Alert archive / Iowa / Severe Thunderstorm Warnings in 2026
Severe Thunderstorm Warning 332, NWS Des Moines, IA
NWS Des Moines, IA issued this severe thunderstorm warning at Sep 6, 2026, 4:13 PM CDT for 4 counties in Iowa. It was in force for 47 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
- Sep 6, 2026, 4:13 PM CDT (21:13 UTC)
- Expired
- Sep 6, 2026, 5:00 PM CDT
- In force
- 47 min
- Issued by
- NWS Des Moines, IA
- Area
- Storm-based polygon
- Hail
- 0.75 in
- Wind
- 60.0 mph
Counties Calhoun County, IA, Carroll County, IA, Greene County, IA, Webster County, IA
The radar
The Des Moines radar (KDMX), 86 km from the middle of the area, began a volume at 21:15 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, 9.2 hours before the alert went out and 302 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
- 257 J/kg
- Mixed-layer CIN
- -330 J/kg
- Mixed-layer LCL
- 1056 m above ground
- 0-6 km bulk shear
- 23 kt
- 0-1 km storm-relative helicity
- 24 m²/s²
- 0-3 km storm-relative helicity
- 55 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
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 Sep 6, 3:31 PM CDT, 42 minutes earlier. Its key messages:
- Flash Flood Watch issued for portions of northwest Iowa through Monday morning.
- Storms continue into Monday morning. Another round of severe storms possible Tuesday afternoon.
- Cooler temperatures and lower humidity arrive late week.
Area forecast discussion, Sep 6, 3:31 PM CDT, 42 minutes before
Area Forecast Discussion National Weather Service Des Moines IA 331 PM CDT Sun Sep 6 2026 .KEY MESSAGES... - Flash Flood Watch issued for portions of northwest Iowa through Monday morning. - Storms continue into Monday morning. Another round of severe storms possible Tuesday afternoon. - Cooler temperatures and lower humidity arrive late week. && .SHORT TERM /THROUGH TUESDAY NIGHT/... Issued at 322 PM CDT Sun Sep 6 2026 We kick off the first Sunday of September on an active note. Showers and storms have lingered throughout the morning and into the early afternoon, fueled by areas of deep moisture convergence. CAMS suggested the potential for more organized cells to form due later on increasing shear, but this has not yet materialized. Convection continuing to develop ahead of the main line is disrupting inflow to the primary updrafts and preventing the development of a single dominant cold pool. Currently, storms are feeding off a robust instability axis with MLCAPE around 3000 J/kg although effective shear around 30 kts is keeping activity disorganized. Regardless, a few severe storms still remain possible with damaging winds being the primary concerns. Slow storm motions and efficient rain have led to some areas recording 3-5 inches of rainfall as storms train over the same areas. With storms expected to persist through the afternoon, CAM QPF highlight localized maximums potentially exceeding 5 inches over west central Iowa. Consequently, the weather prediction center (WPC) has outlined much of northwest Iowa in a Moderate Risk for flash flooding, and a Flash Flood Watch is in effect. Somewhat mitigating the flash flood threat are the dry antecedent conditions; much of NW Iowa remains in a moderate drought, with Ida County experiencing a small sliver of severe drought. Tonight Convection will continue to slowly shift south and east this evening, gradually weakening with the loss of diurnal heating. However, a Strengthening low level jet across central and western Iowa could reignite scattered showers and storms late tonight into early tomorrow morning. Severe weather is not expected overnight as MUCAPE values drop to around ~500 J/KG. Monday into Tuesday Overnight showers and storms should diminish as we head into tomorrow morning and drier air filters in for Monday. Winds across northern Iowa will be breezy ahead of an approaching cold front, at with gusts reaching up to 25 mph at times. Additional storms are possible ahead of this boundary late Monday night into Tuesday morning. A severe weather threat may materialize by Tuesday afternoon; the Storm Prediction Center (SPC) day 3 highlights central Iowa in a Marginal Risk. Details regarding this severe threat will be fine tuned in future AFD issuances. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... Issued at 322 PM CDT Sun Sep 6 2026 Storms will exit the region behind the cold front on Wednesday, ushering in cooler temperatures and lower humidity. Highs in the lower 80s are expected through Thursday, with precipitation chances potentially returning by Friday. && .AVIATION /18Z TAFS THROUGH 18Z MONDAY/... Issued at 1240 PM CDT Sun Sep 6 2026 Most of central Iowa is under at least MVFR conditions due to diurnal cumulus bubbling up. IFR conditions are present at KMCW due to lower ceilings. Storms are expected to increase in coverage across western Iowa and portions of central Iowa. PROB30 groups have been introduced at KDSM and KFOD to highlight this. VFR conditions are expected to return overnight and winds will increase towards the end of this TAF insurance across northern Iowa. && .DMX WATCHES/WARNINGS/ADVISORIES... Flood Watch through late tonight for IAZ004-015-023-033-034- 044. && SHORT TERM...TDR LONG TERM...TDR AVIATION...TDR
Hazardous weather outlook, Sep 6, 1:07 PM CDT, 3 hours 6 minutes before
Hazardous Weather Outlook National Weather Service Des Moines IA 107 PM CDT Sun Sep 6 2026 IAZ005>007-016-017-024>028-035>039-045>050-057>062-070>075- 081>086-092>097-071815- Kossuth-Winnebago-Worth-Hancock-Cerro Gordo-Humboldt-Wright- Franklin-Butler-Bremer-Webster-Hamilton-Hardin-Grundy-Black Hawk- 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- 107 PM CDT Sun Sep 6 2026 This Hazardous Weather Outlook is for portions of central Iowa. .DAY ONE...This afternoon and tonight Thunderstorms are possible through tonight, particularly in western Iowa. A strong storm with damaging wind, heavy rain, or large hail cannot be ruled out. .DAYS TWO THROUGH SEVEN...Monday through Saturday Thunderstorms are possible again Monday night to Tuesday night across a large part of the state. An isolated severe storm is possible. Heat returns Tuesday afternoon with heat indices near 100 degrees currently being forecast. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected. && NWS Des Moines will discontinue the Hazardous Weather Outlook product (HWO) on September 30th, 2026. Weather hazards and outlooks will continue to be provided through the standard forecast channels, including weather briefing packets, forecast discussions, weather story graphics, the experimental graphical hazardous weather outlook, and updated hazard messaging. All local products and visual tools are accessible directly at weather.gov/desmoines. IAZ004-015-023-033-034-044-071815- Emmet-Palo Alto-Pocahontas-Sac-Calhoun-Crawford- 107 PM CDT Sun Sep 6 2026 This Hazardous Weather Outlook is for portions of central Iowa. .DAY ONE...This afternoon and tonight A Flood Watch for Flash Flooding is in effect for the area. Please refer to the National Weather Service website at weather.gov/desmoines for further details. In addition to the heavy rain potential, a few strong storms with damaging winds are also possible. .DAYS TWO THROUGH SEVEN...Monday through Saturday Thunderstorms are possible again Monday night to Tuesday night across a large part of the state. An isolated severe storm is possible. Heat returns Tuesday afternoon with heat indices near 100 degrees currently being forecast. .SPOTTER INFORMATION STATEMENT... Spotter activation is possible and rainfall and severe weather reports are appreciated. && NWS Des Moines will discontinue the Hazardous Weather Outlook product (HWO) on September 30th, 2026. Weather hazards and outlooks will continue to be provided through the standard forecast channels, including weather briefing packets, forecast discussions, weather story graphics, the experimental graphical hazardous weather outlook, and updated hazard messaging. All local products and visual tools are accessible directly at weather.gov/desmoines.
In the hours before
Local storm report, Sep 6, 2:02 PM CDT, 2 hours 11 minutes before
Preliminary Local Storm Report
National Weather Service Des Moines IA
202 PM CDT Sun Sep 6 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0155 PM Flash Flood 1 NNE Graettinger 43.24N 94.75W
09/06/2026 Palo Alto IA Emergency Mngr
Significant ponding several feet deep with
bundles of wood floating at EPS Buildings
location on the north side of town. Water is
also over the road on North Van Gordon Ave.
&&
RDThe office that day
Everything else NWS Des Moines, IA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 6, 10:45 AM CDT | Severe Thunderstorm Warning | DMX | Emmet | 24 min |
| Sep 6, 12:02 PM CDT | Flash Flood Warning | DMX | Emmet, Palo Alto | 6 hr |
| Sep 6, 12:12 PM CDT | Flood Watch | DMX | Calhoun, Crawford, Emmet, Palo Alto, Pocahontas, Sac | 10 hr |
| Sep 6, 2:37 PM CDT | Severe Thunderstorm Warning | DMX | Sac | 38 min |
| Sep 6, 3:45 PM CDT | Severe Thunderstorm Warning | DMX | Adams, Union | 45 min |
| Sep 6, 3:47 PM CDT | Severe Thunderstorm Warning | DMX | Calhoun, Carroll, Crawford, Sac | 43 min |
| Sep 6, 4:19 PM CDT | Flash Flood Warning | DMX | Crawford | 3 hr |
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.