Tornadoes · United States · Iowa · 2026

EF1 tornado, Keokuk to Warsaw, Iowa, June 17, 2026

From Keokuk to Warsaw, this EF1 tornado ran 1.3 miles across Lee and Hancock counties on June 17, 2026, touching down at 9:05 AM CDT and reaching 100 yards wide. It killed nobody.

Preliminary. This is NWS DVN's damage survey, filed in the Damage Assessment Toolkit as Warsaw Tornado. 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
June 17, 2026
Touchdown
9:05 AM CDT (14:05 UTC)
Lifted
9:08 AM CDT (14:08 UTC)
On the ground
3 minutes
Path length
1.3 miles (2.2 km)
Path width
100 yards (91 m)
Deaths
0
Injuries
0
Counties
Lee and Hancock counties
Touchdown point
40.377, -91.453
Lift-off point
40.365, -91.433
Highest wind the damage implies
105 mph
Surveyed by
NWS DVN
The office's name for it
Warsaw Tornado
Survey last edited
June 18, 2026
Record number
None yet. SPC numbers 2026 in the spring of 2027.

What the survey found

A brief EF1 tornado uniquely tracked across three states. This developed just inside Lee County, Iowa, with peak winds of 105 mph, and tracked southeast through Clark County, Missouri. It then continued across the Mississippi River into Hancock County, Illinois, impacting northern parts of Warsaw. This tornado persisted for about 1.3 miles, doing damage largely to numerous trees, with concentrated snapping including along the banks of the Mississippi River, as shown by drone footage. There also was damage to two gas station canopies along US Highway 61 in Missouri.

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

What the Weather Service recorded

A strong storm system for mid-June brought two rounds of thunderstorm on Wednesday June 17th. The strongest round of storms occurred during the morning hours that brough damaging winds (some significant), heavy rain, and two EF-1 tornadoes occurred in Iowa. One of these tornado was in Linby in Jefferson and the second touched down in far southeast Lee County and moved into Clark County Missouri and then into Warsaw Illinois.

A strong storm system for mid-June brought two rounds of thunderstorm on Wednesday June 17th. The strongest round of storms occurred during the morning hours that brough damaging winds (some significant), heavy rain, and two EF-1 tornadoes in Illinois which occurred in Monmouth and Warsaw. |Many trees fell and power lines were damaged, along with several reports of flash flooding. There were also 4-5 train cars that were pushed off the railroad just south of Monmouth, IL in Warren County due to significant straight-line winds (estimated near 100 mph). Additional train cars derailed as a result of these cars being blown off.

A brief EF1 tornado uniquely tracked across three states. This developed just in Lee County, Iowa, with peak winds of 105 mph, and tracked southeast through Clark County, Missouri. It then continued across the Mississippi River into Hancock County Illinois.

A brief EF1 tornado uniquely tracked across three states. This developed just inside Lee County, Iowa, with peak winds of 105 mph, and tracked southeast through Clark County, Missouri. It then continued across the Mississippi River into Hancock County, Illinois, impacting northern parts of Warsaw damaging primarily 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 09:07 UTC and running to 16:00 UTC.

Issued (UTC)ExpiredProductOffice
09:07 UTC16:00 UTCSevere Thunderstorm WatchDVN
12:57 UTC14:00 UTCSevere Thunderstorm WarningDVN
13:06 UTC13:45 UTCSevere Thunderstorm WarningDVN
13:43 UTC14:24 UTCSevere Thunderstorm WarningDVN
15:07 UTC23:24 UTCFlood WatchDVN
20:29 UTC21:07 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 0.05 chance of a tornado within 25 miles, in the hatched area where significant tornadoes were expected. The outlook in force was issued at 12:59 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), 12:00Z

2.1 hours before the tornado, 160 km from the path. June 17, 2026.

Skew-T log-pSkew-T log-p diagram, Davenport, at 12:00Z on 2026-06-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 0 joules per kilogram, CIN -102966, lifted condensation level 2165 meters above ground. Wind barbs in knots down the right edge.LCL10008507005003002001001 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 12:00Z on 2026-06-17The 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 179 square meters per square second, 0 to 6 km bulk shear 52 knots.19395878Sfc1 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
0 J/kg
Mixed-layer CIN
-102966 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
2165 m above ground
0-6 km bulk shear
52 kt
0-1 km bulk shear
20 kt
0-1 km storm-relative helicity
179 m²/s²
0-3 km storm-relative helicity
218 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
4.3 K/km

Open this sounding in Storm Lab

Davenport, (KDVN), 00:00Z

9.9 hours after it, 160 km from the path. June 18, 2026.

Skew-T log-pSkew-T log-p diagram, Davenport, at 00:00Z on 2026-06-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 183 joules per kilogram, CIN -46, lifted condensation level 867 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 2026-06-18The 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 -108 square meters per square second, 0 to 6 km bulk shear 77 knots.1939587897117Sfc1 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
183 J/kg
Mixed-layer CIN
-46 J/kg
Surface CAPE
1587 J/kg
Mixed-layer LCL
867 m above ground
0-6 km bulk shear
77 kt
0-1 km bulk shear
24 kt
0-1 km storm-relative helicity
-108 m²/s²
0-3 km storm-relative helicity
-24 m²/s²
Significant tornado parameter
-0.1
Supercell composite
-1.6
0-3 km lapse rate
5.6 K/km

Open this sounding in Storm Lab

The radar

The Quad Cities radar (KDVN), 156 km away, was scanning. The volume nearest the touchdown began at 14:04 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
13:07 UTCTSTM WND DMG1 Nnw BurlingtonDes Moines, IATrees and power lines down, time estimated from radar.
13:14 UTCTSTM WND DMG1 Sse BurlingtonDes Moines, IATrees down with one on a home. Time estimated from radar.
13:15 UTCTSTM WND GST 611 Se BeaverdaleDes Moines, IAAwning blown off mobile home. Still had 45 to 50 mph winds 10 minutes later.
13:21 UTCTSTM WND GST 581 Se Burlington RegionaDes Moines, IA
14:05 UTCTORNADO3 Sw KeokukLee, IAA brief EF1 tornado uniquely tracked across three states. This developed just in Lee County, Iowa, with peak winds of 105 mph, and tracked southeast through Clark County, Missouri. It then continued across the Mississipp
14:08 UTCTSTM WND DMG1 Nw WarsawHancock, ILtrees down in town.
16:52 UTCFLASH FLOOD1 Se ColchesterMcdonough, ILSpotter reported ditches full, creeks out of their banks between Colchester and Adair across the south central portion of the county with 3 to 5 inches of water on many of the back roads.

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 June 17, 2026

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

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
June 177:23 AM CDTEF1Jefferson, IA2.00
June 178:25 AM CDTEF1Warren, IL1.3100
June 171:28 PM CDTUnratedDale, AL5.30
June 171:30 PM CDTUnratedDale, AL5.10
June 174:12 PM CDTEF0Coffee, AL0.550
June 174:19 PM CDTEF1Menard, IL24.1150
June 174:53 PM CDTEF2Allamakee, IA to WI33.5320
June 175:05 PM CDTEF1Christian, IL10.7700
June 175:27 PM CDTEF1Shelby, IL3.475
June 175:45 PM CDTEF1Grant, WI21.7150
June 176:32 PM CDTEF1Iowa, WI6.6100
June 176:42 PM CDTEF2Coles, IL13.88001
June 176:48 PM CDTEF0Sangamon, IL5.7200
June 177:10 PM CDTEF1Dane, WI2.7300
June 177:16 PM CDTEF0Lafayette, WI1.250
June 177:56 PM CDTEF3Effingham, IL31.95002
June 179:07 PM EDTEF1Vigo, IN6.6300
June 178:36 PM CDTEF1Jasper, IL1.1125
June 178:41 PM CDTUnratedJasper, IL2.020
June 179:44 PM EDTEF3Owen, IN18.58801
June 179:32 PM CDTEF0Lake, IL0.3125
June 1710:43 PM EDTEF1Brown, IN1.4100
June 1712:03 AM EDTEF1Jackson, IN6.3325
June 1712:14 AM EDTEF2Dearborn, IN to KY8.94501
June 1712:34 AM EDTEF1Boone, KY6.2400
June 171:22 AM EDTEF2Franklin, IN to OH7.6400
June 1712:56 AM CDTEF0Terrebonne Parish, LA3.0200

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.