Alert archive / Wisconsin / Severe Thunderstorm Warnings in 2026

Severe Thunderstorm Warning 242, NWS Milwaukee, WI

August 9, 2026Racine County, Waukesha County, Wisconsin

NWS Milwaukee, WI issued this severe thunderstorm warning at Aug 9, 2026, 11:49 PM CDT for Racine County, Waukesha County, Wisconsin. It was in force for 26 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Aug 9, 2026, 11:49 PM CDT (04:49 UTC)
Expired
Aug 10, 2026, 12:15 AM CDT
In force
26 min
Issued by
NWS Milwaukee, WI
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Racine County, WI, Waukesha County, WI

The radar

The Milwaukee radar (KMKX), 41 km from the middle of the area, began a volume at 04:53 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

Davenport, (KDVN), launched 00:00Z, 4.8 hours before the alert went out and 245 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, Davenport, at 00:00Z on 2026-08-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3740 joules per kilogram.LCLEL10008507005003002001001 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, Davenport, at 00:00Z on 2026-08-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 32 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
3740 J/kg
Mixed-layer CIN
-2 J/kg
Mixed-layer LCL
810 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
32 m²/s²
0-3 km storm-relative helicity
322 m²/s²
Significant tornado parameter
4.3
Supercell composite
24.8

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Milwaukee, WI wrote its last area forecast discussion before this severe thunderstorm warning went out at Aug 9, 6:53 PM CDT, 4 hours 56 minutes earlier.

Area forecast discussion, Aug 9, 6:53 PM CDT, 4 hours 56 minutes before
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Hazardous weather outlook, Aug 9, 6:33 PM CDT, 5 hours 16 minutes before
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In the hours before

Special weather statement, Aug 9, 10:42 PM CDT, 1 hour 7 minutes before
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Special weather statement, Aug 9, 10:55 PM CDT, 54 minutes before
Special Weather Statement
National Weather Service Milwaukee/Sullivan WI
1055 PM CDT Sun Aug 9 2026

WIZ070-100445-
Walworth WI-
1055 PM CDT Sun Aug 9 2026

...A STRONG THUNDERSTORM WILL IMPACT NORTHERN WALWORTH COUNTY THROUGH
1145 PM CDT...

At 1054 PM CDT, Doppler radar was tracking a strong thunderstorm near
Whitewater, moving east at 15 mph.

HAZARD...Wind gusts up to 45 to 50 mph and nickel size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor hail damage to vegetation is
         possible.

Locations impacted include...
Whitewater, Elkhorn, East Troy, Potter Lake, Richmond, La Grange,
Abells Corners, Tibbets, Troy Center, and Millard.

This includes the following highways...
 U.S. Highway 12 near mile marker 320.
 Interstate 43 between mile markers 29 and 42.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 4282 8878 4284 8873 4284 8831 4272 8831
      4265 8877
TIME...MOT...LOC 0354Z 247DEG 12KT 4275 8866

MAX HAIL SIZE...0.88 IN
MAX WIND GUST...50 MPH

WAGNER
Local storm report, Aug 9, 11:04 PM CDT, 45 minutes before
Preliminary Local Storm Report
National Weather Service Milwaukee/Sullivan WI
1104 PM CDT Sun Aug 9 2026

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

1050 PM     Hail             3 SSE Fontana-on-Geneva 42.50N 88.55W
08/09/2026  M1.00 Inch       Walworth           WI   Public

&&
Local storm report, Aug 9, 11:16 PM CDT, 33 minutes before
Preliminary Local Storm Report
National Weather Service Milwaukee/Sullivan WI
1116 PM CDT Sun Aug 9 2026

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

1111 PM     Hail             2 W Pell Lake           42.55N 88.40W
08/09/2026  E1.50 Inch       Walworth           WI   Public

            Report from mPING: Ping Pong Ball (1.50
            in.).

&&
Local storm report, Aug 9, 11:19 PM CDT, 30 minutes before
Preliminary Local Storm Report
National Weather Service Milwaukee/Sullivan WI
1119 PM CDT Sun Aug 9 2026

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

1103 PM     Hail             1 SSW Lake Geneva       42.57N 88.44W
08/09/2026  M1.00 Inch       Walworth           WI   Amateur Radio

&&

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 9, 10:42 PM CDTSpecial Weather StatementMKXWalworth48 min
Aug 9, 10:50 PM CDTSevere Thunderstorm WarningMKXKenosha, Racine, Walworth40 min
Aug 9, 10:55 PM CDTSpecial Weather StatementMKXWalworth50 min
Aug 9, 11:55 PM CDTSpecial Marine WarningMKX50 min
Aug 10, 12:05 AM CDTSpecial Weather StatementMKXWalworth25 min
Aug 10, 12:08 AM CDTSpecial Weather StatementMKXRacine22 min
Aug 10, 12:10 AM CDTAreal Flood AdvisoryMKXRacine, Walworth85 min
Aug 10, 12:25 AM CDTFlash Flood WarningMKXRacine, Walworth70 min
Aug 10, 12:37 AM CDTSpecial Weather StatementMKXKenosha38 min
Aug 10, 12:59 AM CDTSpecial Weather StatementMKXKenosha46 min

Nearby

Severe Thunderstorm Warnings in Wisconsin, 2026Every severe thunderstorm warning in 2026

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.