Alert archive / Wisconsin / Flash Flood Warnings in 2025

Flash Flood Warning 13, NWS Milwaukee, WI

August 10, 2025Ozaukee County, Washington County, Wisconsin

NWS Milwaukee, WI issued this flash flood warning at Aug 10, 2025, 1:38 AM CDT for Ozaukee County, Washington County, Wisconsin. It was in force for 4 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Aug 10, 2025, 1:38 AM CDT (06:38 UTC)
Expired
Aug 10, 2025, 5:30 AM CDT
In force
4 hr
Issued by
NWS Milwaukee, WI
Area
Storm-based polygon
Flood severity
None

Counties Ozaukee County, WI, Washington County, WI

The radar

The Milwaukee radar (KMKX), 46 km from the middle of the area, began a volume at 06:38 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.

The nearest sounding before it

Green Bay/Straub, WI (KGRB), launched 00:00Z, 6.6 hours before the alert went out and 135 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-pSkew-T log-p diagram, Green Bay/Straub, WI at 00:00Z on 2025-08-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 42 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Green Bay/Straub, WI at 00:00Z on 2025-08-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 168 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
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
42 J/kg
Mixed-layer CIN
-349 J/kg
Mixed-layer LCL
1159 m above ground
0-6 km bulk shear
36 kt
0-1 km storm-relative helicity
168 m²/s²
0-3 km storm-relative helicity
155 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

284 
WGUS53 KMKX 100638
FFWMKX
WIC089-131-101030-
/O.NEW.KMKX.FF.W.0013.250810T0638Z-250810T1030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Milwaukee/Sullivan WI
138 AM CDT Sun Aug 10 2025

The National Weather Service in Milwaukee/Sullivan has issued a

* Flash Flood Warning for...
  Southern Ozaukee County in southeastern Wisconsin...
  Southern Washington County in southeastern Wisconsin...

* Until 530 AM CDT.

* At 138 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. Additional rainfall amounts of 
  1.5 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 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...
  Northern Milwaukee, Mequon, Hartford, Brown Deer, Grafton, 
  Cedarburg, Jackson, Bayside, Thiensville, Germantown, River Hills, 
  Richfield, Kirchhayn, Hubertus and Holy Hill.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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.

&&

LAT...LON 4331 8842 4332 8789 4325 8791 4319 8789
      4320 8842

FLASH FLOOD...RADAR AND GAUGE INDICATED

$$

GEHRING
1 follow-up statement
871 
WGUS73 KMKX 100742
FFSMKX

Flash Flood Statement
National Weather Service Milwaukee/Sullivan WI
242 AM CDT Sun Aug 10 2025

WIC089-131-101030-
/O.CON.KMKX.FF.W.0013.000000T0000Z-250810T1030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Ozaukee WI-Washington WI-
242 AM CDT Sun Aug 10 2025

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 530 AM CDT EARLY THIS 
MORNING FOR SOUTHERN OZAUKEE AND SOUTHERN WASHINGTON COUNTIES...

At 242 AM CDT, Local law enforcement reported flash flooding of 
streets in Germantown and on Interstate 41 at County Line Road. 
Between 2 and 4 inches of rain have fallen. Additional rainfall 
amounts of 1 to 2 inches are possible in the warned area. Flash 
flooding is already occurring.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Law enforcement reported.

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...
  Northern Milwaukee, Mequon, Hartford, Brown Deer, Grafton, 
  Cedarburg, Jackson, Bayside, Thiensville, Germantown, River Hills, 
  Richfield, Kirchhayn, Hubertus and Holy Hill.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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.

&&

LAT...LON 4331 8842 4332 8789 4325 8791 4319 8789
      4320 8842

FLASH FLOOD...OBSERVED

$$

GEHRING

The office that day

Everything else NWS Milwaukee, WI issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 9, 8:04 PM CDTFlash Flood WarningMKXMilwaukee, Waukesha6 hr
Aug 9, 10:23 PM CDTSpecial Weather StatementMKXJefferson52 min
Aug 9, 11:14 PM CDTFlash Flood WarningMKXWaukesha4 hr
Aug 9, 11:29 PM CDTAreal Flood AdvisoryMKXWaukesha3 hr
Aug 10, 12:02 AM CDTAreal Flood AdvisoryMKXDodge, Milwaukee, Ozaukee, Washington, Waukesha3 hr
Aug 10, 1:07 AM CDTFlash Flood Warning Considerable damage threatMKXMilwaukee, Waukesha4 hr
Aug 10, 1:17 AM CDTRiver Flood WarningMKXWaukesha7 days
Aug 10, 1:18 AM CDTRiver Flood WarningMKXMilwaukee21 days
Aug 10, 2:03 AM CDTRiver Flood WarningMKXMilwaukee21 days
Aug 10, 2:05 AM CDTRiver Flood WarningMKXMilwaukee21 days
Aug 10, 2:38 AM CDTRiver Flood WarningMKXWaukesha4 hr
Aug 10, 2:44 AM CDTRiver Flood WarningMKXMilwaukee3 hr
Aug 10, 3:32 AM CDTAreal Flood AdvisoryMKXDodge, Ozaukee, Washington3 hr
Aug 10, 5:02 AM CDTAreal Flood WarningMKXMilwaukee, Waukesha14 hr
Aug 10, 5:16 AM CDTFlash Flood WarningMKXOzaukee, Washington3 hr
Aug 10, 5:27 AM CDTRiver Flood WarningMKXMilwaukee47 hr
Aug 10, 6:52 AM CDTAreal Flood AdvisoryMKXDane3 hr
Aug 10, 7:59 AM CDTFlash Flood Warning Considerable damage threatMKXMilwaukee, Ozaukee, Washington, Waukesha3 hr
Aug 10, 8:55 AM CDTFlash Flood WarningMKXDodge, Washington, Waukesha3 hr
Aug 10, 9:20 AM CDTAreal Flood WarningMKXOzaukee, Washington10 hr
Aug 10, 11:03 AM CDTAreal Flood WarningMKXMilwaukee, Ozaukee, Washington, Waukesha8 hr
Aug 10, 11:42 AM CDTRiver Flood WarningMKXOzaukee4 days
Aug 10, 11:42 AM CDTRiver Flood WarningMKXOzaukee4 days
Aug 10, 11:49 AM CDTAreal Flood WarningMKXDodge, Washington, Waukesha7 hr
Aug 10, 2:53 PM CDTMarine Dense Fog AdvisoryMKX6 hr
Aug 10, 5:36 PM CDTAreal Flood WarningMKXDodge, Jefferson, Milwaukee, Ozaukee, Racine, Washington and 1 more16 hr

Nearby

Flash Flood Warnings in Wisconsin, 2025Every 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.