Alert archive / Iowa / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 92, NWS Des Moines, IA

August 24, 20214 counties in Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Aug 24, 2021, 12:51 PM CDT for 4 counties in Iowa. It was in force for 54 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 24, 2021, 12:51 PM CDT (17:51 UTC)
Expired: Aug 24, 2021, 1:45 PM CDT
In force: 54 min
Issued by: NWS Des Moines, IA
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Cerro Gordo County, IA, Franklin County, IA, Hancock County, IA, Wright County, IA

The radar

The Des Moines radar (KDMX), 133 km from the middle of the area, began a volume at 17:53 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, 1:17 PM CDT	HAIL 0.25	1 Wnw Sheffield, IA
Aug 24, 1:21 PM CDT	TSTM WND GST 64	2 Sw Hampton, IA

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, 5.9 hours before the alert went out and 221 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 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

Open this sounding in Storm Lab

The text

As transmitted.

293 
WUUS53 KDMX 241751
SVRDMX
IAC033-069-081-197-241845-
/O.NEW.KDMX.SV.W.0092.210824T1751Z-210824T1845Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Des Moines IA
1251 PM CDT Tue Aug 24 2021

The National Weather Service in Des Moines  has issued a

* Severe Thunderstorm Warning for...
  Northeastern Wright County in north central Iowa...
  Northern Franklin County in north central Iowa...
  Southeastern Hancock County in north central Iowa...
  Southern Cerro Gordo County in north central Iowa...

* Until 145 PM CDT.

* At 1251 PM CDT, a severe thunderstorm was located 7 miles northeast
  of Belmond, or 15 miles southeast of Garner, moving east at 35 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...
  Sheffield and Rockwell.

This includes Interstate 35 between mile markers 167 and 183.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4297 9302 4284 9302 4266 9303 4281 9370
      4301 9364
TIME...MOT...LOC 1751Z 276DEG 30KT 4290 9347 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Krull

2 follow-up statements

726 
WWUS53 KDMX 241814
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
114 PM CDT Tue Aug 24 2021

IAC081-241823-
/O.CAN.KDMX.SV.W.0092.000000T0000Z-210824T1845Z/
Hancock IA-
114 PM CDT Tue Aug 24 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN HANCOCK COUNTY IS
CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

LAT...LON 4297 9302 4284 9302 4266 9303 4277 9351
      4300 9343
TIME...MOT...LOC 1813Z 289DEG 36KT 4280 9323 

$$

IAC033-069-197-241845-
/O.CON.KDMX.SV.W.0092.000000T0000Z-210824T1845Z/
Wright IA-Franklin IA-Cerro Gordo IA-
114 PM CDT Tue Aug 24 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 145 PM CDT
FOR NORTHEASTERN WRIGHT...NORTHERN FRANKLIN AND SOUTHERN CERRO GORDO
COUNTIES...

At 113 PM CDT, a severe thunderstorm was located near Hampton, moving
east at 40 mph.

HAZARD...Golf ball size hail and 60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...People and animals outdoors will be injured. Expect hail 
         damage to roofs, siding, windows, and vehicles. Expect wind 
         damage to roofs, siding, and trees.

Locations impacted include...
Hampton, Sheffield, Rockwell, Latimer, Thornton, Coulter, Meservey,
Alexander, Swaledale, Hansell, Chapin, Dougherty, Beeds Lake State
Park and Hampton Municipal Airport.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4297 9302 4284 9302 4266 9303 4277 9351
      4300 9343
TIME...MOT...LOC 1813Z 289DEG 36KT 4280 9323 

THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Krull

177 
WWUS53 KDMX 241823
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
123 PM CDT Tue Aug 24 2021

IAC033-069-197-241845-
/O.CON.KDMX.SV.W.0092.000000T0000Z-210824T1845Z/
Wright IA-Franklin IA-Cerro Gordo IA-
123 PM CDT Tue Aug 24 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 145 PM CDT
FOR NORTHEASTERN WRIGHT...NORTHERN FRANKLIN AND SOUTHERN CERRO GORDO
COUNTIES...

At 122 PM CDT, a severe thunderstorm was located near Hampton, moving
east at 35 mph.

HAZARD...Golf ball size hail and 60 mph wind gusts.

SOURCE...Hampton AWOS reported a 64 MPH wind gust.

IMPACT...People and animals outdoors will be injured. Expect hail 
         damage to roofs, siding, windows, and vehicles. Expect wind 
         damage to roofs, siding, and trees.

Locations impacted include...
Hampton, Sheffield, Rockwell, Latimer, Thornton, Coulter, Meservey,
Alexander, Swaledale, Hansell, Chapin, Dougherty, Beeds Lake State
Park and Hampton Municipal Airport.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4297 9302 4284 9302 4266 9303 4277 9351
      4300 9343
TIME...MOT...LOC 1822Z 276DEG 30KT 4279 9312 

THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.75 IN
WIND THREAT...OBSERVED
MAX WIND GUST...60 MPH

$$

Krull

The 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, 12:26 PM CDT	Severe Thunderstorm Warning	DMX	Cerro Gordo, Hancock	49 min
Aug 24, 1:18 PM CDT	Severe Thunderstorm Warning Considerable damage threat	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, 2021 Every 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.