Widespread scattered thunderstorms remained in place across northern and central Iowa through much of the day as a surface low approached the area. An axis of 1000-1500 J/kg of MLCAPE developed from southern into central Iowa where clearing allowed for quick heating.
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Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS DMX wrote it up.
Widespread scattered thunderstorms remained in place across northern and central Iowa through much of the day as a surface low approached the area. An axis of 1000-1500 J/kg of MLCAPE developed from southern into central Iowa where clearing allowed for quick heating. Weak shear of 15-20 kts limited more organized thunderstorms development. Storms largely remained sub-severe, however collapsing cores in southern Iowa did result in severe winds gusting over 60 mph and resulting in isolated areas of wind damage.
The local office's own words before the first event, 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 the first event at Sep 17, 1:08 PM CST, 2 hours 2 minutes earlier. Its key messages:
Area Forecast Discussion National Weather Service Des Moines IA 208 PM CDT Wed Sep 17 2025 .KEY MESSAGES... - Scattered showers and storms this afternoon through tonight. A few stronger storms may produce hail or gusty winds. Pockets of heavy rain are possible but widespread flooding is not expected. - Scattered showers and storm chances continue for the next several days. It will not be a washout with rain the entire period, but scattered storms will be possible each day. && .DISCUSSION... Issued at 208 PM CDT Wed Sep 17 2025 Widespread scattered thunderstorms have persisted across the area with the surface low to the west slowly easing east. An axis of instability in the form of 1000-1500 J/kg of MLCAPE has developed from central to southern Iowa where clearing earlier in the day allowed for quick heating. Along this axis the thunderstorms are more robust with periodic stronger cores. Even so, shear is quite weak at 15-20 kts or less, limiting more robust and persistent storm development. As such the severe threat remains low today, however a few stronger cores may produce hail or gusty winds as those cores collapse. While a few stronger cores have had pixels of 60-65dbz, this has generally been shallow and short-lived today. These may have produced brief hail, however no reports have been received so far. A few of these stronger cores have produced gusty winds with isolated gusts of 30-40 mph observed so far. Aloft, the upper level cutoff low will remain across the area for the next several days (through Friday and into the weekend) with continued chances for scattered showers and thunderstorms. As we saw yesterday and have seen so far today, activity is more widespread than CAMs would have us believe and expect that this trend will continue until the low finally lifts out of the area early next week and the pattern changes. The environment remains the same through the end of the week and weekend, so pulsey storms producing hail or gusty winds will remain possible while widespread storms are less likely. With little flow, storm motions are fairly slow. These slow moving storms are efficient rain producers in an environment with deep warm cloud layers of 3500+ m and PWATs over 1.5". After several fairly dry weeks, flood concerns are low at this time. While convection remains scattered, pockets of heavy rain with some of the stronger cores may produce areas of ponding. Any potential for flash flooding would come from stronger cells setting up in town where drainage is slower. Another upper level cutoff low drops across the area early next week, pushing the current one out of the area. Differences remain with regards to timing and placement of this low, lending towards uncertainty in precipitation chances into early next week. && .AVIATION /18Z TAFS THROUGH 18Z THURSDAY/... Issued at 1231 PM CDT Wed Sep 17 2025 Scattered thunderstorms across Iowa today are the primary forecast challenge. These will persist into the evening and perhaps overnight. The widespread scattered nature of the storms has made timing a challenge so the most likely near term window has been highlighted in TAFs. Additional thunderstorms are likely, but confidence in placement and timing is too low to include at this time and will be added as need in future issuances. && .DMX WATCHES/WARNINGS/ADVISORIES... None. && DISCUSSION...Hagenhoff AVIATION...Hagenhoff
Hazardous Weather Outlook National Weather Service Des Moines IA 334 PM CDT Wed Sep 17 2025 IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075- 081>086-092>097-182045- 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- 334 PM CDT Wed Sep 17 2025 This Hazardous Weather Outlook is for portions of central Iowa. .DAY ONE...This afternoon and tonight Isolated to scattered thunderstorms are expected. A few stronger storms may produce gusty winds or hail, mainly this afternoon into evening. Locally heavy rainfall is also possible, but widespread flooding is not expected. .DAYS TWO THROUGH SEVEN...Thursday through Tuesday Thunderstorm chances remain in the forecast through the weekend. A few strong to marginally (level 1 out of 5) severe storms are possible again on Thursday as is locally heavy rainfall. .SPOTTER INFORMATION STATEMENT... Spotter activation is not anticipated but rainfall totals are appreciated.
Preliminary Local Storm Report
National Weather Service Des Moines IA
1033 AM CDT Wed Sep 17 2025
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0805 PM Flash Flood Fort Dodge 42.51N 94.18W
09/16/2025 Webster IA Emergency Mngr
Delayed report. EM reports several
intersections flooded in Ft Dodge with with
stalled vehicles and water up to the bottom
of doors. Flooding continued through 9pm
until gradually receding.
&&
FowlePreliminary Local Storm Report
National Weather Service Des Moines IA
1105 AM CDT Wed Sep 17 2025
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0537 AM Hail Hansell 42.76N 93.10W
09/16/2025 E1.00 Inch Franklin IA Public
Delayed report. Relayed via social media.
Time estimated from radar.
0500 AM Hail 6 E Voorhies 42.34N 92.36W
09/16/2025 E1.00 Inch Black Hawk IA Public
Delayed report relayed by social media. Time
estimated from radar.
0400 PM Hail 2 SE Waterloo 42.47N 92.33W
09/16/2025 E1.25 Inch Black Hawk IA Public
Delayed report via social media.
&&Preliminary Local Storm Report
National Weather Service Des Moines IA
139 PM CDT Wed Sep 17 2025
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0659 PM Tstm Wnd Dmg 1 E Fort Dodge 42.51N 94.17W
09/16/2025 Webster IA Public
Delayed report. Several small branches down.
bark stripped off trees just before 7p.
&&Special Weather Statement
National Weather Service Des Moines IA
401 PM CDT Wed Sep 17 2025
IAZ093-094-172130-
Ringgold IA-Decatur IA-
401 PM CDT Wed Sep 17 2025
...A STRONG THUNDERSTORM WILL IMPACT SOUTHWESTERN DECATUR AND
SOUTHEASTERN RINGGOLD COUNTIES THROUGH 430 PM CDT...
At 400 PM CDT, Doppler radar was tracking a strong thunderstorm 6
miles northwest of Eagleville, or 15 miles southeast of Mount Ayr,
moving northeast at 40 mph.
HAZARD...Wind gusts of 50 to 55 mph and nickel size hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor hail damage to vegetation is
possible.
Locations impacted include...
Leon, Lamoni, Kellerton, Grand River, Davis City, Decatur,
Beaconsfield, Lamoni Municipal Airport, and Nine Eagles State Park.
This includes Interstate 35 between mile markers 1 and 14.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
&&
LAT...LON 4086 9404 4069 9367 4058 9381 4057 9424
TIME...MOT...LOC 2100Z 214DEG 34KT 4052 9409
MAX HAIL SIZE...0.88 IN
MAX WIND GUST...55 MPH
05The Des Moines radar (KDMX), 125 km away, was scanning. The volume nearest the first event began at 21:07 UTC.
5 thunderstorm wind. Local standard time, as filed.
Delayed report. Several large trees down in central sections of Lamoni, followed shortly by a 71 mph gust at the Lamoni airport.
A 71 mph gust at the Lamoni airport.
Iowa DOT instrument reported a gust of 61 mph. Also received public reports of strong winds in Osceola.
Delayed report. A few trees and large branches downed on Hwy 152 north of Osceola.
A least 2 large trees downed in Milo. Time estimated by radar.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Iowa in 2025Every state in 2025This day in weather historyWarnings in Iowa, September 2025
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 1297893, 1297894, 1297895, 1297896, 1297897.