Alert archive / Iowa / Flash Flood Warnings in 2026
Flash Flood Warning 19, NWS Des Moines, IA
NWS Des Moines, IA issued this flash flood warning at Jul 8, 2026, 7:29 PM CDT for Cerro Gordo County, Worth County, Iowa. It was in force for 6 hr. 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
- Jul 8, 2026, 7:29 PM CDT (00:29 UTC)
- Expired
- Jul 9, 2026, 1:30 AM CDT
- In force
- 6 hr
- Issued by
- NWS Des Moines, IA
- Area
- Storm-based polygon
- Flood severity
- None
Counties Cerro Gordo County, IA, Worth County, IA
The radar
The Des Moines radar (KDMX), 166 km from the middle of the area, began a volume at 00:30 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
| Time | Report | Where | Remark |
|---|---|---|---|
| Jul 8, 7:40 PM CDT | FLASH FLOOD | Mason City, IA | Local EM reports several streets flooded and stranded motorists. |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
Did it verify
Verified. The Iowa Environmental Mesonet's Cow matched one storm report to this flash flood warning; the first came 11 minutes after it went out.
Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.
The nearest sounding before it
Minneapolis, MN (KMPX), launched 00:00Z, 0.5 hours before the alert went out and 185 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
- 314 J/kg
- Mixed-layer CIN
- -35 J/kg
- Mixed-layer LCL
- 896 m above ground
- 0-6 km bulk shear
- 31 kt
- 0-1 km storm-relative helicity
- -42 m²/s²
- 0-3 km storm-relative helicity
- 40 m²/s²
- Significant tornado parameter
- -0.0
- Supercell composite
- -0.7
The text
As transmitted.
983
WGUS53 KDMX 090029
FFWDMX
IAC033-195-090630-
/O.NEW.KDMX.FF.W.0019.260709T0029Z-260709T0630Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Des Moines IA
729 PM CDT Wed Jul 8 2026
The National Weather Service in Des Moines has issued a
* Flash Flood Warning for...
Cerro Gordo County in north central Iowa...
Southern Worth County in north central Iowa...
* Until 130 AM CDT Thursday.
* At 729 PM CDT, Doppler radar indicated thunderstorms producing
heavy rain across the warned area. Between 1 and 4 inches of rain
have fallen. The expected rainfall rate is 2 to 4 inches per hour.
Additional rainfall amounts of 1 to 2 inches are possible in the
warned area. Flash flooding is ongoing or expected to begin
shortly.
HAZARD...Flash flooding caused by thunderstorms.
SOURCE...Radar.
IMPACT...Flash flooding of small creeks and streams, urban
areas, highways, streets and underpasses as well as
other poor drainage and low-lying areas.
* Some locations that will experience flash flooding include...
Mason City, Nora Springs, Manly, Rockwell, Mason City Municipal
Airport, Clear Lake, Ventura, Plymouth, Fertile, Kensett, Grafton,
Hanlontown, Swaledale, Rock Falls, Burchinal, Portland, Bolan,
Clear Lake State Park and McIntosh Woods State Park.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For the latest stream observations and forecasts refer to
weather.gov/desmoines/water.
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
&&
LAT...LON 4322 9349 4334 9349 4345 9302 4297 9302
4298 9349
FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL RATE...2-4 INCHES IN 1 HOUR
$$
Donavon2 follow-up statements
202
WGUS73 KDMX 090238
FFSDMX
Flash Flood Statement
National Weather Service Des Moines IA
938 PM CDT Wed Jul 8 2026
IAC033-195-090630-
/O.CON.KDMX.FF.W.0019.000000T0000Z-260709T0630Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Cerro Gordo IA-Worth IA-
938 PM CDT Wed Jul 8 2026
...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 130 AM CDT THURSDAY
FOR CERRO GORDO AND SOUTHERN WORTH COUNTIES...
At 938 PM CDT, Emergency management reported heavy rainfall and
significant street flooding from previous thunderstorms across the
warned area. Between 2 and 5 inches of rain have fallen. Flash
flooding is ongoing or expected to begin shortly.
HAZARD...Flash flooding caused by thunderstorms.
SOURCE...Emergency management reported.
IMPACT...Flash flooding of small creeks and streams, urban areas,
highways, streets and underpasses as well as other poor
drainage and low-lying areas.
Some locations that will experience flash flooding include...
Mason City, Nora Springs, Manly, Rockwell, Mason City Municipal
Airport, Clear Lake, Ventura, Plymouth, Fertile, Kensett, Grafton,
Hanlontown, Swaledale, Rock Falls, Burchinal, Portland, Bolan,
Clear Lake State Park and McIntosh Woods State Park.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For the latest stream observations and forecasts refer to
weather.gov/desmoines/water.
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
&&
LAT...LON 4322 9349 4334 9349 4345 9302 4297 9302
4298 9349
FLASH FLOOD...OBSERVED
$$
Donavon102
WGUS73 KDMX 090625
FFSDMX
Flash Flood Statement
National Weather Service Des Moines IA
125 AM CDT Thu Jul 9 2026
IAC033-195-090635-
/O.EXP.KDMX.FF.W.0019.000000T0000Z-260709T0630Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Cerro Gordo IA-Worth IA-
125 AM CDT Thu Jul 9 2026
...FLASH FLOOD WARNING WILL EXPIRE AT 130 AM CDT EARLY THIS MORNING
FOR CERRO GORDO AND SOUTHERN WORTH COUNTIES...
Flooding is no longer expected to pose a threat. Please continue to
heed remaining road closures.
A Flood Watch remains in effect until 1000 AM CDT Thursday for
portions of central, north central, and northeast Iowa.
&&
LAT...LON 4322 9349 4334 9349 4345 9302 4297 9302
4298 9349
$$
BuryWhat forecasters said that day
The local office's own words before this flash flood 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 flash flood warning went out at Jul 8, 6:48 PM CDT, 41 minutes earlier. Its key messages:
- Severe thunderstorms are possible this evening and tonight, with damaging wind gusts as the primary hazard.
- Heavy rainfall is possible with storms tonight, with a slight uptrend in precip totals.
- High pressure is expected to set up over the central U.S. this weekend into next week, bringing much warmer temperatures.
Area forecast discussion, Jul 8, 6:48 PM CDT, 41 minutes before
Area Forecast Discussion National Weather Service Des Moines IA 648 PM CDT Wed Jul 8 2026 ...Updated for the 00z Aviation Discussion... .KEY MESSAGES... - Severe thunderstorms are possible this evening and tonight, with damaging wind gusts as the primary hazard. - Heavy rainfall is possible with storms tonight, with a slight uptrend in precip totals. - High pressure is expected to set up over the central U.S. this weekend into next week, bringing much warmer temperatures. && .SHORT TERM /THROUGH THURSDAY NIGHT/... Issued at 249 PM CDT Wed Jul 8 2026 Currently, showers and thunderstorms are ongoing across southern Minnesota along a boundary which is expected to push south/southeast through the afternoon and evening. This forecast gets tricky because there are two areas where convection is expected. The first is along the aforementioned boundary across southern MN, and the other is along an area of deep moisture convergence across western Iowa/eastern Nebraska. Other than potential forcing mechanisms, the environment is more or less the same for each area. Shear is somewhat lacking for widespread severe weather, with 0-6km values between 25kts on the low end and 45kts on the high end depending on the model. The most favorable areas for shear are across far northern Iowa and southern Minnesota, with another somewhat favorable area in western Iowa. The primary hazards with storms today are damaging wind gusts and heavy rain. As for the damaging winds, soundings have the inverted-V shape to them with T/Td spreads at the surface of nearly 20 degrees. D-CAPE values are between 1000 and 1500 J/kg across much of Iowa and guidance shows wind gusts of between 60 and 70mph through the evening. Some potential uncertainty exists with how long storms would remain severe. Weaker shear values may lead to cold pools outrunning storm clusters which leads to a shorter and less widespread severe window. Should this be the case, after thunderstorms mature redevelopment could occur between the outflow boundary and the main cluster. New updrafts in this in between zone would lower the severe wind threat later this evening. As for heavy rain, PWAT values still remain in the neighborhood of 2". Storms are expected to be somewhat slow-moving today, between 25 and 30mph. Rainfall totals have been trending upward slightly. REFS and HREF values for the 90th percentile are still between 2 and 3 inches in areas of western and northern Iowa. Both are also hinting at a signal for isolated instances of 3-4" or more of rainfall. Mean values from the HREF and REFS are between 1 and 2 inches. Of note, the axis of heaviest rainfall is still being progged away from areas that received heavy rainfall this past weekend. With regards to the hail and tornado threat for tonight, both are low and very conditional. Hail is a balancing act between high CAPE values (2000-3000 J/kg) and decent lapse rates (7+ C/km) will be fighting a very high melting level and weak shear. The tornado threat is much more conditional and will be very short lived. Overall SRH values are very low across much of the area, and a brief spin-up along the boundary with storm initiation is possible, in addition to a few funnel clouds due to enhanced stretching, although both cases have a low chance of happening. Overnight, as the cluster to the west grows it is expected to dive south and ride the CAPE gradient. For the most part, this cluster will be limited in its northern and eastern extent through the evening. Some guidance suggests that after sunset, instability is lost and storms across central Iowa aren't able to sustain themselves, limiting the spatial coverage to west-central and southwestern Iowa. The Low Level Jet is expected to kick in sometime around midnight, although it doesn't look like it will have a large impact on any activity this far north. If the LLJ can nose further into Iowa, this would help increase storm coverage into central and south-central Iowa as the cluster moves to the southeast. Tomorrow will be warm, humid, and largely dry through the day. Highs around the state will range from the mid 80s to potentially the low 90s. Compared to previous forecasts, the LLJ is progged to kick in farther south across Missouri. With the LLJ coming in farther south, some showers and thunderstorms may graze far southern Iowa tomorrow night as opposed to being more widespread across southern Iowa. && .LONG TERM /FRIDAY THROUGH TUESDAY/... Issued at 249 PM CDT Wed Jul 8 2026 Another 500mb shortwave is progged to pass over Iowa Friday before a high sets up this weekend pancakes much of the central U.S. Monday. Once the high sets up, an increase in temperatures is expected with highs making a run for the 90s through the early part of the week. && .AVIATION /00Z TAFS THROUGH 00Z FRIDAY/... Issued at 643 PM CDT Wed Jul 8 2026 Scattered thunderstorms moving across Iowa are the primary aviation highlight this period. Thunderstorms will move from north to south with some redevelopment occurring behind the current activity. Covered storm chances at all sites though KOTM will be later and diminished. MVFR cigs and vsbys are expected with any thunderstorms. MVFR cigs may linger behind the activity, especially over northern Iowa followed by scattering Thursday afternoon. Outflow wind gusts from variable directions is also possible. Otherwise wind will become light overnight then southwesterly on Thursday. && .HYDROLOGY... Issued at 251 PM CDT Wed Jul 8 2026 Area rivers and streams that peaked earlier this week after the heavy rain late last week into the weekend continue to recede but many in the Cedar and Des Moines basins remain elevated, some close to action stage. 3 hour flash flood guidance in much of northern to central Iowa is only 2-2.5" with much higher amounts in western and southern Iowa. This is largely due to the footprint of where the heavy rain has occurred most recently. Similarly, NASA SPoRT 10 cm soil moisture remains elevated near the Hwy 20-Hwy 30 corridors. Some inconsistencies remain in models on how widespread storms will be through portions of central Iowa with greater confidence in the far north/northeast and in the west/southwest. Despite this, it may not take much rain to renew flooding in locations that have recently experienced flooding so issued a Flood Watch for those areas, and in locations in northeast Iowa where model QPF is highest with HREF PMM data suggesting 2-3", localized 4". These QPF totals are also seen in portions of western Iowa, but as previously noted, flash flood guidance is much higher in these areas. In terms of the environment, Pwats top out around 2" near and along the boundary as it moves southward through the night. These are combined with more than sufficient warm cloud depths. Storm motions aren't overly slow, but repeated rounds of rain may still occur as additional storms form on the outflow from initial storms. && .DMX WATCHES/WARNINGS/ADVISORIES... Flood Watch through Thursday morning for IAZ006-007-016-017- 025>028-036>039-047>050-059>061. && SHORT TERM...67 LONG TERM...67 AVIATION...Donavon HYDROLOGY...05
Hazardous weather outlook, Jul 8, 3:32 PM CDT, 3 hours 57 minutes before
Hazardous Weather Outlook National Weather Service Des Moines IA 332 PM CDT Wed Jul 8 2026 IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075- 081>086-092>097-092045- 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- 332 PM CDT Wed Jul 8 2026 This Hazardous Weather Outlook is for portions of central Iowa. .DAY ONE...This afternoon and tonight A Flood Watch is in effect for portions of central and northern Iowa. Please refer to the National Weather Service website at weather.gov/desmoines for further details. Scattered severe thunderstorms are possible across a large portion of Iowa through this afternoon, evening, and overnight. Main threats are damaging wind and flash flooding, though large hail and a tornado cannot be ruled out. .DAYS TWO THROUGH SEVEN...Thursday through Tuesday Additional thunderstorms are also possible late week, with the severe potential better determined in the coming days. .SPOTTER INFORMATION STATEMENT... Spotter activation is possible tonight.
In the hours before
Local storm report, Jul 8, 6:42 PM CDT, 47 minutes before
Preliminary Local Storm Report
National Weather Service Des Moines IA
642 PM CDT Wed Jul 8 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0633 PM Tstm Wnd Gst 5 SW Rockwell City 42.35N 94.69W
07/08/2026 M52 MPH Calhoun IA Public
PWS gust.
&&
MDLocal storm report, Jul 8, 7:14 PM CDT, 15 minutes before
Preliminary Local Storm Report
National Weather Service Des Moines IA
714 PM CDT Wed Jul 8 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0643 PM Tstm Wnd Dmg Rockwell City 42.40N 94.63W
07/08/2026 Calhoun IA Trained Spotter
5 inch tree limbs down.
&&
MDLocal storm report, Jul 8, 7:26 PM CDT, 3 minutes before
Preliminary Local Storm Report
National Weather Service Des Moines IA
726 PM CDT Wed Jul 8 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0647 PM Tstm Wnd Dmg Lohrville 42.27N 94.55W
07/08/2026 Calhoun IA Trained Spotter
Parts of Lohrville is without power. Tree
branches reported down.
&&
MDThe office that day
Everything else NWS Des Moines, IA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 8, 9:03 PM CDT | River Flood Watch | DMX | Black Hawk, Bremer | 3 days |
| Jul 8, 9:03 PM CDT | River Flood Watch | DMX | Black Hawk | 43 hr |
| Jul 8, 9:03 PM CDT | River Flood Watch | DMX | Black Hawk | 47 hr |
| Jul 8, 9:53 PM CDT | Severe Thunderstorm Warning | DMX | Audubon, Cass | 37 min |
| Jul 9, 7:39 AM CDT | River Flood Watch | DMX | Black Hawk, Bremer, Butler | 21 days |
Nearby
Flash Flood Warnings in Iowa, 2026Every flash flood 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.