Tornadoes · United States · Iowa · 2021
Unrated tornado, Garrison to Vinton, Iowa, July 14, 2021
From Garrison to Vinton, this Unrated tornado ran 0.1 miles across Benton County on July 14, 2021, touching down at 8:07 PM CDT and reaching 10 yards wide. It killed nobody.
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 mph
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.
Unratedthis tornado
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
- Unrated
- Date
- July 14, 2021
- Touchdown
- 8:07 PM CDT (01:07 UTC)
- Path length
- 0.1 miles (0.2 km)
- Path width
- 10 yards (9 m)
- Deaths
- 0
- Injuries
- 0
- County
- Benton County
- Touchdown point
- 42.100, -92.050
- Lift-off point
- 42.100, -92.050
- Record number
- 2107141907-01
The damage survey
4 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 101 mph.
- Brief touchdown in a field with no visible damage.
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
Severe thunderstorms developed ahead of an approaching cold front during the afternoon and evening of Wednesday, July 14. Some of the storms produced damaging winds and several tornadoes, most of which only briefly touched down. Brief torrential rainfall was also observed with the stronger storm cells. The areas that were hit hardest were in Delaware and Jones counties in IA, where a total of 5 tornadoes occurred. An additional 7 tornadoes touched down in eastern IA, with no visible damage reported.
Brief touchdown in a field with no visible damage.
Brief touchdown in a field with no visible damage.
Brief touchdown in a field with no visible damage.
From NOAA NCEI's Storm Events Database, the narrative the local forecast office wrote for Storm Data.
The warnings
24 minutes of warning. NWS DVN issued a tornado warning for this county at 00:43 UTC, 24 minutes before the tornado touched down, in force until 01:15 UTC.
The county was under a tornado watch, issued at 19:36 UTC and running to 03:08 UTC.
| Issued (UTC) | Expired | Product | Office |
|---|---|---|---|
| 19:36 UTC | 03:08 UTC | Tornado Watch | DVN |
| 23:32 UTC | 00:15 UTC | Severe Thunderstorm Warning | DVN |
| 23:58 UTC | 00:45 UTC | Tornado Warning | DVN |
| 00:37 UTC | 01:15 UTC | Severe Thunderstorm Warning | DVN |
| 00:43 UTC | 01:15 UTC | Tornado Warning | DVN |
| 00:53 UTC | 01:20 UTC | Tornado Warning | DVN |
| 01:14 UTC | 02:00 UTC | Severe Thunderstorm Warning | DVN |
| 01:19 UTC | 01:41 UTC | Tornado Warning | DVN |
| 01:31 UTC | 02:00 UTC | Tornado Warning | DVN |
| 02:08 UTC | 02:40 UTC | Severe Thunderstorm Warning | DVN |
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 Enhanced Risk, with a 0.05 chance of a tornado within 25 miles. The outlook in force was issued at 00:52 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
1.1 hours before the tornado, 139 km from the path. July 15, 2021.
- Mixed-layer CAPE
- 2569 J/kg
- Mixed-layer CIN
- -10 J/kg
- Surface CAPE
- 4127 J/kg
- Mixed-layer LCL
- 832 m above ground
- 0-6 km bulk shear
- 38 kt
- 0-1 km bulk shear
- 30 kt
- 0-1 km storm-relative helicity
- 253 m²/s²
- 0-3 km storm-relative helicity
- 346 m²/s²
- Significant tornado parameter
- 3.2
- Supercell composite
- 23.4
- 0-3 km lapse rate
- 6.4 K/km
Davenport, (KDVN), 12:00Z
10.9 hours after it, 139 km from the path. July 15, 2021.
- Mixed-layer CAPE
- 78 J/kg
- Mixed-layer CIN
- -116 J/kg
- Surface CAPE
- 177 J/kg
- Mixed-layer LCL
- 688 m above ground
- 0-6 km bulk shear
- 27 kt
- 0-1 km bulk shear
- 19 kt
- 0-1 km storm-relative helicity
- 106 m²/s²
- 0-3 km storm-relative helicity
- 80 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.1
- 0-3 km lapse rate
- 4.5 K/km
The surface observations
Vinton (VTI), 13 km from the path, in the two hours either side.
| Time (UTC) | Temp (°F) | Dew point (°F) | Wind | Gust (kt) | Pressure (mb) | Weather |
|---|---|---|---|---|---|---|
| 02:15 UTC | 71 | 71 | 340° 7 kt | 1012.2 | -RA | |
| 02:35 UTC | 71 | 71 | 10° 5 kt | 1012.5 | +RA | |
| 02:55 UTC | 71 | 71 | 340° 3 kt | 1013.2 | -RA |
From the Iowa Environmental Mesonet's archive of airport observations.
The radar
The Quad Cities radar (KDVN), 133 km away, was scanning. The volume nearest the touchdown began at 01:07 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 |
|---|---|---|---|---|
| 23:17 UTC | TSTM WND DMG | Waterloo | Black Hawk, IA | NUMEROUS TREES DOWN. TIME ESTIMATED FROM RADAR. |
| 23:19 UTC | TORNADO | 1 Nw Waterloo | Black Hawk, IA | BRIEF TORNADO REPORTED NEAR THE JOHN DEERE FACILITY WITH DAMAGE REPORTED NEAR US 218. |
| 23:19 UTC | TORNADO | 1 Nw Waterloo | Black Hawk, IA | DELAYED REPORT - BRIEF TORNADO TOUCHDOWN NEAR JOHN DEERE COMPLEX WITH SOME DAMAGE EITHER SIDE OF US 218. |
| 23:19 UTC | TORNADO | 1 Nw Waterloo | Black Hawk, IA | DELAYED REPORT: BRIEF TORNADO TOUCHDOWN NEAR JOHN DEERE COMPLEX WITH SOME DAMAGE REPORTED EITHER SIDE OF US 218 FROM MAYNARD & ANSBOROUGH AVE SOUTH TOWARD WESTFILED AVE. |
| 23:22 UTC | TSTM WND DMG | Waterloo | Black Hawk, IA | TREES DOWN. TIME ESTIMATED. |
| 00:05 UTC | TORNADO | Dysart | Tama, IA | STRUCTURAL DAMAGE TO BUILDINGS. TIME ESTIMATED FROM RADAR. |
| 00:10 UTC | TORNADO | 3 Sse Aurora | Buchanan, IA | BRIEF TOUCHDOWN IN A FIELD WITH NO VISIBLE DAMAGE. |
| 00:14 UTC | TORNADO | 8 W Garrison | Benton, IA | DELAYED REPORT. RECEIVED VIDEO OF A TORNADO CROSSING INTO BENTON COUNTY. SAME TORNADO THAT HIT DYSART. |
| 00:20 UTC | TORNADO | 1 N Garrison | Benton, IA | BENTON COUNTY EMA RELAYED PUBLIC REPORT OF A BRIEF TORNADO TOUCHDOWN ALONG 18TH AVENUE 1 MILE NORTH OF GARRISON. |
| 00:24 UTC | TSTM WND DMG | Dysart | Tama, IA | DYSART FIRE CALLED OUT FOR A DOWNED TRANSFORMER THAT STARTED A FIRE. |
| 00:36 UTC | TORNADO | 2 E Garrison | Benton, IA | BENTON COUNTY EMA RELAYED A PUBLIC REPORT OF A BRIEF TORNADO TOUCH DOWN NORTH OF 61ST STREET BETWEEN GARRISON AND VINTON. |
| 00:50 UTC | TORNADO | 5 S Vinton | Benton, IA | |
| 00:52 UTC | TORNADO | 3 Ssw Manchester Airpor | Delaware, IA | TORNADO REPORTED ON THE GROUND SOUTH OF HIGHWAY 20 SOUTHWEST OF MANCHESTER. |
| 01:20 UTC | FUNNEL CLOUD | Palo | Linn, IA | RELAYED VIA LINN COUNTY EMA. |
| 01:30 UTC | FUNNEL CLOUD | 3 Sw Center Point | Linn, IA | FUNNEL CLOUD EXTENDING HALF WAY TO THE GROUND. |
| 01:46 UTC | TORNADO | 4 Nne Lafayette | Linn, IA | BRIEF TORNADO. DELAYED REPORT FROM EMERGENCY MANAGER. |
| 01:50 UTC | TSTM WND DMG | 3 Nnw Center Point | Linn, IA | LARGE AREA OF FLATTENED CORN. |
| 01:50 UTC | TORNADO | 4 Nne Lafayette | Linn, IA | BRIEF TOUCHDOWN IN A FIELD WITH NO VISIBLE DAMAGE. |
| 01:52 UTC | TORNADO | 3 N Center Point | Linn, IA | BRIEF TOUCHDOWN IN A FIELD WITH NO VISIBLE DAMAGE. |
| 01:55 UTC | FUNNEL CLOUD | 3 Sw Paris | Linn, IA | BROAD ROTATING FUNNEL CLOUD EXTENDING HALF WAY DOWN FROM CLOUD BASE. |
| 02:10 UTC | FUNNEL CLOUD | Paris | Linn, IA | RELAYING SPOTTER REPORT OF FUNNEL CLOUD CLOSE TO GROUND ALONG PARIS ROAD. DARKNESS MAKING IT DIFFICULT TO SEE IF IT IS REACHING THE GROUND. |
| 02:26 UTC | HEAVY RAIN 2.9 | Walker | Linn, IA |
From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.
This ground now
The live radar over the trackEvery 2021 tornado in IowaEvery tornado in Iowa since 1950Warnings in force in Iowa nowThe forecast where you are
The other tornadoes of July 14, 2021
25 more were confirmed in the United States that day.
| Date | Time | Rating | Where | Path (mi) | Width (yd) | Deaths | Injuries | Damage |
|---|---|---|---|---|---|---|---|---|
| July 14 | 3:52 PM CDT | EF3 | Calhoun, IA | 10.8 | 505 | $2.5 million | ||
| July 14 | 4:05 PM CDT | EF0 | Hamilton, IA | 8.8 | 50 | $2,000 | ||
| July 14 | 4:21 PM CDT | EF1 | Hamilton, IA | 8.9 | 160 | $10,000 | ||
| July 14 | 4:46 PM CDT | Unrated | Webster, IA | 0.3 | 30 | |||
| July 14 | 4:57 PM CDT | Unrated | Butler, IA | 1.2 | 50 | |||
| July 14 | 5:11 PM CDT | Unrated | Sac, IA | 0.6 | 25 | |||
| July 14 | 5:16 PM CDT | EF2 | Butler, IA | 12.9 | 630 | $1.3 million | ||
| July 14 | 5:34 PM CDT | EF1 | Floyd, IA | 12.0 | 60 | $60,000 | ||
| July 14 | 5:35 PM CDT | Unrated | Sac, IA | 0.8 | 30 | |||
| July 14 | 5:52 PM CDT | EF0 | Cerro Gordo, IA | 5.1 | 225 | $10,000 | ||
| July 14 | 6:12 PM CDT | EF0 | Bremer, IA | 2.5 | 150 | $1,000 | ||
| July 14 | 5:15 PM MDT | Unrated | Emery, UT | 0.1 | 10 | |||
| July 14 | 6:43 PM CDT | EF0 | Buchanan, IA | 3.2 | 30 | $275,000 | ||
| July 14 | 7:05 PM CDT | EF1 | Tama, IA | 5.7 | 590 | $25,000 | ||
| July 14 | 7:10 PM CDT | Unrated | Buchanan, IA | 0.1 | 10 | |||
| July 14 | 7:36 PM CDT | Unrated | Benton, IA | 0.1 | 10 | |||
| July 14 | 7:50 PM CDT | EF1 | Delaware, IA | 1.4 | 40 | |||
| July 14 | 7:54 PM CDT | EF1 | Delaware, IA | 1.1 | 30 | |||
| July 14 | 7:56 PM CDT | Unrated | Benton, IA | 0.1 | 10 | |||
| July 14 | 8:50 PM CDT | Unrated | Linn, IA | 0.1 | 10 | |||
| July 14 | 8:52 PM CDT | Unrated | Linn, IA | 0.1 | 10 | |||
| July 14 | 9:40 PM CDT | Unrated | Delaware, IA | 0.4 | 10 | |||
| July 14 | 9:44 PM CDT | EF1 | Jones, IA | 1.8 | 40 | |||
| July 14 | 10:02 PM CDT | EF1 | Jones, IA | 8.0 | 30 | |||
| July 14 | 10:30 PM CDT | EF1 | Jones, IA | 3.1 | 30 |
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.