Alert archive / Iowa / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 100, NWS Des Moines, IA

August 26, 2021Audubon County, Carroll County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Aug 26, 2021, 7:02 PM CDT for Audubon County, Carroll County, Iowa. It was in force for 28 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 26, 2021, 7:02 PM CDT (00:02 UTC)
Expired
Aug 26, 2021, 7:30 PM CDT
In force
28 min
Issued by
NWS Des Moines, IA
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Audubon County, IA, Carroll County, IA

The radar

The Des Moines radar (KDMX), 106 km from the middle of the area, began a volume at 00:03 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, 0.0 hours before the alert went out and 127 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 2021-08-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 5342 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 2021-08-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 111 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
5342 J/kg
Mixed-layer CIN
-16 J/kg
Mixed-layer LCL
1163 m above ground
0-6 km bulk shear
27 kt
0-1 km storm-relative helicity
111 m²/s²
0-3 km storm-relative helicity
199 m²/s²
Significant tornado parameter
3.8
Supercell composite
24.0

Open this sounding in Storm Lab

The text

As transmitted.

207 
WUUS53 KDMX 270002
SVRDMX
IAC009-027-270030-
/O.NEW.KDMX.SV.W.0100.210827T0002Z-210827T0030Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Des Moines IA
702 PM CDT Thu Aug 26 2021

The National Weather Service in Des Moines  has issued a

* Severe Thunderstorm Warning for...
  Northwestern Audubon County in west central Iowa...
  South central Carroll County in west central Iowa...

* Until 730 PM CDT.

* At 701 PM CDT, a severe thunderstorm was located 7 miles northwest
  of Audubon, moving east at 15 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...
  Audubon.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4186 9509 4194 9487 4170 9484 4171 9509
TIME...MOT...LOC 0001Z 252DEG 11KT 4179 9505 

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

$$

Krull
2 follow-up statements
295 
WWUS53 KDMX 270016
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
716 PM CDT Thu Aug 26 2021

IAC009-027-270030-
/O.CON.KDMX.SV.W.0100.000000T0000Z-210827T0030Z/
Audubon IA-Carroll IA-
716 PM CDT Thu Aug 26 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 730 PM CDT
FOR NORTHWESTERN AUDUBON AND SOUTH CENTRAL CARROLL COUNTIES...

At 716 PM CDT, a severe thunderstorm was located near Audubon, moving
east at 20 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...
Audubon, Templeton, Gray and Audubon County Airport. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4186 9509 4194 9487 4170 9484 4171 9509
TIME...MOT...LOC 0016Z 272DEG 16KT 4179 9499 

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

$$

Krull
376 
WWUS53 KDMX 270026
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
726 PM CDT Thu Aug 26 2021

IAC009-027-270035-
/O.EXP.KDMX.SV.W.0100.000000T0000Z-210827T0030Z/
Audubon IA-Carroll IA-
726 PM CDT Thu Aug 26 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN AUDUBON AND SOUTH
CENTRAL CARROLL COUNTIES WILL EXPIRE AT 730 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, gusty winds and heavy rain are still possible with this
thunderstorm.

LAT...LON 4186 9509 4194 9487 4170 9484 4171 9509
TIME...MOT...LOC 0025Z 252DEG 11KT 4180 9496 

$$

Krull

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 26, 8:35 PM CDTSpecial Weather StatementDMXPoweshiek40 min
Aug 26, 8:47 PM CDTSevere Thunderstorm WarningDMXMahaska, Poweshiek58 min
Aug 26, 9:46 PM CDTSpecial Weather StatementDMXMahaska44 min
Aug 26, 10:26 PM CDTSpecial Weather StatementDMXMahaska34 min
Aug 26, 10:30 PM CDTSevere Thunderstorm WarningDMXEmmet, Palo Alto45 min
Aug 26, 10:52 PM CDTSpecial Weather StatementDMXWapello38 min
Aug 26, 11:42 PM CDTSevere Thunderstorm WarningDMXEmmet, Palo Alto33 min
Aug 27, 12:13 AM CDTSpecial Weather StatementDMXEmmet32 min
Aug 27, 2:08 PM CDTSpecial Weather StatementDMXHancock37 min
Aug 27, 2:59 PM CDTSpecial Weather StatementDMXCerro Gordo16 min
Aug 27, 4:23 PM CDTSevere Thunderstorm WarningDMXCerro Gordo, Hancock52 min
Aug 27, 4:48 PM CDTTornado WarningDMXCerro Gordo, Hancock57 min
Aug 27, 4:58 PM CDTSevere Thunderstorm WarningDMXCerro Gordo, Franklin, Hancock32 min
Aug 27, 5:23 PM CDTTornado Warning Tornado observedDMXCerro Gordo37 min
Aug 27, 5:25 PM CDTTornado WarningDMXCerro Gordo35 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.