EF0 tornado, Shullsburg to Dunbarton, Wisconsin, June 1, 2007

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.

Rating

EF0

Date

June 1, 2007

Touchdown

3:31 PM CDT (20:31 UTC)

Lifted

3:32 PM CDT (20:32 UTC)

On the ground

1 minutes

Path length

0.2 miles (0.4 km)

Path width

30 yards (27 m)

Deaths

0

Injuries

0

County

Lafayette County

Touchdown point

42.578, -90.169

Lift-off point

42.582, -90.169

Record number

0706011431-01

On June 1st, isolated severe storms generated a couple weak tornadoes in Lafayette County and dome downburst wind damage (toppled trees) in the counties of Dodge and Walworth. This activity was the first day of a 7-day period of periodic showers and storms across southern Wisconsin as a cut-off, upper-level, low pressure moved slowly east from the Dakotas through the lower Great Lakes Region. Spiral bands of convection developed, and became enhanced with daytime heating. There was a sufficient amount of vertical wind shear to generate isolated supercells and scattered severe storms from time to time.

A brief, weak tornado spun up about 3.8 miles south (168 degrees) of Shullsburg. Only some minor tree damage was noted. Specifically, it occurred about 0.7 miles southwest/225 degrees of the intersection of Blackhawk Rd. and Monticello Rd. The lat/lon data is: N42.51590 W90.21600 for the start point and N42.51696 W90.21577 for the end point. The average path width was about 10 yards. DI#27 (TH), DOD2. Estimated winds 65-70 knots (75-80 mph).

A brief, weak tornado spun up about 2.1 miles west-northwest of Dunbarton, or about 3.3 miles east of Shullsburg, or 0.27 southeast (133 degrees) of the insection of STH 11 and CTH E/Summit Rd. It resulted n only matted-down grasses, since the corn crop wasn't tall enough to sustain damage. It traveled north and cross STH 11, about 0.23 miles east of the intersection of STH 11 and CTH E, and dissipated just north of STH 11. The decaying supercell thunderstorm that generated this tornado also spun up an earlier weak tornado about 3.8 miles south of Shullsburg. The specific lat/lon data for the Dunbarton tornado is: N42.57850 W90.16877 for the start and N42.58176 W90.16859 for the end point. The average path width was 20 yards. No DI. Estimated wind speed is 56-61 knots (65-70 mph).

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

34 minutes of warning. NWS MKX issued a tornado warning for this county at 19:57 UTC, 34 minutes before the tornado touched down, in force until 21:04 UTC.

The county was under a tornado watch, issued at 17:36 UTC and running to 22:56 UTC.

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 Storm Prediction Center had this point in a Slight Risk, with a 0.05 chance of a tornado within 25 miles. The outlook in force was issued at 21:59 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 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.

Mineral Point (MRJ), 35 km from the path, in the two hours either side.

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

The Quad Cities radar (KDVN), 113 km away, was scanning. The volume nearest the touchdown began at 20:31 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.

Local storm reports within 60 km of the path, in the three hours either side.

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

The live radar over the trackEvery 2007 tornado in WisconsinEvery tornado in Wisconsin since 1950Warnings in force in Wisconsin nowThe forecast where you are

9 more were confirmed in the United States that day.

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.

NOAA Storm Prediction Center tornado database, 1950-2025, the official record kept by NOAA's Storm Prediction Center.