Alert archive / Minnesota / Flash Flood Warnings in 2025

Flash Flood Warning 18, NWS Twin Cities, MN

August 17, 2025Redwood County, Minnesota

NWS Twin Cities, MN issued this flash flood warning at Aug 17, 2025, 2:12 AM CDT for Redwood County, Minnesota. It was in force for 5 hr. 2 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Aug 17, 2025, 2:12 AM CDT (07:12 UTC)
Expired: Aug 17, 2025, 7:15 AM CDT
In force: 5 hr
Issued by: NWS Twin Cities, MN
Area: Storm-based polygon
Flood severity: None

County Redwood County, MN

The radar

The Sioux Falls radar (KFSD), 134 km from the middle of the area, began a volume at 07:11 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What was reported inside it

Time	Report	Where	Remark
Aug 17, 5:00 AM CDT	FLOOD	2 Wnw Walnut Grove, MN	Water on bridge near Highway 14 and Camp Ave.
Aug 17, 5:00 AM CDT	FLOOD	3 N Sanborn, MN	Standing water over portion of Highway 71. Time estimated.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Minneapolis, MN (KMPX), launched 00:00Z, 7.2 hours before the alert went out and 153 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 756 J/kg
Mixed-layer CIN: -229 J/kg
Mixed-layer LCL: 1115 m above ground
0-6 km bulk shear: 31 kt
0-1 km storm-relative helicity: -6 m²/s²
0-3 km storm-relative helicity: 104 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.1

Open this sounding in Storm Lab

The text

As transmitted.

036 
WGUS53 KMPX 170712
FFWMPX
MNC127-171215-
/O.NEW.KMPX.FF.W.0018.250817T0712Z-250817T1215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Twin Cities/Chanhassen MN
212 AM CDT Sun Aug 17 2025

The National Weather Service in the Twin Cities has issued a

* Flash Flood Warning for...
  Southwestern Redwood County in southwestern Minnesota...

* Until 715 AM CDT.

* At 212 AM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1.5 and 3 inches of 
  rain have fallen. Additional rainfall amounts of 1 to 3 inches are 
  possible in the warned area. Flash flooding is ongoing or expected 
  to begin shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar indicated.

  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...
  Walnut Grove, Lamberton, Sanborn, Revere and Wanda.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

&&

LAT...LON 4428 9559 4426 9540 4433 9527 4428 9510
      4428 9511 4420 9511 4420 9559

FLASH FLOOD...RADAR INDICATED

$$

TDH

The office that day

Everything else NWS Twin Cities, MN issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 16, 9:30 PM CDT	River Flood Warning	MPX	Chippewa, Renville, Yellow Medicine	15 days
Aug 17, 1:15 AM CDT	Flash Flood Warning	MPX	Redwood	6 hr
Aug 17, 1:52 AM CDT	Flash Flood Warning	MPX	Steele, Waseca	6 hr
Aug 17, 4:54 AM CDT	Special Weather Statement	MPX	Faribault, Waseca	66 min
Aug 17, 6:22 AM CDT	Flash Flood Warning	MPX	Blue Earth, Watonwan	3 hr
Aug 17, 8:14 AM CDT	Flash Flood Warning	MPX	Redwood	3 hr
Aug 17, 8:17 AM CDT	Special Weather Statement	MPX	Brown, Redwood, Watonwan, Yellow Medicine	6 hr
Aug 17, 8:24 AM CDT	Special Weather Statement	MPX	Blue Earth, Faribault, Freeborn, Waseca	5 hr
Aug 17, 10:06 AM CDT	River Flood Warning	MPX	Brown	6 days
Aug 17, 10:06 AM CDT	River Flood Warning	MPX	Brown	6 days
Aug 17, 10:06 AM CDT	River Flood Warning	MPX	Redwood	59 hr
Aug 17, 2:17 PM CDT	Flood Watch	MPX	Anoka, Benton, Blue Earth, Brown, Carver, Chippewa and 36 more	20 hr
Aug 17, 6:59 PM CDT	Tornado Warning	MPX	Faribault	31 min

Nearby

Flash Flood Warnings in Minnesota, 2025 Every flash flood warning in 2025

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.