Alert archive / Iowa / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 63, NWS Des Moines, IA

July 9, 20214 counties in Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Jul 9, 2021, 9:31 PM CDT for 4 counties in Iowa. It was in force for 15 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 9, 2021, 9:31 PM CDT (02:31 UTC)
Expired: Jul 9, 2021, 9:46 PM CDT
In force: 15 min
Issued by: NWS Des Moines, IA
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Clarke County, IA, Decatur County, IA, Ringgold County, IA, Union County, IA

The radar

The Des Moines radar (KDMX), 96 km from the middle of the area, began a volume at 02:33 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, 2.5 hours before the alert went out and 210 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: 2603 J/kg
Mixed-layer CIN: -130 J/kg
Mixed-layer LCL: 1447 m above ground
0-6 km bulk shear: 45 kt
0-1 km storm-relative helicity: 90 m²/s²
0-3 km storm-relative helicity: 186 m²/s²
Significant tornado parameter: 0.6
Supercell composite: 8.1

Open this sounding in Storm Lab

The text

As transmitted.

519 
WUUS53 KDMX 100231
SVRDMX
IAC039-053-159-175-100315-
/O.NEW.KDMX.SV.W.0063.210710T0231Z-210710T0315Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Des Moines IA
931 PM CDT Fri Jul 9 2021

The National Weather Service in Des Moines  has issued a

* Severe Thunderstorm Warning for...
  Northwestern Decatur County in south central Iowa...
  Southeastern Union County in south central Iowa...
  Northeastern Ringgold County in south central Iowa...
  Southwestern Clarke County in south central Iowa...

* Until 1015 PM CDT.

* At 931 PM CDT, a severe thunderstorm was located near Sun Valley
  Lake, or 15 miles southwest of Osceola, moving east at 25 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
  northwestern Decatur, southeastern Union, northeastern Ringgold and
  southwestern Clarke Counties, including the following locations...
  Weldon, Van Wert and Grand River.

This includes Interstate 35 between mile markers 17 and 30.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4085 9409 4097 9407 4099 9368 4076 9370
TIME...MOT...LOC 0231Z 272DEG 23KT 4092 9403 

HAIL...1.00IN
WIND...60MPH
 
$$

Ansorge

1 follow-up statement

540 
WWUS53 KDMX 100246
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
946 PM CDT Fri Jul 9 2021

IAC039-053-159-175-100255-
/O.CAN.KDMX.SV.W.0063.000000T0000Z-210710T0315Z/
Decatur IA-Union IA-Ringgold IA-Clarke IA-
946 PM CDT Fri Jul 9 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN DECATUR...
SOUTHEASTERN UNION...NORTHEASTERN RINGGOLD AND SOUTHWESTERN CLARKE
COUNTIES IS CANCELLED...
                
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 has been cancelled. A different severe 
thunderstorm warning continues for portions of central and southern 
Ringgold County until 1030pm.

LAT...LON 4085 9409 4097 9407 4099 9368 4076 9370
TIME...MOT...LOC 0244Z 272DEG 23KT 4092 9391 

$$

Ansorge

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 9, 9:16 PM CDT	Severe Thunderstorm Warning	DMX	Ringgold	44 min
Jul 9, 9:38 PM CDT	Severe Thunderstorm Warning	DMX	Ringgold	52 min
Jul 9, 10:21 PM CDT	Severe Thunderstorm Warning	DMX	Ringgold	39 min
Jul 9, 11:41 PM CDT	Severe Thunderstorm Warning	DMX	Audubon, Cass	49 min
Jul 9, 11:56 PM CDT	Severe Thunderstorm Warning	DMX	Adair, Adams, Cass	49 min
Jul 10, 12:41 AM CDT	Severe Thunderstorm Warning	DMX	Adair, Adams, Cass, Ringgold, Taylor, Union	64 min
Jul 10, 2:49 PM CDT	Special Weather Statement	DMX	Carroll, Crawford, Sac	56 min
Jul 10, 4:36 PM CDT	Tornado Warning	DMX	Dallas, Guthrie	24 min
Jul 10, 5:00 PM CDT	Tornado Warning	DMX	Dallas	30 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.