Tornadoes · United States · Iowa · 2002
F0 tornado, Waukon, Iowa, May 8, 2002
This F0 tornado ran 0.1 miles across Allamakee County on May 8, 2002, touching down at 8:10 PM CDT and reaching 20 yards wide. It killed nobody, and did $10,000 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.
F040 to 72 mphthis tornado
Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.
F173 to 112 mph
Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.
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.
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.
F4207 to 260 mph
Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.
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.
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
- F0
- Date
- May 8, 2002
- Touchdown
- 8:10 PM CDT (01:10 UTC)
- Path length
- 0.1 miles (0.2 km)
- Path width
- 20 yards (18 m)
- Deaths
- 0
- Injuries
- 0
- Property damage
- $10,000
- County
- Allamakee County
- Touchdown point
- 43.250, -91.450
- Lift-off point
- 43.250, -91.450
- Record number
- 649
What the Weather Service recorded
Straight-line winds of 80 to 100 mph destroyed a pole barn about 1 mile southwest of Protivin (Howard County), blowing debris from the barn about 3/4 of a mile into an open field. A nearby farmer's mill sustained minor damage as well. Several buildings in a lumber yard on the south side of Waukon (Allamakee County) had roof damage, with sections of roof thrown downwind to the southeast. Some sheds and supplies in the lumber yard were also shifted to the east or southeast. Along Highway 76, just southeast of Waukon, a small tornado hit a farm, damaging part of the house and at least one outbuilding. A nearby church was damaged by the same tornado. In fact, a family who had taken shelter inside the church reported a stain glass window was completely gone following the storm, with no evidence of broken glass found anywhere near the building. Storm chasers also reported a brief tornado touchdown in open fields between Ionia and New Hampton (Chickasaw County), but no damage was reported. In addition, hail ranging in size from dimes to quarters was reported by storm spotters and amateur radio operators.
From NOAA NCEI's Storm Events Database, the narrative the local forecast office wrote for Storm Data.
The warnings
9 minutes of warning. NWS ARX issued a tornado warning for this county at 01:01 UTC, 9 minutes before the tornado touched down, in force until 02:00 UTC.
| Issued (UTC) | Expired | Product | Office |
|---|---|---|---|
| 00:37 UTC | 01:30 UTC | Severe Thunderstorm Warning | ARX |
| 01:01 UTC | 02:00 UTC | Tornado Warning | ARX |
| 01:56 UTC | 05:00 UTC | Flash Flood Warning | ARX |
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, with a 0.05 chance of a tornado within 25 miles. The outlook in force was issued at 01:15 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.
Davenport, (KDVN), 00:00Z
1.2 hours before the tornado, 197 km from the path. May 9, 2002.
- Mixed-layer CAPE
- 1642 J/kg
- Mixed-layer CIN
- -8 J/kg
- Surface CAPE
- 1128 J/kg
- Mixed-layer LCL
- 951 m above ground
- 0-6 km bulk shear
- 36 kt
- 0-1 km bulk shear
- 15 kt
- 0-1 km storm-relative helicity
- 108 m²/s²
- 0-3 km storm-relative helicity
- 227 m²/s²
- Significant tornado parameter
- 1.3
- Supercell composite
- 6.8
- 0-3 km lapse rate
- 6.4 K/km
Davenport, (KDVN), 12:00Z
10.8 hours after it, 197 km from the path. May 9, 2002.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- -92503 J/kg
- Surface CAPE
- 5 J/kg
- Mixed-layer LCL
- 1016 m above ground
- 0-6 km bulk shear
- 33 kt
- 0-1 km bulk shear
- 14 kt
- 0-1 km storm-relative helicity
- -92 m²/s²
- 0-3 km storm-relative helicity
- -54 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
- 0-3 km lapse rate
- 3.1 K/km
This ground now
The live radar over the trackEvery 2002 tornado in IowaEvery tornado in Iowa since 1950Warnings in force in Iowa nowThe forecast where you are
The other tornadoes of May 8, 2002
20 more were confirmed in the United States that day.
| Date | Time | Rating | Where | Path (mi) | Width (yd) | Deaths | Injuries | Damage |
|---|---|---|---|---|---|---|---|---|
| May 8 | 3:07 PM CDT | F0 | McPherson, KS | 2.0 | 110 | |||
| May 8 | 3:41 PM CDT | F0 | Marion, KS | 1.0 | 220 | |||
| May 8 | 3:55 PM CDT | F0 | Marion, KS | 1.0 | 220 | |||
| May 8 | 4:09 PM CDT | F0 | Harper, KS | 2.0 | 220 | |||
| May 8 | 5:00 PM CDT | F0 | Sumner, KS | 1.0 | 110 | |||
| May 8 | 6:07 PM EDT | F2 | Gallia, OH | 3.0 | 80 | 3 | $3.5 million | |
| May 8 | 5:10 PM CDT | F0 | Chase, KS | 2.0 | 220 | |||
| May 8 | 6:26 PM CDT | F1 | Jefferson, KS | 0.2 | 100 | $10,000 | ||
| May 8 | 6:30 PM CDT | F1 | Jefferson, KS | 0.2 | 100 | $50,000 | ||
| May 8 | 6:34 PM CDT | F0 | Jefferson, KS | 0.1 | 50 | $10,000 | ||
| May 8 | 6:36 PM CDT | F1 | Jefferson, KS | 0.2 | 100 | $30,000 | ||
| May 8 | 6:43 PM CDT | F0 | Leavenworth, KS | 0.1 | 40 | $1,000 | ||
| May 8 | 6:48 PM CDT | F0 | Cowley, KS | 5.0 | 220 | |||
| May 8 | 6:48 PM CDT | F1 | Leavenworth, KS | 0.5 | 40 | $10,000 | ||
| May 8 | 6:58 PM CDT | F0 | Chickasaw, IA | 0.2 | 25 | |||
| May 8 | 7:20 PM CDT | F0 | Clinton, MO | 0.1 | 25 | |||
| May 8 | 8:15 PM CDT | F0 | Marion, IA | 0.2 | 30 | |||
| May 8 | 8:49 PM CDT | F0 | Grant, OK | 6.0 | 75 | |||
| May 8 | 9:45 PM CDT | F0 | Keokuk, IA | 0.1 | 10 | $30,000 | ||
| May 8 | 12:32 AM CDT | F0 | Woodford, IL | 5.5 | 50 |
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.