Alert archive / Iowa / Severe Thunderstorm Warnings in 2026

Severe Thunderstorm Warning 21, NWS Des Moines, IA

April 12, 2026Winnebago County, Worth County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Apr 12, 2026, 2:55 AM CDT for Winnebago County, Worth County, Iowa. It was in force for 26 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
Apr 12, 2026, 2:55 AM CDT (07:55 UTC)
Expired
Apr 12, 2026, 3:21 AM CDT
In force
26 min
Issued by
NWS Des Moines, IA
Area
Storm-based polygon
Hail
1.25 in
Wind
50.0 mph

Counties Winnebago County, IA, Worth County, IA

The radar

The Minneapolis radar (KMPX), 157 km from the middle of the area, began a volume at 07:54 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
Apr 12, 2:55 AM CDTHAIL 1.251 N Thompson, IAPicture of hail north of Thompson. Relayed by KIOW radio.

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

The nearest sounding before it

Minneapolis, MN (KMPX), launched 00:00Z, 7.9 hours before the alert went out and 157 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, Minneapolis, MN at 00:00Z on 2026-04-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.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.
HodographHodograph, Minneapolis, MN at 00:00Z on 2026-04-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 652 square meters per square second.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.
Mixed-layer CAPE
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
528 m above ground
0-6 km bulk shear
41 kt
0-1 km storm-relative helicity
652 m²/s²
0-3 km storm-relative helicity
891 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

671 
WUUS53 KDMX 120755
SVRDMX
IAC189-195-120845-
/O.NEW.KDMX.SV.W.0021.260412T0755Z-260412T0845Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Des Moines IA
255 AM CDT Sun Apr 12 2026

The National Weather Service in Des Moines has issued a

* Severe Thunderstorm Warning for...
  Northwestern Worth County in north central Iowa...
  Eastern Winnebago County in north central Iowa...

* Until 345 AM CDT.

* At 254 AM CDT, a severe thunderstorm was located over Thompson, or
  9 miles northwest of Forest City, moving northeast at 40 mph.

  HAZARD...Half dollar size hail.

  SOURCE...Radar indicated.

  IMPACT...Damage to vehicles is expected.

* Locations impacted include...
  Lake Mills, Emmons, Rice Lake, Thompson, Scarville, Lake Mills
  Municipal Airport, Hogsback Wildlife Area, and Rice Lake State
  Park.

This includes Interstate 35 between mile markers 216 and 218.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4347 9330 4330 9376 4340 9385 4350 9372
      4350 9332
TIME...MOT...LOC 0754Z 243DEG 34KT 4337 9375 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.25 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...<50 MPH

$$

Fowle
3 follow-up statements
699 
WWUS53 KDMX 120801
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
301 AM CDT Sun Apr 12 2026

IAC189-195-120845-
/O.CON.KDMX.SV.W.0021.000000T0000Z-260412T0845Z/
Worth IA-Winnebago IA-
301 AM CDT Sun Apr 12 2026

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 345 AM CDT
FOR NORTHWESTERN WORTH AND NORTHEASTERN WINNEBAGO COUNTIES...

At 301 AM CDT, a severe thunderstorm was located 5 miles southwest of
Scarville, or 11 miles north of Forest City, moving northeast at 40
mph.

HAZARD...Ping pong ball size hail.

SOURCE...Radar indicated.

IMPACT...People and animals outdoors will be injured. Expect damage 
         to roofs, siding, windows, and vehicles.

Locations impacted include...
Lake Mills, Emmons, Rice Lake, Leland, Scarville, Lake Mills
Municipal Airport, Hogsback Wildlife Area, and Rice Lake State Park.

This includes Interstate 35 between mile markers 216 and 218.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

Prepare immediately for large hail and deadly cloud to ground
lightning. Seek shelter inside a well-built structure. Stay away from
windows.

&&

LAT...LON 4333 9367 4343 9381 4350 9372 4350 9332
      4347 9330
TIME...MOT...LOC 0801Z 239DEG 34KT 4341 9368 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.50 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...<50 MPH

$$

Fowle
807 
WWUS53 KDMX 120808
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
308 AM CDT Sun Apr 12 2026

IAC189-195-120845-
/O.CON.KDMX.SV.W.0021.000000T0000Z-260412T0845Z/
Worth IA-Winnebago IA-
308 AM CDT Sun Apr 12 2026

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 345 AM CDT
FOR NORTHWESTERN WORTH AND NORTHEASTERN WINNEBAGO COUNTIES...

At 308 AM CDT, a severe thunderstorm was located over Scarville, or
14 miles north of Forest City, moving northeast at 40 mph.

HAZARD...Ping pong ball size hail.

SOURCE...Radar indicated.

IMPACT...People and animals outdoors will be injured. Expect damage 
         to roofs, siding, windows, and vehicles.

Locations impacted include...
Lake Mills, Emmons, Scarville, and Hogsback Wildlife Area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Prepare immediately for large hail and deadly cloud to ground
lightning. Seek shelter inside a well-built structure. Stay away from
windows.

&&

LAT...LON 4337 9362 4347 9376 4350 9372 4350 9336
TIME...MOT...LOC 0808Z 235DEG 33KT 4347 9363 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.50 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...<50 MPH

$$

Fowle
220 
WWUS53 KDMX 120821
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
321 AM CDT Sun Apr 12 2026

IAC189-195-120830-
/O.CAN.KDMX.SV.W.0021.000000T0000Z-260412T0845Z/
Worth IA-Winnebago IA-
321 AM CDT Sun Apr 12 2026

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN WORTH AND
NORTHEASTERN WINNEBAGO COUNTIES IS CANCELLED...

The storm which prompted the warning has moved out of the area.
Therefore, the warning has been cancelled.

LAT...LON 4337 9362 4347 9376 4350 9372 4350 9336
TIME...MOT...LOC 0818Z 243DEG 34KT 4352 9348 

$$

Fowle

The office that day

Everything else NWS Des Moines, IA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 12, 1:56 AM CDTSpecial Weather StatementDMXHancock, Humboldt, Kossuth, Winnebago64 min

Nearby

Severe Thunderstorm Warnings in Iowa, 2026Every severe thunderstorm warning 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.