Alert archive / Wisconsin / Tornado Warnings in 2026

Tornado Warning 80, NWS Milwaukee, WI

August 18, 2026Green Lake County, Marquette County, Wisconsin

NWS Milwaukee, WI issued this tornado warning at Aug 18, 2026, 4:12 PM CDT for Green Lake County, Marquette County, Wisconsin. It was in force for 48 min. 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 18, 2026, 4:12 PM CDT (21:12 UTC)
Expired
Aug 18, 2026, 5:00 PM CDT
In force
48 min
Issued by
NWS Milwaukee, WI
Area
Storm-based polygon
Tornado
Radar indicated
Hail
1.5 in

Counties Green Lake County, WI, Marquette County, WI

The radar

The Green Bay radar (KGRB), 98 km from the middle of the area, began a volume at 21:11 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.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Aug 18, 2:48 PM CDTSevere Thunderstorm WatchSPC6 hr

The nearest sounding before it

Minneapolis, MN (KMPX), launched 12:00Z, 9.2 hours before the alert went out and 377 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, Minneapolis, MN at 12:00Z on 2026-08-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1301 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Minneapolis, MN at 12:00Z on 2026-08-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 72 square meters per square second.1939587897Sfc1 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
1301 J/kg
Mixed-layer CIN
-78 J/kg
Mixed-layer LCL
956 m above ground
0-6 km bulk shear
50 kt
0-1 km storm-relative helicity
72 m²/s²
0-3 km storm-relative helicity
88 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.9

Open this sounding in Storm Lab

The text

As transmitted.

575 
WFUS53 KMKX 182112
TORMKX
WIC047-077-182200-
/O.NEW.KMKX.TO.W.0080.260818T2112Z-260818T2200Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Milwaukee/Sullivan WI
412 PM CDT Tue Aug 18 2026

The National Weather Service in Milwaukee/Sullivan has issued a

* Tornado Warning for...
  Northern Green Lake County in south central Wisconsin...
  Northeastern Marquette County in south central Wisconsin...

* Until 500 PM CDT.

* At 412 PM CDT, a severe thunderstorm capable of producing a tornado
  was located over Wautoma, moving southeast at 35 mph.

  HAZARD...Tornado and ping pong ball size hail.

  SOURCE...Radar indicated rotation.

  IMPACT...Flying debris will be dangerous to those caught without 
           shelter. Mobile homes will be damaged or destroyed. 
           Damage to roofs, windows, and vehicles will occur.  Tree 
           damage is likely.

* This dangerous storm will be near...
  Berlin and Princeton around 425 PM CDT.
  Green Lake around 435 PM CDT.

Other locations impacted by this tornadic thunderstorm include
Neshkoro.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

&&

LAT...LON 4398 8889 4371 8889 4398 8939 4399 8914
TIME...MOT...LOC 2112Z 295DEG 32KT 4403 8931 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...1.50 IN

$$

SHEPPARD
1 follow-up statement
244 
WWUS53 KMKX 182152
SVSMKX

Severe Weather Statement
National Weather Service Milwaukee/Sullivan WI
452 PM CDT Tue Aug 18 2026

WIC077-182201-
/O.CAN.KMKX.TO.W.0080.000000T0000Z-260818T2200Z/
Marquette WI-
452 PM CDT Tue Aug 18 2026

...THE TORNADO WARNING FOR NORTHEASTERN MARQUETTE COUNTY IS
CANCELLED...

The tornadic thunderstorm which prompted the warning has moved out 
of the warned area. Therefore, the warning has been cancelled.

A Severe Thunderstorm Watch remains in effect until 1000 PM CDT for
south central Wisconsin.

&&

LAT...LON 4398 8889 4371 8889 4383 8910
TIME...MOT...LOC 2151Z 301DEG 31KT 4384 8893 

$$

WIC047-182200-
/O.CON.KMKX.TO.W.0080.000000T0000Z-260818T2200Z/
Green Lake WI-
452 PM CDT Tue Aug 18 2026

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 500 PM CDT FOR
NORTHEASTERN GREEN LAKE COUNTY...

At 451 PM CDT, a severe thunderstorm capable of producing a tornado
was located over Green Lake, or near Ripon, moving southeast at 35
mph.

HAZARD...Tornado and quarter size hail.

SOURCE...Radar indicated rotation.

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be damaged or destroyed. Damage 
         to roofs, windows, and vehicles will occur.  Tree damage is 
         likely.

This tornadic thunderstorm will remain over mainly rural areas of
northeastern Green Lake County.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

&&

LAT...LON 4398 8889 4371 8889 4383 8910
TIME...MOT...LOC 2151Z 301DEG 31KT 4384 8893 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...1.00 IN

$$

SHEPPARD

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 18, 2:44 PM CDTSpecial Weather StatementMKXDodge61 min
Aug 18, 3:57 PM CDTSevere Thunderstorm WarningMKXColumbia, Sauk78 min
Aug 18, 3:59 PM CDTSevere Thunderstorm WarningMKXGreen Lake, Marquette76 min
Aug 18, 4:11 PM CDTSpecial Marine WarningMKX2 hr
Aug 18, 4:48 PM CDTTornado WarningMKXColumbia, Sauk42 min
Aug 18, 4:52 PM CDTSevere Thunderstorm WarningMKXFond du Lac, Sheboygan38 min
Aug 18, 4:56 PM CDTSevere Thunderstorm WarningMKXDodge, Fond du Lac49 min
Aug 18, 5:07 PM CDTAreal Flood AdvisoryMKXGreen Lake, Marquette3 hr
Aug 18, 5:08 PM CDTSevere Thunderstorm WarningMKXColumbia, Dane, Sauk52 min
Aug 18, 5:16 PM CDTSevere Thunderstorm WarningMKXFond du Lac33 min
Aug 18, 5:27 PM CDTSevere Thunderstorm WarningMKXDodge, Fond du Lac, Sheboygan, Washington63 min
Aug 18, 5:42 PM CDTSevere Thunderstorm WarningMKXColumbia, Dane, Dodge, Jefferson63 min
Aug 18, 5:45 PM CDTTornado WarningMKXColumbia, Dane, Dodge18 min
Aug 18, 5:54 PM CDTSevere Thunderstorm WarningMKXDodge, Washington36 min
Aug 18, 6:23 PM CDTSevere Thunderstorm WarningMKXDane, Dodge, Jefferson, Milwaukee, Ozaukee, Washington and 1 more67 min
Aug 18, 6:28 PM CDTSpecial Marine WarningMKX2 hr
Aug 18, 6:33 PM CDTTornado WarningMKXWashington, Waukesha42 min
Aug 18, 6:42 PM CDTTornado WarningMKXWaukesha33 min
Aug 18, 6:51 PM CDTTornado WarningMKXMilwaukee23 min
Aug 18, 6:54 PM CDTSevere Thunderstorm WarningMKXMilwaukee, Racine, Waukesha51 min

Nearby

Tornado Warnings in Wisconsin, 2026Every tornado warning in 2026Tornadoes 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.