Alert archive / Iowa / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 109, NWS Des Moines, IA

August 30, 2021Carroll County, Crawford County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Aug 30, 2021, 10:50 PM CDT for Carroll County, Crawford County, Iowa. It was in force for 55 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
Aug 30, 2021, 10:50 PM CDT (03:50 UTC)
Expired
Aug 30, 2021, 11:45 PM CDT
In force
55 min
Issued by
NWS Des Moines, IA
Area
Storm-based polygon
Hail
1.25 in
Wind
60.0 mph

Counties Carroll County, IA, Crawford County, IA

The radar

The Omaha radar (KOAX), 106 km from the middle of the area, began a volume at 03:52 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

Omaha, NE (KOAX), launched 00:00Z, 3.8 hours before the alert went out and 106 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, Omaha, NE at 00:00Z on 2021-08-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1443 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, Omaha, NE at 00:00Z on 2021-08-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 4 square meters per square second.193958Sfc1 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
1443 J/kg
Mixed-layer CIN
-31 J/kg
Mixed-layer LCL
1305 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
4 m²/s²
0-3 km storm-relative helicity
143 m²/s²
Significant tornado parameter
0.3
Supercell composite
3.5

Open this sounding in Storm Lab

The text

As transmitted.

098 
WUUS53 KDMX 310350
SVRDMX
IAC027-047-310445-
/O.NEW.KDMX.SV.W.0109.210831T0350Z-210831T0445Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Des Moines IA
1050 PM CDT Mon Aug 30 2021

The National Weather Service in Des Moines  has issued a

* Severe Thunderstorm Warning for...
  Southwestern Crawford County in west central Iowa...
  Southwestern Carroll County in west central Iowa...

* Until 1145 PM CDT.

* At 1050 PM CDT, a severe thunderstorm was located near Ute, or 15
  miles west of Denison, moving southeast at 25 mph.

  HAZARD...60 mph wind gusts and half dollar size hail.

  SOURCE...Radar indicated.

  IMPACT...Hail damage to vehicles is expected. Expect wind damage 
           to roofs, siding, and trees.

* Locations impacted include...
  Denison.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4215 9567 4219 9566 4191 9502 4186 9506
      4186 9561 4189 9567
TIME...MOT...LOC 0350Z 305DEG 23KT 4209 9564 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.25 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

REV
2 follow-up statements
507 
WWUS53 KDMX 310421
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
1121 PM CDT Mon Aug 30 2021

IAC027-047-310445-
/O.CON.KDMX.SV.W.0109.000000T0000Z-210831T0445Z/
Crawford IA-Carroll IA-
1121 PM CDT Mon Aug 30 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1145 PM CDT
FOR SOUTHWESTERN CRAWFORD AND SOUTHWESTERN CARROLL COUNTIES...

At 1121 PM CDT, a severe thunderstorm was located near Denison,
moving southeast at 25 mph.

HAZARD...60 mph wind gusts and half dollar size hail.

SOURCE...Radar indicated.

IMPACT...Hail damage to vehicles is expected. Expect wind damage to 
         roofs, siding, and trees.

Locations impacted include...
Denison, Manning, Dunlap, Manilla, Dow City, Charter Oak, Ricketts,
Arion, Buck Grove, Aspinwall, Manning Municipal Airport and Denison
Municipal Airport.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4215 9567 4219 9566 4191 9502 4186 9506
      4186 9561 4189 9567
TIME...MOT...LOC 0421Z 305DEG 23KT 4198 9542 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.25 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

REV
738 
WWUS53 KDMX 310439
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
1139 PM CDT Mon Aug 30 2021

IAC027-047-310449-
/O.EXP.KDMX.SV.W.0109.000000T0000Z-210831T0445Z/
Crawford IA-Carroll IA-
1139 PM CDT Mon Aug 30 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN CRAWFORD AND
SOUTHWESTERN CARROLL COUNTIES WILL EXPIRE AT 1145 PM CDT...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning will be allowed to expire.  However small hail
and gusty winds are still possible with this thunderstorm.

To report severe weather, contact your nearest law enforcement
agency. They will relay your report to the National Weather Service
Des Moines .

LAT...LON 4215 9567 4219 9566 4191 9502 4186 9506
      4186 9561 4189 9567
TIME...MOT...LOC 0439Z 305DEG 23KT 4199 9544 

$$

REV

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 30, 9:58 PM CDTSevere Thunderstorm WarningDMXCarroll, Crawford, Sac62 min
Aug 30, 10:58 PM CDTSevere Thunderstorm WarningDMXAudubon, Carroll, Crawford, Greene, Guthrie62 min
Aug 30, 11:29 PM CDTSevere Thunderstorm WarningDMXBoone, Dallas, Marshall, Polk, Story46 min
Aug 30, 11:50 PM CDTSevere Thunderstorm WarningDMXJasper, Marshall40 min
Aug 30, 11:54 PM CDTSevere Thunderstorm WarningDMXJasper, Madison, Marion, Polk, Warren36 min
Aug 31, 12:07 AM CDTSevere Thunderstorm WarningDMXAdair, Audubon, Cass, Guthrie38 min
Aug 31, 12:35 AM CDTSpecial Weather StatementDMXClarke, Lucas, Madison, Marion, Union, Warren70 min
Aug 31, 9:16 AM CDTAreal Flood WarningDMXBlack Hawk2 hr

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.