Tornadoes · United States · Wisconsin · 2017

EF0 tornado, Leyden to Downtown Janesville, Wisconsin, June 28, 2017

From Leyden to Downtown Janesville, this EF0 tornado ran 0.8 miles across Rock County on June 28, 2017, touching down at 7:38 PM CDT and reaching 100 yards wide. It killed nobody, and did $60,000 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
June 28, 2017
Touchdown
7:38 PM CDT (00:38 UTC)
Lifted
7:40 PM CDT (00:40 UTC)
On the ground
2 minutes
Path length
0.8 miles (1.3 km)
Path width
100 yards (91 m)
Deaths
0
Injuries
0
Property damage
$60,000
County
Rock County
Touchdown point
42.687, -89.099
Lift-off point
42.687, -89.084
Record number
1706281838-01

The damage survey

22 damage points were recorded along this path by NWS MKX, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF0. The highest wind the damage implies is 80 mph.

Survey points are preliminary and are the raw material the published rating was built from. Source: NWS Damage Assessment Toolkit.

What the Weather Service recorded

A powerful line of thunderstorms moved across southern Wisconsin during the evening of June 28, 2017. These storms brought damaging winds and 3 tornadoes to the area.

This short lived tornado topped, snapped, or uprooted many trees and damaged the roof on two farm buildings.

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

The warnings

0 minutes of warning. NWS MKX issued a tornado warning for this county at 00:38 UTC, 0 minutes before the tornado touched down, in force until 01:00 UTC.

The county was under a tornado watch, issued at 22:15 UTC and running to 02:09 UTC.

Issued (UTC)ExpiredProductOffice
22:15 UTC02:09 UTCTornado WatchMKX
23:57 UTC00:30 UTCSevere Thunderstorm WarningMKX
00:22 UTC01:00 UTCSevere Thunderstorm WarningMKX
00:38 UTC01:00 UTCTornado WarningMKX
04:38 UTC05:01 UTCSevere Thunderstorm WarningMKX

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 19:58 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.

Davenport, (KDVN), 00:00Z

0.6 hours before the tornado, 166 km from the path. June 29, 2017.

Skew-T log-pSkew-T log-p diagram, Davenport, at 00:00Z on 2017-06-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1521 joules per kilogram, CIN -10, lifted condensation level 1099 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, Davenport, at 00:00Z on 2017-06-29The 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 259 square meters per square second, 0 to 6 km bulk shear 50 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
1521 J/kg
Mixed-layer CIN
-10 J/kg
Surface CAPE
2161 J/kg
Mixed-layer LCL
1099 m above ground
0-6 km bulk shear
50 kt
0-1 km bulk shear
26 kt
0-1 km storm-relative helicity
259 m²/s²
0-3 km storm-relative helicity
334 m²/s²
Significant tornado parameter
2.7
Supercell composite
15.1
0-3 km lapse rate
6.8 K/km

Open this sounding in Storm Lab

Davenport, (KDVN), 12:00Z

11.4 hours after it, 166 km from the path. June 29, 2017.

Skew-T log-pSkew-T log-p diagram, Davenport, at 12:00Z on 2017-06-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 27 joules per kilogram, CIN -369, lifted condensation level 968 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, Davenport, at 12:00Z on 2017-06-29The 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 163 square meters per square second, 0 to 6 km bulk shear 27 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
27 J/kg
Mixed-layer CIN
-369 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
968 m above ground
0-6 km bulk shear
27 kt
0-1 km bulk shear
14 kt
0-1 km storm-relative helicity
163 m²/s²
0-3 km storm-relative helicity
175 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
4.4 K/km

Open this sounding in Storm Lab

The radar

The Milwaukee radar (KMKX), 54 km away, was scanning. The volume nearest the touchdown began at 00:38 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
23:50 UTCTSTM WND DMG5 E MonroeGreen, WIA FARM BUILDING WAS DESTROYED AND 1 TREE WAS DOWNED.
23:50 UTCTSTM WND DMG5 E MonroeGreen, WITREES AND POWERLINES DOWNED.
23:55 UTCTORNADO3 Ssw MonticelloGreen, WIREPORTS OF ROOF DAMAGE AND POWER POLES SNAPPED BETWEEN MONROE AND MONTICELLO...DAMAGE PATH CROSSES WI HWY 69.
23:55 UTCTORNADO3 Ssw MonticelloGreen, WIDAMAGE SURVEY DETERMINED A SHORT LIVED TORNADO IMPACTED FAITH ENGINEERING LAST EVENING. 2 BUILDINGS SUSTAINED ROOF DAMAGE AND HAD WINDOWS BROKEN. A TRAILER WAS FLIPPED. MULTIPLE TREES WERE EITHER SNAPPED OR UPROOTED. AND
23:55 UTCTORNADO5 S MonticelloGreen, WITORNADO BEGAN NEAR INTERSECTION OF HWY 69 AND COLD SPRINGS RD AND ENDED NEAR THE INTERSECTION OF SULZER AND FELD RDS. ALONG THE PATH A BARN AND POLE SHED WERE DESTROYED, 4 HOUSES SUSTAINED DAMAGE, 4 POWER POLES SNAPPED,
00:10 UTCTSTM WND DMG3 Ssw McfarlandDane, WITREES SNAPPED AND UPROOTED.
00:20 UTCTSTM WND DMGOrfordvilleRock, WIWIDESPREAD TREE DAMAGE ACROSS SOUTHWESTERN ROCK COUNTY.
00:25 UTCTSTM WND DMG4 Ese McfarlandDane, WI3 FOOT DIAMETER TREE SNAPPED.
00:25 UTCTSTM WND DMGWaterlooJefferson, WI2.5 FOOT TREE TRUNK SNAPPED.
00:37 UTCTSTM WND DMG2 Nw BeloitRock, WI12 INCH TREE BRANCH SNAPPED OFF OF CHERRY TREE. PICTURE SHARED VIA SOCIAL MEDIA.
00:40 UTCTSTM WND DMGFort AtkinsonJefferson, WISEVERAL LARGE BRANCHES DOWN.

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

This ground now

The live radar over the trackEvery 2017 tornado in WisconsinEvery tornado in Wisconsin since 1950Warnings in force in Wisconsin nowThe forecast where you are

The other tornadoes of June 28, 2017

25 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
June 283:46 PM CDTEF2Fremont, IA3.7135
June 283:57 PM CDTEF0Adair, IA14.9100$5,000
June 284:21 PM CDTEF1Page, IA2.175
June 284:21 PM CDTEF1Adams, IA3.8100$10,000
June 284:25 PM CDTEF1Pierce, WI11.3700
June 284:43 PM CDTEF0Adams, IA1.930$1,000
June 284:45 PM CDTEF1Adair, IA7.6100$20,000
June 284:49 PM CDTEF1Burnett, WI2.2180
June 285:05 PM CDTEF2Taylor, IA7.01,000$75,000
June 285:54 PM CDTEF1Warren, IA17.8500$85,000
June 286:18 PM CDTEF0Warren, IA0.525
June 286:22 PM CDTEF0Olmsted, MN0.025
June 286:38 PM CDTEF2Linn, IA11.72001
June 286:42 PM CDTEF0Olmsted, MN0.425$5,000
June 286:48 PM CDTEF1Gentry, MO16.475
June 286:55 PM CDTEF1Green, WI2.2300$325,000
June 286:55 PM CDTEF1Green, WI0.6150$145,000
June 287:07 PM CDTEF0Olmsted, MN0.525$3,000
June 287:14 PM CDTEF2Jones, IA2.530
June 287:26 PM CDTEF0Benton, IA0.010
June 287:56 PM CDTEF1Jones, IA2.015
June 288:14 PM CDTEF1Boone, IL5.9200
June 288:23 PM CDTEF1Winnebago, IL1.6100
June 288:31 PM CDTEF0Nodaway, MO1.325
June 288:50 PM CDTEF0Gentry, MO1.425

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.