Alert archive / Iowa / Severe Thunderstorm Warnings in 2026

Severe Thunderstorm Warning 307, NWS Des Moines, IA

August 7, 20264 counties in Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Aug 7, 2026, 1:25 PM CDT for 4 counties in Iowa. It was in force for 50 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Aug 7, 2026, 1:25 PM CDT (18:25 UTC)
Expired
Aug 7, 2026, 2:15 PM CDT
In force
50 min
Issued by
NWS Des Moines, IA
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Cerro Gordo County, IA, Hancock County, IA, Winnebago County, IA, Worth County, IA

The radar

The Des Moines radar (KDMX), 168 km from the middle of the area, began a volume at 18:26 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.

The nearest sounding before it

Minneapolis, MN (KMPX), launched 12:00Z, 6.4 hours before the alert went out and 180 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 12:00Z on 2026-08-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 506 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Minneapolis, MN at 12:00Z on 2026-08-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 211 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
506 J/kg
Mixed-layer CIN
-343 J/kg
Mixed-layer LCL
1332 m above ground
0-6 km bulk shear
33 kt
0-1 km storm-relative helicity
211 m²/s²
0-3 km storm-relative helicity
250 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Des Moines, IA wrote its last area forecast discussion before this severe thunderstorm warning went out at Aug 7, 12:40 PM CDT, 45 minutes earlier.

Area forecast discussion, Aug 7, 12:40 PM CDT, 45 minutes before
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Hazardous weather outlook, Aug 7, 12:50 PM CDT, 35 minutes before
Hazardous Weather Outlook
National Weather Service Des Moines IA
1250 PM CDT Fri Aug 7 2026

IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-
081>086-092>097-081800-
Emmet-Kossuth-Winnebago-Worth-Palo Alto-Hancock-Cerro Gordo-
Pocahontas-Humboldt-Wright-Franklin-Butler-Bremer-Sac-Calhoun-
Webster-Hamilton-Hardin-Grundy-Black Hawk-Crawford-Carroll-Greene-
Boone-Story-Marshall-Tama-Audubon-Guthrie-Dallas-Polk-Jasper-
Poweshiek-Cass-Adair-Madison-Warren-Marion-Mahaska-Adams-Union-
Clarke-Lucas-Monroe-Wapello-Taylor-Ringgold-Decatur-Wayne-
Appanoose-Davis-
1250 PM CDT Fri Aug 7 2026

This Hazardous Weather Outlook is for portions of central Iowa.

.DAY ONE...This afternoon and tonight

There is a Slight (Level 2 of 5) Risk for severe weather across much
of Iowa today. Large hail is the primary threat but damaging winds
and a tornado is possible.

There is a Marginal (Level 1 of 4) Risk for excessive rainfall
across much of Iowa today.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday

There is a Marginal (Level 1 of 5) Risk for severe weather across
much of Iowa Saturday and again on Sunday. Damaging winds are the
primary threat.

There is a Marginal (Level 1 of 4) Risk for excessive rainfall
across much of Iowa Saturday and again on Sunday.

Shower and thunderstorm chances will continue through the weekend.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed, but any storm reports are
appreciated.

In the hours before

Local storm report, Aug 7, 1:22 PM CDT, 3 minutes before
Preliminary Local Storm Report
National Weather Service Des Moines IA
122 PM CDT Fri Aug 7 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0113 PM     Hail             Forest City             43.26N 93.64W
08/07/2026  E1.00 Inch       Winnebago          IA   Public

            From social media.

&&

TDR

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 7, 2:52 AM CDTDense Fog AdvisoryDMXAdair, Adams, Appanoose, Audubon, Black Hawk, Boone and 44 more6 hr
Aug 7, 12:46 PM CDTSevere Thunderstorm WarningDMXWinnebago, Worth29 min
Aug 7, 1:07 PM CDTSevere Thunderstorm WarningDMXCerro Gordo, Hancock, Winnebago, Worth23 min
Aug 7, 1:12 PM CDTSevere Thunderstorm WarningDMXHancock, Wright48 min
Aug 7, 1:37 PM CDTSevere Thunderstorm WarningDMXCerro Gordo, Hancock53 min
Aug 7, 2:52 PM CDTSevere Thunderstorm WarningDMXBremer, Butler38 min
Aug 7, 3:49 PM CDTSevere Thunderstorm Warning Considerable damage threatDMXBlack Hawk, Bremer26 min
Aug 7, 3:53 PM CDTTornado Warning Tornado observedDMXBlack Hawk, Bremer22 min
Aug 7, 4:16 PM CDTSevere Thunderstorm WarningDMXBlack Hawk, Grundy, Tama59 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.