Tornadoes · United States · Wisconsin · 2016

EF0 tornado, Kewaunee, Wisconsin, August 20, 2016

This EF0 tornado ran 0.7 miles across Kewaunee County on August 20, 2016, touching down at 10:03 AM CDT and reaching 125 yards wide. It killed nobody, and did $25,000 of property damage.

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 20, 2016
Touchdown
10:03 AM CDT (15:03 UTC)
Lifted
10:06 AM CDT (15:06 UTC)
On the ground
3 minutes
Path length
0.7 miles (1.1 km)
Path width
125 yards (114 m)
Deaths
0
Injuries
0
Property damage
$25,000
County
Kewaunee County
Touchdown point
44.451, -87.522
Lift-off point
44.459, -87.512
Record number
1608200903-01

What the Weather Service recorded

A thunderstorm, which formed near an area of low pressure that was exiting Wisconsin, produced a weak tornado near the city of Kewaunee.

A tornado formed and moved northeast on the west side of the city of Kewaunee. About 100 trees sustained some damage (DI 27,28 DOD 1,2) and several were uprooted in wet soil. Several homes had shingle or siding damage (DI 2, DOD 1,2). A baseball dugout at a school was blown down. Average path width was about 75 yards.

From NOAA NCEI's Storm Events Database, the narrative the local forecast office wrote for Storm Data.

The warnings

No tornado warning for this county appears in the archive as in force at the moment the tornado touched down.

Issued (UTC)ExpiredProductOffice
20:11 UTC04:00 UTCBeach Hazard StatementGRB

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 Marginal Risk. The outlook in force was issued at 12:37 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

3.1 hours before the tornado, 46 km from the path. August 20, 2016.

Skew-T log-pSkew-T log-p diagram, Green Bay/Straub, WI at 12:00Z on 2016-08-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 162 joules per kilogram, CIN -61, lifted condensation level 888 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 2016-08-20The 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 143 square meters per square second, 0 to 6 km bulk shear 34 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
162 J/kg
Mixed-layer CIN
-61 J/kg
Surface CAPE
187 J/kg
Mixed-layer LCL
888 m above ground
0-6 km bulk shear
34 kt
0-1 km bulk shear
19 kt
0-1 km storm-relative helicity
143 m²/s²
0-3 km storm-relative helicity
249 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.5
0-3 km lapse rate
5.0 K/km

Open this sounding in Storm Lab

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

8.9 hours after it, 46 km from the path. August 21, 2016.

Skew-T log-pSkew-T log-p diagram, Green Bay/Straub, WI at 00:00Z on 2016-08-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1 joules per kilogram, CIN -37, lifted condensation level 730 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 2016-08-21The 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 -49 square meters per square second, 0 to 6 km bulk shear 51 knots.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. 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
1 J/kg
Mixed-layer CIN
-37 J/kg
Surface CAPE
135 J/kg
Mixed-layer LCL
730 m above ground
0-6 km bulk shear
51 kt
0-1 km bulk shear
12 kt
0-1 km storm-relative helicity
-49 m²/s²
0-3 km storm-relative helicity
56 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
6.0 K/km

Open this sounding in Storm Lab

The surface observations

Manitowac Municipal (MTW), 39 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
13:04 UTC69.86890° 7 kt1004.4RA BR
13:05 UTC100° 9 kt1004.4RA BR
13:10 UTC 1004.4RA BR
13:15 UTC80° 7 kt1004.1-RA
13:20 UTC80° 6 kt1004.1-RA
13:25 UTC80° 7 kt1003.7-RA
13:30 UTC80° 5 kt1003.7
13:35 UTC 1003.4
13:47 UTC71.669.8 1002.7VCTS RA BR
13:48 UTC716960° 4 kt1002.7VCTS RA BR
13:55 UTC50° 4 kt1002.4-RA BR
14:00 UTC0° 0 kt1002.4RA BR
14:05 UTC0° 0 kt1002RA BR
14:07 UTC71.669.80° 0 kt1002RA BR
14:10 UTC 1002RA BR
14:13 UTC71.669.80° 0 kt1002+RA BR
14:15 UTC150° 3 kt1002+RA BR
14:20 UTC210° 3 kt1002+RA BR
14:22 UTC71.669.8 1002VCTS RA BR
14:25 UTC220° 7 kt1002.7RA BR
14:30 UTC240° 10 kt1002.7+RA BR
14:32 UTC71.669.8250° 12 kt171002.7+TSRA BR
14:35 UTC 1002.7+RA BR
14:40 UTC310° 6 kt1002.4-RA BR
14:41 UTC6866.2300° 5 kt1002.4-TSRA BR
14:45 UTC 1002-RA
14:50 UTC330° 5 kt1002-RA
14:54 UTC6866.2310° 5 kt1001.7-TSRA
14:55 UTC310° 5 kt1001.7-RA
14:56 UTC6866 1001.7-TSRA
15:00 UTC 1002-RA
15:05 UTC290° 3 kt1002
15:07 UTC69.866.2 1001.7
15:10 UTC0° 0 kt1001.7
15:15 UTC110° 3 kt1001.7
15:20 UTC 1001.7
15:24 UTC69.866.2260° 5 kt1001.7
15:25 UTC270° 5 kt1001.7
15:30 UTC250° 3 kt1001.7
15:35 UTC250° 5 kt1001.7
15:40 UTC250° 5 kt1001.4
15:45 UTC260° 5 kt1001.4
15:50 UTC270° 5 kt1001
15:55 UTC 1001
15:56 UTC7367280° 5 kt1001
16:00 UTC270° 4 kt1001
16:05 UTC280° 3 kt1000.7
16:07 UTC73.468 1000.7
16:10 UTC250° 4 kt1000.7
16:15 UTC220° 4 kt1000.7
16:20 UTC220° 4 kt1000.7
16:25 UTC240° 7 kt1000.7
16:30 UTC 1000.7
16:35 UTC210° 8 kt1000.7
16:40 UTC240° 8 kt1000.7
16:45 UTC220° 8 kt1000.7
16:50 UTC220° 12 kt1000.7
16:55 UTC 1000.7
16:56 UTC7768220° 11 kt1000.7
17:00 UTC 1000.7

From the Iowa Environmental Mesonet's archive of airport observations.

The radar

The Green Bay radar (KGRB), 47 km away, was scanning. The volume nearest the touchdown began at 15:03 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
15:03 UTCTORNADO1 W KewauneeKewaunee, WIA BRIEF EF0 TORNADO HIT THE WEST SIDE OF THE CITY OF KEWAUNEE. ABOUT 100 TREES SUSTAINED BROKEN LIMBS OR WERE UPROOTED. SEVERAL HOMES HAD SHINGLE OR SIDING DAMAGE.
15:05 UTCTSTM WND DMGKewauneeKewaunee, WIUPDATE OF PREVIOUS REPORT. KEWAUNEE COUNTY EM REPORTS 20+ TREES UPROOTED OR DAMAGED. SEVERAL ROOFS WITH SHINGLE DAMAGE. SIDING OFF AT LEAST 1 HOME. SMALL TRAILER FLIPPED OVER AT HIGH SCHOOL. BOAT ROLLED ON ITS SIDE. OUTD
15:12 UTCMARINE TSTM WIND 51KewauneeKewaunee, WI

From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.

This ground now

The live radar over the trackEvery 2016 tornado in WisconsinEvery tornado in Wisconsin since 1950Warnings in force in Wisconsin nowThe forecast where you are

The other tornadoes of August 20, 2016

12 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
August 201:13 PM EDTEF1Allegan, MI10.6150$2.0 million
August 201:42 PM EDTEF1Allegan, MI12.8100$1.5 million
August 202:18 PM EDTEF1Ottawa, MI4.1100$500,000
August 202:34 PM EDTEF0Kent, MI4.375$500,000
August 202:50 PM EDTEF0Kent, MI0.950$25,000
August 202:53 PM EDTEF0Kosciusko, IN1.610
August 203:10 PM EDTEF1Ionia, MI7.8100$750,000
August 203:19 PM EDTEF0Elkhart, IN0.150
August 205:42 PM EDTEF0Allen, IN2.470
August 206:15 PM EDTEF0Darke, OH4.750$11,000
August 206:37 PM EDTEF0Delaware, OH3.3100$20,000
August 206:30 PM CDTEF0Barren, KY1.630$50,000

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.