Flash Flood Warning Issued for Plymouth County IA and Union County SD
This alert is no longer in effect.
NOAA issued it on May 26, 2026, 3 months ago. Warnings of this kind stay in effect for hours to a few days, so this page is a historical record of what was issued, not a current warning. For conditions where you are right now, check weather.gov (US), weather.gc.ca (Canada), the Met Office (UK), or the Bureau of Meteorology (Australia).
Areazine synthesizes this NWS weather alert directly from NOAA's official public data feed. See our methodology for full source attribution and refresh cadence.
NWS Sioux Falls SD has issued a Flash Flood Warning for southwestern Plymouth County in Iowa and east central Union County in South Dakota until 5:15 AM CDT.
Read this weather record in 30 seconds
- Record type
- Flash Flood Warning
- Affected area
- Northwestern Iowa and Southeastern South Dakota
- Issued
- May 26, 2026
- Issuing authority
- NWS Sioux Falls SD
Flood notices turn on location and timing. Treat the named area as this record's scope; do not assume nearby counties, parishes, or waterways were included.
Record status: historical. It was issued 3 months ago; use the issuing agency's live warning service for current conditions in Northwestern Iowa and Southeastern South Dakota.
Alert Details
Flash Flood Warning issued by NWS Sioux Falls SD. Effective from May 17 at 1:10 AM CDT until May 17 at 5:15 AM CDT. Severity: Severe. Certainty: Likely. Urgency: Immediate.
Affected Areas
Southwestern Plymouth County in northwestern Iowa and East Central Union County in southeastern South Dakota. Some locations that will experience flash flooding include Elk Point.
What You Should Do
Turn around, don't drown when encountering flooded roads. Most flood deaths occur in vehicles. Be especially cautious at night when it is harder to recognize the dangers of flooding.
Expected Conditions
At 1:10 AM CDT, Doppler radar indicated thunderstorms producing heavy rain across the warned area. Between 1.5 and 2.5 inches of rain have fallen. The expected rainfall rate is 0.5 to 1 inch in 1 hour. Additional rainfall amounts of 0.5 to 1.5 inches are possible. Flash flooding is ongoing or expected to begin shortly. Hazard: Flash flooding caused by slow moving thunderstorms.
Timeline
Alert effective May 17 at 1:10 AM CDT. Expires and ends May 17 at 5:15 AM CDT.
Original source: NOAA Official Notice ↗
Related Weather Alerts
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Two Areazine-derived peer sets for this NWS weather alert: nearest notices by body length and by same severity near the same agency date. Peers come from other categories so they are not the same-feed Related list above.
Similar body length
Nearest notices by article body length (1,091 characters here).
Similar severity timing
Same severity (high) notices issued closest in time to May 26, 2026.
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