Another round of locally heavy rain across the Upper Big Sioux Basin resulted in downstream minor flooding along portions of the Middle Big Sioux River.
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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 FSD wrote it up.
Another round of locally heavy rain across the Upper Big Sioux Basin resulted in downstream minor flooding along portions of the Middle Big Sioux River.
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 Sioux Falls, SD wrote its last area forecast discussion before the first event at Aug 6, 1:56 PM CST, 1 hour 4 minutes earlier.
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</html>The national radar mosaic for the moment the first event began.
2 flood. Local standard time, as filed.
The Big Sioux River near Estelline rose above flood stage on the afternoon of August 6th, cresting around 0.47 feet above flood stage (1644.47 ft) on August 8th. The river then fell below flood stage on the evening of August 10th.
The Big Sioux River near Bruce rose above flood stage on the evening of August 7th, cresting around 0.47 feet above flood stage (8.47 ft) on August 8th. The river then fell below flood stage on the morning of August 11th.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in South Dakota in 2025Every state in 2025This day in weather historyWarnings in South Dakota, 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: 1282764, 1282765.