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.

  1. EF065 to 85 mphthis tornado

    Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.

  2. EF186 to 110 mph

    Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.

  3. 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.

  4. 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.

  5. EF4166 to 200 mph

    Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.

  6. 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.

  7. 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)ExpiredProductOffice
03:05 UTC04:15 UTCFlood AdvisoryGRB
17:18 UTC23:19 UTCTornado WatchGRB
19:07 UTC19:30 UTCTornado WarningGRB
19:27 UTC20:02 UTCSevere Thunderstorm WarningGRB
19:51 UTC20:20 UTCSevere Thunderstorm WarningGRB
20:30 UTC21:05 UTCSevere Thunderstorm WarningGRB

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.

Skew-T log-pSkew-T log-p diagram, Green Bay/Straub, WI at 12:00Z on 2021-08-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1499 joules per kilogram, CIN -136, lifted condensation level 678 meters above ground. Wind barbs in knots down the right edge.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. The warm shading is its CAPE, the cool shading the inhibition it has to break through.
HodographHodograph, Green Bay/Straub, WI at 12:00Z on 2021-08-11The wind through the lowest 10 kilometers as a curve, rings every 10 meters per second labeled in knots. Zero to 1 km storm-relative helicity 156 square meters per square second, 0 to 6 km bulk shear 41 knots.19395878Sfc1 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. RM and LM are the right and left moving storms Bunkers' method gives; the shaded area is the 0 to 1 km storm-relative helicity.
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

Open this sounding in Storm Lab

Green Bay/Straub, WI (KGRB), 00:00Z

4.8 hours after it, 23 km from the path. August 12, 2021.

Skew-T log-pSkew-T log-p diagram, Green Bay/Straub, WI at 00:00Z on 2021-08-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 798 joules per kilogram, CIN -118, lifted condensation level 1018 meters above ground. Wind barbs in knots down the right edge.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. The warm shading is its CAPE, the cool shading the inhibition it has to break through.
HodographHodograph, Green Bay/Straub, WI at 00:00Z on 2021-08-12The wind through the lowest 10 kilometers as a curve, rings every 10 meters per second labeled in knots. Zero to 1 km storm-relative helicity 228 square meters per square second, 0 to 6 km bulk shear 48 knots.19395878Sfc1 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. RM and LM are the right and left moving storms Bunkers' method gives; the shaded area is the 0 to 1 km storm-relative helicity.
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

Open this sounding in Storm Lab

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)ReportWhereCountyRemark
18:36 UTCTSTM WND DMG1 Sw ShawanoShawano, WIREPORT FROM MPING: 1-INCH TREE LIMBS BROKEN; SHINGLES BLOWN OFF.
19:06 UTCTORNADOAngelicaShawano, WIBRIEF TOUCHDOWN SOUTHWEST OF ANGELICA NEAR HWY 55 AND HWY 160.
19:12 UTCTORNADO2 Wnw PulaskiShawano, WI
19:18 UTCTSTM WND DMG1 Nnw PulaskiBrown, WIREPORT FROM MPING: 3-INCH TREE LIMBS BROKEN; POWER POLES BROKEN.
19:18 UTCTSTM WND DMG1 N PulaskiBrown, WIREPORT FROM MPING: TREES UPROOTED OR SNAPPED; ROOF BLOWN OFF.
19:55 UTCTSTM WND DMG3 Nne BrusselsDoor, WITREES DOWN IN THE TOWN OF GARDNER.
19:57 UTCTSTM WND DMG3 Sw BrusselsDoor, WITREES DOWN IN THE TOWN OF UNION.
20:10 UTCHAIL 1ClintonvilleWaupaca, WIDELAYED REPORT
20:10 UTCHAIL 1ClintonvilleWaupaca, WIDELAYED REPORT.
20:20 UTCTSTM WND DMG1 Nnw HowardBrown, WIPOWER POLE AND POWER LINES IN THE ROAD. LAKEVIEW AND COTTAGE GROVE. TIME ESTIMATED BY RADAR.
20:20 UTCTSTM WND DMG3 N HowardBrown, WITREE DOWN
20:20 UTCTSTM WND DMG3 N HowardBrown, WITREE DOWN.
20:21 UTCTSTM WND DMGSuamicoBrown, WILARGE TREE ON TRUCK. FROM SOCIAL MEDIA. DELAYED REPORT. TIME ESTIMATED.
20:30 UTCTSTM WND GST 39NorthportWaupaca, WINORTHPORT PIER
20:30 UTCTSTM WND GST 39NorthportWaupaca, WINORTHPORT PIER.
20:41 UTCTSTM WND DMG1 Nnw HowardBrown, WICORRECTS 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 UTCTSTM WND DMG2 Ssw SuamicoBrown, WICORRECTS PREVIOUS TSTM WND DMG REPORT FROM 2 SSW SUAMICO. TREE DOWN.
20:42 UTCTSTM WND DMGSuamicoBrown, WICORRECTS PREVIOUS TSTM WND DMG REPORT FROM SUAMICO. LARGE TREE ON TRUCK. FROM SOCIAL MEDIA. DELAYED REPORT. TIME ESTIMATED.
20:43 UTCTSTM WND GST 47Green BayBrown, 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.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
August 112:40 PM EDTEF1Fulton, OH0.270
August 111:45 PM CDTEF1Monroe, WI5.980$40,000
August 112:49 PM EDTUnratedVan Wert, OH2.030
August 111:55 PM CDTEF1Monroe, WI2.875$3,000
August 113:00 PM EDTEF0Van Wert, OH4.750
August 112:08 PM CDTEF0Shawano, WI0.441
August 114:04 PM EDTEF0Chippewa, MI1.575
August 115:40 PM CDTEF0Dubuque, IA0.620
August 116:08 PM CDTEF0Iowa, WI0.125
August 116:12 PM CDTEF0Iowa, WI1.025
August 119:01 PM EDTEF0Allegan, MI2.8100$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.