EF0 tornado, Wolf to Ridgeport, Iowa, June 7, 2015

1. EF065 to 85 mphthis tornado

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

2. EF186 to 110 mph

   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

EF0

Date

June 7, 2015

Touchdown

1:15 AM CDT (06:15 UTC)

Lifted

1:18 AM CDT (06:18 UTC)

On the ground

3 minutes

Path length

2.8 miles (4.6 km)

Path width

40 yards (37 m)

Deaths

0

Injuries

0

Property damage

$15,000

Crop damage

$4,000

County

Boone County

Touchdown point

42.099, -94.021

Lift-off point

42.108, -93.967

Record number

1506070015-01

15 damage points were recorded along this path by NWS DMX, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF0. The highest wind the damage implies is 70 mph.

• Several large limbs broken on a couple of trees on the NW corner of farmstead. Tornado looks to have gusted out by this time.
• A number of small limbs broken in this tree. One or two branches on the lower limb of the tree across the street were snapped. Maybe inflow? Other trees looked untouched.
• Tree had been removed prior to the survey. Fall direction of ESE based on the orientation of the piles of sawdust from when the trunk was cut up. Was the only tree in this stand to fall or sustain any damage.
• A couple of larger branches from this tree were snapped, but the damage had already been cleaned up prior to the survey. Unable to tell where the branches landed.

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

An upper level trough pushed through the northern plains with an associated cold front extending southward into the central plains. Storms fired along the front to the west of Iowa in the evening and developed into a large MCS as it moved into Iowa. An MCV and a large squall line moved through northern and central Iowa during the overnight hours producing strong, damaging winds and heavy rain. Four brief tornadoes also occurred in central Iowa along the leading edge of the squall line in an area of stronger shear and higher moisture. The tornadoes mainly damaged trees and crops, however one did strike a barn and silo in rural Boone County. Another damaged traffic signals and an Iowa DNR nursery in the Ames area of Story County.

This small and weak tornado formed on the leading edge of a squall line and tracked quickly across fields before striking a farm, causing light to moderate tree damage and damaging a storage silo and barn.

This was a short-lived tornado that formed on the leading edge of a QLCS. It stayed in rural areas and caused some minor crop and tree damage, but did not cause any known damage to structures.

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.

The county was under a severe thunderstorm watch, issued at 04:23 UTC and running to 07:45 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 General Thunderstorms Risk. The outlook in force was issued at 05:59 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 Des Moines radar (KDMX), 47 km away, was scanning. The volume nearest the touchdown began at 06:16 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 2015 tornado in IowaEvery tornado in Iowa since 1950Warnings in force in Iowa nowThe forecast where you are

8 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.