F1 tornado, Marxville to Middleton, Wisconsin, June 23, 2004

1. F040 to 72 mph

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

2. F173 to 112 mphthis tornado

   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

F1

Date

June 23, 2004

Touchdown

8:35 PM CDT (01:35 UTC)

Path length

7.8 miles (12.6 km)

Path width

200 yards (183 m)

Deaths

0

Injuries

0

Property damage

$1.5 million

County

Dane County

Touchdown point

43.070, -89.530

Lift-off point

43.030, -89.420

Record number

1299

Two rounds of severe weather affected parts of south-central and southeast Wisconsin on June 23rd, with the second round featuring 8 tornadoes, large hail (up to golf-ball size), and powerful straight-line downburst winds. A warm front moving north through the area resulted in favorable vertical wind shear to allow for supercell development.The 1st round of severe weather was due to a broken line of intense thunderstorms moving across Walworth, Milwaukee, Racine and Kenosha counties. Hail of up to 1 inch in diameter and torrential rainfall accompanied these storms before they moved over Lake Michigan and weakened. The 2nd round of severe weather was dominated by 2 cyclic supercells - one moved east/southeast through Marquette, Green Lake, Fond du Lac, and Washington Counties, spinning up 5 separate tornadoes, dumping hail stones up to 3 inches in diameter, and hurricane-force downburst winds. The large hail dented several vehicles. Two of these were rated F3. Refer to the individual tornado reports for more details. A more southerly supercell tracked across extreme southern Sauk County and then made a partial right turn and headed southeast through Dane County, spinning up 2 tornadoes in the process, as well as large hail and downburst winds. One powerful downburst wind in Madison (Dane Co.) blew equipment off the roof of a business at the Midvale Shopping Mall. A semi southwest of Ft. Atkinson was blown over by straight-line wind gusts. This southern supercell eventually spun up another tornado in south-central Jefferson County which moved into north-central Walworth County. Refer to the individual tornado reports for more details.Both supercells had downbursts that generated large hail and powerful, hurricane-force winds north and south of their tracks. Over all of Wisconsin, 16 tornadoes were documented on June 23rd, which is the 4th highest single-day total (record is 24 on May 8, 1988). For south-central and southeast Wisconsin, the 8 tornadoes on June 23rd was tied for the 4th highest single-day total (record is 11 on May 8, 1988).

A brief tornado spun up along Old Settlers Rd., just south of the Township line (or about 0.2 mile south of of the intersection of Old Settlers Rd. and Katzenbuechel Rd.). One home had a couple windows damaged by flying debris, and several large trees were uprooted or twisted/sheared on a couple properties. The typical sequence of events was observed by the home's owner's - heavy rain and some wind, then calm, then the freight-train noise, and they could barely close the front door. The responsible supercell moved southeast toward Madison and eventually spun up another tornado on the southwest side of Madison.

A weak F1 tornado (100-110 mph) spun up just west of the southwest Beltline at a point 2.5 miles SW of Middleton (half-mile north of intersection of CTH S and Pleasant View Rd.). It moved east-southeast across the West Town Mall, through the UW-Madison Research Park, ultimately ending about 1/3 mile east of STH 151/Park St (2.3 miles south of Capitol Square). In the Research Park many windows were blown out of business offices, and damage was inflicted to UW-MSN agricultural buildings. At least 194 residential homes had minor damage (roof/siding), and 11 had major damage (windows/roofs - total of $410K). At least 8 businesses had minor damage, and 1 had major damage (roof partially torn off and 1 wall damaged). Total business damage was about $246K. The UW-Madison Research Park had about $729K in damage. Many vehicles sustained some degree of damage ($100K), and one semi was blown over. At least 1000 large trees were damaged. Estimated total tornado damage is $1.485M. An additional cleanup cost of about $347K was reported. At least 2000 customers lost their electrical power. Average path width was about 150 yards.

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

30 minutes of warning. NWS MKX issued a tornado warning for this county at 01:05 UTC, 30 minutes before the tornado touched down, in force until 02:00 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 Moderate Risk, with a 0.15 chance of a tornado within 25 miles. The outlook in force was issued at 00:36 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.

Madison (MSN), 15 km from the path, in the two hours either side.

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

The Milwaukee radar (KMKX), 76 km away, was scanning. The volume nearest the touchdown began at 01:35 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 2004 tornado in WisconsinEvery tornado in Wisconsin since 1950Warnings in force in Wisconsin nowThe forecast where you are

23 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.