Alert archive / Iowa / Tornado Warnings in 2026

Tornado Warning 73, NWS Des Moines, IA

August 7, 2026Black Hawk County, Bremer County, Iowa

NWS Des Moines, IA issued this tornado warning at Aug 7, 2026, 3:53 PM CDT for Black Hawk County, Bremer County, Iowa. It was in force for 22 min. 2 reports 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
Aug 7, 2026, 3:53 PM CDT (20:53 UTC)
Expired
Aug 7, 2026, 4:15 PM CDT
In force
22 min
Issued by
NWS Des Moines, IA
Area
Storm-based polygon
Tornado
Observed
Hail
0.75 in

Counties Black Hawk County, IA, Bremer County, IA

The radar

The La Crosse radar (KARX), 151 km from the middle of the area, began a volume at 20:56 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
Aug 7, 3:58 PM CDTHAIL 1.255 Se Readlyn, IAReport from mPING: Half Dollar (1.25 in.).
Aug 7, 4:02 PM CDTHAIL 1.255 N Dunkerton, IAReport via mPING.

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

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this tornado warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Aug 7, 1:40 PM CDTSevere Thunderstorm WatchSPC8 hr

The nearest sounding before it

Minneapolis, MN (KMPX), launched 12:00Z, 8.9 hours before the alert went out and 266 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

The text

As transmitted.

587 
WFUS53 KDMX 072053
TORDMX
IAC013-017-072115-
/O.NEW.KDMX.TO.W.0073.260807T2053Z-260807T2115Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Des Moines IA
353 PM CDT Fri Aug 7 2026

The National Weather Service in Des Moines has issued a

* Tornado Warning for...
  Northeastern Black Hawk County in northeastern Iowa...
  Southeastern Bremer County in northeastern Iowa...

* Until 415 PM CDT.

* At 353 PM CDT, a confirmed tornado was located over Readlyn, or 13
  miles west of Oelwein, moving east at 40 mph.

  HAZARD...Damaging tornado.

  SOURCE...Weather spotters confirmed tornado.

  IMPACT...Flying debris will be dangerous to those caught without 
           shelter. Mobile homes will be damaged or destroyed. 
           Damage to roofs, windows, and vehicles will occur.  Tree 
           damage is likely.

* This tornadic thunderstorm will remain over mainly rural areas of
  northeastern Black Hawk and southeastern Bremer Counties, including
  the following locations... Readlyn.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

To repeat, a tornado is on the ground. TAKE COVER NOW! Move to a
basement or an interior room on the lowest floor of a sturdy
building. Avoid windows. If you are outdoors, in a mobile home, or in
a vehicle, move to the closest substantial shelter and protect
yourself from flying debris.

&&

LAT...LON 4265 9229 4277 9225 4275 9208 4259 9209
TIME...MOT...LOC 2053Z 288DEG 37KT 4271 9218 

TORNADO...OBSERVED
MAX HAIL SIZE...<.75 IN

$$

Hagenhoff

What forecasters said that day

The local office's own words before this tornado 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 tornado warning went out at Aug 7, 2:45 PM CDT, 1 hour 8 minutes earlier. Its key messages:

  • Scattered thunderstorms through early this evening. A few severe storms remain possible.
  • Mostly dry tonight into Saturday.
  • Additional thunderstorm chances late Saturday night into Sunday.
  • Active weather will persist through much of next week.
Area forecast discussion, Aug 7, 2:45 PM CDT, 1 hour 8 minutes before
Area Forecast Discussion
National Weather Service Des Moines IA
245 PM CDT Fri Aug 7 2026

.KEY MESSAGES...

- Scattered thunderstorms through early this evening. A few
  severe storms remain possible.

- Mostly dry tonight into Saturday.

- Additional thunderstorm chances late Saturday night into
  Sunday.

- Active weather will persist through much of next week.

&&

.SHORT TERM /THROUGH SATURDAY/...
Issued at 243 PM CDT Fri Aug 7 2026

Thunderstorms are ongoing over north central Iowa in advance of a
boundary that is moving in from the northwest. MLCAPE values of 2000-
3000 J/kg along with mid-level lapse rates at 8-8.5 C/km have led to
strong initial updrafts with 65 dBZ over 20 kft occurring. The
primary storm initialization is on a pre-frontal trough that has
extended into northern Iowa from west to east. Expect much of the
activity this afternoon to remain associated with the current storm
cluster with the potential for some additional development back
west/southwest along the pre-frontal trough. These storms will
maintain a damaging wind and large hail threat through the remainder
of the afternoon as the entire system settles south/southeast. These
storms should exit south into Missouri by early this evening.

The remainder of tonight into much of Saturday is expected to be
dry. Much drier dew points will settle into the state behind the
boundary with dew point values falling into the low 50s north to low
to mid 60s south. Deep layer drying will also be occurring which
will further support the dry forecast.

&&

.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
Issued at 243 PM CDT Fri Aug 7 2026

Return flow begins Saturday night as high pressure moves to the
east of the state. Strong theta- e advection and an increasing
low level jet of 40-45 kts will lead to increasing instability
and thunderstorm chances.

Upper high pressure over Hudson Bay combined with upper high
pressure over the Four Corners region, will lead to progressive
westerly flow over much of the northern CONUS with periodic embedded
short waves passing across Iowa. This flow will also keep a surface
boundary in the Midwest area and resulting in several chances for
thunderstorms before Canadian high pressure arrives early next week.
PWAT values of 1.50-2.00" will be common during active storm periods
that could lead to an aggregate heavy rain threat through the week.
Temperatures will be seasonal and mainly in the 80s through midweek
the gradual cooling as the Canadian high pressure approaches for the
end of next week.

&&

.AVIATION /18Z TAFS THROUGH 18Z SATURDAY/...
Issued at 1237 PM CDT Fri Aug 7 2026

Morning fog has transitioned to a dissipating MVFR stratus
layer. In addition, new MVFR cumulus has developed from this
residual moisture. Expect these cigs to continue to rise and
diminish this afternoon. A boundary will enter the state this
afternoon and will bring thunderstorms from north to south into
the early evening. MVFR or lower vsbys and cigs are possible in
vicinity of storms. Outflow winds are also possible with gusts
over 35 kt. Otherwise, the wind will be mostly 12 kts or less.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
None.

&&

SHORT TERM...Donavon
LONG TERM...Donavon
AVIATION...Donavon
Hazardous weather outlook, Aug 7, 12:50 PM CDT, 3 hours 3 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, 2 hours 31 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
Local storm report, Aug 7, 2:12 PM CDT, 1 hour 41 minutes before
Preliminary Local Storm Report
National Weather Service Des Moines IA
212 PM CDT Fri Aug 7 2026

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

0149 PM     Hail             2 WNW Thornton          42.95N 93.43W
08/07/2026  E1.00 Inch       Cerro Gordo        IA   Public

            Report from mPING. Time estimated via radar.

&&

TDR
Local storm report, Aug 7, 2:52 PM CDT, 1 hour 1 minute before
Preliminary Local Storm Report
National Weather Service Des Moines IA
252 PM CDT Fri Aug 7 2026

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

0142 PM     Hail             Manly                   43.29N 93.20W
08/07/2026  E1.50 Inch       Worth              IA   Public

            Time estimated via radar.

&&

TDR
Local storm report, Aug 7, 3:05 PM CDT, 48 minutes before
Preliminary Local Storm Report
National Weather Service Des Moines IA
305 PM CDT Fri Aug 7 2026

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

0254 PM     Hail             7 E Greene              42.89N 92.67W
08/07/2026  E1.25 Inch       Butler             IA   Public

            Report via mPING. Time estimated via radar.

&&

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, 1:25 PM CDTSevere Thunderstorm WarningDMXCerro Gordo, Hancock, Winnebago, Worth50 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, 4:16 PM CDTSevere Thunderstorm WarningDMXBlack Hawk, Grundy, Tama59 min

Nearby

Tornado Warnings in Iowa, 2026Every tornado warning in 2026Tornadoes 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.