Tornadoes · United States · Iowa · 2022

EF1 tornado, Waukon, Iowa, July 23, 2022

This EF1 tornado ran 1.5 miles across Allamakee County on July 23, 2022, touching down at 11:44 PM CDT and reaching 90 yards wide. It killed nobody, and did $60,000 of property damage.

The rating scale

Tracks are drawn in the color of the rating. The Enhanced Fujita scale rates the damage rather than measuring the wind: the speeds are what that damage is taken to imply.

  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.

The record

Rating
EF1
Date
July 23, 2022
Touchdown
11:44 PM CDT (04:44 UTC)
Lifted
11:46 PM CDT (04:46 UTC)
On the ground
2 minutes
Path length
1.5 miles (2.3 km)
Path width
90 yards (82 m)
Deaths
0
Injuries
0
Property damage
$60,000
County
Allamakee County
Touchdown point
43.263, -91.529
Lift-off point
43.245, -91.512
Record number
2207232244-01

The damage survey

8 damage points were recorded along this path by NWS ARX, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF1. The highest wind the damage implies is 88 mph.

  • Lots of tree damage in city park
  • Mixture of large branches broken and trunks snapped as seen from aerial video.
  • Panels over an open-walled enclosure popped off per aerial video.

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

What the Weather Service recorded

A line of storms moved across northeast Iowa during the evening of July 23rd. These storms produced an EF1 tornado west of Waukon (Allamakee County) that damaged a farm and trees. Strong thunderstorm winds caused extensive damage to several buildings at the community college in Calmar (Winneshiek County) and flipped over a couple vehicles. The public school athletic fields in Calmar were also heavily damaged. The press box was blown off the high school football stands, metal light poles were downed at the softball field, and metal bleachers were thrown over a fence and onto the field. In Waukon, the roofs were damaged on numerous buildings and several trees and power lines were blown down. The Governor of Iowa issued a disaster proclamation for Allamakee, Clayton and Winneshiek Counties.

A brief EF1 tornado touched down southwest of Waukon. The tornado damaged the roofs on farm outbuildings along with some trees.

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

The warnings

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 01:55 UTC and running to 06:51 UTC.

Issued (UTC)ExpiredProductOffice
16:34 UTC22:06 UTCSevere Thunderstorm WatchARX
01:55 UTC06:51 UTCSevere Thunderstorm WatchARX
04:24 UTC05:00 UTCSevere Thunderstorm WarningARX
04:53 UTC05:26 UTCSevere Thunderstorm WarningARX

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, with a 0.02 chance of a tornado within 25 miles. The outlook in force was issued at 00:47 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

4.7 hours before the tornado, 200 km from the path. July 24, 2022.

Skew-T log-pSkew-T log-p diagram, Davenport, at 00:00Z on 2022-07-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 3986 joules per kilogram, CIN -12, lifted condensation level 1390 meters above ground. Wind barbs in knots down the right edge.LCLEL10008507005003002001001 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 2022-07-24The 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 123 square meters per square second, 0 to 6 km bulk shear 36 knots.19395878Sfc1 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
3986 J/kg
Mixed-layer CIN
-12 J/kg
Surface CAPE
5897 J/kg
Mixed-layer LCL
1390 m above ground
0-6 km bulk shear
36 kt
0-1 km bulk shear
17 kt
0-1 km storm-relative helicity
123 m²/s²
0-3 km storm-relative helicity
229 m²/s²
Significant tornado parameter
3.4
Supercell composite
26.8
0-3 km lapse rate
7.6 K/km

Open this sounding in Storm Lab

Davenport, (KDVN), 12:00Z

7.3 hours after it, 200 km from the path. July 24, 2022.

Skew-T log-pSkew-T log-p diagram, Davenport, at 12:00Z on 2022-07-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 509 joules per kilogram, CIN -142, lifted condensation level 1132 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 12:00Z on 2022-07-24The 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 235 square meters per square second, 0 to 6 km bulk shear 40 knots.19395878Sfc1 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
509 J/kg
Mixed-layer CIN
-142 J/kg
Surface CAPE
1105 J/kg
Mixed-layer LCL
1132 m above ground
0-6 km bulk shear
40 kt
0-1 km bulk shear
32 kt
0-1 km storm-relative helicity
235 m²/s²
0-3 km storm-relative helicity
346 m²/s²
Significant tornado parameter
0.3
Supercell composite
2.2
0-3 km lapse rate
4.7 K/km

Open this sounding in Storm Lab

The radar

The La Crosse radar (KARX), 69 km away, was scanning. The volume nearest the touchdown began at 04:43 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.

What was reported nearby

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

Time (UTC)ReportWhereCountyRemark
03:45 UTCTSTM WND DMGDecorahWinneshiek, IANUMEROUS TREES AND POWER LINES BLOWN DOWN.
04:25 UTCTSTM WND DMG3 E DecorahWinneshiek, IATREES DOWN IN FREEPORT. TREE COMPLETELY BLOCKING ROAD NEAR CHURCH/CEMETERY DOWN FROM WELLINGTON. ANOTHER IN THE ROAD BUT CAN GET THROUGH ACROSS FROM RECYCLING CENTER.
04:25 UTCTSTM WND DMGDecorahWinneshiek, IAMANY TREES AND POWERLINES DOWN ACROSS CENTRAL WINNESHIEK COUNTY FROM NORTH OF DECORAH TO FORT ATKINSON. TIME ESTIMATED FROM RADAR.
04:27 UTCTSTM WND DMG1 S CalmarWinneshiek, IAREPORT OF A ROOF OFF A HOUSE AND CARS OVERTURNED NEAR THE NORTHEAST IOWA COMMUNITY COLLEGE CAMPUS. TIME ESTIMATED FROM RADAR.
04:30 UTCHEAVY RAIN 3.7DecorahWinneshiek, IANO POWER.
04:35 UTCTSTM WND GST 486 Nw FrankvilleWinneshiek, IAMESONET STATION RDCI4 DECORAH.
04:40 UTCTSTM WND GST 304 Ene ConoverWinneshiek, IAMESONET STATION DVI03565 CALMAR.
04:41 UTCTSTM WND GST 604 W WaukonAllamakee, IADEPUTY ESTIMATED AT INTERSECTION OF HIGHWAYS 9 AND 51
04:41 UTCTSTM WND GST 604 W WaukonAllamakee, IADEPUTY ESTIMATED AT INTERSECTION OF HIGHWAYS 9 AND 51.
04:42 UTCTSTM WND DMG2 Sw WaukonAllamakee, IAA FARM LOST A BARN, 2 SILOS, AND 2 POWER POLES.
04:44 UTCTSTM WND DMGWaukonAllamakee, IAROOF BLOWN OFF VET CLINIC. PARTIAL ROOF BLOWN OFF A RESIDENCE. OTHER BUSINESSES IN DOWNTOWN AREA HAD SOME ROOF DAMAGE. SEVERAL FLAGPOLES, TREES, AND SIGNS BLOWN DOWN.
04:45 UTCTSTM WND GST 60WaukonAllamakee, IASMALL BRANCHES DOWN IN TOWN ALONG WITH SOME MINOR FLOODING.
05:02 UTCTSTM WND DMG4 Ne Strawberry PointClayton, IAREPORTS OF POWER LINES DOWN
05:02 UTCTSTM WND DMG4 Ne Strawberry PointClayton, IAREPORTS OF POWER LINES DOWN.
07:00 UTCHEAVY RAIN 3.99Vernon SpringsHoward, IASTORM TOTAL RAINFALL.

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

This ground now

The live radar over the trackEvery 2022 tornado in IowaEvery tornado in Iowa since 1950Warnings in force in Iowa nowThe forecast where you are

The other tornadoes of July 23, 2022

7 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
July 235:40 AM CDTEF0DuPage, IL4.5150
July 235:52 AM CDTEF0Will, IL4.1200
July 236:05 AM CDTEF0Will, IL0.7150
July 2310:45 AM EDTEF1Miami, OH1.8200$100,000
July 232:41 PM CDTEF0Winona, MN1.330$5,000
July 233:01 PM CDTEF0Houston, MN4.240$125,000
July 233:33 PM CDTEF0La Crosse, WI2.540$10,000

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.