Tornadoes · United States · Iowa · 2026

EF1 tornado, Monti to Masonville, Iowa, April 14, 2026

From Monti to Masonville, this EF1 tornado ran 4.3 miles across Buchanan and Delaware counties on April 14, 2026, touching down at 5:25 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 Masonville. 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 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 survey

Rating, as surveyed
EF1, preliminary
Date
April 14, 2026
Touchdown
5:25 PM CDT (22:25 UTC)
Lifted
5:33 PM CDT (22:33 UTC)
On the ground
8 minutes
Path length
4.3 miles (6.9 km)
Path width
50 yards (46 m)
Deaths
0
Injuries
0
Counties
Buchanan and Delaware counties
Touchdown point
42.453, -91.645
Lift-off point
42.471, -91.564
Highest wind the damage implies
105 mph
Surveyed by
NWS DVN
The office's name for it
Masonville
Survey last edited
April 17, 2026
Record number
None yet. SPC numbers 2026 in the spring of 2027.

What the survey found

EF1 tornado with peak winds of 100-105 mph began east-southeast of Winthrop and tracked into Delaware County to just east-southeast of Masonville. A barn was completely destroyed at the beginning of its 4.3 mile long path. Additional damage to outbuildings and numerous trees was observed. The tornado also crossed U.S. Highway 20 just south of Masonville. The tornado did roll over a semi trailer.

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

The damage survey

9 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 105 mph.

  • Outbuilding damaged. Insulation not strewn around. Likely RFD.

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

Significant severe storms on the afternoon and evening of April 14th brought numerous reports of large hail, damaging wind, and multiple tornadoes. The U.S. Hwy 20 corridor saw a long lived supercell that producing large hail (up to baseball size), damaging wind (88 mph gust at the Dubuque Airport), and several tornadoes. Additional storms developed further south between I-80 and Hwy 20 that brought large hail and a photogenic tornado near Onslow, IA. ||More storms quickly followed overnight and again on the next day, April 15th, bringing heavy rain, large hail, and isolated wind damage. Rainfall amounts over 1.5 were common north of I-80, with the highest totals over 3.5 seen in northwest IL. This caused a mudslide on Hwy 84 in Carroll County closing the road for an extended period of time.

EF1 tornado with peak winds of 100-105 mph began east-southeast of Winthrop and tracked into Delaware County to just east-southeast of Masonville. A barn was completely destroyed at the beginning of its 4.3 mile long path. Additional damage to outbuildings and numerous trees was observed. The tornado also crossed U.S. Highway 20 just south of Masonville. The tornado did roll over a semi trailer.

EF1 tornado with peak winds of 100-105 mph began east-southeast of Winthrop and tracked into Delaware County to just east-southeast of Masonville. A barn was completely destroyed at the beginning of its 4.3 mile long path. Additional damage to outbuildings and numerous trees was observed. The tornado also crossed U.S. Highway 20 just south of Masonville. The tornado did roll over a semi trailer.

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

The warnings

32 minutes of warning. NWS DVN issued a tornado warning for this county at 21:53 UTC, 32 minutes before the tornado touched down, in force until 22:35 UTC.

The county was under a tornado watch, issued at 19:35 UTC and running to 00:48 UTC.

Issued (UTC)ExpiredProductOffice
19:35 UTC00:48 UTCTornado WatchDVN
21:32 UTC22:45 UTCSevere Thunderstorm WarningDVN
21:53 UTC22:35 UTCTornado WarningDVN
22:01 UTC22:30 UTCSevere Thunderstorm WarningDVN
22:21 UTC22:45 UTCSevere Thunderstorm WarningDVN
22:44 UTC22:52 UTCSevere Thunderstorm WarningDVN
22:51 UTC23:28 UTCSevere Thunderstorm WarningDVN

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 0.10 chance of a tornado within 25 miles, in the hatched area where significant tornadoes were expected. The outlook in force was issued at 19:36 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

1.6 hours after it, 131 km from the path. April 15, 2026.

Skew-T log-pSkew-T log-p diagram, Davenport, at 00:00Z on 2026-04-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1575 joules per kilogram, CIN -39, lifted condensation level 1493 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 00:00Z on 2026-04-15The 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 251 square meters per square second, 0 to 6 km bulk shear 58 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
1575 J/kg
Mixed-layer CIN
-39 J/kg
Surface CAPE
2770 J/kg
Mixed-layer LCL
1493 m above ground
0-6 km bulk shear
58 kt
0-1 km bulk shear
27 kt
0-1 km storm-relative helicity
251 m²/s²
0-3 km storm-relative helicity
371 m²/s²
Significant tornado parameter
1.9
Supercell composite
19.9
0-3 km lapse rate
7.6 K/km

Open this sounding in Storm Lab

The surface observations

Independence (IIB), 28 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
20:35 UTC80.664.4190° 17 kt1004.4
20:55 UTC78.664.8200° 12 kt1004.1
21:15 UTC77.564.8180° 14 kt1003.4
21:35 UTC77.464170° 11 kt1002.4HZ
21:55 UTC73.265.7140° 11 kt171000.3RA
22:15 UTC6762340° 19 kt351002.4RA
22:35 UTC6662300° 6 kt1003-RA
22:55 UTC6562.410° 10 kt1002.7RA
23:15 UTC64.862100° 7 kt1003.4RA
23:35 UTC64.262.2120° 8 kt1003.4-RA
23:55 UTC64.26240° 3 kt1003.7
00:15 UTC6462.2100° 4 kt1003.4

From the Iowa Environmental Mesonet's archive of airport observations.

The radar

The Quad Cities radar (KDVN), 127 km away, was scanning. The volume nearest the touchdown began at 22:22 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
21:21 UTCHAIL 1.751 Ene WaterlooBlack Hawk, IA
21:24 UTCHAIL 2.51 Ene WaterlooBlack Hawk, IAEstimated in comparison to tennis ball. Time estimated from radar.
21:29 UTCHAIL 21 Sw WaterlooBlack Hawk, IA
21:35 UTCHAIL 1.753 N RaymondBlack Hawk, IA
22:02 UTCHAIL 3.253 E OttervilleBuchanan, IAImage from Buchanan County Emergency Manager in NWS Chat. Time estimated from radar.
22:02 UTCHAIL 3.253 E OttervilleBuchanan, IAImage from Buchanan County Emergency Manager in NWS Chat. Time estimated from radar.
22:02 UTCHAIL 3.253 E OttervilleBuchanan, IAImage from Buchanan County Emergency Manager in NWS Chat. Time estimated from radar.
22:05 UTCHAIL 1.751 N IndependenceBuchanan, IA
22:05 UTCHAIL 1.751 N IndependenceBuchanan, IA
22:05 UTCHAIL 1.751 N IndependenceBuchanan, IA
22:06 UTCHAIL 2.754 Nne IndependenceBuchanan, IATime estimated from radar.
22:06 UTCHAIL 2.754 Nne IndependenceBuchanan, IATime estimated from radar.
22:06 UTCHAIL 2.754 Nne IndependenceBuchanan, IATime estimated from radar.
22:08 UTCTSTM WND DMG1 S IndependenceBuchanan, IASheet metal off a building roof. This was determined to likely be from a rear flank downdraft (RFD) based on nature of damage and trained spotter videos.
22:08 UTCTSTM WND DMG1 S IndependenceBuchanan, IASheet metal roofs ripped off near Walmart in Independence. Tornado possible.
22:08 UTCTSTM WND DMG1 S IndependenceBuchanan, IASheet metal roofs ripped off near Walmart in Independence. Tornado possible.
22:08 UTCTSTM WND DMG1 S IndependenceBuchanan, IASheet metal roofs ripped off near Walmart in Independence. Tornado possible.
22:09 UTCHAIL 11 Sw VintonBenton, IA
22:09 UTCHAIL 11 Sw VintonBenton, IA
22:09 UTCHAIL 11 Sw VintonBenton, IA
22:09 UTCHAIL 1.252 Ne IndependenceBuchanan, IAReport from mPING: Half Dollar (1.25 in.).
22:09 UTCHAIL 1.252 Ne IndependenceBuchanan, IAReport from mPING: Half Dollar (1.25 in.).
22:09 UTCHAIL 1.252 Ne IndependenceBuchanan, IAReport from mPING: Half Dollar (1.25 in.).
22:11 UTCHAIL 12 Ese Mount AuburnBenton, IA
22:11 UTCHAIL 12 Ese Mount AuburnBenton, IA
22:11 UTCHAIL 12 Ese Mount AuburnBenton, IA
22:16 UTCHAIL 1UrbanaBenton, IA
22:16 UTCHAIL 1UrbanaBenton, IA
22:16 UTCHAIL 1UrbanaBenton, IA
22:20 UTCFUNNEL CLOUD2 Wnw Strawberry PointClayton, IA
22:20 UTCFUNNEL CLOUD2 Wnw Strawberry PointClayton, IA
22:25 UTCTORNADO3 Wsw MasonvilleBuchanan, IAAn EF1 tornado began east-southeast of Winthrop and tracked into Delaware County to just east-southeast of Masonville. A barn was completely destroyed at the beginning of its 4.3 mile long path. Additional damage to outb
22:28 UTCHAIL 1.751 Ne FairfaxLinn, IAReport from mPING: Golf Ball (1.75 in.).
22:28 UTCHAIL 1.751 Ne FairfaxLinn, IAReport from mPING: Golf Ball (1.75 in.).
22:28 UTCHAIL 1.751 Ne FairfaxLinn, IAReport from mPING: Golf Ball (1.75 in.).
22:29 UTCHAIL 1.251 Ne FairfaxLinn, IAReport from mPING: Half Dollar (1.25 in.).
22:29 UTCHAIL 1.251 Ne FairfaxLinn, IAReport from mPING: Half Dollar (1.25 in.).
22:29 UTCHAIL 1.251 Ne FairfaxLinn, IAReport from mPING: Half Dollar (1.25 in.).
22:30 UTCTSTM WND DMG1 Se MasonvilleDelaware, IAEmergency Manager reported damage to a building near Masonville. Tornado Possible.
22:30 UTCTSTM WND DMG1 Se MasonvilleDelaware, IAEmergency Manager reported damage to a building near Masonville. Tornado Possible.

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 14, 2026

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

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
April 143:14 PM CDTEF0Hardin, IA1.225
April 143:22 PM CDTEF0Hardin, IA0.625
April 145:35 PM CDTEF3Vernon, WI7.0125
April 146:24 PM CDTEF2Waukesha, WI3.8150
April 146:26 PM CDTEF1Marquette, WI4.950
April 146:36 PM CDTEF1Dubuque, IA3.425
April 147:39 PM CDTEF1Stephenson, IL5.1100
April 148:26 PM CDTEF1Walworth, WI7.475
April 148:38 PM CDTEF1Racine, WI5.275
April 148:42 PM CDTEF0Racine, WI3.850
April 149:02 PM CDTEF1Kenosha, WI4.0150
April 1410:51 PM EDTEF1Montcalm, MI18.7110
April 149:52 PM CDTEF1Creek, OK1.7225
April 1411:38 PM EDTEF0Allegan, MI6.8100
April 1411:52 PM EDTEF1Allegan, MI15.8175
April 1411:53 PM EDTEF1Saginaw, MI3.90
April 1410:57 PM CDTEF1Muskogee, OK14.31,000
April 1411:58 PM EDTEF0Shiawassee, MI1.70
April 1412:06 AM EDTEF0Saginaw, MI0.675
April 1411:24 PM CDTEF1Cherokee, OK7.71,100
April 1411:38 PM CDTEF1Cherokee, OK to AR24.2800
April 1411:54 PM CDTEF1Adair, OK to AR7.5700
April 141:04 AM EDTEF1Branch, MI2.6100
April 141:44 AM EDTEF1Washtenaw, MI1.7500

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.