Alert archive / Iowa / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 71, NWS Des Moines, IA

July 14, 20214 counties in Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Jul 14, 2021, 8:43 AM CDT for 4 counties in Iowa. It was in force for 62 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, 8:43 AM CDT (13:43 UTC)
Expired
Jul 14, 2021, 9:45 AM CDT
In force
62 min
Issued by
NWS Des Moines, IA
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Cerro Gordo County, IA, Hancock County, IA, Winnebago County, IA, Worth County, IA

The radar

The Minneapolis radar (KMPX), 171 km from the middle of the area, began a volume at 13:46 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 171 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.

225 
WUUS53 KDMX 141343
SVRDMX
IAC033-081-189-195-141445-
/O.NEW.KDMX.SV.W.0071.210714T1343Z-210714T1445Z/

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

The National Weather Service in Des Moines  has issued a

* Severe Thunderstorm Warning for...
  Worth County in north central Iowa...
  Northeastern Hancock County in north central Iowa...
  Northern Cerro Gordo County in north central Iowa...
  Winnebago County in north central Iowa...

* Until 945 AM CDT.

* At 843 AM CDT, severe thunderstorms were located along a line
  extending from near Mansfield to near Clear Lake, moving northeast
  at 40 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

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

* Severe thunderstorms will be near...
  Emmons and Mason City Municipal Airport around 855 AM CDT.

Other locations in the path of these severe thunderstorms include
Mason City and Manly.

This includes Interstate 35 between mile markers 194 and 218.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4323 9302 4300 9374 4335 9397 4337 9397
      4350 9383 4350 9302
TIME...MOT...LOC 1343Z 232DEG 33KT 4353 9369 4312 9349 

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

Small
3 follow-up statements
208 
WWUS53 KDMX 141404
SVSDMX

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

IAC033-081-189-195-141445-
/O.CON.KDMX.SV.W.0071.000000T0000Z-210714T1445Z/
Worth IA-Hancock IA-Cerro Gordo IA-Winnebago IA-
904 AM CDT Wed Jul 14 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 945 AM CDT
FOR WORTH...NORTHEASTERN HANCOCK...NORTHERN CERRO GORDO AND EASTERN
WINNEBAGO COUNTIES...

At 904 AM CDT, severe thunderstorms were located along a line
extending from near Twin Lakes to near Mason City, moving northeast
at 40 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

These severe thunderstorms will remain over mainly rural areas of
Worth, northeastern Hancock, northern Cerro Gordo and eastern
Winnebago Counties, including the following locations... Joice, Pilot
Knob State Park, Lake Mills Municipal Airport, McIntosh Woods State
Park, Hogsback Wildlife Area, Plymouth, Scarville, Grafton, Fertile
and Hanlontown.

This includes Interstate 35 between mile markers 194 and 218.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4307 9352 4350 9369 4350 9302 4323 9302
TIME...MOT...LOC 1404Z 231DEG 33KT 4360 9346 4319 9326 

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

Small
772 
WWUS53 KDMX 141431
SVSDMX

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

IAC081-189-141440-
/O.CAN.KDMX.SV.W.0071.000000T0000Z-210714T1445Z/
Hancock IA-Winnebago IA-
931 AM CDT Wed Jul 14 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN HANCOCK AND
EASTERN WINNEBAGO 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
north central Iowa.

LAT...LON 4319 9316 4350 9321 4350 9302 4323 9302
TIME...MOT...LOC 1430Z 234DEG 32KT 4358 9313 4317 9293 

$$

IAC033-195-141445-
/O.CON.KDMX.SV.W.0071.000000T0000Z-210714T1445Z/
Worth IA-Cerro Gordo IA-
931 AM CDT Wed Jul 14 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 945 AM CDT
FOR EASTERN WORTH AND NORTHEASTERN CERRO GORDO COUNTIES...

At 930 AM CDT, severe thunderstorms were located along a line
extending from near London to near Rudd, moving northeast at 35 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

Locations impacted include...
Northwood, Plymouth, Grafton, Rock Falls, Carpenter, Bolan and
Northwood Municipal.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4319 9316 4350 9321 4350 9302 4323 9302
TIME...MOT...LOC 1430Z 234DEG 32KT 4358 9313 4317 9293 

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

Small
531 
WWUS53 KDMX 141441
SVSDMX

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

IAC033-195-141451-
/O.EXP.KDMX.SV.W.0071.000000T0000Z-210714T1445Z/
Worth IA-Cerro Gordo IA-
941 AM CDT Wed Jul 14 2021

...THE SEVERE THUNDERSTORM WARNING FOR EASTERN WORTH AND NORTHEASTERN
CERRO GORDO COUNTIES WILL EXPIRE AT 945 AM CDT...
    
The storms which prompted the warning have moved out of the area.
Therefore, the warning will be allowed to expire.

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

LAT...LON 4319 9316 4350 9321 4350 9302 4323 9302
TIME...MOT...LOC 1441Z 232DEG 33KT 4363 9305 4322 9285 

$$

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, 8:39 AM CDTSevere Thunderstorm WarningDMXButler, Cerro Gordo, Franklin, Grundy, Hancock, Hardin and 1 more66 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.