F1 tornado, Chillicothe, Iowa, June 1, 2000

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 1, 2000

Touchdown

6:08 PM CDT (23:08 UTC)

Path length

10.7 miles (17.2 km)

Path width

50 yards (46 m)

Deaths

0

Injuries

0

Property damage

$10,000

County

Wapello County

Touchdown point

41.100, -92.520

Lift-off point

41.080, -92.320

Record number

253

At long last, the stationary front that had been over northwest Iowa for several days previous finally began to move southeast as a cold front. A surface low pressure moved northeast along the front during the previous night and was located to the north of Iowa on the afternoon of the first. A mid level cap of warm air was in place over most of Iowa, preventing convection from firing until the late afternoon hours. Surface based CAPE was in excess of 5000 J/kg by the mid afternoon hours. A line of thunderstorms erupted along the cold front by the late afternoon hours. The sheer profile was somewhat weak and thus most of the storms remained below severe limits. Storms did become severe along one area of the line in Wapello and a small part of Mahaska Counties. The main outcome of the severe storms was high winds and hail. Winds as high as 75 MPH were reported by law enforcement officials in Wapello County. There were numerous trees toppled by the winds and power line damage was reported as well. Hail up to the size of golf balls was reported in Chillicothe. The north edge of the storm produced nickle size hail and 60 MPH winds over southeast Mahaska County as well. One tornado was observed as it passed north of the Ottumwa area. The tornado caused little damage as it tracked across open country.

Moved through open country

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

13 minutes of warning. NWS DMX issued a tornado warning for this county at 22:55 UTC, 13 minutes before the tornado touched down, in force until 23:30 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. The outlook in force was issued at 20:21 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 Des Moines radar (KDMX), 130 km away, was scanning. The volume nearest the touchdown began at 23:07 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 2000 tornado in IowaEvery tornado in Iowa since 1950Warnings in force in Iowa nowThe forecast where you are

5 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.