Tornadoes · United States · Wisconsin · 2021
EF0 tornado, Pulaski, Wisconsin, August 11, 2021
This EF0 tornado ran 2.3 miles across Brown County on August 11, 2021, touching down at 2:14 PM CDT and reaching 75 yards wide. It killed nobody.
The rating scale
Tracks are drawn in the color of the rating. The Enhanced Fujita scale rates the damage rather than measuring the wind: the speeds are what that damage is taken to imply.
EF065 to 85 mphthis tornado
Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.
EF186 to 110 mph
Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.
EF2111 to 135 mph
Considerable damage. Roofs torn off well-built houses, frame homes shifted on their foundations, mobile homes destroyed, large trees snapped or uprooted, cars lifted off the ground.
EF3136 to 165 mph
Severe damage. Whole stories of well-built houses destroyed, large buildings badly damaged, trains overturned, trees debarked, heavy cars lifted and thrown.
EF4166 to 200 mph
Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.
EF5over 200 mph
Incredible damage. Strong frame houses swept off their foundations, car-sized missiles thrown more than 100 meters, steel-reinforced concrete badly damaged, high-rise buildings deformed.
Unrated
The survey recorded a tornado but could not put a number on it, most often because it crossed open country and damaged nothing a rating can be read from.
The record
- Rating
- EF0
- Date
- August 11, 2021
- Touchdown
- 2:14 PM CDT (19:14 UTC)
- Lifted
- 2:22 PM CDT (19:22 UTC)
- On the ground
- 8 minutes
- Path length
- 2.3 miles (3.7 km)
- Path width
- 75 yards (69 m)
- Deaths
- 0
- Injuries
- 0
- County
- Brown County
- Touchdown point
- 44.675, -88.245
- Lift-off point
- 44.670, -88.200
- Record number
- 2108111314-01
What the Weather Service recorded
Thunderstorms developed ahead of a cold front during the afternoon across northeast Wisconsin. The strongest storms produced wind damage, large hail and 2 tornadoes. Rainfall amounts of 2 to 4 inches fell across central and southern Marathon County, producing flash flooding across these areas.
A tornado touched down at 2:14 pm CDT just northwest of Pulaski, moved east across the north side of the city, then dissipated about 1 mile east of Pulaski at 2:22 pm CDT. The tornado produced damage to trees (DI 28, DOD 2,4). Total path length is estimated to be 2.27 miles long, with a width of 75 yards. Peak wind estimated to be around 70 mph.
From NOAA NCEI's Storm Events Database, the narrative the local forecast office wrote for Storm Data.
The warnings
7 minutes of warning. NWS GRB issued a tornado warning for this county at 19:07 UTC, 7 minutes before the tornado touched down, in force until 19:30 UTC.
The county was under a tornado watch, issued at 17:18 UTC and running to 23:19 UTC.
| Issued (UTC) | Expired | Product | Office |
|---|---|---|---|
| 03:05 UTC | 04:15 UTC | Flood Advisory | GRB |
| 17:18 UTC | 23:19 UTC | Tornado Watch | GRB |
| 19:07 UTC | 19:30 UTC | Tornado Warning | GRB |
| 19:27 UTC | 20:02 UTC | Severe Thunderstorm Warning | GRB |
| 19:51 UTC | 20:20 UTC | Severe Thunderstorm Warning | GRB |
| 20:30 UTC | 21:05 UTC | Severe Thunderstorm Warning | GRB |
Every warning and watch covering the touchdown point that day, from the Iowa Environmental Mesonet's archive of National Weather Service products. Lead time is measured from the issue of the warning in force to the touchdown time in the database, both of which were recorded to the minute by different people.
The forecast that day
The Storm Prediction Center had this point in a Enhanced Risk, with a 0.05 chance of a tornado within 25 miles. The outlook in force was issued at 16:27 UTC.
SPC's Day 1 convective outlook as it stood when the tornado began, read at the touchdown point. The same archive is on the radar archive.
The air that afternoon
The radiosonde launches on either side of the tornado, from the nearest station that was launching then, drawn and analyzed the way Storm Lab does: the same diagram, the same parcel and shear definitions SPC's mesoanalysis uses.
Green Bay/Straub, WI (KGRB), 12:00Z
7.2 hours before the tornado, 23 km from the path. August 11, 2021.
- Mixed-layer CAPE
- 1499 J/kg
- Mixed-layer CIN
- -136 J/kg
- Surface CAPE
- 40 J/kg
- Mixed-layer LCL
- 678 m above ground
- 0-6 km bulk shear
- 41 kt
- 0-1 km bulk shear
- 22 kt
- 0-1 km storm-relative helicity
- 156 m²/s²
- 0-3 km storm-relative helicity
- 206 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 2.1
- 0-3 km lapse rate
- 4.0 K/km
Green Bay/Straub, WI (KGRB), 00:00Z
4.8 hours after it, 23 km from the path. August 12, 2021.
- Mixed-layer CAPE
- 798 J/kg
- Mixed-layer CIN
- -118 J/kg
- Surface CAPE
- 617 J/kg
- Mixed-layer LCL
- 1018 m above ground
- 0-6 km bulk shear
- 48 kt
- 0-1 km bulk shear
- 30 kt
- 0-1 km storm-relative helicity
- 228 m²/s²
- 0-3 km storm-relative helicity
- 302 m²/s²
- Significant tornado parameter
- 0.2
- Supercell composite
- 1.5
- 0-3 km lapse rate
- 4.6 K/km
The radar
The Green Bay radar (KGRB), 21 km away, was scanning. The volume nearest the touchdown began at 19:11 UTC.
Open the radar archive at this moment, over the track
Reflectivity and velocity, decoded from the Level II archive in the browser. Volumes take a few seconds to open the first time.
What was reported nearby
Local storm reports within 60 km of the path, in the three hours either side.
| Time (UTC) | Report | Where | County | Remark |
|---|---|---|---|---|
| 18:36 UTC | TSTM WND DMG | 1 Sw Shawano | Shawano, WI | REPORT FROM MPING: 1-INCH TREE LIMBS BROKEN; SHINGLES BLOWN OFF. |
| 19:06 UTC | TORNADO | Angelica | Shawano, WI | BRIEF TOUCHDOWN SOUTHWEST OF ANGELICA NEAR HWY 55 AND HWY 160. |
| 19:12 UTC | TORNADO | 2 Wnw Pulaski | Shawano, WI | |
| 19:18 UTC | TSTM WND DMG | 1 Nnw Pulaski | Brown, WI | REPORT FROM MPING: 3-INCH TREE LIMBS BROKEN; POWER POLES BROKEN. |
| 19:18 UTC | TSTM WND DMG | 1 N Pulaski | Brown, WI | REPORT FROM MPING: TREES UPROOTED OR SNAPPED; ROOF BLOWN OFF. |
| 19:55 UTC | TSTM WND DMG | 3 Nne Brussels | Door, WI | TREES DOWN IN THE TOWN OF GARDNER. |
| 19:57 UTC | TSTM WND DMG | 3 Sw Brussels | Door, WI | TREES DOWN IN THE TOWN OF UNION. |
| 20:10 UTC | HAIL 1 | Clintonville | Waupaca, WI | DELAYED REPORT |
| 20:10 UTC | HAIL 1 | Clintonville | Waupaca, WI | DELAYED REPORT. |
| 20:20 UTC | TSTM WND DMG | 1 Nnw Howard | Brown, WI | POWER POLE AND POWER LINES IN THE ROAD. LAKEVIEW AND COTTAGE GROVE. TIME ESTIMATED BY RADAR. |
| 20:20 UTC | TSTM WND DMG | 3 N Howard | Brown, WI | TREE DOWN |
| 20:20 UTC | TSTM WND DMG | 3 N Howard | Brown, WI | TREE DOWN. |
| 20:21 UTC | TSTM WND DMG | Suamico | Brown, WI | LARGE TREE ON TRUCK. FROM SOCIAL MEDIA. DELAYED REPORT. TIME ESTIMATED. |
| 20:30 UTC | TSTM WND GST 39 | Northport | Waupaca, WI | NORTHPORT PIER |
| 20:30 UTC | TSTM WND GST 39 | Northport | Waupaca, WI | NORTHPORT PIER. |
| 20:41 UTC | TSTM WND DMG | 1 Nnw Howard | Brown, WI | CORRECTS PREVIOUS TSTM WND DMG REPORT FROM 1 NNW HOWARD. POWER POLE AND POWER LINES IN THE ROAD. LAKEVIEW AND COTTAGE GROVE. TIME ESTIMATED BY RADAR. |
| 20:41 UTC | TSTM WND DMG | 2 Ssw Suamico | Brown, WI | CORRECTS PREVIOUS TSTM WND DMG REPORT FROM 2 SSW SUAMICO. TREE DOWN. |
| 20:42 UTC | TSTM WND DMG | Suamico | Brown, WI | CORRECTS PREVIOUS TSTM WND DMG REPORT FROM SUAMICO. LARGE TREE ON TRUCK. FROM SOCIAL MEDIA. DELAYED REPORT. TIME ESTIMATED. |
| 20:43 UTC | TSTM WND GST 47 | Green Bay | Brown, WI |
From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.
This ground now
The live radar over the trackEvery 2021 tornado in WisconsinEvery tornado in Wisconsin since 1950Warnings in force in Wisconsin nowThe forecast where you are
The other tornadoes of August 11, 2021
11 more were confirmed in the United States that day.
| Date | Time | Rating | Where | Path (mi) | Width (yd) | Deaths | Injuries | Damage |
|---|---|---|---|---|---|---|---|---|
| August 11 | 2:40 PM EDT | EF1 | Fulton, OH | 0.2 | 70 | |||
| August 11 | 1:45 PM CDT | EF1 | Monroe, WI | 5.9 | 80 | $40,000 | ||
| August 11 | 2:49 PM EDT | Unrated | Van Wert, OH | 2.0 | 30 | |||
| August 11 | 1:55 PM CDT | EF1 | Monroe, WI | 2.8 | 75 | $3,000 | ||
| August 11 | 3:00 PM EDT | EF0 | Van Wert, OH | 4.7 | 50 | |||
| August 11 | 2:08 PM CDT | EF0 | Shawano, WI | 0.4 | 41 | |||
| August 11 | 4:04 PM EDT | EF0 | Chippewa, MI | 1.5 | 75 | |||
| August 11 | 5:40 PM CDT | EF0 | Dubuque, IA | 0.6 | 20 | |||
| August 11 | 6:08 PM CDT | EF0 | Iowa, WI | 0.1 | 25 | |||
| August 11 | 6:12 PM CDT | EF0 | Iowa, WI | 1.0 | 25 | |||
| August 11 | 9:01 PM EDT | EF0 | Allegan, MI | 2.8 | 100 | $300,000 |
What this means
Ratings are the survey's, read off the damage rather than measured; the rating scale is above. Tornado counts rise through the record as reporting improved, so a year in the 1950s is not comparable with one today except for the strongest tornadoes, which were always noticed.
Sources
NOAA Storm Prediction Center tornado database, 1950-2025, the official record kept by NOAA's Storm Prediction Center.