Alert archive / Iowa / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 70, NWS Des Moines, IA

July 14, 20217 counties in Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Jul 14, 2021, 8:39 AM CDT for 7 counties in Iowa. It was in force for 66 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Jul 14, 2021, 8:39 AM CDT (13:39 UTC)
Expired
Jul 14, 2021, 9:45 AM CDT
In force
66 min
Issued by
NWS Des Moines, IA
Area
Storm-based polygon
Hail
0.88 in
Wind
60.0 mph

Counties Butler County, IA, Cerro Gordo County, IA, Franklin County, IA, Grundy County, IA, Hancock County, IA, Hardin County, IA, Wright County, IA

The radar

The Des Moines radar (KDMX), 135 km from the middle of the area, began a volume at 13:41 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.

The nearest sounding before it

Minneapolis, MN (KMPX), launched 12:00Z, 1.7 hours before the alert went out and 226 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 2021-07-14Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2820 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Minneapolis, MN at 12:00Z on 2021-07-14The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -8 square meters per square second.1939587897117Sfc1 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
2820 J/kg
Mixed-layer CIN
-46 J/kg
Mixed-layer LCL
1084 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
-8 m²/s²
0-3 km storm-relative helicity
69 m²/s²
Significant tornado parameter
0.0
Supercell composite
2.3

Open this sounding in Storm Lab

The text

As transmitted.

278 
WUUS53 KDMX 141339
SVRDMX
IAC023-033-069-075-081-083-197-141445-
/O.NEW.KDMX.SV.W.0070.210714T1339Z-210714T1445Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Des Moines IA
839 AM CDT Wed Jul 14 2021

The National Weather Service in Des Moines  has issued a

* Severe Thunderstorm Warning for...
  Northern Hardin County in central Iowa...
  Northeastern Wright County in north central Iowa...
  Franklin County in north central Iowa...
  Southeastern Hancock County in north central Iowa...
  Northwestern Grundy County in central Iowa...
  Butler County in north central Iowa...
  Cerro Gordo County in north central Iowa...

* Until 945 AM CDT.

* At 838 AM CDT, severe thunderstorms were located along a line
  extending from 9 miles south of Clear Lake to near Iowa Falls,
  moving east 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...
  Ackley, Rockwell, Aplington and Parkersburg.

This includes Interstate 35 between mile markers 154 and 194.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4291 9303 4291 9278 4255 9255 4240 9342
      4302 9376 4325 9303
TIME...MOT...LOC 1338Z 257DEG 24KT 4299 9342 4250 9322 

HAIL...0.88IN
WIND...60MPH
 
$$

Small
3 follow-up statements
860 
WWUS53 KDMX 141406
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
906 AM CDT Wed Jul 14 2021

IAC081-197-141415-
/O.CAN.KDMX.SV.W.0070.000000T0000Z-210714T1445Z/
Wright IA-Hancock IA-
906 AM CDT Wed Jul 14 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN WRIGHT AND
SOUTHEASTERN HANCOCK COUNTIES IS CANCELLED...

The storms which prompted the warning have moved out of the warned 
area.  Therefore, the warning has been cancelled.

A Severe Thunderstorm Watch remains in effect until 300 PM CDT for
central, north central and northeastern Iowa.

LAT...LON 4291 9303 4291 9278 4255 9255 4244 9321
      4308 9345 4325 9303
TIME...MOT...LOC 1405Z 256DEG 25KT 4303 9309 4254 9290 

$$

IAC023-033-069-075-083-141445-
/O.CON.KDMX.SV.W.0070.000000T0000Z-210714T1445Z/
Hardin IA-Franklin IA-Grundy IA-Butler IA-Cerro Gordo IA-
906 AM CDT Wed Jul 14 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 945 AM CDT
FOR NORTHEASTERN HARDIN...FRANKLIN...NORTHWESTERN GRUNDY...BUTLER AND
CERRO GORDO COUNTIES...

At 905 AM CDT, severe thunderstorms were located along a line
extending from near Rockwell to near Aplington, moving east at 30
mph.

HAZARD...60 mph wind gusts and nickel size hail.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

Locations impacted include...
  Aplington and Parkersburg.

This includes Interstate 35 between mile markers 172 and 193.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4291 9303 4291 9278 4255 9255 4244 9321
      4308 9345 4325 9303
TIME...MOT...LOC 1405Z 256DEG 25KT 4303 9309 4254 9290 

HAIL...0.88IN
WIND...60MPH
 
$$

Small
227 
WWUS53 KDMX 141429
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
929 AM CDT Wed Jul 14 2021

IAC069-083-141439-
/O.CAN.KDMX.SV.W.0070.000000T0000Z-210714T1445Z/
Hardin IA-Franklin IA-
929 AM CDT Wed Jul 14 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN HARDIN AND
FRANKLIN COUNTIES IS CANCELLED...

The storms which prompted the warning have moved out of the warned 
area. Therefore, the warning has been cancelled.

A Severe Thunderstorm Watch remains in effect until 300 PM CDT for
central, north central and northeastern Iowa.

LAT...LON 4325 9303 4291 9303 4291 9278 4255 9255
      4249 9291 4280 9303 4290 9303 4291 9307
      4315 9316
TIME...MOT...LOC 1429Z 256DEG 24KT 4305 9286 4256 9267 

$$

IAC023-033-075-141445-
/O.CON.KDMX.SV.W.0070.000000T0000Z-210714T1445Z/
Grundy IA-Butler IA-Cerro Gordo IA-
929 AM CDT Wed Jul 14 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 945 AM CDT
FOR NORTH CENTRAL GRUNDY...BUTLER AND SOUTHEASTERN CERRO GORDO
COUNTIES...

At 929 AM CDT, severe thunderstorms were located along a line
extending from near Rockford to near Parkersburg, moving east at 30
mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

Locations impacted include...
Mason City, Allison, Parkersburg, Greene, Aplington, Dumont, New
Hartford, Stout, Bristow, Rock Falls, Aredale, Dougherty, Portland
and Allison Municipal Airport.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4325 9303 4291 9303 4291 9278 4255 9255
      4249 9291 4280 9303 4290 9303 4291 9307
      4315 9316
TIME...MOT...LOC 1429Z 256DEG 24KT 4305 9286 4256 9267 

HAIL...<.75IN
WIND...60MPH
 
$$

Small
418 
WWUS53 KDMX 141442
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
942 AM CDT Wed Jul 14 2021

IAC023-033-075-141452-
/O.EXP.KDMX.SV.W.0070.000000T0000Z-210714T1445Z/
Grundy IA-Butler IA-Cerro Gordo IA-
942 AM CDT Wed Jul 14 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTH CENTRAL GRUNDY...BUTLER
AND SOUTHEASTERN CERRO GORDO COUNTIES WILL EXPIRE AT 945 AM CDT...
    
The storms which prompted the warning have weakened below severe 
limits, or have exited the warned area. Therefore, the warning will 
be allowed to expire.  However gusty winds are still possible with 
these thunderstorms.

A Severe Thunderstorm Watch remains in effect until 300 PM CDT for
central, north central and northeastern Iowa.

LAT...LON 4325 9303 4291 9303 4291 9278 4255 9255
      4249 9291 4280 9303 4290 9303 4291 9307
      4315 9316
TIME...MOT...LOC 1442Z 257DEG 24KT 4306 9278 4257 9259 

$$

Small

The office that day

Everything else NWS Des Moines, IA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 14, 7:17 AM CDTSpecial Weather StatementDMXEmmet, Humboldt, Kossuth, Palo Alto, Pocahontas58 min
Jul 14, 8:08 AM CDTSevere Thunderstorm WarningDMXKossuth, Winnebago52 min
Jul 14, 8:24 AM CDTSpecial Weather StatementDMXButler, Cerro Gordo, Franklin, Hancock, Winnebago, Worth66 min
Jul 14, 8:43 AM CDTSevere Thunderstorm WarningDMXCerro Gordo, Hancock, Winnebago, Worth62 min
Jul 14, 8:49 AM CDTSevere Thunderstorm WarningDMXGrundy, Hardin, Marshall, Story, Tama56 min
Jul 14, 9:40 AM CDTSpecial Weather StatementDMXBlack Hawk, Bremer, Tama65 min
Jul 14, 3:55 PM CDTTornado WarningDMXCalhoun, Carroll, Greene35 min
Jul 14, 4:04 PM CDTTornado WarningDMXBoone, Hamilton, Story, Webster41 min
Jul 14, 4:23 PM CDTTornado WarningDMXFranklin, Hamilton, Hardin, Wright37 min
Jul 14, 4:29 PM CDTTornado Warning Tornado observedDMXCalhoun, Greene, Webster31 min
Jul 14, 4:29 PM CDTTornado Warning Tornado observedDMXHamilton, Hardin31 min
Jul 14, 4:30 PM CDTTornado WarningDMXButler30 min
Jul 14, 4:35 PM CDTTornado WarningDMXFranklin, Hardin40 min
Jul 14, 4:53 PM CDTTornado WarningDMXBremer, Butler37 min
Jul 14, 4:56 PM CDTTornado Warning Tornado observedDMXHamilton, Hardin25 min
Jul 14, 5:00 PM CDTTornado WarningDMXHamilton, Hardin, Story25 min
Jul 14, 5:18 PM CDTSevere Thunderstorm WarningDMXBlack Hawk, Bremer, Butler42 min
Jul 14, 5:18 PM CDTSevere Thunderstorm WarningDMXGrundy, Hardin42 min
Jul 14, 5:23 PM CDTTornado Warning Tornado observedDMXBlack Hawk, Bremer, Butler37 min
Jul 14, 5:49 PM CDTSevere Thunderstorm WarningDMXBlack Hawk, Bremer, Butler, Grundy41 min
Jul 14, 5:50 PM CDTTornado WarningDMXCerro Gordo25 min
Jul 14, 5:53 PM CDTTornado Warning Tornado observedDMXBlack Hawk, Bremer37 min
Jul 14, 5:58 PM CDTTornado WarningDMXCalhoun47 min
Jul 14, 6:02 PM CDTTornado WarningDMXBlack Hawk, Grundy, Marshall, Tama43 min
Jul 14, 6:42 PM CDTSevere Thunderstorm WarningDMXTama48 min
Jul 14, 6:42 PM CDTTornado WarningDMXWebster36 min
Jul 14, 6:55 PM CDTTornado WarningDMXTama19 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.