F1 tornado, Potterville to Lansing, Michigan, September 9, 2001

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

September 9, 2001

Touchdown

6:34 PM EDT (22:34 UTC)

Path length

8.5 miles (13.7 km)

Path width

300 yards (274 m)

Deaths

0

Injuries

1

Property damage

$15 million

Counties

Eaton and Ingham counties

Touchdown point

42.630, -84.730

Lift-off point

42.730, -84.530

Record number

1111

A F1 tornado with a path length of 8.5 miles, which was 300 yards wide, produced maximum wind speeds of 110 m.p.h. that caused extensive damage. Fortunately, there were no serious injuries. The tornado touched down on Windsor Highway in Eaton county three quarters of a mile west of I-69. The tornado began as a F0 about 150 feet wide. The tornado moved northeast at about 40 m.p.h. and caused a considerable amount of tree damage, major damage to barns and outbuildings, and minor damage to homes. It crossed I-69 just south of Davis Highway, blowing over a semi trailer causing minor injuries. It began to strengthen and widen as it crossed Davis Highway, and numerous trees were blown down and barns destroyed. As it crossed I-96 it continued to strengthen and it destroyed a large metal building that housed a used parts store on Canal road. It lifted a double wide mobile home off its foundation, but did not cause major damage because the mobile home was securely tied down at all supports. Several trees were blown down in the area. The tornado continued northeast on Canal road and destroyed a large cooling tower at the Erickson power plant, at which time the tornado's peak intensity of F1 with 110 m.p.h. winds was attained. It was estimated that more than 4 million dollars in damage was incurred to the Lansing Board of Water and Light's Erickson power plant. The tornado continued to move northeast, gradually weakening and becoming wider. It caused damage to semi trailers and trees along Creyts road, and to the roof of the Meijer warehouse. It proceeded across Mt. Hope highway and crossed I-496 near Snow road. It knocked down a large tree and sent branches of the tree flying through the air like missiles, which broke windows out of numerous cars in a church parking lot. The tornado continued to weaken as it moved through residential areas just north of I-96, causing mainly tree damage. The last damage occurred on a golf course just east of Waverly road in Ingham county, where a tree was blown down. An isolated severe thunderstorm earlier in the day blew down several large limbs in Oakfield township (Kent county). In Harrison (Clare county), trained spotters reported that a large tree was blown down by a thunderstorm wind gusts. Finally, spotters in DeWitt (Clinton county) reported that a large tree was blown down onto a power line.

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. One was issued for the county at another hour that day.

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 19:52 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 Grand Rapids radar (KGRR), 78 km away, was scanning. The volume nearest the touchdown began at 22:34 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 2001 tornado in MichiganEvery tornado in Michigan since 1950Warnings in force in Michigan nowThe forecast where you are

7 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.