F0 tornado, Pleasantville, Iowa, May 19, 1998

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.

Rating

F0

Date

May 19, 1998

Touchdown

4:45 PM CDT (21:45 UTC)

Path length

0.7 miles (1.1 km)

Path width

30 yards (27 m)

Deaths

0

Injuries

0

County

Marion County

Touchdown point

41.380, -93.280

Lift-off point

41.380, -93.270

Record number

970

A warm and humid air mass was located over Iowa during the afternoon of the 19th. Temperatures in this air were around 90 degrees F. Dew point temperatures were in the low to mid 70s, making for an unstable situation. A cold front was poised to the north of Iowa and was sagging southward slowly. Thunderstorms began to form over central Iowa during the mid afternoon hours. They formed rather quickly into a cluster of storms, with repeated development in the same areas. Most of the individual cells were right turning cells and many produced hail. Numerous reports of hail up to golf ball in size were received from in the Des Moines area, southeast toward Ottumwa. The cluster of storms that initially formed over central Iowa did eventually drift southeast toward the Ottumwa area just before sunset. The largest hail report came from Colo in Story County. Three inch diameter hail covered the ground to a depth of 4 inches between Colo and Collins. Needless to say, there were many reports of damage to roofs and cars. Fortunately, the largest hail remained just north and east of the densely populated Des Moines metro area. During the early stages of the storms development, a couple small tornadoes were reported. One was in Polk County, while the second was over Marian County. Both were small and only touched down briefly. The one over Marian County dipped up and down from the clouds several times during it's brief life span. No serious damage occurred as the tornadoes touched down in rural areas. In addition to the hail and tornadoes, the storms produced copious amounts of rainfall. Reports from the Ankeny area east toward Newton indicated very heavy rainfall from the storms. The southeast side of Ankeny reported 3.27 inches of rain in less than two hours time. This resulted in local flooding, however no widespread flooding occurred.

Small tornado with numerous brief touchdowns

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

11 minutes of warning. NWS DMX issued a tornado warning for this county at 21:34 UTC, 11 minutes before the tornado touched down, in force until 22:10 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 Slight Risk. The outlook in force was issued at 10:48 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.

Knoxville (OXV), 16 km from the path, in the two hours either side.

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

The Des Moines radar (KDMX), 54 km away, was scanning. The volume nearest the touchdown began at 21:45 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 1998 tornado in IowaEvery tornado in Iowa since 1950Warnings in force in Iowa nowThe forecast where you are

12 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.