Tornadoes · United States · Iowa · 2026

Unrated tornado, Archer, Iowa, April 13, 2026

This Unrated tornado ran 0.9 miles across O'Brien County on April 13, 2026, touching down at 6:30 PM CDT and reaching 25 yards wide. It killed nobody.

Preliminary. This is NWS FSD's damage survey, filed in the Damage Assessment Toolkit as 20260413. 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.

  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 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. 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 survey

Rating, as surveyed
Unrated, preliminary
Date
April 13, 2026
Touchdown
6:30 PM CDT (23:30 UTC)
Lifted
6:35 PM CDT (23:35 UTC)
On the ground
5 minutes
Path length
0.9 miles (1.4 km)
Path width
25 yards (23 m)
Deaths
0
Injuries
0
County
O'Brien County
Touchdown point
43.138, -95.712
Lift-off point
43.147, -95.725
Surveyed by
NWS FSD
The office's name for it
20260413
Survey last edited
April 14, 2026
Record number
None yet. SPC numbers 2026 in the spring of 2027.

What the survey found

Locations estimated by video and first hand account.

Written by NWS FSD in the NWS Damage Assessment Toolkit. A survey is revised as better evidence arrives.

The damage survey

2 damage points were recorded along this path by NWS FSD, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EFU.

  • Estimated starting point based on first hand account and radar.
  • Estimated ending point based on first hand account and radar.

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

At late afternoon, considerable moisture focused near a strong warm front from low pressure across northeastern Nebraska through northwest Iowa. Climatologically significant mid-level lapse rates produced a strong capping inversion which gradually weakened north of the warm front. Storms initiated with effective deep-layer shear from 40 to 50 knots and quickly became severe hail producers north of the warm front across southeast South Dakota into southwest Minnesota during the late afternoon, with additional storms developing in proximity to the surface wave across northwest Iowa. One of these latter storms produced two weak tornadoes across northwest Iowa.

An eyewitness observed a tornado develop 2 miles northeast of Archer south of 350th Street in an open field. The tornado tracked northwest slowly over the next five minutes through open fields. After crossing Pierce Avenue, the tornado dissipated. There was no known damage, resulting in an EFU rating. The location, track, and a maximum path width of 25 yards was estimated from video.

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 21:41 UTC and running to 02:14 UTC.

Issued (UTC)ExpiredProductOffice
21:41 UTC02:14 UTCSevere Thunderstorm WatchFSD
23:05 UTC23:45 UTCSevere Thunderstorm WarningFSD
23:45 UTC23:58 UTCSevere Thunderstorm WarningFSD
23:53 UTC00:31 UTCSevere Thunderstorm WarningFSD

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, in the hatched area where significant tornadoes were expected. The outlook in force was issued at 19:56 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.

Omaha, NE (KOAX), 00:00Z

0.5 hours after it, 210 km from the path. April 14, 2026.

Skew-T log-pSkew-T log-p diagram, Omaha, NE at 00:00Z on 2026-04-14Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 215 joules per kilogram, CIN -51, lifted condensation level 3086 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, Omaha, NE at 00:00Z on 2026-04-14The 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 152 square meters per square second, 0 to 6 km bulk shear 29 knots.1939587897Sfc1 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
215 J/kg
Mixed-layer CIN
-51 J/kg
Surface CAPE
733 J/kg
Mixed-layer LCL
3086 m above ground
0-6 km bulk shear
29 kt
0-1 km bulk shear
22 kt
0-1 km storm-relative helicity
152 m²/s²
0-3 km storm-relative helicity
239 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.0
0-3 km lapse rate
9.0 K/km

Open this sounding in Storm Lab

The radar

The Sioux Falls radar (KFSD), 96 km away, was scanning. The volume nearest the touchdown began at 23:27 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
22:37 UTCHAIL 1.257 S RemsenPlymouth, IA
22:42 UTCHAIL 2.755 Ssw RemsenPlymouth, IA
22:51 UTCHAIL 0.5AshtonOsceola, IAReport from mPING: Half-inch (0.50 in.).
23:08 UTCHAIL 1.754 Se GranvilleO'Brien, IA
23:08 UTCHAIL 1.754 Se GranvilleObrien, IA
23:10 UTCHAIL 1.754 S RemsenPlymouth, IA
23:25 UTCHAIL 17 Ene MelvinOsceola, IASpotter report of quarter inch hail with pictures.
23:27 UTCHAIL 18 Se OcheyedanOsceola, IASocial media report with a coin for reference. Time estimated by radar.
23:28 UTCHAIL 1PrimgharO'Brien, IA
23:28 UTCHAIL 1PrimgharObrien, IA
23:30 UTCHAIL 1.751 S HarrisOsceola, IASocial media report with picture. Time estimated by radar.
23:30 UTCTORNADO2 Ne ArcherO'Brien, IACorrects time of previous tornado report from 2 NE Archer. Start of brief tornado which tracked generally north and northwest for around 5 minutes. Track was through open fields with no visible damage. Location and track
23:32 UTCHAIL 0.755 S Lake ParkDickinson, IA
23:34 UTCHAIL 1.753 Nne ArcherO'Brien, IASocial media report with picture of estimated hail size.
23:34 UTCHAIL 1.753 Nne ArcherObrien, IASocial media report with picture of estimated hail size.
23:40 UTCHAIL 13 S SanbornO'Brien, IAReport from mPING: Quarter (1.00 in.).
23:40 UTCHAIL 13 S SanbornObrien, IAReport from mPING: Quarter (1.00 in.).
23:40 UTCHAIL 1.5SanbornO'Brien, IAReport from mPING: Ping Pong Ball (1.50 in.).
23:40 UTCHAIL 1.5SanbornObrien, IAReport from mPING: Ping Pong Ball (1.50 in.).
23:41 UTCHAIL 1.25SanbornO'Brien, IA
23:41 UTCHAIL 1.25SanbornObrien, IA
23:44 UTCHAIL 1.5SanbornO'Brien, IA
23:44 UTCHAIL 1.5SanbornObrien, IA
23:53 UTCHAIL 1MelvinOsceola, IA
00:20 UTCHAIL 0.754 Ese Arnolds ParkDickinson, IA
00:24 UTCHAIL 12 Nw PetersonClay, IABreif heavy rain and hail up to the size of quarters.

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 April 13, 2026

15 more have been surveyed in the United States that day, so far.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
April 135:38 PM CDTEF0Taylor, WI3.520
April 136:12 PM CDTUnratedWatonwan, MN0.725
April 136:15 PM CDTEF1Watonwan, MN8.5200
April 136:47 PM CDTEF2Palo Alto, IA4.8450
April 136:47 PM CDTEF1Emmet, IA0.940
April 137:02 PM CDTEF0Osage, KS0.00
April 137:15 PM CDTEF1Faribault, MN4.550
April 137:23 PM CDTEF2Franklin, KS7.303
April 137:49 PM CDTEF0Clay, IA1.850
April 138:00 PM CDTEF1Linn, KS to MO23.802
April 138:05 PM CDTEF1Freeborn, MN2.7140
April 138:09 PM CDTUnratedLinn, KS0.60
April 138:18 PM CDTEF2Miami, KS3.02501
April 1312:44 AM CDTEF0Dodge, WI0.350
April 1312:45 AM CDTEF1Dane, WI5.975

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.