F0 tornado, Onslow to Oxford Mills, Iowa, May 15, 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 15, 1998

Touchdown

6:30 PM CDT (23:30 UTC)

Path length

0.2 miles (0.3 km)

Path width

30 yards (27 m)

Deaths

0

Injuries

0

Property damage

$1,000

County

Jones County

Touchdown point

42.020, -91.080

Lift-off point

41.970, -90.950

Record number

1252

A tornado developed two miles Southwest of Washington Iowa and produced a 30 mile long continuous path of damage and debris as it moved to the Northeast at nearly 30 mph. The tornado weakened and lifted before reaching I-80 near West Branch Iowa shortly before 6pm. The tornado continued Northeast across Cedar County Iowa producing another 15 miles of isolated damage...not continuous. The storm producing this tornado continued Northeast producing a brief touchdown one mile west of Oxford Mills Iowa near the intersection of county roads E53 and X64. Another brief touchdown occurred south of Dubuque near Zwingle Iowa before the storm moved into Wisconsin. In Washington Iowa extensive damage was reported to businesses, a church, numerous homes, an apartment complex housing elderly residents and a livestock sale barn. Fourteen single family homes were destroyed, another fourteen received major damage and forty five reported minor damage. Three multi-family housing units were destroyed and two received major damage. Twenty six detached units (sheds and garages) were destroyed or sustained major damage. Across Washington county fourteen farmsteads were hit by the tornado with damage ranging from moderate to heavy. Utility damage was listed at $218,000. In the city of Washington twenty seven individuals sustained minor injuries requiring medical treatment. One person was hospitalized for treatment of injuries he received when his automobile was picked up and rolled over by the tornado. In Johnson County twenty miles of power lines and poles were damaged, fifteen roads were closed due to debris and one bridge was destroyed. Six residences were destroyed, eight more sustained minor the major damage, and three farms were affected. Seventeen people were treated and released for injuries in Johnson County. In Cedar County moderate to heavy damage was reported to five different properties as the tornado destroyed a home, barns, grain bins, machine and hog sheds, a hog nursery and a chicken coop. Two persons near Downey suffered injuries requiring stitches when bricks and debris fell upon them while they were taking shelter in their basement.

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

8 minutes of warning. NWS DVN issued a tornado warning for this county at 23:22 UTC, 8 minutes before the tornado touched down, in force until 00:10 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 Moderate Risk. The outlook in force was issued at 11:01 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.

Monticello Municipal (MXO), 28 km from the path, in the two hours either side.

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

The Quad Cities radar (KDVN), 56 km away, was scanning. The volume nearest the touchdown began at 23:32 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

25 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.