidance. Light winds out of the south this morning will become more westerly by the afternoon before returning to light and variable once again overnight tonight. && .HYDROLOGY... Issued at 343 AM CDT Sun Aug 10 2025 Most rivers near and north of I-90 have handled the 3-5" rains well with rises but little flooding. Rivers located in the Flood Watch across northeast Iowa into southwest Wisconsin will be the most susceptible to flooding, most notably the Turkey River and Kickapoo River. Ensemble guidance indicates that most points along these rivers should remain either below or nudge into Action Stage given the most likely rainfall amounts of 1 to 3 inches. Values above 5 inches could result in rises along the Turkey river reaching Minor to Moderate Flood Stage (5-10% chance), while values of 3-4 inches (10-20%) would be needed for Minor flooding on the Kickapoo. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...Flood Watch through this evening for WIZ054-055-061. MN...None. IA...Flood Watch through this evening for IAZ029-030. && DISCUSSION...Baumgardt AVIATION...Barendse HYDROLOGY...Baumgardt
Hazardous Weather Outlook National Weather Service La Crosse WI 405 AM CDT Sun Aug 10 2025 IAZ008>011-018-019-MNZ079-086>088-094>096-WIZ017-029-032>034- 041>044-053-111200- Mitchell-Howard-Winneshiek-Allamakee-Floyd-Chickasaw-Wabasha- Dodge-Olmsted-Winona-Mower-Fillmore-Houston-Taylor-Clark-Buffalo- Trempealeau-Jackson-La Crosse-Monroe-Juneau-Adams-Vernon- 405 AM CDT Sun Aug 10 2025 This Hazardous Weather Outlook is for portions of southeast Minnesota...northeast Iowa and southwest into central Wisconsin. .DAY ONE...Today and Tonight Scattered storms will be possible today. The main threat will be lightning. .DAYS TWO THROUGH SEVEN...Monday through Saturday No hazardous weather is expected at this time. .SPOTTER INFORMATION STATEMENT... No action needed. .EMERGENCY MANAGEMENT COORDINATION... No webinar is scheduled. IAZ029-030-WIZ054-055-061-111200- Fayette-Clayton-Crawford-Richland-Grant- 405 AM CDT Sun Aug 10 2025 This Hazardous Weather Outlook is for portions of northeast Iowa and southwest Wisconsin. .DAY ONE...Today and Tonight Flood Watch through today. Storms producing heavy rainfall expected across southwest WI and portions of northeast IA today. If storms repeat over the same locations, rainfall totals of 2 to 4 inches may occur (15-25% chance), with locally higher amounts, which could lead to flash flooding. .DAYS TWO THROUGH SEVEN...Monday through Saturday No hazardous weather is expected at this time. .SPOTTER INFORMATION STATEMENT... No action needed. .EMERGENCY MANAGEMENT COORDINATION... No webinar is scheduled. Baumgardt
Special Weather Statement National Weather Service La Crosse WI 457 AM CDT Sun Aug 10 2025 MNZ088-095-096-WIZ032>034-041-042-101200- Winona-Fillmore-Houston-Buffalo-Trempealeau-Jackson-La Crosse- Monroe- Including the cities of Winona, Preston, Caledonia, Alma, Arcadia, Whitehall, Black River Falls, La Crosse, Sparta, and Tomah 457 AM CDT Sun Aug 10 2025 ...Pockets of Dense Fog This Morning... Fog has formed over parts of west-central Wisconsin and southeast Minnesota with some visibilities dropping below one-quarter of a mile. Locally, there could be near zero visibility in dense fog through 7 am. If traveling, be sure to slow down in the fog. Dont make risky vehicle maneuvers like turning around in the highway when visibility is very low. Oncoming traffic will have little time to stop. Baumgardt
Special Weather Statement National Weather Service La Crosse WI 636 AM CDT Sun Aug 10 2025 MNZ079-086>088-094>096-WIZ032>034-041-042-101300- Wabasha-Dodge-Olmsted-Winona-Mower-Fillmore-Houston-Buffalo- Trempealeau-Jackson-La Crosse-Monroe- Including the cities of Wabasha, Dodge Center, Rochester, Winona, Austin, Preston, Caledonia, Alma, Arcadia, Whitehall, Black River Falls, La Crosse, Sparta, and Tomah 636 AM CDT Sun Aug 10 2025 ...Pockets of Dense Fog This Morning... Fog has formed over parts of west-central Wisconsin and southeast Minnesota with some visibilities dropping below one-quarter of a mile. Locally, there could be near zero visibility in dense fog through 8 am. If traveling, be sure to slow down in the fog. Dont make risky vehicle maneuvers like turning around in the highway when visibility is very low. Oncoming traffic will have little time to stop. Baumgardt
The La Crosse radar (KARX), 87 km away, was scanning. The volume nearest the first event began at 11:37 UTC.
3 flash flood. Local standard time, as filed.
Law enforcement reported water over highway 133 in Blue River with some homes being evacuated. Additionally, street flooding was reported by emergency management in Boscobel in northern Grant County.
Emergency management reported debris blocking a railroad bridge resulting in storm water to overflow into portions of Bagley. This resulted in the inundation of several residences and prompted evacuations in the town.
Emergency management reported numerous streets and intersections were closed due to flash flooding in Lancaster.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Wisconsin in 2025Every state in 2025This day in weather historyWarnings in Wisconsin, 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: 1288838, 1288845, 1288846.