Alert archive / Iowa / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 22, NWS Des Moines, IA

June 18, 2021Cass County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Jun 18, 2021, 11:32 PM CDT for Cass 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
Jun 18, 2021, 11:32 PM CDT (04:32 UTC)
Expired
Jun 19, 2021, 12:00 AM CDT
In force
28 min
Issued by
NWS Des Moines, IA
Area
Storm-based polygon
Hail
1.5 in
Wind
60.0 mph

County Cass County, IA

The radar

The Omaha radar (KOAX), 112 km from the middle of the area, began a volume at 04:35 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Jun 18, 10:08 PM CDTSevere Thunderstorm WatchSPC8 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 4.5 hours before the alert went out and 112 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 2021-06-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2090 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Omaha, NE at 00:00Z on 2021-06-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 46 square meters per square second.19395878Sfc1 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
2090 J/kg
Mixed-layer CIN
-169 J/kg
Mixed-layer LCL
1569 m above ground
0-6 km bulk shear
59 kt
0-1 km storm-relative helicity
46 m²/s²
0-3 km storm-relative helicity
307 m²/s²
Significant tornado parameter
-0.0
Supercell composite
-0.3

Open this sounding in Storm Lab

The text

As transmitted.

991 
WUUS53 KDMX 190432
SVRDMX
IAC029-190500-
/O.NEW.KDMX.SV.W.0022.210619T0432Z-210619T0500Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Des Moines IA
1132 PM CDT Fri Jun 18 2021

The National Weather Service in Des Moines  has issued a

* Severe Thunderstorm Warning for...
  Southwestern Cass County in southwestern Iowa...

* Until midnight CDT.

* At 1132 PM CDT, a severe thunderstorm was located near Griswold, or
  11 miles southwest of Atlantic, moving east at 40 mph.

  HAZARD...Ping pong 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.

* This severe thunderstorm will be near...
  Griswold around 1140 PM CDT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4138 9516 4131 9480 4116 9486 4116 9516
TIME...MOT...LOC 0432Z 286DEG 35KT 4130 9519 

HAIL...1.50IN
WIND...60MPH
 
$$

Curtis

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 18, 9:56 PM CDTSevere Thunderstorm WarningDMXClarke, Lucas, Madison, Marion, Warren49 min
Jun 18, 10:06 PM CDTSevere Thunderstorm WarningDMXAdair, Clarke, Madison, Union39 min
Jun 18, 10:39 PM CDTSevere Thunderstorm WarningDMXLucas, Monroe, Wayne51 min
Jun 18, 10:43 PM CDTSevere Thunderstorm WarningDMXClarke, Lucas, Madison, Union, Warren47 min
Jun 18, 10:45 PM CDTSevere Thunderstorm WarningDMXMahaska, Marion, Monroe, Wapello45 min
Jun 18, 10:54 PM CDTSevere Thunderstorm WarningDMXAdair, Cass51 min
Jun 18, 11:05 PM CDTSevere Thunderstorm WarningDMXMahaska, Marion25 min
Jun 18, 11:10 PM CDTSevere Thunderstorm WarningDMXAppanoose, Lucas, Monroe, Wayne50 min
Jun 18, 11:14 PM CDTSevere Thunderstorm WarningDMXAdair, Madison46 min
Jun 18, 11:19 PM CDTSevere Thunderstorm WarningDMXMahaska26 min
Jun 18, 11:22 PM CDTSevere Thunderstorm WarningDMXAppanoose, Davis, Monroe, Wapello53 min
Jun 18, 11:25 PM CDTSevere Thunderstorm WarningDMXClarke, Decatur, Lucas, Wayne50 min
Jun 18, 11:37 PM CDTSevere Thunderstorm WarningDMXAdair, Adams, Union53 min
Jun 18, 11:54 PM CDTSevere Thunderstorm WarningDMXClarke, Madison, Warren36 min
Jun 18, 11:55 PM CDTSevere Thunderstorm WarningDMXAppanoose, Lucas, Monroe, Wayne50 min
Jun 18, 11:59 PM CDTSevere Thunderstorm WarningDMXAdair, Adams, Clarke, Madison, Ringgold, Union46 min
Jun 19, 12:13 AM CDTSevere Thunderstorm WarningDMXAdams26 min
Jun 19, 12:14 AM CDTSevere Thunderstorm WarningDMXDavis, Wapello31 min
Jun 19, 12:25 AM CDTSevere Thunderstorm WarningDMXClarke, Lucas, Marion, Warren35 min
Jun 19, 12:29 AM CDTSevere Thunderstorm WarningDMXAppanoose, Davis46 min
Jun 19, 12:44 AM CDTSevere Thunderstorm WarningDMXLucas, Marion, Monroe31 min
Jun 19, 3:59 AM CDTSpecial Weather StatementDMXDavis46 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.