Alert archive / Iowa / Tornado Warnings in 2021

Tornado Warning 46, NWS Des Moines, IA

December 15, 20215 counties in Iowa

NWS Des Moines, IA issued this tornado warning at Dec 15, 2021, 5:58 PM CST for 5 counties in Iowa. It was in force for 32 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: Dec 15, 2021, 5:58 PM CST (23:58 UTC)
Expired: Dec 15, 2021, 6:30 PM CST
In force: 32 min
Issued by: NWS Des Moines, IA
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 0.75 in

Counties Hancock County, IA, Humboldt County, IA, Kossuth County, IA, Palo Alto County, IA, Pocahontas County, IA

The radar

The Des Moines radar (KDMX), 132 km from the middle of the area, began a volume at 00:03 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, 6:00 PM CST	TORNADO	Bradgate, IA	PUBLIC REPORTED TORNADO ON THE GROUND. NO ADDITIONAL INFORMATION AT THIS TIME.
Dec 15, 6:12 PM CST	TORNADO	6 S Algona, IA	TORNADO CONFIRMED, APPROX 6 MILES SOUTH OF ALGONA.

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

Minneapolis, MN (KMPX), launched 12:00Z, 12.0 hours before the alert went out and 231 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: -51 J/kg
Mixed-layer LCL: 455 m above ground
0-6 km bulk shear: 56 kt
0-1 km storm-relative helicity: 251 m²/s²
0-3 km storm-relative helicity: 291 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

002 
WFUS53 KDMX 152358
TORDMX
IAC081-091-109-147-151-160030-
/O.NEW.KDMX.TO.W.0046.211215T2358Z-211216T0030Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Des Moines IA
558 PM CST Wed Dec 15 2021

The National Weather Service in Des Moines  has issued a

* Tornado Warning for...
  East central Pocahontas County in northwestern Iowa...
  Southern Kossuth County in north central Iowa...
  Southwestern Hancock County in north central Iowa...
  Western Humboldt County in north central Iowa...
  Southeastern Palo Alto County in northwestern Iowa...

* Until 630 PM CST.
    
* At 558 PM CST, a severe thunderstorm capable of producing a tornado
  was located 9 miles northwest of Humboldt, or 10 miles west of
  Dakota City, moving northeast at 70 mph.

  HAZARD...Tornado.

  SOURCE...Radar indicated rotation.

  IMPACT...Flying debris will be dangerous to those caught without 
           shelter. Mobile homes will be damaged or destroyed. 
           Damage to roofs, windows, and vehicles will occur.  Tree 
           damage is likely.

* This tornadic thunderstorm will remain over mainly rural areas of
  east central Pocahontas, southern Kossuth, southwestern Hancock,
  western Humboldt and southeastern Palo Alto Counties, including the
  following locations... Bode, Bradgate, Livermore, Rutland, Stinson
  Prairie State Park, Ottosen, Gilmore City, St. Joseph, Irvington
  and Lu Verne.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

&&

LAT...LON 4268 9437 4274 9450 4305 9440 4303 9395
TIME...MOT...LOC 2358Z 217DEG 59KT 4278 9440 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...<.75 IN

$$

Cogil

1 follow-up statement

459 
WWUS53 KDMX 160023
SVSDMX

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

IAC081-091-109-147-151-160033-
/O.EXP.KDMX.TO.W.0046.000000T0000Z-211216T0030Z/
Pocahontas IA-Kossuth IA-Hancock IA-Humboldt IA-Palo Alto IA-
623 PM CST Wed Dec 15 2021

...THE TORNADO WARNING FOR EAST CENTRAL POCAHONTAS...SOUTHERN
KOSSUTH...SOUTHWESTERN HANCOCK...WESTERN HUMBOLDT AND SOUTHEASTERN
PALO ALTO COUNTIES WILL EXPIRE AT 630 PM CST...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning will be allowed to expire.

A Tornado Watch remains in effect until 800 PM CST for north central
and northwestern Iowa.

LAT...LON 4268 9437 4274 9450 4305 9440 4303 9395
TIME...MOT...LOC 0023Z 270DEG 59KT 4308 9409 

$$

Cogil

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, 5:22 PM CST	Severe Thunderstorm Warning Considerable damage threat	DMX	Adair, Adams, Clarke, Decatur, Madison, Ringgold and 3 more	68 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

Nearby

Tornado Warnings in Iowa, 2021 Every tornado warning in 2021 Tornadoes 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.