F0 tornado, Ft Atkinson, Wisconsin, August 13, 2002

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

August 13, 2002

Touchdown

5:02 PM CDT (22:02 UTC)

Path length

4.5 miles (7.2 km)

Path width

50 yards (46 m)

Deaths

0

Injuries

0

Property damage

$10,000

County

Jefferson County

Touchdown point

42.920, -88.880

Lift-off point

42.880, -88.780

Record number

249

Several clusters of thunderstorms with heavy rains developed over and moved northeast across southeast Wisconsin out ahead of a cold front on August 13, 2002, resulting in urban and small stream flooding in Waukesha, Milwaukee, and Ozaukee counties. Rainfall totals were in the 2 to 4 range. In addition, gust winds of 35 to 43 kts (40 to 50 mph) accompanied the storms, resulting in broken tree branches. On the south side of the city of Waukesha, 1.5 inches of rain fell in 20 minutes in the afternoon, once again sending small streams out of their banks and allowing water to accumulate in low-lying areas. The 2-day rain total at this location near the corner of Hwy 164 and CTY I was 8.80 inches! Also on the 13th in the afternoon, 3.4 inches of rain fell at the home of an Amateur Radio operator in the southeast part of the city of Milwaukee. Urban flooding resulted. Some closed roads in both Waukesha and Milwaukee Counties had 3 feet of water on them. Urban flooding affected the Port Washington area (Ozaukee Co.) after about 2 inches of rain fell in about 75 minutes during the afternoon hours. A couple roads were closed in that city. Urban flooding was also reported in Ft. Atkinson (Jefferson Co.) after the tornado event. Heavy rains in this city produced swift currents that knocked a boy down, sending him through a culvert. He was rescued by the Fire Department, and treated for slight injuries.

A weak tornado spun up 1.8 miles southwest of Ft. Atkinson near the Rock River, and proceeded to move east-southeast across the far southern parts of the city to just north of the intersection of Hwy 89 and M, and then across rural, farm locations to a point just west of N about .5 mile north of Cold Spring. Maximum wind speeds were estimated to be in the 52 to 61 kts (60 to 70) mph range based on F0 damage left behind. Some light damage to shingles and siding was noted on several residential homes. Several large trees were uprooted, and loose lumber and debris was picked up at a lumber yard. At other locations along the path, lawn furniture and other objects were overturned or displaced. Eyewitness reports indicated that the condensation funnel was not visible all the way to the ground, but they noted that dirt was ingested into the circulation, thereby making the tornado visible at ground level. There were no fatalities or injuries. Meteorologically, the tornado was the result of two thunderstorm cells, in a line of storms along a cold front, merging just southwest of Ft. Atkinson. No other severe weather was reported.

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

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

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 General Thunderstorms Risk. The outlook in force was issued at 19:43 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), 24 km away, was scanning. The volume nearest the touchdown began at 22:03 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.

The live radar over the trackEvery 2002 tornado in WisconsinEvery tornado in Wisconsin since 1950Warnings in force in Wisconsin nowThe forecast where you are

2 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.