NWS Sioux Falls SDFF.W 0012September 6, 2026
Flash Flood Warning: Lyon, Osceola and Nobles, IA and MN
The National Weather Service office in Sioux Falls issued a flash flood warning for Lyon, Osceola and Nobles in Iowa, Minnesota, which was in force until 4:00 p.m. local time on September 6. It was the 12th flash flood warning the NWS office in Sioux Falls issued in 2026. Iowa had 17 flash flood warnings in September 2026, against 9 in an average September of 2008-2025 (Iowa's flash flood warnings by year).
ExpiredWarning
In force for 4 hours; it has expired. The agency may have replaced it with a new notice.
The notice
- Issued by
- National Weather Service, Sioux Falls SD
- Area
- Lyon, Osceola and Nobles
- State
- Iowa
- Level
- Warning
- Issued
- 11:58 a.m. CDT, September 6, 2026
- Expires
- 4:00 p.m. CDT, September 6, 2026
- CAP severity, certainty, urgency
- Severe, Likely, Immediate
- VTEC event
- KFSD FF.W 0012
- Official source
- National Weather Service: the notice at its source
Flash Flood Warnings in Iowa since 2008Every warning type in Iowa
Source: National Weather Service: the notice at its source. AreaZine rebuilds this page from the agency's record; the agency's page is the one to act on. A U.S. Government work, in the public domain.
The notice as issued
FFWFSD The National Weather Service in Sioux Falls has issued a * Flash Flood Warning for... Northeastern Lyon County in northwestern Iowa... Northwestern Osceola County in northwestern Iowa... Southern Nobles County in southwestern Minnesota... * Until 400 PM CDT. * At 1158 AM CDT, Doppler radar and automated rain gauges indicated thunderstorms producing heavy rain across the warned area. Between 1 and 3 inches of rain have fallen. The expected rainfall rate is 1.5 to 3 inches in 1 hour. Additional rainfall amounts of 2 to 4 inches are possible in the warned area. Flash flooding is ongoing or expected to begin shortly. HAZARD...Flash flooding caused by thunderstorms. SOURCE...Radar and automated gauges. IMPACT...Flash flooding of small creeks and streams, urban areas, highways, streets and underpasses as well as other poor drainage and low-lying areas. * Some locations that will experience flash flooding include... Worthington, Ellsworth, Little Rock, Rushmore and Bigelow. Low lying portions of Interstate 90 near and west of Worthington could see standing water.
What the agency told people to do
Turn around, don't drown when encountering flooded roads. Most flood deaths occur in vehicles. Be aware of your surroundings and do not drive on flooded roads. Flooding is occurring or is imminent. It is important to know where you are relative to streams, rivers, or creeks which can become killers in heavy rains. Campers and hikers should avoid streams or creeks. Please report observed flooding to local emergency services or law enforcement and request they pass this information to the National Weather Service when you can do so safely.
Source: National Weather Service: the notice at its source. The text is the agency's, unedited. A U.S. Government work, in the public domain.