EF1 tornado, Covington to Hiawatha, Iowa, September 3, 2018

1. EF065 to 85 mph

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

2. EF186 to 110 mphthis tornado

   Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.

3. EF2111 to 135 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. EF3136 to 165 mph

   Severe damage. Whole stories of well-built houses destroyed, large buildings badly damaged, trains overturned, trees debarked, heavy cars lifted and thrown.

5. EF4166 to 200 mph

   Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.

6. EF5over 200 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

EF1

Date

September 3, 2018

Touchdown

9:08 PM CDT (02:08 UTC)

Lifted

9:14 PM CDT (02:14 UTC)

On the ground

6 minutes

Path length

2.2 miles (3.5 km)

Path width

30 yards (27 m)

Deaths

0

Injuries

0

Property damage

$35,000

County

Linn County

Touchdown point

41.971, -91.739

Lift-off point

41.993, -91.710

Record number

1809032008-01

37 damage points were recorded along this path by NWS DVN, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF1. The highest wind the damage implies is 110 mph.

• GARAGE DESTROYED TREE SNAPPED
• limbs laying in different directions
• tree down on home w its damage to soffit
• tree s and power lines dow n

Survey points are preliminary and are the raw material the published rating was built from. Source: NWS Damage Assessment Toolkit.

Scattered showers and thunderstorms developed across eastern Iowa, northwest Illinois, and northeast Missouri during the afternoon and evening as an upper level disturbance tracked across the region. One supercell thunderstorm produced four tornadoes as it tracked across Benton and Linn counties during the late afternoon and early evening. Another storm produced a tornado on the west side of Cedar Rapids later in the evening.

A NWS storm survey team determined an EF-1 tornado with maximum winds around 100 mph touched down near the intersection of Skyline Drive NW and Meadowlark Lane NW in the northwest portion of Cedar Rapids, around 908 pm. The tornado moved northeast through residential neighborhoods. The tornado destroyed a garage, uprooted and snapped large trees and power poles, and caused minor damage to roofs. The tornado lifted near the intersection of 29th St. NW and Q Ave. NW around 914 pm. The storm also caused straight line wind damage at a business near the intersection of Collins Road NE and I-380. Winds estimated around 80 mph caused a partial collapse of a metal pole barn.

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

No tornado warning for this county appears in the archive as in force at the moment the tornado touched down. One was issued for the county at another hour that day.

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, with a 0.05 chance of a tornado within 25 miles. The outlook in force was issued at 00:37 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.

The Quad Cities radar (KDVN), 103 km away, was scanning. The volume nearest the touchdown began at 02:11 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.

Local storm reports within 60 km of the path, in the three hours either side.

From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.

The live radar over the trackEvery 2018 tornado in IowaEvery tornado in Iowa since 1950Warnings in force in Iowa nowThe forecast where you are

5 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.