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.
EF065 to 85 mph
Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.
EF186 to 110 mphthis tornado
Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.
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.
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.
EF4166 to 200 mph
Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.
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.
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) | Expired | Product | Office |
|---|---|---|---|
| 16:34 UTC | 22:06 UTC | Severe Thunderstorm Watch | ARX |
| 01:55 UTC | 06:51 UTC | Severe Thunderstorm Watch | ARX |
| 04:24 UTC | 05:00 UTC | Severe Thunderstorm Warning | ARX |
| 04:53 UTC | 05:26 UTC | Severe Thunderstorm Warning | ARX |
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.
- 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
Davenport, (KDVN), 12:00Z
7.3 hours after it, 200 km from the path. July 24, 2022.
- 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
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) | Report | Where | County | Remark |
|---|---|---|---|---|
| 03:45 UTC | TSTM WND DMG | Decorah | Winneshiek, IA | NUMEROUS TREES AND POWER LINES BLOWN DOWN. |
| 04:25 UTC | TSTM WND DMG | 3 E Decorah | Winneshiek, IA | TREES 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 UTC | TSTM WND DMG | Decorah | Winneshiek, IA | MANY TREES AND POWERLINES DOWN ACROSS CENTRAL WINNESHIEK COUNTY FROM NORTH OF DECORAH TO FORT ATKINSON. TIME ESTIMATED FROM RADAR. |
| 04:27 UTC | TSTM WND DMG | 1 S Calmar | Winneshiek, IA | REPORT OF A ROOF OFF A HOUSE AND CARS OVERTURNED NEAR THE NORTHEAST IOWA COMMUNITY COLLEGE CAMPUS. TIME ESTIMATED FROM RADAR. |
| 04:30 UTC | HEAVY RAIN 3.7 | Decorah | Winneshiek, IA | NO POWER. |
| 04:35 UTC | TSTM WND GST 48 | 6 Nw Frankville | Winneshiek, IA | MESONET STATION RDCI4 DECORAH. |
| 04:40 UTC | TSTM WND GST 30 | 4 Ene Conover | Winneshiek, IA | MESONET STATION DVI03565 CALMAR. |
| 04:41 UTC | TSTM WND GST 60 | 4 W Waukon | Allamakee, IA | DEPUTY ESTIMATED AT INTERSECTION OF HIGHWAYS 9 AND 51 |
| 04:41 UTC | TSTM WND GST 60 | 4 W Waukon | Allamakee, IA | DEPUTY ESTIMATED AT INTERSECTION OF HIGHWAYS 9 AND 51. |
| 04:42 UTC | TSTM WND DMG | 2 Sw Waukon | Allamakee, IA | A FARM LOST A BARN, 2 SILOS, AND 2 POWER POLES. |
| 04:44 UTC | TSTM WND DMG | Waukon | Allamakee, IA | ROOF 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 UTC | TSTM WND GST 60 | Waukon | Allamakee, IA | SMALL BRANCHES DOWN IN TOWN ALONG WITH SOME MINOR FLOODING. |
| 05:02 UTC | TSTM WND DMG | 4 Ne Strawberry Point | Clayton, IA | REPORTS OF POWER LINES DOWN |
| 05:02 UTC | TSTM WND DMG | 4 Ne Strawberry Point | Clayton, IA | REPORTS OF POWER LINES DOWN. |
| 07:00 UTC | HEAVY RAIN 3.99 | Vernon Springs | Howard, IA | STORM 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.
| Date | Time | Rating | Where | Path (mi) | Width (yd) | Deaths | Injuries | Damage |
|---|---|---|---|---|---|---|---|---|
| July 23 | 5:40 AM CDT | EF0 | DuPage, IL | 4.5 | 150 | |||
| July 23 | 5:52 AM CDT | EF0 | Will, IL | 4.1 | 200 | |||
| July 23 | 6:05 AM CDT | EF0 | Will, IL | 0.7 | 150 | |||
| July 23 | 10:45 AM EDT | EF1 | Miami, OH | 1.8 | 200 | $100,000 | ||
| July 23 | 2:41 PM CDT | EF0 | Winona, MN | 1.3 | 30 | $5,000 | ||
| July 23 | 3:01 PM CDT | EF0 | Houston, MN | 4.2 | 40 | $125,000 | ||
| July 23 | 3:33 PM CDT | EF0 | La Crosse, WI | 2.5 | 40 | $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.