Alert archive / Iowa / Tornado Warnings in 2026

Tornado Warning 13, NWS Sioux Falls, SD

May 17, 2026Cherokee County, Plymouth County, Woodbury County, Iowa

NWS Sioux Falls, SD issued this tornado warning at May 17, 2026, 7:47 PM CDT for Cherokee County, Plymouth County, Woodbury County, Iowa. It was in force for 43 min. 15 reports 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, 7:47 PM CDT (00:47 UTC)
Expired
May 17, 2026, 8:30 PM CDT
In force
43 min
Issued by
NWS Sioux Falls, SD
Area
Storm-based polygon
Tornado
Radar indicated
Hail
1.0 in

Counties Cherokee County, IA, Plymouth County, IA, Woodbury County, IA

The radar

The Sioux Falls radar (KFSD), 133 km from the middle of the area, began a volume at 00:49 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

TimeReportWhereRemark
May 17, 7:48 PM CDTTSTM WND GST 67Lawton, IAVia personal weather station.
May 17, 7:48 PM CDTTSTM WND GST 67Lawton, IAVia personal weather station.
May 17, 7:49 PM CDTTSTM WND GST 63Moville, IAVia personal weather station.
May 17, 7:49 PM CDTTSTM WND GST 63Moville, IAVia personal weather station.
May 17, 7:50 PM CDTTSTM WND GST 77Moville, IAVia personal weather station. Exact time estimated via radar.
May 17, 7:50 PM CDTTSTM WND GST 77Moville, IAVia personal weather station. Exact time estimated via radar.
May 17, 7:51 PM CDTTSTM WND DMGMoville, IASeveral videos and photos via social media of large trees down, including some on houses or other structures.
May 17, 7:56 PM CDTTSTM WND GST 753 Ne Moville, IAVia personal weather station. Exact time estimated via radar.
May 17, 7:56 PM CDTTSTM WND GST 753 Ne Moville, IAVia personal weather station. Exact time estimated via radar.
May 17, 7:56 PM CDTTORNADO5 Nw Kingsley, IAKingsley Fire reported brief tornado near C60 and Pioneer Ave.
May 17, 7:56 PM CDTTORNADO5 Nw Kingsley, IAKingsley Fire reported brief tornado near C60 and Pioneer Ave.
May 17, 7:57 PM CDTTSTM WND GST 741 Sw Pierson, IAVia personal weather station. Exact time estimated via radar.
May 17, 7:57 PM CDTTSTM WND GST 741 Sw Pierson, IAVia personal weather station. Exact time estimated via radar.
May 17, 8:03 PM CDTTSTM WND DMG3 Ne Pierson, IAPhotos via social media of destroyed outbuilding and tree damage 6 miles west of Washta.
May 17, 8:12 PM CDTTORNADO7 S Marcus, IAVideo of brief gustnado. Location estimated.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
May 17, 1:42 PM CDTTornado WatchSPC8 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 0.8 hours before the alert went out and 140 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.

Skew-T log-pSkew-T log-p diagram, Omaha, NE at 00:00Z on 2026-05-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2478 joules per kilogram.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.
HodographHodograph, Omaha, NE at 00:00Z on 2026-05-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 178 square meters per square second.193958Sfc1 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.
Mixed-layer CAPE
2478 J/kg
Mixed-layer CIN
-15 J/kg
Mixed-layer LCL
1258 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
178 m²/s²
0-3 km storm-relative helicity
298 m²/s²
Significant tornado parameter
2.0
Supercell composite
17.9

Open this sounding in Storm Lab

The text

As transmitted.

455 
WFUS53 KFSD 180047
TORFSD
IAC035-149-193-180130-
/O.NEW.KFSD.TO.W.0013.260518T0047Z-260518T0130Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Sioux Falls SD
747 PM CDT Sun May 17 2026

The National Weather Service in Sioux Falls has issued a

* Tornado Warning for...
  Southwestern Cherokee County in northwestern Iowa...
  Northeastern Woodbury County in west central Iowa...
  Southeastern Plymouth County in northwestern Iowa...

* Until 830 PM CDT.

* At 747 PM CDT, severe thunderstorms capable of producing both
  tornadoes and extensive straight line wind damage were located over
  Lawton, or 12 miles east of Sioux City, moving northeast at 40 mph.

  HAZARD...Tornado and quarter size hail.

  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.

* These dangerous storms will be near...
  Moville and Kingsley around 755 PM CDT.
  Pierson around 800 PM CDT.

Other locations in the path of this tornadic thunderstorm include
Washta.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

This cluster of thunderstorms is capable of producing tornadoes and
widespread significant wind damage. Do not wait to see or hear the
tornado. For your protection move to an interior room on the lowest
floor of a building.

&&

LAT...LON 4242 9622 4253 9626 4276 9576 4256 9566
      4256 9574 4252 9575
TIME...MOT...LOC 0047Z 244DEG 35KT 4248 9616 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...1.00 IN

$$

BP
3 follow-up statements
324 
WWUS53 KFSD 180059
SVSFSD

Severe Weather Statement
National Weather Service Sioux Falls SD
759 PM CDT Sun May 17 2026

IAC035-149-193-180130-
/O.CON.KFSD.TO.W.0013.000000T0000Z-260518T0130Z/
Cherokee IA-Woodbury IA-Plymouth IA-
759 PM CDT Sun May 17 2026

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 830 PM CDT FOR
SOUTHWESTERN CHEROKEE...NORTHEASTERN WOODBURY AND SOUTHEASTERN
PLYMOUTH COUNTIES...

At 759 PM CDT, a severe squall line capable of producing both
tornadoes and extensive straight line wind damage was located near
Moville, or 19 miles southeast of Le Mars, moving northeast at 40
mph.

HAZARD...Tornado and quarter size hail.

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.

These dangerous storms will be near...
  Kingsley and Pierson around 805 PM CDT.

Other locations in the path of this tornadic thunderstorm include
Washta.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

This cluster of thunderstorms is capable of producing tornadoes and
widespread significant wind damage. Do not wait to see or hear the
tornado. For your protection move to an interior room on the lowest
floor of a building.

&&

LAT...LON 4246 9604 4257 9618 4276 9576 4256 9566
      4256 9574 4252 9575
TIME...MOT...LOC 0059Z 244DEG 35KT 4253 9602 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...1.00 IN

$$

BP
187 
WWUS53 KFSD 180107
SVSFSD

Severe Weather Statement
National Weather Service Sioux Falls SD
807 PM CDT Sun May 17 2026

IAC035-149-193-180130-
/O.CON.KFSD.TO.W.0013.000000T0000Z-260518T0130Z/
Cherokee IA-Woodbury IA-Plymouth IA-
807 PM CDT Sun May 17 2026

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 830 PM CDT FOR
SOUTHWESTERN CHEROKEE...NORTHEASTERN WOODBURY AND SOUTHEASTERN
PLYMOUTH COUNTIES...

At 807 PM CDT, a confirmed tornado was located over Kingsley, or 19
miles southeast of Le Mars, moving northeast at 40 mph.

HAZARD...Damaging tornado and quarter size hail.

SOURCE...Emergency management confirmed tornado. At 757 PM CDT, the 
         local fire department reported a tornado 5 miles northwest 
         of Kingsley.

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 tornado will be near...
  Pierson and Washta around 810 PM CDT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

To repeat, a tornado is on the ground. TAKE COVER NOW! Move to a
basement or an interior room on the lowest floor of a sturdy
building. Avoid windows. If you are outdoors, in a mobile home, or in
a vehicle, move to the closest substantial shelter and protect
yourself from flying debris.

&&

LAT...LON 4250 9597 4259 9613 4276 9576 4256 9566
      4256 9574 4252 9575
TIME...MOT...LOC 0107Z 244DEG 35KT 4256 9593 

TORNADO...OBSERVED
MAX HAIL SIZE...1.00 IN

$$

BP
084 
WWUS53 KFSD 180124
SVSFSD

Severe Weather Statement
National Weather Service Sioux Falls SD
824 PM CDT Sun May 17 2026

IAC035-149-193-180134-
/O.EXP.KFSD.TO.W.0013.000000T0000Z-260518T0130Z/
Cherokee IA-Woodbury IA-Plymouth IA-
824 PM CDT Sun May 17 2026

...THE TORNADO WARNING FOR SOUTHWESTERN CHEROKEE...NORTHEASTERN
WOODBURY AND SOUTHEASTERN PLYMOUTH COUNTIES WILL EXPIRE AT 830 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 1000 PM CDT for northwestern
and west central Iowa.

&&

LAT...LON 4250 9597 4259 9613 4276 9576 4256 9566
      4256 9574 4252 9575
TIME...MOT...LOC 0124Z 244DEG 35KT 4262 9575 

$$

BP

The office that day

Everything else NWS Sioux Falls, SD issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 17, 7:20 PM CDTSevere Thunderstorm WarningFSDPlymouth, Sioux28 min
May 17, 7:20 PM CDTSevere Thunderstorm WarningFSDO'Brien, Osceola26 min
May 17, 7:26 PM CDTTornado WarningFSDWoodbury49 min
May 17, 7:32 PM CDTSevere Thunderstorm Warning Considerable damage threatFSDCherokee, Ida, Plymouth, Woodbury58 min
May 17, 8:00 PM CDTSevere Thunderstorm WarningFSDO'Brien, Osceola, Plymouth, Sioux45 min
May 17, 8:03 PM CDTFlash Flood WarningFSDPlymouth, Sioux3 hr
May 17, 8:21 PM CDTSevere Thunderstorm Warning Destructive damage threatFSDBuena Vista, Cherokee, Clay, Dickinson, Ida, O'Brien and 3 more54 min
May 17, 8:26 PM CDTTornado WarningFSDBuena Vista, Cherokee, Clay, O'Brien28 min
May 17, 8:48 PM CDTTornado WarningFSDClay, Dickinson27 min
May 17, 8:54 PM CDTTornado WarningFSDClay, Dickinson51 min
May 18, 5:11 PM CDTSevere Thunderstorm WarningFSDCherokee, Ida, Plymouth, Woodbury49 min
May 18, 5:48 PM CDTSevere Thunderstorm Warning Considerable damage threatFSDBuena Vista, Cherokee, Clay, O'Brien42 min
May 18, 6:08 PM CDTSevere Thunderstorm WarningFSDPlymouth, Sioux37 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.