Alert archive / Iowa / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 91, NWS Des Moines, IA
NWS Des Moines, IA issued this severe thunderstorm warning at Aug 24, 2021, 12:26 PM CDT for Cerro Gordo County, Hancock County, Iowa. It was in force for 49 min. 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
- Aug 24, 2021, 12:26 PM CDT (17:26 UTC)
- Expired
- Aug 24, 2021, 1:15 PM CDT
- In force
- 49 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
The radar
The Des Moines radar (KDMX), 149 km from the middle of the area, began a volume at 17:27 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 |
|---|---|---|---|
| Aug 24, 1:23 PM CDT | HAIL 0.7 | 2 N Mason City, IA | 1 MILE NORTH OF MASON CITY. |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
The nearest sounding before it
Minneapolis, MN (KMPX), launched 12:00Z, 5.4 hours before the alert went out and 202 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
- 1192 J/kg
- Mixed-layer CIN
- -180 J/kg
- Mixed-layer LCL
- 1234 m above ground
- 0-6 km bulk shear
- 51 kt
- 0-1 km storm-relative helicity
- 141 m²/s²
- 0-3 km storm-relative helicity
- 178 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 6.9
The text
As transmitted.
954
WUUS53 KDMX 241726
SVRDMX
IAC033-081-241815-
/O.NEW.KDMX.SV.W.0091.210824T1726Z-210824T1815Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Des Moines IA
1226 PM CDT Tue Aug 24 2021
The National Weather Service in Des Moines has issued a
* Severe Thunderstorm Warning for...
Eastern Hancock County in north central Iowa...
Cerro Gordo County in north central Iowa...
* Until 115 PM CDT.
* At 1226 PM CDT, a severe thunderstorm was located near Garner,
moving east at 60 mph.
HAZARD...60 mph wind gusts and quarter size hail.
SOURCE...Radar indicated.
IMPACT...Hail damage to vehicles is expected. Expect wind damage
to roofs, siding, and trees.
* Locations impacted include...
Rockwell.
This includes Interstate 35 between mile markers 180 and 200.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 4291 9303 4295 9388 4321 9377 4324 9303
TIME...MOT...LOC 1726Z 279DEG 51KT 4303 9367
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
Krull1 follow-up statement
675
WWUS53 KDMX 241756
SVSDMX
Severe Weather Statement
National Weather Service Des Moines IA
1256 PM CDT Tue Aug 24 2021
IAC033-081-241815-
/O.CON.KDMX.SV.W.0091.000000T0000Z-210824T1815Z/
Hancock IA-Cerro Gordo IA-
1256 PM CDT Tue Aug 24 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 115 PM CDT
FOR EASTERN HANCOCK AND CERRO GORDO COUNTIES...
At 1256 PM CDT, a severe thunderstorm was located near Rockwell, or
11 miles south of Mason City, moving east at 45 mph.
HAZARD...60 mph wind gusts and quarter size hail.
SOURCE...Radar indicated.
IMPACT...Hail damage to vehicles is expected. Expect wind damage to
roofs, siding, and trees.
Locations impacted include...
Mason City, Garner, Britt, Rockwell, Mason City Municipal Airport,
Clear Lake, Eagle Lake, Ventura, Klemme, Thornton, Swaledale, Rock
Falls, Duncan, Miller, Dougherty, Hayfield, Burchinal, Portland,
McIntosh Woods State Park and Clear Lake State Park.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 4291 9303 4295 9388 4321 9377 4324 9303
TIME...MOT...LOC 1756Z 278DEG 40KT 4299 9328
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
KrullThe office that day
Everything else NWS Des Moines, IA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 24, 11:06 AM CDT | Special Weather Statement | DMX | Emmet | 24 min |
| Aug 24, 11:30 AM CDT | Special Weather Statement | DMX | Kossuth, Winnebago | 45 min |
| Aug 24, 12:07 PM CDT | Special Weather Statement | DMX | Cerro Gordo, Hancock, Worth | 68 min |
| Aug 24, 12:51 PM CDT | Severe Thunderstorm Warning | DMX | Cerro Gordo, Franklin, Hancock, Wright | 54 min |
| Aug 24, 1:18 PM CDT | Severe Thunderstorm Warning | DMX | Butler | 57 min |
| Aug 24, 1:44 PM CDT | Severe Thunderstorm Warning | DMX | Butler | 31 min |
| Aug 24, 1:53 PM CDT | Severe Thunderstorm Warning | DMX | Black Hawk, Bremer | 67 min |
| Aug 24, 2:17 PM CDT | Special Weather Statement | DMX | Butler | 28 min |
| Aug 24, 3:00 PM CDT | Special Weather Statement | DMX | Black Hawk, Bremer | 30 min |
| Aug 24, 3:28 PM CDT | Severe Thunderstorm Warning | DMX | Hamilton, Hardin, Marshall, Story | 47 min |
| Aug 24, 4:03 PM CDT | Severe Thunderstorm Warning | DMX | Black Hawk, Grundy, Hardin, Marshall, Poweshiek, Tama | 57 min |
Nearby
Severe Thunderstorm Warnings in Iowa, 2021Every severe thunderstorm warning in 2021
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.