Iowa, 2026

Tornado in Iowa, June 17, 2026

June 17, 2026 · NWS ARX · 1 event in 1 county or zone

This long-track EF-2 tornado developed about 5 miles east of Waukon during the late afternoon hours and trekked east-southeast through Allamakee County resulting in significant tree damage and some structural damage. The tornado eventually reached the Mississippi River just north of Harpers Ferry, where it crossed into Crawford County, Wisconsin near US Lock and Dam No.

Where it happened

Every event with a place to put it. Tap one for its entry below.

  • Tornadoes
  • Tropical storms and surge
  • Floods
  • Wind
  • Hail
  • Winter weather
  • Heat and drought
  • Cold
  • Fire, smoke and dust
  • Marine and coastal
  • Other

Open the live radar over this ground

The toll

Deaths
0
Injuries
0
Property damage
$450,000
Crop damage
$228,000
Events
1

Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.

What happened

The episode as NWS ARX wrote it up.

This long-track EF-2 tornado developed about 5 miles east of Waukon during the late afternoon hours and trekked east-southeast through Allamakee County resulting in significant tree damage and some structural damage. The tornado eventually reached the Mississippi River just north of Harpers Ferry, where it crossed into Crawford County, Wisconsin near US Lock and Dam No. 9.

What forecasters said that day

The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS La Crosse, WI wrote its last area forecast discussion before the first event at Jun 17, 1:05 PM CST, 2 hours 48 minutes earlier. Its key messages:

  • Scattered showers and storms this afternoon into the evening. Some of these storms could be severe. Large hail and damaging winds will continue to be the main threats with the tornado threat dependent on amount of destabilization.
  • Periodic showers and storms from Thursday into early next week with high temperatures remaining in the 70s for most locations.
Area forecast discussion, Jun 17, 1:05 PM CST, 2 hours 48 minutes before
Area Forecast Discussion
National Weather Service La Crosse WI
205 PM CDT Wed Jun 17 2026

.KEY MESSAGES...

- Scattered showers and storms this afternoon into the evening.
  Some of these storms could be severe. Large hail and damaging
  winds will continue to be the main threats with the tornado
  threat dependent on amount of destabilization.

- Periodic showers and storms from Thursday into early next
  week with high temperatures remaining in the 70s for most
  locations.

&&

.DISCUSSION...
Issued at 205 PM CDT Wed Jun 17 2026

Today: Scattered Showers and Storms

The initial round of storms this morning largely stayed south of the
forecast area with many locations seeing little to no rain. The
majority of the rain fell north of I-94 and our far southern
counties within our CWA. Much of the forecast area has remained dry
through much of the morning. As we head into through the afternoon a
surface low and associated cold front currently over central
Minnesota will move southeastward over our area. This will help to
bring scattered showers and storms through the afternoon and
evening. There remains a potential for severe thunderstorms to
occur. With cooler temperatures aloft and strong deep layer shear,
around 45 to 60 kts of 0-6km shear, large hail and damaging winds
will be possible with any stronger storm. A couple of tornadoes
could also be possible given the amount of surface vorticity right
along the front and the 1000 to 1500 J/kg of SBCAPE. All
precipitation chances end later this evening as the low shifts off to
the east. With the heavy rain staying well to our south this
morning, the flooding potential has decreased a bit. There still
remains some potential for localized flooding due to repeated storms
or a heavier storm over a given location. Our current forecasted QPF
is between 0.2 to 0.5" for areas in southeast Minnesota and areas
along and north of I-90 in Wisconsin. Areas in northeast Iowa and
far southwest Wisconsin are generally under 0.25", but this could
change as there is a little uncertainty on how far southeast the
stronger storms will go.

Thursday: Spotty Showers and Storms

Northwest flow over the area with weak moisture advection will be in
place for Thursday. A weak theta-e boundary moves from northwest to
southeast across the forecast area during the afternoon. With around
300 to 600 J/kg of MUCAPE, there is a low chance (15 to 25%) for
showers and storms to form during the afternoon along this boundary.
The last couple of runs from CAMs continue to show increased
coverage in these showers and storms so would not be surprised if
PoP chances increase for the afternoon.

Friday-Early Next Week: Periodic Shower and Storm Chances

Primarily northwest to west flow aloft continues through at least
early next week. Another shortwave moves down into the Upper Midwest
on Friday increasing rain chances for the afternoon. The latest LREF
has a 60 to 75% chance for measurable rain to occur across the
forecast area. The next chance for rain is for Saturday night into
Sunday, however this has continued to gradually shift southward. The
LREF has around a 40 to 55% chance for measurable rain for areas
south of I-90. After a brief break from the rain chances on Monday
due to shortwave ridging, another shortwave trough moves down on
Tuesday bringing another chance for rain. Temperatures through the
forecast period remain mostly in the 70s for highs and 50s for
lows.

&&

.AVIATION /18Z TAFS THROUGH 18Z THURSDAY/...
Issued at 1250 PM CDT Wed Jun 17 2026

Widespread MVFR ceilings persist through the afternoon with
pockets of IFR ceilings during the evening and overnight hours,
mainly at higher elevation locations. A line of showers and
storms move through this afternoon, decreasing in intensity in
the evening. These ceilings last through the overnight and lift
through the morning on Thursday. Current southerly winds as of
midday veer to the west and northwest behind the front bringing
these storms with gusts of 20-30kts in its wake. These winds
slowly decrease overnight to 5-10kts by Thursday morning.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
IA...None.

&&

DISCUSSION...Cecava
AVIATION...Skow
Hazardous weather outlook, Jun 17, 7:50 AM CST, 8 hours 3 minutes before
Hazardous Weather Outlook
National Weather Service La Crosse WI
850 AM CDT Wed Jun 17 2026

IAZ008>011-018-019-029-030-MNZ079-086>088-094>096-WIZ017-029-
032>034-041>044-053>055-061-181800-
Mitchell-Howard-Winneshiek-Allamakee-Floyd-Chickasaw-Fayette-
Clayton-Wabasha-Dodge-Olmsted-Winona-Mower-Fillmore-Houston-
Taylor-Clark-Buffalo-Trempealeau-Jackson-La Crosse-Monroe-Juneau-
Adams-Vernon-Crawford-Richland-Grant-
850 AM CDT Wed Jun 17 2026

This Hazardous Weather Outlook is for portions of southeast
Minnesota...northeast Iowa and southwest into central Wisconsin.

.DAY ONE...Today and Tonight

Severe storms will be possible this afternoon and evening with
the potential for all hazards including large hail, damaging
winds, a few tornadoes, and heavy rainfall leading to localized
flooding.

.DAYS TWO THROUGH SEVEN...Thursday through Tuesday

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

No action needed.

.EMERGENCY MANAGEMENT COORDINATION...

No webinar is scheduled.

The radar

The La Crosse radar (KARX), 62 km away, was scanning. The volume nearest the first event began at 21:55 UTC.

Open the radar archive at this moment

Event by event

1 tornado. Local standard time, as filed.

Tornado, Allamakee

When
June 17, 3:53 PM CST to 4:10 PM CST
Where
Allamakee County, 2.12 mi WNW of Elon to 3.08 mi ENE of Harpers Ferry
Rating
EF2
Path length
14.52 mi
Path width
320 yd
Continued into
Crawford, Wi (ARX)
Property damage
$450,000
Crop damage
$228,000
Reported by
NWS Storm Survey
Coordinates
43.277, -91.371

This strong and long-tracked EF-2 tornado began about 5 miles east of Waukon and continued east-southeast causing a continuous path of tree damage all the way to the Misssissippi River near Lock and Dam 9. The tornado also damaged farm outbuildings and a few residences. Extensive tree damage along Waterville Road formed the basis for the EF-2 rating for this tornado. The tornado crossed the Mississippi River and continued east into Wisconsin.

What these are

Tornado
A violently rotating column of air in contact with the ground and extending from a thunderstorm, filed with its path, width and Fujita or Enhanced Fujita rating from the damage survey.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

More

Every storm in Iowa in 2026Every state in 2026This day in weather historyThe tornado archive for Iowa, 2026Warnings in Iowa, June 2026

Sources

NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 1353960.