Alert archive / Iowa / Tornado Warnings in 2021

Tornado Warning 43, NWS Des Moines, IA

December 15, 20215 counties in Iowa

NWS Des Moines, IA issued this tornado warning at Dec 15, 2021, 5:36 PM CST for 5 counties in Iowa. It was in force for 24 min. 1 report 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, 5:36 PM CST (23:36 UTC)
Expired
Dec 15, 2021, 6:00 PM CST
In force
24 min
Issued by
NWS Des Moines, IA
Area
Storm-based polygon
Tornado
Radar indicated
Hail
0.75 in

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

The radar

The Des Moines radar (KDMX), 129 km from the middle of the area, began a volume at 23:41 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

TimeReportWhereRemark
Dec 15, 6:00 PM CSTTORNADOBradgate, IAPUBLIC REPORTED TORNADO ON THE GROUND. NO ADDITIONAL INFORMATION AT THIS TIME.

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.

IssuedProductOfficeLasted
Dec 15, 1:23 PM CSTTornado WatchSPC7 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 12:00Z, 11.6 hours before the alert went out and 203 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-pSkew-T log-p diagram, Omaha, NE at 12:00Z on 2021-12-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Omaha, NE at 12:00Z on 2021-12-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 346 square meters per square second.1939587897Sfc1 km3 km6 km9 kmRMLM
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.

045 
WFUS53 KDMX 152336
TORDMX
IAC025-091-109-147-151-160000-
/O.NEW.KDMX.TO.W.0043.211215T2336Z-211216T0000Z/

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

The National Weather Service in Des Moines  has issued a

* Tornado Warning for...
  Pocahontas County in northwestern Iowa...
  Southwestern Kossuth County in north central Iowa...
  Northwestern Calhoun County in west central Iowa...
  Northwestern Humboldt County in north central Iowa...
  Southeastern Palo Alto County in northwestern Iowa...

* Until 600 PM CST.
    
* At 536 PM CST, a severe thunderstorm capable of producing a tornado
  was located 8 miles northwest of South Twin Lake, or 12 miles
  northwest of Rockwell 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 dangerous storm will be near...
  Pocahontas around 550 PM CST.

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 4246 9477 4249 9490 4291 9472 4291 9425
TIME...MOT...LOC 2336Z 211DEG 63KT 4253 9479 

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

$$

Cogil
2 follow-up statements
847 
WWUS53 KDMX 152341
SVSDMX

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

IAC025-152350-
/O.CAN.KDMX.TO.W.0043.000000T0000Z-211216T0000Z/
Calhoun IA-
541 PM CST Wed Dec 15 2021

...THE TORNADO WARNING FOR NORTHWESTERN CALHOUN COUNTY IS
CANCELLED...
    
The tornadic thunderstorm which prompted the warning has moved out 
of the warned area. Therefore, the warning has been cancelled.

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

LAT...LON 4256 9466 4257 9486 4291 9472 4291 9425
TIME...MOT...LOC 2340Z 211DEG 63KT 4260 9473 

$$

IAC091-109-147-151-160000-
/O.CON.KDMX.TO.W.0043.000000T0000Z-211216T0000Z/
Pocahontas IA-Kossuth IA-Humboldt IA-Palo Alto IA-
541 PM CST Wed Dec 15 2021

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 600 PM CST FOR
POCAHONTAS...SOUTHWESTERN KOSSUTH...NORTHWESTERN HUMBOLDT AND
SOUTHEASTERN PALO ALTO COUNTIES...
    
At 540 PM CST, a severe thunderstorm capable of producing a tornado
was located 9 miles northwest of North Twin Lake, or 9 miles south of
Pocahontas, 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 dangerous storm will be near...
  Pocahontas around 550 PM CST.

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 4256 9466 4257 9486 4291 9472 4291 9425
TIME...MOT...LOC 2340Z 211DEG 63KT 4260 9473 

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

$$

Cogil
183 
WWUS53 KDMX 152359
SVSDMX

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

IAC091-109-147-151-160008-
/O.EXP.KDMX.TO.W.0043.000000T0000Z-211216T0000Z/
Pocahontas IA-Kossuth IA-Humboldt IA-Palo Alto IA-
559 PM CST Wed Dec 15 2021

...THE TORNADO WARNING FOR POCAHONTAS...SOUTHWESTERN KOSSUTH...
NORTHWESTERN HUMBOLDT AND SOUTHEASTERN PALO ALTO COUNTIES WILL EXPIRE
AT 600 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 4256 9466 4257 9486 4291 9472 4291 9425
TIME...MOT...LOC 2358Z 211DEG 63KT 4287 9451 

$$

Cogil

The office that day

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

IssuedProductOfficeCountiesLasted
Dec 15, 4:13 PM CSTSevere Thunderstorm Warning Destructive damage threatDMXAdair, Adams, Audubon, Cass, Guthrie, Ringgold and 2 more77 min
Dec 15, 4:16 PM CSTSevere Thunderstorm Warning Destructive damage threatDMXCarroll, Crawford, Sac74 min
Dec 15, 4:37 PM CSTTornado Warning Tornado observedDMXCass23 min
Dec 15, 4:44 PM CSTTornado WarningDMXCrawford36 min
Dec 15, 4:53 PM CSTTornado WarningDMXAdair, Audubon, Cass, Guthrie33 min
Dec 15, 5:07 PM CSTTornado WarningDMXSac27 min
Dec 15, 5:10 PM CSTSevere Thunderstorm Warning Destructive damage threatDMXAdair, Audubon, Boone, Dallas, Greene, Guthrie and 4 more80 min
Dec 15, 5:10 PM CSTTornado WarningDMXCarroll, Crawford35 min
Dec 15, 5:14 PM CSTTornado WarningDMXAudubon, Calhoun, Carroll, Greene, Guthrie31 min
Dec 15, 5:15 PM CSTTornado WarningDMXCalhoun, Carroll, Crawford, Sac30 min
Dec 15, 5:18 PM CSTTornado Warning Tornado observedDMXAdair, Boone, Dallas, Greene, Guthrie42 min
Dec 15, 5:19 PM CSTSevere Thunderstorm Warning Destructive damage threatDMXBoone, Calhoun, Carroll, Emmet, Greene, Humboldt and 5 more71 min
Dec 15, 5:22 PM CSTSevere Thunderstorm Warning Destructive damage threatDMXCarroll, Crawford, Sac23 min
Dec 15, 5:22 PM CSTSevere Thunderstorm Warning Considerable damage threatDMXAdair, Adams, Clarke, Decatur, Madison, Ringgold and 3 more68 min
Dec 15, 5:38 PM CSTTornado Warning Tornado observedDMXBoone, Calhoun, Greene, Hamilton, Webster37 min
Dec 15, 5:45 PM CSTTornado WarningDMXCalhoun, Pocahontas, Webster30 min
Dec 15, 5:52 PM CSTSevere Thunderstorm Warning Destructive damage threatDMXBoone, Franklin, Hamilton, Hancock, Hardin, Humboldt and 6 more53 min
Dec 15, 5:58 PM CSTTornado WarningDMXHancock, Humboldt, Kossuth, Palo Alto, Pocahontas32 min

Nearby

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