Alert archive / Iowa / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 115, NWS Des Moines, IA

September 13, 2021Carroll County, Crawford County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Sep 13, 2021, 10:18 PM CDT for Carroll County, Crawford County, Iowa. It was in force for 27 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: Sep 13, 2021, 10:18 PM CDT (03:18 UTC)
Expired: Sep 13, 2021, 10:45 PM CDT
In force: 27 min
Issued by: NWS Des Moines, IA
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Carroll County, IA, Crawford County, IA

The radar

The Des Moines radar (KDMX), 126 km from the middle of the area, began a volume at 03:19 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, 3.3 hours before the alert went out and 137 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1361 J/kg
Mixed-layer CIN: -168 J/kg
Mixed-layer LCL: 1731 m above ground
0-6 km bulk shear: 42 kt
0-1 km storm-relative helicity: 98 m²/s²
0-3 km storm-relative helicity: 213 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 6.1

Open this sounding in Storm Lab

The text

As transmitted.

163 
WUUS53 KDMX 140318
SVRDMX
IAC027-047-140345-
/O.NEW.KDMX.SV.W.0115.210914T0318Z-210914T0345Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Des Moines IA
1018 PM CDT Mon Sep 13 2021

The National Weather Service in Des Moines  has issued a

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

* Until 1045 PM CDT.

* At 1017 PM CDT, a severe thunderstorm was located near Denison,
  moving east at 40 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.

* This severe thunderstorm will remain over mainly rural areas of
  northeastern Crawford and northwestern Carroll Counties, including
  the following locations... Arcadia, Deloit, Vail and Westside.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4221 9507 4221 9500 4204 9496 4203 9536
      4212 9538
TIME...MOT...LOC 0317Z 257DEG 35KT 4208 9532 

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

$$

Hagenhoff

1 follow-up statement

822 
WWUS53 KDMX 140344
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
1044 PM CDT Mon Sep 13 2021

IAC027-047-140352-
/O.EXP.KDMX.SV.W.0115.000000T0000Z-210914T0345Z/
Crawford IA-Carroll IA-
1044 PM CDT Mon Sep 13 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN CRAWFORD AND
NORTHWESTERN CARROLL COUNTIES WILL EXPIRE AT 1045 PM CDT...
        
The storm which prompted the warning has weakened below severe
limits, and has exited the warned area. Therefore, the warning will
be allowed to expire.  However small hail is still possible with this
thunderstorm.

LAT...LON 4221 9507 4221 9500 4204 9496 4203 9536
      4212 9538
TIME...MOT...LOC 0342Z 257DEG 35KT 4213 9501 

$$

Hagenhoff

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 13, 10:02 PM CDT	Special Weather Statement	DMX	Crawford	28 min
Sep 14, 1:08 AM CDT	Special Weather Statement	DMX	Hamilton	37 min

Nearby

Severe Thunderstorm Warnings in Iowa, 2021 Every 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.