Alert archive / Iowa / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 126, NWS Des Moines, IA

December 15, 20219 counties in Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Dec 15, 2021, 5:22 PM CST for 9 counties in Iowa. It was in force for 68 min. 9 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: Dec 15, 2021, 5:22 PM CST (23:22 UTC)
Expired: Dec 15, 2021, 6:30 PM CST
In force: 68 min
Issued by: NWS Des Moines, IA
Area: Storm-based polygon
Tornado: Possible
Damage threat: Considerable
Hail: 0.75 in
Wind: 70.0 mph

Counties Adair County, IA, Adams County, IA, Clarke County, IA, Decatur County, IA, Madison County, IA, Ringgold County, IA, Taylor County, IA, Union County, IA, Warren County, IA

The radar

The Des Moines radar (KDMX), 108 km from the middle of the area, began a volume at 23:26 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
Dec 15, 5:27 PM CST	TSTM WND GST 60	2 Ene Lamoni, IA	LAMONI MUNICIPAL AIRPORT RECORDED 52 KT WIND GUST.
Dec 15, 5:51 PM CST	TSTM WND DMG	Mount Ayr, IA	METAL ROOF PEELED OFF ON THE TEK BUILDERS BUILDING IN MT AYR. DELAYED REPORT. TIME ESTIMATED VIA RADAR.
Dec 15, 5:55 PM CST	TSTM WND GST 70	3 S Creston, IA	AT CRESTON AIRPORT, KCSQ AWOS 61 KTS.
Dec 15, 5:56 PM CST	TSTM WND DMG	1 N Creston, IA	TREE DOWN ON POWER LINE AND HOUSE. TIME ESTIMATED FROM RADAR.
Dec 15, 5:56 PM CST	TSTM WND DMG	1 Nne Creston, IA	EM REPORTS SEVERAL TREES DOWN IN CRESTON, AFFECTING TRAFFIC AND POWER LINES. TIME ESTIMATED FROM RADAR.
Dec 15, 5:56 PM CST	TSTM WND DMG	1 Nne Creston, IA	TREE DOWN ON HOUSE. TIME ESTIMATED FROM RADAR.
Dec 15, 6:18 PM CST	TSTM WND DMG	Osceola, IA	TREES DOWN ON POWER LINES IN OSCEOLA. TIME ESTIMATED FROM RADAR.
Dec 15, 6:25 PM CST	TSTM WND GST 67	2 Ene Lamoni, IA
Dec 15, 6:29 PM CST	TSTM WND GST 60	5 Ene Osceola, IA

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

The watch it was issued in

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

Issued	Product	Office	Lasted
Dec 15, 1:23 PM CST	Tornado Watch	SPC	7 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 12:00Z, 11.4 hours before the alert went out and 168 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 2165 m above ground
0-6 km bulk shear: 42 kt
0-1 km storm-relative helicity: 346 m²/s²
0-3 km storm-relative helicity: 384 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

312 
WUUS53 KDMX 152322 RRA
SVRDMX
IAC001-003-039-053-121-159-173-175-181-160030-
/O.NEW.KDMX.SV.W.0126.211215T2322Z-211216T0030Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Des Moines IA
522 PM CST Wed Dec 15 2021

The National Weather Service in Des Moines  has issued a

* Severe Thunderstorm Warning for...
  Decatur County in south central Iowa...
  Southern Madison County in south central Iowa...
  Union County in south central Iowa...
  Adams County in southwestern Iowa...
  Ringgold County in south central Iowa...
  Taylor County in southwestern Iowa...
  Clarke County in south central Iowa...
  Southern Adair County in southwestern Iowa...
  Southwestern Warren County in south central Iowa...

* Until 630 PM CST.

* At 522 PM CST, severe thunderstorms were located along a line
  extending from near Lake Icaria to 6 miles northwest of Ravenwood,
  moving northeast at 85 mph.

  HAZARD...70 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...Expect considerable tree damage. Damage is likely to 
           mobile homes, roofs, and outbuildings.

* Locations impacted include...
  Mount Ayr and Leon.

This includes Interstate 35 between mile markers 1 and 44.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

A Tornado Watch remains in effect until 800 PM CST for south central
and southwestern Iowa.

&&

LAT...LON 4057 9478 4116 9477 4116 9470 4118 9470
      4118 9354 4058 9376
TIME...MOT...LOC 2322Z 240DEG 73KT 4112 9471 4041 9476 

TORNADO...POSSIBLE
THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...70 MPH

$$

Martin

1 follow-up statement

792 
WWUS53 KDMX 152357
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
557 PM CST Wed Dec 15 2021

IAC001-003-039-053-121-159-173-175-181-160030-
/O.CON.KDMX.SV.W.0126.000000T0000Z-211216T0030Z/
Decatur IA-Madison IA-Union IA-Adams IA-Ringgold IA-Taylor IA-
Clarke IA-Adair IA-Warren IA-
557 PM CST Wed Dec 15 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 630 PM CST
FOR DECATUR...SOUTHERN MADISON...UNION...EASTERN ADAMS...RINGGOLD...
EASTERN TAYLOR...CLARKE...SOUTHEASTERN ADAIR AND SOUTHWESTERN WARREN
COUNTIES...

At 556 PM CST, severe thunderstorms were located along a line
extending from near Winterset to 6 miles west of Lamoni, moving east
at 55 mph.

HAZARD...70 mph wind gusts.

SOURCE...Trained weather spotters.

IMPACT...Expect considerable tree damage. Damage is likely to mobile 
         homes, roofs, and outbuildings.

Locations impacted include...
Creston, Osceola, Leon, Mount Ayr, Lamoni, Lenox, Sun Valley Lake,
Green Valley Lake, Lakeside Casino, Afton, Murray, New Virginia,
Clearfield, Lorimor, Diagonal, Kellerton, Grand River, Van Wert,
Davis City and Woodburn.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Tornado Watch remains in effect until 800 PM CST for south central
and southwestern Iowa.

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

&&

LAT...LON 4058 9463 4117 9453 4118 9354 4058 9376
TIME...MOT...LOC 2356Z 260DEG 48KT 4130 9399 4059 9405 

TORNADO...POSSIBLE
THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...70 MPH

$$

Martin

The office that day

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

Issued	Product	Office	Counties	Lasted
Dec 15, 4:13 PM CST	Severe Thunderstorm Warning Destructive damage threat	DMX	Adair, Adams, Audubon, Cass, Guthrie, Ringgold and 2 more	77 min
Dec 15, 4:16 PM CST	Severe Thunderstorm Warning Destructive damage threat	DMX	Carroll, Crawford, Sac	74 min
Dec 15, 4:37 PM CST	Tornado Warning Tornado observed	DMX	Cass	23 min
Dec 15, 4:44 PM CST	Tornado Warning	DMX	Crawford	36 min
Dec 15, 4:53 PM CST	Tornado Warning	DMX	Adair, Audubon, Cass, Guthrie	33 min
Dec 15, 5:07 PM CST	Tornado Warning	DMX	Sac	27 min
Dec 15, 5:10 PM CST	Severe Thunderstorm Warning Destructive damage threat	DMX	Adair, Audubon, Boone, Dallas, Greene, Guthrie and 4 more	80 min
Dec 15, 5:10 PM CST	Tornado Warning	DMX	Carroll, Crawford	35 min
Dec 15, 5:14 PM CST	Tornado Warning	DMX	Audubon, Calhoun, Carroll, Greene, Guthrie	31 min
Dec 15, 5:15 PM CST	Tornado Warning	DMX	Calhoun, Carroll, Crawford, Sac	30 min
Dec 15, 5:18 PM CST	Tornado Warning Tornado observed	DMX	Adair, Boone, Dallas, Greene, Guthrie	42 min
Dec 15, 5:19 PM CST	Severe Thunderstorm Warning Destructive damage threat	DMX	Boone, Calhoun, Carroll, Emmet, Greene, Humboldt and 5 more	71 min
Dec 15, 5:22 PM CST	Severe Thunderstorm Warning Destructive damage threat	DMX	Carroll, Crawford, Sac	23 min
Dec 15, 5:36 PM CST	Tornado Warning	DMX	Calhoun, Humboldt, Kossuth, Palo Alto, Pocahontas	24 min
Dec 15, 5:38 PM CST	Tornado Warning Tornado observed	DMX	Boone, Calhoun, Greene, Hamilton, Webster	37 min
Dec 15, 5:45 PM CST	Tornado Warning	DMX	Calhoun, Pocahontas, Webster	30 min
Dec 15, 5:52 PM CST	Severe Thunderstorm Warning Destructive damage threat	DMX	Boone, Franklin, Hamilton, Hancock, Hardin, Humboldt and 6 more	53 min
Dec 15, 5:58 PM CST	Tornado Warning	DMX	Hancock, Humboldt, Kossuth, Palo Alto, Pocahontas	32 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.