F1 tornado, Imlay City, Michigan, May 23, 1999

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

May 23, 1999

Touchdown

6:51 PM EDT (22:51 UTC)

Path length

3.9 miles (6.3 km)

Path width

0 yards (0 m)

Deaths

0

Injuries

0

Property damage

$40,000

County

Lapeer County

Touchdown point

43.070, -83.070

Lift-off point

43.120, -83.030

Record number

997

A low pressure system moved northeast across northern lower Michigan late in the day. An associated cold front moved across southeast Michigan in the evening. Numerous showers developed ahead of the cold front in lower Michigan. Even though there was little, if any, thunder, these showers managed to produce two tornadoes in southeast Michigan.In Lenawee County, a tornado moved northeast across Rome Township. This tornado produced F0 damage along most of its path, but briefly reached F1 intensity about 2 miles northeast of Rome Center. At this point, the tornado destroyed a large metal shed, blowing debris up to a quarter mile away. The tornado also damaged an antique gas pump at the same site. Along the rest of its path, the tornado snapped off a number of trees, and damaged siding and rain gutters to a farmhouse. Just before it lifted, the tornado shifted a barn off its foundation, and partially deroofed two barns.As an historical note, the path of this tornado coincided almost exactly with a segment of the paths of the Palm Sunday tornadoes of April 11 1965 - which were the strongest tornadoes in Lenawee County since 1950. In fact, local property owners commented that the structures that were damaged by the 1999 tornado were also damaged (much more heavily) back in 1965!The second tornado of the day affected Imlay and Goodland Townships in eastern Lapeer County. Just after touchdown, the tornado moved a two story home along Bowers Road off its foundation, resulting in serious structural damage. A barn across the street was partially deroofed, and portions of the walls collapsed. A livestock trailer and a dog pen were also moved, and a large tree was downed nearby.Damage was comparatively slight in the middle portion of the track. Just before it lifted, however, the tornado struck another home, this one along Shaw Road. This two-year-old home was largely deroofed, with pieces of the roof found a quarter mile away. Several windows were blown out, and substantial tree damage occurred on the property.The damage near the beginning and the end of the track are both consistent with an F1 tornado.

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 20:03 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 Detroit radar (KDTX), 56 km away, was scanning. The volume nearest the touchdown began at 22:50 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 1999 tornado in MichiganEvery tornado in Michigan since 1950Warnings in force in Michigan nowThe forecast where you are

1 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.