F1 tornado, Leonard, Michigan, May 5, 2003

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 5, 2003

Touchdown

8:00 PM EDT (00:00 UTC)

Path length

1.0 miles (1.6 km)

Path width

100 yards (91 m)

Deaths

0

Injuries

0

Property damage

$90,000

County

Oakland County

Touchdown point

42.850, -83.150

Lift-off point

42.850, -83.130

Record number

153

During the afternoon of the 5th, thunderstorms initiated along a lake breeze (off Lake Michigan) in Southwest Lower Michigan. These thunderstorms then moved along a warm front which was located over Southeast Michigan. Thunderstorms produced mostly hail, with a few damaging wind gusts reported as well. The largest hail (golf ball size) occurred near Ann Arbor and Oxford. Wind Shear in the vicinity of the warm front produced numerous wall and funnel clouds. One tornado did occur near Leonard in Oakland County. It was reported a couple thousand homes and businesses lost power during the storms.

A tornado touched down 1 mile southwest of Leonard and was on the ground for about 1 mile. Several large trees were uprooted from the tornado. A large pole barn was destroyed, a camper and trailer were overturned, the roof on a home was lifted off, and a truck was heavily damaged when a large tree fell onto it. The most extensive damage was reported on Quattro Lane, south of Leonard.

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

7 minutes of warning. NWS DTX issued a tornado warning for this county at 23:53 UTC, 7 minutes before the tornado touched down, in force until 00:45 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 General Thunderstorms Risk. The outlook in force was issued at 16:24 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.

Pontiac (PTK), 31 km from the path, in the two hours either side.

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

The Detroit radar (KDTX), 32 km away, was scanning. The volume nearest the touchdown began at 00:00 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 2003 tornado in MichiganEvery tornado in Michigan since 1950Warnings in force in Michigan nowThe forecast where you are

24 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.