Alert archive / Iowa / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 47, NWS Des Moines, IA

June 22, 2021Calhoun County, Sac County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Jun 22, 2021, 5:22 PM CDT for Calhoun County, Sac County, Iowa. It was in force for 38 min. 2 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Jun 22, 2021, 5:22 PM CDT (22:22 UTC)
Expired: Jun 22, 2021, 6:00 PM CDT
In force: 38 min
Issued by: NWS Des Moines, IA
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Calhoun County, IA, Sac County, IA

The radar

The Des Moines radar (KDMX), 131 km from the middle of the area, began a volume at 22:22 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.

What was reported inside it

Time	Report	Where	Remark
Jun 22, 5:39 PM CDT	HAIL 1	1 E Lytton, IA	MOSTLY PEA TO NICKEL SIZE HAIL WITH A FEW QUARTERS MIXED IN.
Jun 22, 5:45 PM CDT	HAIL 1.5	Lytton, IA

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Omaha, NE (KOAX), launched 12:00Z, 10.4 hours before the alert went out and 174 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: 1 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1910 m above ground
0-6 km bulk shear: 59 kt
0-1 km storm-relative helicity: 259 m²/s²
0-3 km storm-relative helicity: 324 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

661 
WUUS53 KDMX 222222
SVRDMX
IAC025-161-222300-
/O.NEW.KDMX.SV.W.0047.210622T2222Z-210622T2300Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Des Moines IA
522 PM CDT Tue Jun 22 2021

The National Weather Service in Des Moines  has issued a

* Severe Thunderstorm Warning for...
  Eastern Sac County in west central Iowa...
  Northwestern Calhoun County in west central Iowa...

* Until 600 PM CDT.

* At 522 PM CDT, a severe thunderstorm was located near Sac City,
  moving southeast 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.

* Locations impacted include...
  Rockwell City.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4256 9513 4256 9493 4244 9450 4221 9489
      4253 9518
TIME...MOT...LOC 2222Z 302DEG 33KT 4246 9497 

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

Krull

1 follow-up statement

265 
WWUS53 KDMX 222239
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
539 PM CDT Tue Jun 22 2021

IAC025-161-222300-
/O.CON.KDMX.SV.W.0047.000000T0000Z-210622T2300Z/
Sac IA-Calhoun IA-
539 PM CDT Tue Jun 22 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 600 PM CDT
FOR EAST CENTRAL SAC AND WESTERN CALHOUN COUNTIES...

At 538 PM CDT, a severe thunderstorm was located 8 miles north of
Lake City, or 8 miles west of Rockwell City, moving southeast 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.

Locations impacted include...
Sac City, Rockwell City, South Twin Lake, Twin Lakes, Lytton, Jolley,
Yetter, Rockwell City Municipal Airport and Twin Lakes State Park.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4254 9487 4243 9453 4226 9483 4245 9501
TIME...MOT...LOC 2238Z 302DEG 33KT 4238 9479 

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

Krull

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 22, 4:59 PM CDT	Severe Thunderstorm Warning	DMX	Dallas, Polk	46 min
Jun 22, 5:30 PM CDT	Severe Thunderstorm Warning	DMX	Polk	45 min
Jun 22, 5:50 PM CDT	Severe Thunderstorm Warning	DMX	Calhoun	40 min
Jun 22, 5:52 PM CDT	Special Weather Statement	DMX	Poweshiek	23 min
Jun 22, 5:58 PM CDT	Severe Thunderstorm Warning	DMX	Polk, Warren	47 min
Jun 22, 6:09 PM CDT	Severe Thunderstorm Warning	DMX	Boone, Calhoun, Carroll, Greene, Webster	51 min
Jun 22, 6:30 PM CDT	Severe Thunderstorm Warning	DMX	Lucas, Marion, Warren	45 min
Jun 22, 6:33 PM CDT	Severe Thunderstorm Warning	DMX	Carroll, Greene	42 min
Jun 22, 6:42 PM CDT	Special Weather Statement	DMX	Tama	63 min
Jun 22, 6:49 PM CDT	Severe Thunderstorm Warning	DMX	Dallas, Guthrie	41 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.