F0 tornado, Helena to Barneveld, Wisconsin, June 6, 2006

1. F040 to 72 mphthis tornado

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

2. F173 to 112 mph

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

3. F2113 to 157 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. F3158 to 206 mph

   Severe damage. Whole stories of well-built houses destroyed, large buildings badly damaged, trains overturned, trees debarked, heavy cars lifted and thrown.

5. F4207 to 260 mph

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

6. F5261 to 318 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

F0

Date

June 6, 2006

Touchdown

7:14 PM CDT (00:14 UTC)

Path length

2.7 miles (4.3 km)

Path width

30 yards (27 m)

Deaths

0

Injuries

0

County

Iowa County

Touchdown point

43.070, -90.030

Lift-off point

43.050, -89.950

Record number

604

Several supercell thunderstorms developed along a cold front across southwest Wisconsin and pushed east southeast into south-central Wisconsin during the late afternoon and early evening. Six tornadoes resulted from these storms (listed with details above) of the F0 to F1 variety across the counties of Sauk, Columbia, and Iowa. A couple funnel clouds were reported in Green and Columbia counties, as well as large hail in Green Lake and Columbia counties, and thunderstorm wind damage in Dane and Columbia counties. Synoptically, with temperatures in the low or mid 70s and dewpoints in the mid 60s with cold air aloft, high instability resulted. Vertical wind shear, in addition to lift with the cold front, allowed supercell thunderstorms to develop. Sufficient low-level shear allowed tornadic development with two of the supercells.

A tornado spun up 2.8 miles southwest of Helena at 1753CST on the Wisconsin River just west/northwest of the STH 23 bridge that crosses the river. It moved southeast and on-shore just east of the bridge and quickly dissipated at 1755CST. The tornado resulted in only minor tree damage and was rated F0 with winds around 50 knots (58 mph).

A tornado spun up 5.6 miles NNW of Ridgeway at 1814CST just south of Erdman Rd. (or about 1.5 WNW of an unincorporated hamlet of Hyde). It headed southeast for 2.7 miles and dissipated 3.3 miles NNE of Ridgeway at 1825 CST near a big curve on Dugway Rd. This tornado resulted in only minor tree damage and was rated F0 with winds around 50 knots (58 mph).

A tornado spun up 1.5 miles west of Barneveld at 1833 CST just northwest of the intersection of STH 18/151 and Ihm-Harris Rd. It traveled southeast across the intersection of these two roads and dissipated about 100 yards southeast of the intersection about 1.4 miles WSW of Barneveld at 1835CST. About 5,000 dollars in damage occurred to a shed and home. The tornado was rated an F0 with winds around 56 knots (65 mph).

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

45 minutes of warning. NWS MKX issued a tornado warning for this county at 23:29 UTC, 45 minutes before the tornado touched down, in force until 00:30 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 0.02 chance of a tornado within 25 miles. The outlook in force was issued at 19:55 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.

The Milwaukee radar (KMKX), 117 km away, was scanning. The volume nearest the touchdown began at 00:15 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 2006 tornado in WisconsinEvery tornado in Wisconsin since 1950Warnings in force in Wisconsin nowThe forecast where you are

6 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.