Tornadoes · United States · Iowa · 2026
EF1 tornado, Croton to Franklin, Iowa, March 10, 2026
From Croton to Franklin, this EF1 tornado ran 1.5 miles across Lee County on March 10, 2026, touching down at 9:05 PM CDT and reaching 50 yards wide. It killed nobody.
Preliminary. This is NWS DVN's damage survey, filed in the Damage Assessment Toolkit as SW Donnellson. The rating, the path and the casualties are the survey's and can change while it is revised. The Storm Prediction Center compiles the official record of 2026 from these surveys and publishes it in the spring of 2027; this page moves to that tornado's permanent address when it does.
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 survey
- Rating, as surveyed
- EF1, preliminary
- Date
- March 10, 2026
- Touchdown
- 9:05 PM CDT (02:05 UTC)
- Lifted
- 9:08 PM CDT (02:08 UTC)
- On the ground
- 3 minutes
- Path length
- 1.5 miles (2.4 km)
- Path width
- 50 yards (46 m)
- Deaths
- 0
- Injuries
- 0
- County
- Lee County
- Touchdown point
- 40.624, -91.627
- Lift-off point
- 40.627, -91.599
- Highest wind the damage implies
- 100 mph
- Surveyed by
- NWS DVN
- The office's name for it
- SW Donnellson
- Survey last edited
- March 11, 2026
- Record number
- None yet. SPC numbers 2026 in the spring of 2027.
What the survey found
An EF1 tornado with peak winds of 95 to 100 mph begun its 1.5 mile long path by downing some tree branches. The tornado increased in strength causing damage to the door of a farm outbuilding along with damage to additional farm out buildings. The tornado continued east along 230th street, causing sporadic tree damage for around 1 mile. The tornado then strengthened even more near 230th street and 160th avenue, where it destroyed two farm outbuildings and snapped numerous tree trunks. This is where the tornado was the strongest. Shortly after crossing 160th street, the tornado weakened and eventually dissipated.
Written by NWS DVN in the NWS Damage Assessment Toolkit. A survey is revised as better evidence arrives.
What the Weather Service recorded
Numerous severe thunderstorms developed during the afternoon on Tuesday producing hail that ranged in size from penny (0.88) to baseball (2.75) in diameter. There was a total of 10 reports with hail over 2.00 inches in diameter. During the early evening hours, one storm produced three different EF-1 tornadoes in Lee County near Donnellson.
An EF1 tornado with peak winds of 95 to 100 mph began its 1.5 mile long path by downing some tree branches. The tornado increased in strength causing damage to the door of a farm outbuilding along with damage to additional farm out buildings. The tornado continued east along 230th street, causing sporadic tree damage for around 1 mile. The tornado then strengthened even more near 230th street and 160th avenue, where it destroyed two farm outbuildings and snapped numerous tree trunks. This is where the tornado was the strongest. Shortly after crossing 160th street, the tornado weakened and eventually dissipated. The tornado had a max width of 50 yards.
An EF1 tornado with max winds near 90 mph begun its 2.1 mile long path with damage to tree branches. The tornado then caused damage to some fascia on a house and then crossed into Wilson Lake Park where additional trees were downed. Some trees were uprooted with a couple of trees had their trunks snapped. Tree damage became more sporadic as the tornado continued east leading to minor tree damage through the remainder of its path. The max width was 50 yards.
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 01:41 UTC, 24 minutes before the tornado touched down, in force until 02:45 UTC.
The county was under a tornado watch, issued at 20:58 UTC and running to 03:46 UTC.
| Issued (UTC) | Expired | Product | Office |
|---|---|---|---|
| 20:58 UTC | 03:46 UTC | Tornado Watch | DVN |
| 01:41 UTC | 02:45 UTC | Tornado Warning | DVN |
| 02:36 UTC | 02:59 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, in the hatched area where significant tornadoes were expected. The outlook in force was issued at 00:34 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
2.1 hours before the tornado, 145 km from the path. March 11, 2026.
- Mixed-layer CAPE
- 343 J/kg
- Mixed-layer CIN
- -359 J/kg
- Surface CAPE
- 0 J/kg
- Mixed-layer LCL
- 771 m above ground
- 0-6 km bulk shear
- 78 kt
- 0-1 km bulk shear
- 44 kt
- 0-1 km storm-relative helicity
- 529 m²/s²
- 0-3 km storm-relative helicity
- 725 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 25.6
- 0-3 km lapse rate
- 2.4 K/km
The radar
The Quad Cities radar (KDVN), 140 km away, was scanning. The volume nearest the touchdown began at 02:08 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 |
|---|---|---|---|---|
| 23:39 UTC | HAIL 1 | Wayland | Henry, IA | Occurring right now. |
| 23:40 UTC | HAIL 1 | 1 Ene Fairfield Municip | Jefferson, IA | Lasted from 640 to 650 PM. Covered the deck. No wind. |
| 23:45 UTC | HAIL 1 | 1 Sw Perlee | Jefferson, IA | Up to quarter size hail. Time of the event was estimated using radar. |
| 00:30 UTC | HAIL 1.25 | 2 E Swedesburg | Henry, IA | Delayed report via social media. |
| 02:05 UTC | TSTM WND DMG | 3 Wsw Donnellson | Lee, IA | Cattle shed and feed shed were blown down. Possible tornado. |
| 02:05 UTC | TORNADO | 4 Wsw Donnellson | Lee, IA | An EF1 tornado with peak winds of 95 to 100 mph begun its 1.5 mile long path by downing some tree branches. The tornado increased in strength causing damage to the door of a farm outbuilding along with damage to addition |
| 02:10 UTC | HAIL 1.5 | 2 Sw Donnellson | Lee, IA | |
| 02:10 UTC | HAIL 1.5 | 2 Sw Donnellson | Lee, IA | |
| 02:26 UTC | TORNADO | 2 Sse Franklin | Lee, IA | An EF1 tornado with max winds near 90 mph begun its 2.1 mile long path with damage to tree branches. The tornado then caused damage to some fascia on a house. It then crossed into Wilson Lake park where additional trees |
| 02:38 UTC | TORNADO | 2 W Wever | Lee, IA | In coordination with the Denmark, IA Fire Dept, an EF1 tornado with maximum winds of 100 mph and path length of 1.2 miles was determined to have occurred on March 10. Numerous trees were snapped or uprooted, and one powe |
| 02:50 UTC | TSTM WND GST 60 | Burlington Regional Air | Des Moines, IA | KBRL reported a 52 knot wind gust. |
From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.
This ground now
The live radar over the trackEvery 2026 tornado in IowaEvery tornado in Iowa since 1950Warnings in force in Iowa nowThe forecast where you are
The other tornadoes of March 10, 2026
20 more have been surveyed in the United States that day, so far.
| Date | Time | Rating | Where | Path (mi) | Width (yd) | Deaths | Injuries | Damage |
|---|---|---|---|---|---|---|---|---|
| March 10 | 4:49 PM CDT | EF0 | Livingston, IL | 1.1 | 175 | |||
| March 10 | 4:57 PM CDT | Unrated | Livingston, IL | 0.3 | 10 | |||
| March 10 | 6:18 PM CDT | Unrated | Kankakee, IL | 0.6 | 10 | |||
| March 10 | 6:19 PM CDT | Unrated | Kankakee, IL | 0.5 | 60 | |||
| March 10 | 6:21 PM CDT | EF3 | Kankakee, IL to IN | 35.6 | 1,550 | 3 | 19 | |
| March 10 | 6:33 PM CDT | EF1 | Kankakee, IL | 1.3 | 150 | |||
| March 10 | 6:36 PM CDT | Unrated | Kankakee, IL | 0.1 | 20 | |||
| March 10 | 6:43 PM CDT | Unrated | Kankakee, IL | 0.1 | 20 | |||
| March 10 | 6:51 PM CDT | Unrated | Kankakee, IL | 1.8 | 80 | |||
| March 10 | 7:22 PM CDT | EF1 | Knox, IL | 5.0 | 100 | $300 | ||
| March 10 | 7:30 PM CDT | EF0 | Stark, IL | 6.2 | 40 | |||
| March 10 | 7:43 PM CDT | EF1 | Jasper, IN | 10.5 | 900 | 3 | ||
| March 10 | 8:01 PM CDT | EF0 | Marshall, IL | 12.6 | 50 | |||
| March 10 | 8:07 PM CDT | EF2 | Starke, IN | 15.5 | 1,200 | |||
| March 10 | 8:35 PM CDT | EF0 | Starke, IN | 0.7 | 150 | |||
| March 10 | 9:26 PM CDT | EF1 | Lee, IA | 2.1 | 50 | |||
| March 10 | 9:38 PM CDT | EF1 | Lee, IA | 1.2 | 50 | |||
| March 10 | 11:52 PM CDT | EF1 | Mason, IL | 5.6 | 200 | |||
| March 10 | 12:06 AM CDT | EF1 | Mason, IL | 10.2 | 50 | |||
| March 10 | 12:30 AM CDT | EF2 | McCurtain, OK | 2.5 | 240 | 1 |
What this means
Ratings are the survey's, read off the damage rather than measured; the rating scale is above. A survey can be revised, so the rating, the path and the casualties can all still change.
Sources
NWS Damage Assessment Toolkit, the record the survey teams file from the damage, and NOAA Storm Prediction Center storm reports. Neither is the official database for 2026, which SPC publishes in the spring of 2027.