Flash Flood Warning 12, NWS Milwaukee, WI

848 
WGUS73 KMKX 100737
FFSMKX

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

WIC079-133-101000-
/O.CON.KMKX.FF.W.0012.000000T0000Z-250810T1000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Milwaukee WI-Waukesha WI-
237 AM CDT Sun Aug 10 2025

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 5 AM CDT EARLY THIS 
MORNING FOR MILWAUKEE AND EASTERN WAUKESHA COUNTIES...

At 237 AM CDT, Local law enforcement and the public reports numerous 
instances of flash flooding of streets and creeks, including 
stranded vehicles and flooded basements. Between 5 and 9 inches of 
rain have fallen. Additional rainfall amounts of 1 to 3 inches are 
possible in the warned area. Flash flooding is already occurring.

HAZARD...Life threatening flash flooding. Thunderstorms producing
         flash flooding.

SOURCE...Law enforcement reported.

IMPACT...Life threatening flash flooding of creeks and streams,
         urban areas, highways, streets and underpasses.

Some locations that will experience flash flooding include...
  Milwaukee, Waukesha, West Allis, Wauwatosa, New Berlin, 
  Brookfield, Greenfield, Menomonee Falls, Oak Creek, Muskego, South 
  Milwaukee, Cudahy, Whitefish Bay, Greendale, Pewaukee, Brown Deer, 
  Sussex, St. Francis, Hales Corners and Mukwonago.

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 4319 8827 4319 8790 4319 8789 4317 8788
      4313 8790 4310 8788 4307 8786 4305 8788
      4305 8789 4304 8790 4303 8790 4300 8789
      4298 8786 4296 8785 4293 8785 4291 8784
      4289 8785 4284 8783 4284 8831

FLASH FLOOD...OBSERVED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

GEHRING

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
828 PM CDT Sat Aug 9 2025

.KEY MESSAGES...

- Flood Watch expanded to cover southeast Wisconsin tonight
  until 7 AM CDT Monday. Numerous thunderstorms and heavy rain
  are expected over se WI into portions of south central WI.
  Flash flooding is possible especially in urban areas including
  the Milwaukee metro area.

- Additional periods of storms expected Sunday afternoon into
  Monday, posing additional heavy rainfall potential. A Flood
  Watch remains in effect through 7 AM Monday morning for all of
  S WI.

&&

.UPDATE...
Issued 828 PM CDT Sat Aug 9 2025

925-850 mb moisture transport is increasing out of the southwest
early this evening and riding up and over the outflow boundary
over far srn WI. In addition, corfidi vector ridging is present
over se WI along the PWAT axis of 2 inches. Expect numerous
thunderstorms and heavy rain to continue over se WI including
MKE this evening. Flash flooding will likely occur in these
areas. This could continue into overnight, but also refocus
farther west into south central WI as the swly LLJ of 25 kts
broadens into that area. The Flood Watch for the potential for
flash flooding has been expanded to include all of southern WI
until 12Z Mon.

Gehring

&&

.SHORT TERM...
Issued 300 PM CDT Sat Aug 9 2025

Tonight through Sunday night:

Synopsis/Mesoanalysis: A weak surface boundary is working into
southern Wisconsin this afternoon, encouraging shower and storm
development from the Madison metro north into the Fox River Valley.
Lift from the surface boundary is being further supported by subtle
MCV extending from central Wisconsin into the Wisconsin River
Valley, with an additional MCV apparent over the Waterloo, IA
vicinity. Expect shower and storm activity to continue sagging south
and east with the surface boundary through the remainder of the
afternoon, with additional storm development anticipated this
evening as the Waterloo MCV tracks into southern Wisconsin. An
isolated strong to severe storm is possible in this activity, with
damaging winds being the primary concern. A brief lull may follow
the evening activity, with additional storm development anticipated
after midnight as the low level jet ramps up. Torrential downpours
will be possible in this evening's & overnight's storms, which could
lead to hydro impacts across the area, with the greatest potential
for impacts (particularly any flash flooding) in areas experiencing
multiple rounds of storms. Additional storm development is
anticipated Sunday afternoon into Monday morning, with development
corridors being highly dependent on MCV's & where the progressing
surface boundary settles following tonight's convection. Additional
torrential downpours and flooding potential will exist in these
storms, with potential once more being maximized in areas of
training. A Flood Watch remains in effect through 7 AM Monday to the
northwest of the Milwaukee metro, where training potential will be
greatest.

Rest Of This Afternoon & Tonight: Heat and humidity will continue,
with heat indices in the upper 90s over southeastern Wisconsin. A
few spots will briefly climb to the 100 degree mark over this part
of the area. A high swimming risk continues through the first part
of this evening at Ozaukee and Sheboygan County beaches, with a
moderate swimming risk further south. Exercise extreme caution if
heading lakeside through this evening.

Quigley

&&

.LONG TERM...
Issued 300 PM CDT Sat Aug 9 2025

Monday through Saturday:

Synopsis: The surface boundary at the center of the short term's
shower and storm chances will linger across southern Wisconsin
during the Monday-Tuesday timeframe, supporting additional periods
of showers and thunderstorms. Much like in the short term period,
weak wind shear should keep severe potential lower in any Monday-
Tuesday activity, though a still very humid air mass will support
additional torrential downpour potential (particularly on Monday).
Additional hydrologic impacts are thus possible in early week
thunderstorms, particularly in regions experiencing repeated rounds
of heavy rainfall. What's left of the surface boundary will push
east of the region Tuesday night, resulting in a brief period of
west-northwest winds & slightly less humid conditions through
Wednesday. The briefly lower humidity will be short-lived, as re-
establishing south-southeasterly winds will push dew points upward
Wednesday night through Saturday. Additional periods of showers and
storms return to the forecast during this time period as
temperatures gradually trend upward.

Monday through Tuesday: With a surface boundary still draped across
the area, additional periods of showers and embedded storms are
forecast. Chances for storms are overall higher Monday relative to
Tuesday (~40-60% Monday compared to ~15-30% Tuesday), with activity
expected to shutdown entirely by Tuesday night as the responsible
boundary pushes east of the region. Shear will remain weak through
the entirety of this time frame, making severe potential overall low
in any storm development. Still elevated humidity & precipitable
waters pooled along the surface boundary, however, will support the
continued possibility for heavy downpours. Could thus continue to
see more minor hydro impacts (urban/small stream flooding, small
rises on area rivers/creeks) through Tuesday afternoon. Have
maintained the 12Z Monday end time of the Flood Watch in this
forecast, but will continue to monitor trends in the coming
updates.

Quigley

&&

.AVIATION...
Issued 828 PM CDT Sat Aug 9 2025

Sct-bkn040-050 tnt-Sun with rounds of showers and thunderstorms.
Areas of MVFR Cigs and Vsbys tnt becoming more widespread over
south central WI on Sunday. Local low Cigs and Vsbys at times
near and after storms.

Gehring

&&

.MARINE...
Issued 300 PM CDT Sat Aug 9 2025

1002 mb low pressure will linger across Manitoba into this evening,
with 1024 mb high pressure remaining centered over the Mid-Atlantic
states. Placed between the two surface features, breezy southerly
winds will continue across the open waters through the first half of
tonight. Prevailing southerlies will gradually decrease after
midnight as the aforementioned surface high migrates east into the
Atlantic Ocean. Generally southerly winds will continue into the day
on Sunday as a weak surface front moves into western Wisconsin,
ultimately stopping short of the open waters. Periods of showers and
storms are forecast this evening through Sunday night. Widespread
severe weather is not expected, though a few storms could produce
brief gusty winds. Winds will trend south to southwesterly during
the day Monday as 1002 mb low pressure moves into the Hudson Bay.

Breezy southerly winds will continue in nearshore zones through the
rest of this afternoon, with widespread 22-25 knot gusts
anticipated. The gusts will be accompanied by elevated wave heights,
particularly from Port Washington and points north. Gusts and wave
heights will gradually taper from south to north through this
evening, with decreasing trends continuing after midnight. A Small
Craft Advisory thus remains in effect until 7 PM CDT from Port
Washington south to Winthrop Harbor, and until 10 PM CDT from Port
Washington to Sheboygan. Periods of showers and thunderstorms are
forecast this evening through early Monday morning. A few storms
could produce gusty winds, particularly this evening.

Quigley

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...Beach Hazards Statement...WIZ052-WIZ060 until 10 PM Saturday.

     Flood Watch...WIZ046-WIZ047-WIZ051-WIZ052-WIZ056-WIZ057-WIZ058-
     WIZ059-WIZ060-WIZ062-WIZ063-WIZ064-WIZ065-WIZ066-WIZ067-
     WIZ068-WIZ069-WIZ070-WIZ071-WIZ072 until 7 AM Monday.

LM...Small Craft Advisory...LMZ643 until 10 PM Saturday.

&&

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Hazardous Weather Outlook
National Weather Service Milwaukee/Sullivan WI
752 PM CDT Sat Aug 9 2025

WIZ046-047-051-052-056>060-062>072-110100-
Marquette-Green Lake-Fond du Lac-Sheboygan-Sauk-Columbia-Dodge-
Washington-Ozaukee-Iowa-Dane-Jefferson-Waukesha-Milwaukee-
Lafayette-Green-Rock-Walworth-Racine-Kenosha-
752 PM CDT Sat Aug 9 2025

This Hazardous Weather Outlook is for portions of east central
Wisconsin, south central Wisconsin and southeast Wisconsin.

.DAY ONE...Tonight

A Flood Watch is in effect for the potential for flash flooding
across all of southern Wisconsin into Monday morning. Multiple
rounds of thunderstorms with heavy rain are forecast.

.DAYS TWO THROUGH SEVEN...Sunday through Saturday

A Flood Watch will remain in effect for the potential for flash
flooding across all of southern Wisconsin into Monday morning.
Multiple rounds of thunderstorms with heavy rain are forecast.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not anticipated.

LMZ643>646-110100-
Sheboygan to Port Washington WI-
Port Washington to North Point Light WI-
North Point Light to Wind Point WI-
Wind Point WI to Winthrop Harbor IL-
752 PM CDT Sat Aug 9 2025

This Hazardous Weather Outlook is for the nearshore waters from
Sheboygan Wisconsin to Winthrop Harbor Illinois.

.DAY ONE...Tonight

Numerous thunderstorms with frequent lightning and heavy rain.

.DAYS TWO THROUGH SEVEN...Sunday through Saturday

Thunderstorm chances linger into next week.

LMZ080-261-362-364-366-563-565-567-669-671-673-675-777-779-868-
870-872-874-876-878-110100-
Lake Michigan Michigan City IN to St. Joseph MI 5 NM offshore to
mid-line of lake.-
Lake Michigan from Seul Choix Point to Rock Island Passage 5NM
offshore to Mid Lake-
Lake Michigan South of a line from Seul Choix Point to the
Mackinac Bridge and North of a line from Charlevoix MI to South
Fox Island 5NM offshore-
Lake Michigan from Charlevoix to Point Betsie MI 5NM Offshore to
mid lake-
Lake Michigan from Point Betsie to Manistee MI 5NM offshore to
Mid Lake-
Lake Michigan from Rock Island Passage to Sturgeon Bay WI 5NM
offshore to mid lake-
Lake Michigan from Sturgeon Bay to Two Rivers WI 5NM offshore to
Mid Lake-
Lake Michigan from Two Rivers to Sheboygan WI 5NM offshore to Mid
Lake-
Lake Michigan from Sheboygan to Port Washington WI 5NM offshore
to Mid Lake-
Lake Michigan from Port Washington to North Point Light WI 5NM
offshore to Mid Lake-
Lake Michigan from North Point Light to Wind Point WI 5NM
offshore to Mid Lake-
Lake Michigan from Wind Point WI to Winthrop Harbor IL 5NM
offshore to Mid Lake-
Lake Michigan from Winthrop Harbor to Wilmette Harbor IL 5NM
offshore to Mid Lake-
Lake Michigan from Wilmette Harbor to Michigan City in 5NM
offshore to Mid Lake-
Lake Michigan from Pentwater to Manistee MI 5NM offshore to Mid
Lake-
Lake Michigan from Whitehall to Pentwater MI 5NM offshore to Mid
Lake-
Lake Michigan from Grand Haven to Whitehall MI 5NM offshore to
Mid Lake-
Lake Michigan from Holland to Grand Haven MI 5NM offshore to Mid
Lake-
Lake Michigan from South Haven to Holland MI 5NM offshore to Mid
lake-
Lake Michigan from St Joseph to South Haven MI 5NM offshore to
Mid Lake-
752 PM CDT Sat Aug 9 2025

This Hazardous Weather Outlook is for the open waters of Lake Michigan.

.DAY ONE...Tonight

Numerous thunderstorms with frequent lightning and heavy rain over
the south half.

.DAYS TWO THROUGH SEVEN...Sunday through Saturday

Thunderstorm chances linger into next week.

www.weather.gov/mkx

Preliminary Local Storm Report
National Weather Service Milwaukee/Sullivan WI
1026 PM CDT Sat Aug 9 2025

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1010 PM     Rain             3 SE Waukesha           42.99N 88.20W
08/09/2025  M3.35 Inch       Waukesha           WI   Trained Spotter

            Trained spotter reports 3.35 inches of rain
            from 5:15 PM thru time of report (10:10 PM).

&&

BHS

Preliminary Local Storm Report
National Weather Service Milwaukee/Sullivan WI
1134 PM CDT Sat Aug 9 2025

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0930 PM     Rain             1 N Greenfield          42.98N 88.01W
08/09/2025  M3.40 Inch       Milwaukee          WI   Trained Spotter

            Delayed Report: From 7pm to 9:30pm, measured
            3.40 inches with gauge. Trained Spotter.

&&

BHS

Preliminary Local Storm Report
National Weather Service Milwaukee/Sullivan WI
1145 PM CDT Sat Aug 9 2025

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1130 PM     Rain             2 W Milwaukee           43.04N 87.95W
08/09/2025  M3.93 Inch       Milwaukee          WI   Trained Spotter

            Trained spotter reports daily total of 3.93
            inches near 27th and Highland BLVD in
            Milwaukee, measured 11:30 PM.

&&

BHS

Preliminary Local Storm Report
National Weather Service Milwaukee/Sullivan WI
1221 AM CDT Sun Aug 10 2025

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1219 AM     Flash Flood      New Berlin              42.97N 88.13W
08/10/2025                   Waukesha           WI   911 Call Center

            Lots of street flooding in New Berlin area
            with cars stuck in the water.

&&

Wood

Preliminary Local Storm Report
National Weather Service Milwaukee/Sullivan WI
1228 AM CDT Sun Aug 10 2025

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1150 PM     Rain             3 W Brown Deer          43.17N 88.04W
08/09/2025  M3.36 Inch       Milwaukee          WI   Mesonet

            MMSD Gauge. Daily total measurement, taken
            1150 PM.

1150 PM     Rain             1 SE Elm Grove          43.04N 88.07W
08/09/2025  M5.14 Inch       Waukesha           WI   Mesonet

            MMSD Gauge. Daily total measurement, taken
            1150 PM.

1150 PM     Rain             2 NNE West Allis        43.03N 88.02W
08/09/2025  M4.98 Inch       Milwaukee          WI   Mesonet

            MMSD Gauge. Daily total measurement, taken
            1150 PM.

1150 PM     Rain             1 W Hales Corners       42.94N 88.06W
08/09/2025  M4.84 Inch       Milwaukee          WI   Mesonet

            MMSD Gauge. Daily total measurement, taken
            1150 PM.

1150 PM     Rain             2 SSW West Allis        42.98N 88.04W
08/09/2025  M5.99 Inch       Milwaukee          WI   Mesonet

            MMSD Gauge. Daily total measurement, taken
            1150 PM.

1150 PM     Rain             2 SSE South Milwaukee   42.89N 87.85W
08/09/2025  M2.91 Inch       Milwaukee          WI   Mesonet

            MMSD Gauge. Daily total measurement, taken
            1150 PM.

1150 PM     Rain             3 S Milwaukee           43.00N 87.91W
08/09/2025  M4.28 Inch       Milwaukee          WI   Mesonet

            MMSD Gauge. Daily total measurement, taken
            1150 PM.

1150 PM     Rain             1 SSE Milwaukee         43.02N 87.90W
08/09/2025  M4.38 Inch       Milwaukee          WI   Mesonet

            MMSD Gauge. Daily total measurement, taken
            1150 PM.

1150 PM     Rain             4 NW Milwaukee          43.08N 87.96W
08/09/2025  M3.92 Inch       Milwaukee          WI   Mesonet

            MMSD Gauge. Daily total measurement, taken
            1150 PM.

1150 PM     Rain             1 SSW Glendale          43.12N 87.93W
08/09/2025  M5.21 Inch       Milwaukee          WI   Mesonet

            MMSD Gauge. Daily total measurement, taken
            1150 PM.

1150 PM     Rain             1 N Glendale            43.14N 87.93W
08/09/2025  M5.86 Inch       Milwaukee          WI   Mesonet

            MMSD Gauge between Fox Point and Glendale.
            Daily total measurement, taken 1150 PM.

&&

Preliminary Local Storm Report
National Weather Service Milwaukee/Sullivan WI
1237 AM CDT Sun Aug 10 2025

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1200 AM     Rain             New Berlin              42.97N 88.13W
08/10/2025  M5.77 Inch       Waukesha           WI   Mesonet

            New Berlin Wisconet site storm total.

&&

Wood