Tornadoes · United States · Iowa · 2002

F0 tornado, Pleasantville, Iowa, May 8, 2002

This F0 tornado ran 0.2 miles across Marion County on May 8, 2002, touching down at 8:15 PM CDT and reaching 30 yards wide. It killed nobody.

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 mphthis tornado

    Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.

  2. F173 to 112 mph

    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
F0
Date
May 8, 2002
Touchdown
8:15 PM CDT (01:15 UTC)
Path length
0.2 miles (0.3 km)
Path width
30 yards (27 m)
Deaths
0
Injuries
0
County
Marion County
Touchdown point
41.380, -93.270
Lift-off point
41.380, -93.270
Record number
54

What the Weather Service recorded

Low pressure over north central Kansas at sunrise on the 8th lifted northeast during the day. The low tracked northeast across west central, into northeast Iowa by the evening of the 8th. A warm front extending east from the low lifted north across the state rapidly during the morning hours. Dew points warmed into the mid 60s ahead of the low in the warm sector as surface temperatures warmed into the low 80s. The airmass became unstable by the afternoon hours as the heating of the day eliminated the cap. Thunderstorms erupted along the cold front by the late afternoon. The event was mainly of wind and hail. Several reports of winds of 60 to as much as 75 MPH were received over central, south central, and southeast Iowa. The hail was generally around an inch in diameter, though golf ball size hail was reported with one of the storms as it moved over Searsboro, in Poweshiek County. One tornado was reported in central Iowa in Marion County. The tornado was a brief spin-up gustnado developed near the town of Pleasantville. It touched down in an open area and caused very little damage.

Brief spin up gustnado in open area.

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

The warnings

14 minutes of warning. NWS DMX issued a tornado warning for this county at 01:01 UTC, 14 minutes before the tornado touched down, in force until 01:45 UTC.

Issued (UTC)ExpiredProductOffice
00:55 UTC02:00 UTCSevere Thunderstorm WarningDMX
01:01 UTC01:45 UTCTornado WarningDMX
01:36 UTC02:15 UTCTornado WarningDMX

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 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

1.3 hours before the tornado, 232 km from the path. May 9, 2002.

Skew-T log-pSkew-T log-p diagram, Davenport, at 00:00Z on 2002-05-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1642 joules per kilogram, CIN -8, lifted condensation level 951 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°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, Davenport, at 00:00Z on 2002-05-09The 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 108 square meters per square second, 0 to 6 km bulk shear 36 knots.1939587897117Sfc1 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
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

Open this sounding in Storm Lab

Davenport, (KDVN), 12:00Z

10.7 hours after it, 232 km from the path. May 9, 2002.

Skew-T log-pSkew-T log-p diagram, Davenport, at 12:00Z on 2002-05-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 0 joules per kilogram, CIN -92503, lifted condensation level 1016 meters above ground. Wind barbs in knots down the right edge.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°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, Davenport, at 12:00Z on 2002-05-09The 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 -92 square meters per square second, 0 to 6 km bulk shear 33 knots.1939587897117Sfc1 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
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

Open this sounding in Storm Lab

The radar

The Des Moines radar (KDMX), 54 km away, was scanning. The volume nearest the touchdown began at 01:15 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 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.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
May 83:07 PM CDTF0McPherson, KS2.0110
May 83:41 PM CDTF0Marion, KS1.0220
May 83:55 PM CDTF0Marion, KS1.0220
May 84:09 PM CDTF0Harper, KS2.0220
May 85:00 PM CDTF0Sumner, KS1.0110
May 86:07 PM EDTF2Gallia, OH3.0803$3.5 million
May 85:10 PM CDTF0Chase, KS2.0220
May 86:26 PM CDTF1Jefferson, KS0.2100$10,000
May 86:30 PM CDTF1Jefferson, KS0.2100$50,000
May 86:34 PM CDTF0Jefferson, KS0.150$10,000
May 86:36 PM CDTF1Jefferson, KS0.2100$30,000
May 86:43 PM CDTF0Leavenworth, KS0.140$1,000
May 86:48 PM CDTF0Cowley, KS5.0220
May 86:48 PM CDTF1Leavenworth, KS0.540$10,000
May 86:58 PM CDTF0Chickasaw, IA0.225
May 87:20 PM CDTF0Clinton, MO0.125
May 88:10 PM CDTF0Allamakee, IA0.120$10,000
May 88:49 PM CDTF0Grant, OK6.075
May 89:45 PM CDTF0Keokuk, IA0.110$30,000
May 812:32 AM CDTF0Woodford, IL5.550

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.