Tornadoes · United States · Michigan · 2001

F1 tornado, Shepherd, Michigan, May 21, 2001

This F1 tornado ran 4.0 miles across Isabella County on May 21, 2001, touching down at 4:40 PM EDT and reaching 40 yards wide. It killed nobody and injured 1, and did $150,000 of property damage.

The rating scale

Tracks are drawn in the color of the rating. The Fujita scale rates the damage rather than measuring the wind: the speeds are what that damage is taken to imply.

  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.

The record

Rating
F1
Date
May 21, 2001
Touchdown
4:40 PM EDT (20:40 UTC)
Path length
4.0 miles (6.4 km)
Path width
40 yards (37 m)
Deaths
0
Injuries
1
Property damage
$150,000
County
Isabella County
Touchdown point
43.520, -84.680
Lift-off point
43.520, -84.680
Record number
900

What the Weather Service recorded

A F1 tornado with a path length of 4 miles and width of 40 yards produced maximum estimated wind speeds to 80 m.p.h. It touched down just north of Pleasant Valley road and moved north, parallel to Mission road, then ended just north of Wing road. One man was slightly injured when his car was forced off the road by the winds associated with the tornado. A small radio tower was blown down and a barn sustained extensive damage. Metal roofing from the barn was carried more than 100 yards.

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

The warnings

26 minutes of warning. NWS GRR issued a tornado warning for this county at 20:14 UTC, 26 minutes before the tornado touched down, in force until 20:45 UTC.

Issued (UTC)ExpiredProductOffice
20:14 UTC20:45 UTCTornado WarningGRR
20:45 UTC21:15 UTCTornado WarningGRR
21:15 UTC21:45 UTCTornado WarningGRR

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 forecast that day

The Storm Prediction Center had this point in a Slight Risk. The outlook in force was issued at 19:56 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 air that afternoon

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.

Detroit, MI (KDTX), 12:00Z

8.7 hours before the tornado, 135 km from the path. May 21, 2001.

Skew-T log-pSkew-T log-p diagram, Detroit, MI at 12:00Z on 2001-05-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 293 joules per kilogram, CIN -53, lifted condensation level 630 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed. The warm shading is its CAPE, the cool shading the inhibition it has to break through.
HodographHodograph, Detroit, MI at 12:00Z on 2001-05-21The wind through the lowest 10 kilometers as a curve, rings every 10 meters per second labeled in knots. Zero to 1 km storm-relative helicity 134 square meters per square second, 0 to 6 km bulk shear 39 knots.193958Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km. RM and LM are the right and left moving storms Bunkers' method gives; the shaded area is the 0 to 1 km storm-relative helicity.
Mixed-layer CAPE
293 J/kg
Mixed-layer CIN
-53 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
630 m above ground
0-6 km bulk shear
39 kt
0-1 km bulk shear
20 kt
0-1 km storm-relative helicity
134 m²/s²
0-3 km storm-relative helicity
164 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.9
0-3 km lapse rate
4.7 K/km

Open this sounding in Storm Lab

Detroit, MI (KDTX), 00:00Z

3.3 hours after it, 135 km from the path. May 22, 2001.

Skew-T log-pSkew-T log-p diagram, Detroit, MI at 00:00Z on 2001-05-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 167 joules per kilogram, CIN 0, lifted condensation level 512 meters above ground. Wind barbs in knots down the right edge.LCLEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed. The warm shading is its CAPE, the cool shading the inhibition it has to break through.
HodographHodograph, Detroit, MI at 00:00Z on 2001-05-22The wind through the lowest 10 kilometers as a curve, rings every 10 meters per second labeled in knots. Zero to 1 km storm-relative helicity 171 square meters per square second, 0 to 6 km bulk shear 34 knots.193958Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km. RM and LM are the right and left moving storms Bunkers' method gives; the shaded area is the 0 to 1 km storm-relative helicity.
Mixed-layer CAPE
167 J/kg
Mixed-layer CIN
0 J/kg
Surface CAPE
357 J/kg
Mixed-layer LCL
512 m above ground
0-6 km bulk shear
34 kt
0-1 km bulk shear
30 kt
0-1 km storm-relative helicity
171 m²/s²
0-3 km storm-relative helicity
147 m²/s²
Significant tornado parameter
0.1
Supercell composite
0.9
0-3 km lapse rate
5.6 K/km

Open this sounding in Storm Lab

The surface observations

Mount Pleasant (MOP), 12 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
18:55 UTC71.668110° 13 kt16998.3BR
19:15 UTC6866.2100° 13 kt998-RA
19:35 UTC6866.290° 10 kt997.6+RA
19:55 UTC6866.290° 9 kt996.6RA
20:15 UTC66.264.490° 13 kt996.3+RA
20:35 UTC66.264.4100° 16 kt22994.9-RA
21:15 UTC64.462.6160° 6 kt995.6+RA
21:17 UTC64.464.4160° 9 kt995.6RA
21:35 UTC6866.2160° 11 kt16995.6RA
21:55 UTC6864.4180° 11 kt15995.6-RA
22:15 UTC66.262.6180° 12 kt17995.3-RA
22:35 UTC66.262.6180° 10 kt17995.3RA

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

The radar

The Grand Rapids radar (KGRR), 99 km away, was scanning. The volume nearest the touchdown began at 20:39 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.

This ground now

The live radar over the trackEvery 2001 tornado in MichiganEvery tornado in Michigan since 1950Warnings in force in Michigan nowThe forecast where you are

The other tornadoes of May 21, 2001

25 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
May 211:23 PM EDTF0Oakland, MI1.0150$70,000
May 212:15 PM EDTF0Eaton, MI6.050$300,000
May 212:20 PM EDTF2Kalamazoo, MI1.0150$500,000
May 212:34 PM EDTF2Livingston, MI10.92003$3.0 million
May 212:35 PM EDTF0Kent, MI0.650$100,000
May 212:35 PM EDTF0Ottawa, MI0.150$50,000
May 212:50 PM EDTF0Barry, MI1.050$200,000
May 212:52 PM EDTF0Allegan, MI1.550$50,000
May 212:55 PM EDTF1Clinton, MI4.550$300,000
May 213:00 PM EDTF0Shiawassee, MI0.130
May 213:29 PM EDTF1Kent, MI0.350$200,000
May 213:30 PM EDTF0Ionia, MI1.050$100,000
May 213:40 PM EDTF0Kent, MI0.150$50,000
May 213:50 PM EDTF0Kent, MI0.150$70,000
May 214:20 PM EDTF1Gratiot, MI3.0401$150,000
May 214:40 PM EDTF0Gratiot, MI2.550$30,000
May 215:02 PM EDTF0Genesee, MI7.3100$140,000
May 215:25 PM EDTF2Medina, OH7.580$1.0 million
May 215:30 PM EDTF0Clare, MI0.130$10,000
May 216:05 PM EDTF0City of Suffolk, VA0.225$30,000
May 216:35 PM EDTF1Meigs, OH4.0200$400,000
May 217:43 PM EDTF1Stark, OH0.51001$450,000
May 218:10 PM EDTF0Wood, WV0.7100$180,000
May 219:15 PM CDTF1Hidalgo, TX0.175$30,000
May 219:25 PM CDTF1Hidalgo, TX0.275$70,000

What this means

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.

Sources

NOAA Storm Prediction Center tornado database, 1950-2025, the official record kept by NOAA's Storm Prediction Center.