Alert archive / Iowa / Tornado Warnings in 2021

Tornado Warning 48, NWS Des Moines, IA

December 15, 2021Butler County, Cerro Gordo County, Franklin County, Iowa

NWS Des Moines, IA issued this tornado warning at Dec 15, 2021, 6:37 PM CST for Butler County, Cerro Gordo County, Franklin County, Iowa. It was in force for 20 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, 6:37 PM CST (00:37 UTC)
Expired: Dec 15, 2021, 6:57 PM CST
In force: 20 min
Issued by: NWS Des Moines, IA
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 0.75 in

Counties Butler County, IA, Cerro Gordo County, IA, Franklin County, IA

The radar

The Des Moines radar (KDMX), 135 km from the middle of the area, began a volume at 00:40 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, 6:38 PM CST	TSTM WND GST 64	1 Nw Hampton, IA	PERSONAL WEATHER STATION.

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 00:00Z, 0.6 hours before the alert went out and 227 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: 633 J/kg
Mixed-layer CIN: -55 J/kg
Mixed-layer LCL: 770 m above ground
0-6 km bulk shear: 75 kt
0-1 km storm-relative helicity: 443 m²/s²
0-3 km storm-relative helicity: 470 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 5.7

Open this sounding in Storm Lab

The text

As transmitted.

714 
WFUS53 KDMX 160037
TORDMX
IAC023-033-069-160115-
/O.NEW.KDMX.TO.W.0048.211216T0037Z-211216T0115Z/

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

The National Weather Service in Des Moines  has issued a

* Tornado Warning for...
  Eastern Franklin County in north central Iowa...
  Northwestern Butler County in north central Iowa...
  Southeastern Cerro Gordo County in north central Iowa...

* Until 715 PM CST.
    
* At 637 PM CST, a severe thunderstorm capable of producing a tornado
  was located near Hampton, 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
  eastern Franklin, northwestern Butler and southeastern Cerro Gordo
  Counties, including the following locations... Dougherty, Aredale,
  Hampton Municipal Airport, Hansell, Geneva and Beeds Lake State
  Park.

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 4291 9302 4291 9276 4263 9321 4268 9330
      4303 9303
TIME...MOT...LOC 0037Z 214DEG 59KT 4269 9321 

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

$$

Cogil

2 follow-up statements

048 
WWUS53 KDMX 160048
SVSDMX

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

IAC023-033-069-160115-
/O.CON.KDMX.TO.W.0048.000000T0000Z-211216T0115Z/
Franklin IA-Butler IA-Cerro Gordo IA-
648 PM CST Wed Dec 15 2021

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 715 PM CST FOR
NORTHEASTERN FRANKLIN...NORTHWESTERN BUTLER AND SOUTHEASTERN CERRO
GORDO COUNTIES...
    
At 648 PM CST, a severe thunderstorm capable of producing a tornado
was located 9 miles southeast of Sheffield, or 9 miles northeast of
Hampton, moving northeast at 60 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.

Locations impacted include...
Greene, Aredale and Dougherty. 

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 4291 9302 4291 9276 4277 9301 4282 9315
      4303 9303
TIME...MOT...LOC 0048Z 217DEG 50KT 4283 9305 

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

$$

Cogil

837 
WWUS53 KDMX 160057
SVSDMX

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

IAC023-033-069-160107-
/O.CAN.KDMX.TO.W.0048.000000T0000Z-211216T0115Z/
Franklin IA-Butler IA-Cerro Gordo IA-
657 PM CST Wed Dec 15 2021

...THE TORNADO WARNING FOR NORTHEASTERN FRANKLIN...NORTHWESTERN
BUTLER AND SOUTHEASTERN CERRO GORDO COUNTIES 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
Iowa.

LAT...LON 4291 9302 4291 9276 4277 9301 4282 9315
      4303 9303
TIME...MOT...LOC 0056Z 214DEG 59KT 4296 9293 

$$

Cogil

The office that day

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

Issued	Product	Office	Counties	Lasted
Dec 15, 6:13 PM CST	Severe Thunderstorm Warning	DMX	Appanoose, Clarke, Decatur, Lucas, Marion, Monroe and 2 more	62 min
Dec 15, 6:19 PM CST	Tornado Warning	DMX	Hancock, Kossuth, Winnebago	41 min
Dec 15, 6:24 PM CST	Severe Thunderstorm Warning Considerable damage threat	DMX	Clarke, Dallas, Jasper, Lucas, Madison, Mahaska and 5 more	66 min
Dec 15, 6:30 PM CST	Severe Thunderstorm Warning Considerable damage threat	DMX	Black Hawk, Bremer, Butler, Cerro Gordo, Franklin, Grundy and 6 more	75 min
Dec 15, 6:47 PM CST	Severe Thunderstorm Warning Considerable damage threat	DMX	Grundy, Hardin, Marshall, Story	43 min
Dec 15, 7:09 PM CST	Severe Thunderstorm Warning Considerable damage threat	DMX	Appanoose, Davis, Jasper, Lucas, Mahaska, Marion and 5 more	66 min
Dec 15, 7:44 PM CST	Severe Thunderstorm Warning Considerable damage threat	DMX	Black Hawk, Bremer, Butler, Grundy, Tama	27 min
Dec 15, 11:52 PM CST	Wind Advisory	DMX	Adair, Adams, Appanoose, Audubon, Black Hawk, Boone and 45 more	6 hr

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.