Alert archive / Iowa / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 124, NWS Des Moines, IA

December 15, 202111 counties in Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Dec 15, 2021, 5:19 PM CST for 11 counties in Iowa. It was in force for 71 min. 23 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, 5:19 PM CST (23:19 UTC)
Expired: Dec 15, 2021, 6:30 PM CST
In force: 71 min
Issued by: NWS Des Moines, IA
Area: Storm-based polygon
Tornado: Possible
Damage threat: Destructive
Hail: 0.75 in
Wind: 80.0 mph

Counties Boone County, IA, Calhoun County, IA, Carroll County, IA, Emmet County, IA, Greene County, IA, Humboldt County, IA, Kossuth County, IA, Palo Alto County, IA, Pocahontas County, IA, Sac County, IA, Webster County, IA

The radar

The Des Moines radar (KDMX), 109 km from the middle of the area, began a volume at 23:19 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, 5:23 PM CST	HAIL 1	Coon Rapids, IA
Dec 15, 5:27 PM CST	TSTM WND GST 70	Coon Rapids, IA
Dec 15, 5:27 PM CST	TSTM WND GST 73	4 S Scranton, IA	PWS RECORDED WIND GUST OF 73 MPH.
Dec 15, 5:31 PM CST	TSTM WND GST 70	Ralston, IA	WIND ESTIMATES OF AT LEAST 70 MPH FROM RALSTON FIRE DEPT. SOME SPORADIC DAMAGE BEGINNING TO OCCUR.
Dec 15, 5:34 PM CST	TORNADO	2 W Jefferson, IA	PUBLIC RELAYED POSSIBLE TORNADO DAMAGE WEST OF JEFFERSON, INCLUDING LARGE PORTION OF GARAGE DAMAGED/MISSING. TIME ESTIMATED FROM RADAR.
Dec 15, 5:35 PM CST	TSTM WND DMG	3 S Glidden, IA	OUTBUILDING DESTROYED AT 240TH ST. AND TIMBER AVE. SIZE OF BUILDING UNKNOWN.
Dec 15, 5:39 PM CST	TSTM WND DMG	Grand Junction, IA	PUBLIC RELAYED SIDING MISSING ON HOUSE ON SE SIDE OF GRAND JUNCTION. TIME ESTIMATED FROM RADAR.
Dec 15, 5:41 PM CST	TSTM WND DMG	2 Wnw Jefferson, IA	DAMAGE TO POWER POLES ALONG HIGHWAY 30 WEST OF JEFFERSON. REPORT VIA SOCIAL MEDIA. DELAYED REPORT AND TIME/LOCATION ESTIMATED BY RADAR.
Dec 15, 5:42 PM CST	TSTM WND DMG	3 Ne Ayrshire, IA	EXTENSIVE BUILDING DAMAGE TO THE NORTHEAST OF AYRSHIR.
Dec 15, 5:45 PM CST	TSTM WND DMG	2 Ese Ruthven, IA	HOG BUILDING COMPLETELY DESTROYED.
Dec 15, 5:45 PM CST	TSTM WND DMG	2 Se Graettinger, IA	DAMAGE TO OUTBUILDING AND TREES UPROOTED. TIME ESTIMATED FROM RADAR.
Dec 15, 5:45 PM CST	TORNADO	4 Sw Dana, IA	DAMAGE TO FARMSTEAD BUILDINGS NORTHEAST OF JEFFERSON NEAR INTERSECTION OF 195TH AND R AVE. TIME ESTIMATED BY RADAR. REPORT VIA SOCIAL MEDIA.
Dec 15, 5:48 PM CST	TSTM WND DMG	Knierim, IA	MACHINE SHED DAMAGED 1 MILE NORTH OF SOMERS AND STOP SIGNS/HIGHWAY SIGNS BLOWN OVER HWY 20 AT KNIERIM.
Dec 15, 5:49 PM CST	TSTM WND DMG	2 Wnw Harcourt, IA	EMERGENCY MANAGER RELAYED BUILDING/DEBRIS BLOWN ONTO HIGHWAY 175. TIME ESTIMATED FROM RADAR.
Dec 15, 5:49 PM CST	TORNADO	6 Ne Fraser, IA	LOCATION ESTIMATED BY RADAR. REPORT VIA SOCIAL MEDIA WITH VIDEO EVIDENCE. UNKNOWN DAMAGE. DELAYED REPORT.
Dec 15, 5:51 PM CST	TSTM WND DMG	3 Nw Harcourt, IA	POWERLINES AND POLES, OUTBUILDING AND TREE DAMAGE STARTING NEAR HARCOURT AND EXTENDING NORTHEAST TOWARDS DUNCOMBE IN WEBSTER COUNTY.
Dec 15, 6:00 PM CST	TORNADO	Bradgate, IA	PUBLIC REPORTED TORNADO ON THE GROUND. NO ADDITIONAL INFORMATION AT THIS TIME.
Dec 15, 6:02 PM CST	TSTM WND GST 73	3 Nnw Fort Dodge, IA
Dec 15, 6:12 PM CST	TORNADO	6 S Algona, IA	TORNADO CONFIRMED, APPROX 6 MILES SOUTH OF ALGONA.
Dec 15, 6:15 PM CST	TSTM WND DMG	Algona, IA	14 INCH DIAMETER TREE ON HOUSE.
Dec 15, 6:15 PM CST	TSTM WND GST 62	2 W Algona, IA
Dec 15, 6:15 PM CST	TSTM WND GST 67	2 Wnw Algona, IA
Dec 15, 6:15 PM CST	TSTM WND GST 70	2 W Algona, IA	NICKEL SIZED HAIL AT ALGONA AIRPORT, STRONG WINDS GUSTS 60 TO 70 MPH WINDS.

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, 11.3 hours before the alert went out and 230 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.

330 
WUUS53 KDMX 152319
SVRDMX
IAC015-025-027-063-073-091-109-147-151-161-187-160030-
/O.NEW.KDMX.SV.W.0124.211215T2319Z-211216T0030Z/

BULLETIN - EAS ACTIVATION REQUESTED
Severe Thunderstorm Warning
National Weather Service Des Moines IA
519 PM CST Wed Dec 15 2021

The National Weather Service in Des Moines  has issued a

* Severe Thunderstorm Warning for...
  Greene County in west central Iowa...
  Emmet County in northwestern Iowa...
  Webster County in central Iowa...
  Pocahontas County in northwestern Iowa...
  Eastern Sac County in west central Iowa...
  Kossuth County in north central Iowa...
  Calhoun County in west central Iowa...
  Humboldt County in north central Iowa...
  Boone County in central Iowa...
  Carroll County in west central Iowa...
  Palo Alto County in northwestern Iowa...

* Until 630 PM CST.

* At 518 PM CST, severe thunderstorms were located along a line
  extending from Sioux Rapids to near Coon Rapids, moving northeast
  at 80 mph.

  THESE ARE DESTRUCTIVE STORMS FOR portions of central Iowa.

  HAZARD...80 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...Flying debris will be dangerous to those caught without 
           shelter. Mobile homes will be heavily damaged. Expect 
           considerable damage to roofs, windows, and vehicles. 
           Extensive tree damage and power outages are likely.

* Severe thunderstorms will be near...
  Silver Lake and Rush Lake around 530 PM CST.
  Jefferson around 535 PM CST.

Other locations in the path of these severe thunderstorms include
Emmetsburg and Five Island Lake.

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 central, north
central, northwestern and west central Iowa.

&&

LAT...LON 4350 9424 4244 9393 4221 9393 4221 9387
      4187 9377 4187 9496 4350 9491
TIME...MOT...LOC 2318Z 237DEG 71KT 4288 9513 4192 9474 

TORNADO...POSSIBLE
THUNDERSTORM DAMAGE THREAT...DESTRUCTIVE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...80 MPH

$$

Cogil

4 follow-up statements

083 
WWUS53 KDMX 152348
SVSDMX

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

IAC027-161-152357-
/O.CAN.KDMX.SV.W.0124.000000T0000Z-211216T0030Z/
Sac IA-Carroll IA-
548 PM CST Wed Dec 15 2021

...THE SEVERE THUNDERSTORM WARNING FOR EASTERN SAC AND CARROLL
COUNTIES IS CANCELLED...

The storms which prompted the warning have moved out of the warned 
area. Therefore, the warning has been cancelled.

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

LAT...LON 4350 9424 4244 9393 4221 9393 4221 9387
      4187 9377 4187 9437 4279 9493 4350 9491
TIME...MOT...LOC 2347Z 237DEG 71KT 4319 9448 4223 9410 

$$

IAC015-025-063-073-091-109-147-151-187-160030-
/O.CON.KDMX.SV.W.0124.000000T0000Z-211216T0030Z/
Greene IA-Emmet IA-Webster IA-Pocahontas IA-Kossuth IA-Calhoun IA-
Humboldt IA-Boone IA-Palo Alto IA-
548 PM CST Wed Dec 15 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 630 PM CST
FOR GREENE...EMMET...WEBSTER...POCAHONTAS...KOSSUTH...EASTERN
CALHOUN...HUMBOLDT...BOONE AND PALO ALTO COUNTIES...

At 547 PM CST, severe thunderstorms were located along a line
extending from 9 miles east of Five Island Lake to 10 miles east of
Gowrie, moving northeast at 80 mph.

THESE ARE DESTRUCTIVE STORMS FOR portions of central and northern 
iowa.

HAZARD...80 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be heavily damaged. Expect 
         considerable damage to roofs, windows, and vehicles. 
         Extensive tree damage and power outages are likely.

These severe thunderstorms will remain over mainly rural areas of
Greene, Emmet, Webster, Pocahontas, Kossuth, eastern Calhoun,
Humboldt, Boone and Palo Alto Counties, including the following
locations... Ayrshire, Woodman Hollow State Park, Kearney State Park,
Curlew, Whittemore, Ottosen, Pomeroy, Jolley, Jefferson Municipal
Airport and Swea City.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 4350 9424 4244 9393 4221 9393 4221 9387
      4187 9377 4187 9437 4279 9493 4350 9491
TIME...MOT...LOC 2347Z 237DEG 71KT 4319 9448 4223 9410 

TORNADO...POSSIBLE
THUNDERSTORM DAMAGE THREAT...DESTRUCTIVE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...80 MPH

$$

Cogil

270 
WWUS53 KDMX 160002
SVSDMX

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

IAC015-025-063-073-091-109-147-151-187-160030-
/O.CON.KDMX.SV.W.0124.000000T0000Z-211216T0030Z/
Greene IA-Emmet IA-Webster IA-Pocahontas IA-Kossuth IA-Calhoun IA-
Humboldt IA-Boone IA-Palo Alto IA-
602 PM CST Wed Dec 15 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 630 PM CST
FOR NORTHEASTERN GREENE...EMMET...WEBSTER...EASTERN POCAHONTAS...
KOSSUTH...NORTHEASTERN CALHOUN...HUMBOLDT...BOONE AND PALO ALTO
COUNTIES...

At 601 PM CST, severe thunderstorms were located along a line
extending from 6 miles north of Union Slogh to near Webster City,
moving northeast at 80 mph.

THESE ARE DESTRUCTIVE STORMS FOR portions of central and northern 
iowa.

HAZARD...80 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be heavily damaged. Expect 
         considerable damage to roofs, windows, and vehicles. 
         Extensive tree damage and power outages are likely.

Locations impacted include...
Fort Dodge, Boone, Algona, Emmetsburg, Dakota City, Humboldt, Madrid,
Ogden, Gowrie, Swan Lake, Five Island Lake, Ingham Lake, Iowa Lake,
Fort Dodge Regional Airport, High Lake, Okamanpedan Lake, Boone
Speedway, Armstrong, Graettinger and Dayton.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 4350 9424 4244 9393 4221 9393 4221 9387
      4187 9377 4187 9417 4220 9424 4293 9476
      4350 9478
TIME...MOT...LOC 0001Z 237DEG 71KT 4334 9415 4238 9378 

TORNADO...POSSIBLE
THUNDERSTORM DAMAGE THREAT...DESTRUCTIVE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...80 MPH

$$

Cogil

105 
WWUS53 KDMX 160022
SVSDMX

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

IAC015-025-073-151-187-160032-
/O.CAN.KDMX.SV.W.0124.000000T0000Z-211216T0030Z/
Greene IA-Webster IA-Pocahontas IA-Calhoun IA-Boone IA-
622 PM CST Wed Dec 15 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN GREENE...
WEBSTER...EASTERN POCAHONTAS...NORTHEASTERN CALHOUN AND BOONE
COUNTIES IS CANCELLED...

The storms which prompted the warning have 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 4350 9424 4274 9402 4288 9433 4349 9454
TIME...MOT...LOC 0022Z 237DEG 71KT 4356 9369 4260 9332 

$$

IAC063-091-109-147-160030-
/O.CON.KDMX.SV.W.0124.000000T0000Z-211216T0030Z/
Emmet IA-Kossuth IA-Humboldt IA-Palo Alto IA-
622 PM CST Wed Dec 15 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 630 PM CST
FOR EASTERN EMMET...WESTERN KOSSUTH...NORTHEASTERN HUMBOLDT AND
NORTHEASTERN PALO ALTO COUNTIES...

At 622 PM CST, severe thunderstorms were located along a line
extending from near Mansfield to 6 miles northwest of Iowa Falls,
moving northeast at 80 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...
Algona, Iowa Lake, Armstrong, Bancroft, Swea City, Burt, Livermore,
Bode, Fenton, Lu Verne, Lone Rock, St. Joseph, Hardy, Irvington,
Stinson Prairie State Park, Algona Municipal Airport and Aa Call
State Park.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 4350 9424 4274 9402 4288 9433 4349 9454
TIME...MOT...LOC 0022Z 237DEG 71KT 4356 9369 4260 9332 

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

$$

Cogil

224 
WWUS53 KDMX 160033
SVSDMX

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

IAC063-091-109-147-160043-
/O.EXP.KDMX.SV.W.0124.000000T0000Z-211216T0030Z/
Emmet IA-Kossuth IA-Humboldt IA-Palo Alto IA-
633 PM CST Wed Dec 15 2021

...THE SEVERE THUNDERSTORM WARNING FOR EASTERN EMMET...WESTERN
KOSSUTH...NORTHEASTERN HUMBOLDT AND NORTHEASTERN PALO ALTO COUNTIES
HAS EXPIRED...
    
The storms which prompted the warning have moved out of the area.
Therefore, the warning has been allowed to expire.

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

LAT...LON 4350 9424 4274 9402 4288 9433 4349 9454
TIME...MOT...LOC 0033Z 237DEG 71KT 4365 9349 4269 9312 

$$

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, 5:22 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
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.