Alert archive / Iowa / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 106, NWS Des Moines, IA
NWS Des Moines, IA issued this severe thunderstorm warning at Aug 27, 2021, 7:10 PM CDT for Cerro Gordo County, Worth County, Iowa. It was in force for 65 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 27, 2021, 7:10 PM CDT (00:10 UTC)
- Expired
- Aug 27, 2021, 8:15 PM CDT
- In force
- 65 min
- Issued by
- NWS Des Moines, IA
- Area
- Storm-based polygon
- Hail
- 1.0 in
- Wind
- 60.0 mph
Counties Cerro Gordo County, IA, Worth County, IA
The radar
The La Crosse radar (KARX), 170 km from the middle of the area, began a volume at 00:12 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 27, 8:12 PM CDT | TSTM WND DMG | 2 Ese Plymouth, IA | DELAYED REPORT. AREAL PHOTOGRAPHY SHOWS EXTENSIVE WIND DAMAGE TO CROPS ABOUT 2 MILES NORTH OF ROCK FALLS IOWA. TIME ESTIMATED VIA RADAR. |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
The watch it was issued in
The SPC watch in force over the same counties when this warning went out.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Aug 27, 5:15 PM CDT | Tornado Watch | SPC | 6 hr |
The nearest sounding before it
Minneapolis, MN (KMPX), launched 00:00Z, 0.2 hours before the alert went out and 174 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
- 652 J/kg
- Mixed-layer CIN
- -66 J/kg
- Mixed-layer LCL
- 643 m above ground
- 0-6 km bulk shear
- 45 kt
- 0-1 km storm-relative helicity
- 140 m²/s²
- 0-3 km storm-relative helicity
- 175 m²/s²
- Significant tornado parameter
- 0.5
- Supercell composite
- 3.5
The text
As transmitted.
140
WUUS53 KDMX 280010
SVRDMX
IAC033-195-280115-
/O.NEW.KDMX.SV.W.0106.210828T0010Z-210828T0115Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Des Moines IA
710 PM CDT Fri Aug 27 2021
The National Weather Service in Des Moines has issued a
* Severe Thunderstorm Warning for...
Eastern Worth County in north central Iowa...
Northern Cerro Gordo County in north central Iowa...
* Until 815 PM CDT.
* At 709 PM CDT, a severe thunderstorm was located over Clear Lake,
or 10 miles west of Mason City, moving northeast at 30 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.
* This severe thunderstorm will be near...
Mason City Municipal Airport around 715 PM CDT.
Other locations in the path of this severe thunderstorm include Mason
City and Manly.
This includes Interstate 35 between mile markers 193 and 208.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
A Tornado Watch remains in effect until 1100 PM CDT for north central
Iowa.
For your protection move to an interior room on the lowest floor of a
building.
A Tornado Watch remains in effect until 1100 PM CDT for north central
Iowa.
&&
LAT...LON 4337 9302 4318 9303 4308 9350 4323 9350
4350 9314 4350 9307
TIME...MOT...LOC 0009Z 242DEG 27KT 4316 9341
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
REV3 follow-up statements
756
WWUS53 KDMX 280034
SVSDMX
Severe Weather Statement
National Weather Service Des Moines IA
734 PM CDT Fri Aug 27 2021
IAC033-195-280115-
/O.CON.KDMX.SV.W.0106.000000T0000Z-210828T0115Z/
Worth IA-Cerro Gordo IA-
734 PM CDT Fri Aug 27 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 815 PM CDT
FOR EASTERN WORTH AND NORTHERN CERRO GORDO COUNTIES...
At 733 PM CDT, a severe thunderstorm was located near Manly, or near
Mason City, moving east at 30 mph.
HAZARD...60 mph wind gusts and quarter size hail.
SOURCE...Radar indicated.
IMPACT...Hail damage to vehicles is expected. Expect wind damage to
roofs, siding, and trees.
This severe thunderstorm will remain over mainly rural areas of
eastern Worth and northern Cerro Gordo Counties, including the
following locations... Kensett, Plymouth, Northwood Municipal, Rock
Falls, Grafton, Bolan, Fertile and Hanlontown.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
A Tornado Watch remains in effect until 1100 PM CDT for north central
Iowa.
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 4337 9302 4318 9303 4311 9334 4323 9350
4350 9314 4350 9307
TIME...MOT...LOC 0033Z 259DEG 26KT 4322 9317
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
REV283
WWUS53 KDMX 280050
SVSDMX
Severe Weather Statement
National Weather Service Des Moines IA
750 PM CDT Fri Aug 27 2021
IAC033-195-280115-
/O.CON.KDMX.SV.W.0106.000000T0000Z-210828T0115Z/
Worth IA-Cerro Gordo IA-
750 PM CDT Fri Aug 27 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 815 PM CDT
FOR EASTERN WORTH AND NORTHEASTERN CERRO GORDO COUNTIES...
At 749 PM CDT, a severe thunderstorm was located near Manly, or 9
miles northeast of Mason City, moving northeast at 25 mph.
HAZARD...60 mph wind gusts and nickel size hail.
SOURCE...Radar indicated.
IMPACT...Expect damage to roofs, siding, and trees.
Locations impacted include...
Mason City, Northwood, Manly, Plymouth, Kensett, Grafton, Rock Falls,
Bolan and Northwood Municipal.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
A Tornado Watch remains in effect until 1100 PM CDT for north central
Iowa.
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 4337 9302 4318 9303 4313 9331 4335 9334
4350 9314 4350 9307
TIME...MOT...LOC 0049Z 241DEG 23KT 4326 9308
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.88 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
REV532
WWUS53 KDMX 280106
SVSDMX
Severe Weather Statement
National Weather Service Des Moines IA
806 PM CDT Fri Aug 27 2021
IAC033-195-280115-
/O.CON.KDMX.SV.W.0106.000000T0000Z-210828T0115Z/
Worth IA-Cerro Gordo IA-
806 PM CDT Fri Aug 27 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 815 PM CDT
FOR EASTERN WORTH AND NORTHEASTERN CERRO GORDO COUNTIES...
At 805 PM CDT, a severe thunderstorm was located near Manly, or 11
miles northeast of Mason City, moving northeast at 30 mph.
HAZARD...60 mph wind gusts and quarter size hail.
SOURCE...Radar indicated.
IMPACT...Hail damage to vehicles is expected. Expect wind damage to
roofs, siding, and trees.
Locations impacted include...
Northwood, Manly, Plymouth, Kensett, Grafton, Rock Falls, Bolan and
Northwood Municipal.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
A Tornado Watch remains in effect until 1100 PM CDT for north central
Iowa.
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 4337 9302 4321 9303 4321 9332 4335 9334
4350 9314 4350 9307
TIME...MOT...LOC 0105Z 228DEG 25KT 4328 9306
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
REVThe office that day
Everything else NWS Des Moines, IA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 27, 8:15 PM CDT | Severe Thunderstorm Warning | DMX | Cerro Gordo, Worth | 30 min |
| Aug 27, 8:21 PM CDT | Flash Flood Warning | DMX | Cerro Gordo, Hancock, Winnebago, Worth | 6 hr |
| Aug 28, 10:17 AM CDT | River Flood Warning | DMX | Black Hawk, Bremer, Butler | 3 days |
| Aug 28, 10:17 AM CDT | River Flood Warning | DMX | Black Hawk | 4 days |
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.