Alert archive / Iowa / Tornado Warnings in 2026
Tornado Warning 40, NWS La Crosse, WI
NWS La Crosse, WI issued this tornado warning at May 17, 2026, 10:24 PM CDT for Floyd County, Mitchell County, Iowa. It was in force for 51 min. 1 report came from inside the area while it was in force.
The area
The outline as issued, with what was reported inside it.
The facts
- Issued
- May 17, 2026, 10:24 PM CDT (03:24 UTC)
- Expired
- May 17, 2026, 11:15 PM CDT
- In force
- 51 min
- Issued by
- NWS La Crosse, WI
- Area
- Storm-based polygon
- Tornado
- Radar indicated
- Hail
- 0.0 in
Counties Floyd County, IA, Mitchell County, IA
The radar
The La Crosse radar (KARX), 151 km from the middle of the area, began a volume at 03:23 UTC, the scan nearest the moment this went out.
Open the radar archive at this moment
The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| May 17, 10:34 PM CDT | TSTM WND GST 70 | Nora Springs, IA |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
Did it verify
Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this tornado warning while it was in force. That is not proof nothing happened: reports are thin where few people live.
Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.
The watch it was issued in
The SPC watch in force over the same counties when this warning went out.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| May 17, 6:12 PM CDT | Tornado Watch | SPC | 6 hr |
The nearest sounding before it
Minneapolis, MN (KMPX), launched 00:00Z, 3.4 hours before the alert went out and 197 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 1101 m above ground
- 0-6 km bulk shear
- 42 kt
- 0-1 km storm-relative helicity
- 154 m²/s²
- 0-3 km storm-relative helicity
- 237 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
419
WFUS53 KARX 180324
TORARX
IAC067-131-180415-
/O.NEW.KARX.TO.W.0040.260518T0324Z-260518T0415Z/
BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service La Crosse WI
1024 PM CDT Sun May 17 2026
The National Weather Service in La Crosse has issued a
* Tornado Warning for...
Southeastern Mitchell County in north central Iowa...
Northern Floyd County in north central Iowa...
* Until 1115 PM CDT.
* At 1023 PM CDT, a severe thunderstorm capable of producing a
tornado was located near Mason City, moving east at 55 mph.
HAZARD...Tornado.
SOURCE...Radar indicated rotation.
IMPACT...Flying debris will be dangerous to those caught without
shelter. Mobile homes will be damaged or destroyed.
Damage to roofs, windows, and vehicles will occur. Tree
damage is likely.
* This dangerous storm will be near...
Rudd around 1035 PM CDT.
Other locations impacted by this tornadic thunderstorm include
Colwell County Park, Orchard, New Haven, Idlewilde State Park,
Howardville, County Roads 147 And T 34, and County Roads B 20 And T
26.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Heavy rainfall may hide this tornado. Do not wait to see or hear the
tornado. TAKE COVER NOW!
&&
LAT...LON 4321 9302 4331 9256 4312 9256 4300 9302
TIME...MOT...LOC 0323Z 247DEG 48KT 4308 9317
TORNADO...RADAR INDICATED
MAX HAIL SIZE...0.00 IN
$$
Baumgardt3 follow-up statements
483
WWUS53 KARX 180336
SVSARX
Severe Weather Statement
National Weather Service La Crosse WI
1036 PM CDT Sun May 17 2026
IAC067-131-180415-
/O.CON.KARX.TO.W.0040.000000T0000Z-260518T0415Z/
Mitchell IA-Floyd IA-
1036 PM CDT Sun May 17 2026
...A TORNADO WARNING REMAINS IN EFFECT UNTIL 1115 PM CDT FOR
SOUTHEASTERN MITCHELL AND NORTHERN FLOYD COUNTIES...
At 1035 PM CDT, a severe thunderstorm capable of producing a tornado
was located over Nora Springs, or 10 miles east of Mason City, moving
northeast at 55 mph.
HAZARD...Tornado.
SOURCE...Radar indicated rotation. This circulation produced a
tornado near Rockwell in the last 30 minutes.
IMPACT...Flying debris will be dangerous to those caught without
shelter. Mobile homes will be damaged or destroyed. Damage
to roofs, windows, and vehicles will occur. Tree damage is
likely.
This dangerous storm will be near...
Rudd around 1040 PM CDT.
Other locations impacted by this tornadic thunderstorm include
Colwell County Park, Orchard, New Haven, Idlewilde State Park,
Howardville, County Roads 147 And T 34, and County Roads B 20 And T
26.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Heavy rainfall may hide this tornado. Do not wait to see or hear the
tornado. TAKE COVER NOW!
&&
LAT...LON 4321 9302 4331 9256 4312 9256 4300 9302
TIME...MOT...LOC 0335Z 243DEG 46KT 4315 9300
TORNADO...RADAR INDICATED
MAX HAIL SIZE...0.00 IN
$$
Baumgardt184
WWUS53 KARX 180356
SVSARX
Severe Weather Statement
National Weather Service La Crosse WI
1056 PM CDT Sun May 17 2026
IAC067-131-180415-
/O.CON.KARX.TO.W.0040.000000T0000Z-260518T0415Z/
Mitchell IA-Floyd IA-
1056 PM CDT Sun May 17 2026
...A TORNADO WARNING REMAINS IN EFFECT UNTIL 1115 PM CDT FOR
SOUTHEASTERN MITCHELL AND NORTHEASTERN FLOYD COUNTIES...
At 1055 PM CDT, a severe thunderstorm capable of producing a tornado
was located 8 miles east of Osage, moving east at 50 mph.
HAZARD...Tornado.
SOURCE...Radar indicated rotation.
IMPACT...Flying debris will be dangerous to those caught without
shelter. Mobile homes will be damaged or destroyed. Damage
to roofs, windows, and vehicles will occur. Tree damage is
likely.
This tornadic thunderstorm will remain over mainly rural areas of
southeastern Mitchell and northeastern Floyd Counties, including the
following locations... Colwell County Park, New Haven, Idlewilde
State Park, Howardville, Colwell, County Roads 17 And T 72, and Floyd
Crossing.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Heavy rainfall may hide this tornado. Do not wait to see or hear the
tornado. TAKE COVER NOW!
&&
LAT...LON 4326 9277 4331 9256 4312 9256 4307 9276
TIME...MOT...LOC 0355Z 249DEG 45KT 4325 9266
TORNADO...RADAR INDICATED
MAX HAIL SIZE...0.00 IN
$$
Baumgardt729 WWUS53 KARX 180409 SVSARX Severe Weather Statement National Weather Service La Crosse WI 1109 PM CDT Sun May 17 2026 IAC067-131-180418- /O.EXP.KARX.TO.W.0040.000000T0000Z-260518T0415Z/ Mitchell IA-Floyd IA- 1109 PM CDT Sun May 17 2026 ...THE TORNADO WARNING FOR SOUTHEASTERN MITCHELL AND NORTHEASTERN FLOYD COUNTIES WILL EXPIRE AT 1115 PM CDT... The storm which prompted the warning has moved out of the area. Therefore, the warning will be allowed to expire. A Tornado Watch remains in effect until 100 AM CDT for north central Iowa. && LAT...LON 4326 9277 4331 9256 4312 9256 4307 9276 TIME...MOT...LOC 0408Z 247DEG 48KT 4331 9245 $$ Baumgardt
What forecasters said that day
The local office's own words before this tornado warning went out, 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 this tornado warning went out at May 17, 8:19 PM CDT, 2 hours 5 minutes earlier. Its key messages:
- Severe weather possible between 7 PM and 1 AM tonight. All hazards are possible mainly west of the Mississippi River.
- Another round of severe weather possible on Monday night between 9 PM and 4 AM. The main threat will be damaging winds. With isolated threats of hail and maybe a few QLCS tornadoes.
Area forecast discussion, May 17, 8:19 PM CDT, 2 hours 5 minutes before
Area Forecast Discussion National Weather Service La Crosse WI 819 PM CDT Sun May 17 2026 .KEY MESSAGES... - Severe weather possible between 7 PM and 1 AM tonight. All hazards are possible mainly west of the Mississippi River. - Another round of severe weather possible on Monday night between 9 PM and 4 AM. The main threat will be damaging winds. With isolated threats of hail and maybe a few QLCS tornadoes. && .UPDATE... Issued at 805 PM CDT Sun May 17 2026 Ongoing non-severe scattered storms across the local area are inhibiting northward progression of warm front seen through north-central Iowa on surface observations this evening, keeping local severe threat conditional, i.e., lower overall confidence. Intensification of the low level jet, 45 kt south wind on DMX VWP, suggests a northern shift in warm front surging instability farther north in the next 1-2 hours. Therefore, initial threat of surface based, semi-discrete storm mode remains a low confidence scenario to remain cognizant of until the eventual MCS on radar imagery quickly shifting east through central Minnesota arrives in 3+ hours. While main threat with this line will be damaging winds, should the warm front reach farther north, a QLCS tornado threat would exist primarily along the frontal boundary. Therefore, the ongoing Tornado Watch may require a switch to Severe Thunderstorm Watch. && .DISCUSSION... Issued at 1257 PM CDT Sun May 17 2026 This Afternoon The remnant MCV which brought rain mainly south of Interstate 94 will continue to move northeast away from the area this afternoon. As it does, the showers and isolated storms currently along Interstates 90 and 94 will move east northeast away from the area. Additional rainfall amounts will be up to a half inch. As a warm front gradually lifts northward, temperatures along and south of Interstate 94 will warm into the 60s and lower 70s, and into 60s north of this Interstate. This will result in surface-based CAPES climbing into the 1000 to 2500 J/kg along and south of Interstate 90 by 7 pm. Tonight Late this afternoon and evening, 2-3K J/kg CAPES will develop ahead of a squall line moving east across eastern South Dakota, eastern Nebraska, northern Iowa, and southern Minnesota. with 0-6 km shear approaching 40 knots, there could potentially be some supercells located along the line (these would likely stay west of the Upper Mississippi River Vally) and along the warm front near the Minnesota and Iowa boarder. In addition to the deep shear, there is 200-300 EHI along the Minnesota and Iowa boarder and downdraft CAPEs up to 1K J/kg. The discrete supercells ahead of the squall line would be capable of producing wet microbursts, large hail, and isolated tornadoes between 7 PM and 10 PM in southeast Minnesota and northeast Iowa. The threat will then shift to more damaging winds and maybe a few QLCS tornadoes as the squall line moves into southeast Minnesota and northeast Iowa between 10 PM and 11 PM. This line will then gradually weaken as the instability wanes. The severe weather threat will likely wane by 1 AM Monday. Monday night A cold front will move east through the area. There will be 1-2K J/kg CAPES ahead of this front. With much of the deep (0-6 km) shear located post frontal, not anticipating any supercells. As a result, if there is severe weather, it would be located along the cold front as a squall line. The primary threat would be damaging winds with secondary threats as hail and QLCS tornadoes. Timing looks to be rather similar tonight with the squall line moving into northeast Iowa and southeast Minnesota between 9 PM and 10 PM. It will exit the area between 2 AM and 4 AM. By this time, the winds will likely be sub-severe. Friday into Saturday A shortwave trough will move east through the area. This will result in another round of showers and isolated storms. With CAPES less than 250 J/kg and 0-3 km and 0-6 km shear less than 25 knots, not anticipating any organized severe weather at this time. && .AVIATION /00Z TAFS THROUGH 00Z TUESDAY/... Issued at 636 PM CDT Sun May 17 2026 MVFR to IFR conditions currently present across the region with some isolated instances of LIFR along and south of the I-90 corridor. Low clouds are expected to linger for most areas through later tonight with some low precip chances. The main chance for storms looks to push east into the region late this evening - likely between 04-08Z for the terminals. The main threat with this line of storms will be strong winds and heavy rainfall so have continued with the TEMPO groups that bring stronger winds in for a short time period. Lower rain chances will continue into tomorrow morning behind the line of storms with most locations lifting back to VFR CIGs through the morning. Some lower MVFR/IFR CIGs may linger across portions of SE Minnesota and WC Wisconsin so have kept them at the KRST terminal through the end of the period. && .HYDROLOGY... Issued at 106 AM CDT Sun May 17 2026 One to two inch totals are still forecast across the area, with areas further west more favored for the 2 inch totals. This will likely not cause river flooding, only within bank rises. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. IA...None. && UPDATE...JAR DISCUSSION...Boyne AVIATION...Barendse HYDROLOGY...Baumgardt
Hazardous weather outlook, May 17, 1:29 PM CDT, 8 hours 55 minutes before
Hazardous Weather Outlook National Weather Service La Crosse WI 129 PM CDT Sun May 17 2026 IAZ008>011-018-019-029-030-MNZ079-086>088-094>096-WIZ032>034-041- 181100- Mitchell-Howard-Winneshiek-Allamakee-Floyd-Chickasaw-Fayette- Clayton-Wabasha-Dodge-Olmsted-Winona-Mower-Fillmore-Houston- Buffalo-Trempealeau-Jackson-La Crosse- 129 PM CDT Sun May 17 2026 This Hazardous Weather Outlook is for portions of north central Iowa...northeast Iowa...southeast Minnesota and west central Wisconsin. .DAY ONE...This Afternoon and Tonight Scattered severe storms are possible later this evening and early overnight with damaging wind as the main threat as a line of storms progresses from west to east. .DAYS TWO THROUGH SEVEN...Monday through Saturday Scattered severe storms possible Monday evening and overnight with damaging wind the main threat. .SPOTTER INFORMATION STATEMENT... Severe storm reports would be greatly appreciated. .EMERGENCY MANAGEMENT COORDINATION... No webinar is scheduled. WIZ017-029-042>044-053>055-061-181100- Taylor-Clark-Monroe-Juneau-Adams-Vernon-Crawford-Richland-Grant- 129 PM CDT Sun May 17 2026 This Hazardous Weather Outlook is for portions of central Wisconsin...north central Wisconsin...southwest Wisconsin and west central Wisconsin. .DAY ONE...This Afternoon and Tonight Scattered strong storms are possible overnight with wind gusts as high as 45 mph as a line of storms progresses from west to east. .DAYS TWO THROUGH SEVEN...Monday through Saturday Scattered severe storms possible late Monday evening and overnight with damaging wind as the main threat. .SPOTTER INFORMATION STATEMENT... Severe storm reports would be greatly appreciated. .EMERGENCY MANAGEMENT COORDINATION... No webinar is scheduled. Boyne
The office that day
Everything else NWS La Crosse, WI issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 17, 10:09 PM CDT | Severe Thunderstorm Warning | ARX | Floyd, Mitchell | 66 min |
| May 17, 10:13 PM CDT | Tornado Warning | ARX | Mitchell | 62 min |
| May 17, 10:49 PM CDT | Severe Thunderstorm Warning | ARX | Chickasaw, Howard | 56 min |
| May 17, 10:54 PM CDT | Tornado Warning | ARX | Chickasaw, Howard | 51 min |
| May 17, 11:40 PM CDT | Severe Thunderstorm Warning | ARX | Winneshiek | 28 min |
| May 18, 12:07 AM CDT | Special Weather Statement | ARX | Allamakee | 38 min |
Nearby
Tornado Warnings in Iowa, 2026Every tornado warning in 2026Tornadoes in 2026
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.