Alert archive / Iowa / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 176, NWS Sioux Falls, SD

December 15, 2021Dickinson County, Iowa; Jackson County, Minnesota

NWS Sioux Falls, SD issued this severe thunderstorm warning at Dec 15, 2021, 5:29 PM CST for Dickinson County, Iowa; Jackson County, Minnesota. It was in force for 46 min. 4 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, 5:29 PM CST (23:29 UTC)
Expired: Dec 15, 2021, 6:15 PM CST
In force: 46 min
Issued by: NWS Sioux Falls, SD
Area: Storm-based polygon
Tornado: Possible
Damage threat: Considerable
Hail: 0.75 in
Wind: 70.0 mph

Counties Dickinson County, IA, Jackson County, MN

The radar

The Sioux Falls radar (KFSD), 136 km from the middle of the area, began a volume at 23:28 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, 5:35 PM CST	TSTM WND GST 60	8 Wsw Milford, IA
Dec 15, 5:40 PM CST	TSTM WND DMG	4 Ene Fostoria, IA	ROOF GONE OFF OF A LARGE SHED, 2-3 TREES UPROOTED AND SEVERAL POWER POLES WERE KNOCKED DOWN. TIME ESTIMATED FROM RADAR.
Dec 15, 5:49 PM CST	TSTM WND DMG	1 E Spirit Lake, IA	POWER POLES DOWN IN TOWN. TIME ESTIMATED FROM RADAR.
Dec 15, 5:52 PM CST	TSTM WND DMG	Superior, IA	LARGE BRANCHES DOWN AND SHINGLES OFF OF ROOF. GARAGE BLOWN OFF OF FOUNDATION. TIME ESTIMATED FROM RADAR.

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, 11.5 hours before the alert went out and 187 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.

236 
WUUS53 KFSD 152329
SVRFSD
IAC059-MNC063-160015-
/O.NEW.KFSD.SV.W.0176.211215T2329Z-211216T0015Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Sioux Falls SD
529 PM CST Wed Dec 15 2021

The National Weather Service in Sioux Falls has issued a

* Severe Thunderstorm Warning for...
  Dickinson County in northwestern Iowa...
  Jackson County in southwestern Minnesota...

* Until 615 PM CST.

* At 528 PM CST, severe thunderstorms were located along a line
  extending from 8 miles south of Harris to near Lost Island Lake,
  moving north at 70 mph.

  HAZARD...70 mph wind gusts and penny size hail.

  SOURCE...Radar indicated.

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

* Severe thunderstorms will be near...
  Lake Park and Terril around 535 PM CST.
  Superior around 545 PM CST.
  Jackson around 555 PM CST. 

Other locations in the path of these severe thunderstorms include
Lakefield.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This is a DANGEROUS SITUATION. These storms are producing widespread 
wind damage across parts of Nebraska and northwest Iowa. SEEK 
SHELTER NOW inside a sturdy structure and stay away from windows! A 
Tornado Watch remains in effect until 800 PM CST for northwestern 
Iowa...and southwestern Minnesota.

&&

LAT...LON 4350 9488 4350 9491 4326 9491 4326 9539
      4350 9538 4385 9511 4384 9486
TIME...MOT...LOC 2328Z 195DEG 63KT 4333 9543 4315 9494 

TORNADO...POSSIBLE
THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...70 MPH

$$

Weisser

2 follow-up statements

115 
WWUS53 KFSD 152344 RRA
SVSFSD

Severe Weather Statement
National Weather Service Sioux Falls SD
544 PM CST Wed Dec 15 2021

IAC059-MNC063-160015-
/O.CON.KFSD.SV.W.0176.000000T0000Z-211216T0015Z/
Dickinson IA-Jackson MN-
544 PM CST Wed Dec 15 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 615 PM CST
FOR DICKINSON AND JACKSON COUNTIES...

At 544 PM CST, severe thunderstorms were located along a line
extending from near Harris to near Terril, moving north at 45 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...
  Lake Park, Superior, Jackson In Jackson County and Bergen.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Tornado Watch remains in effect until 800 PM CST for northwestern
Iowa...and southwestern Minnesota.

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

&&

LAT...LON 4350 9488 4350 9491 4326 9491 4326 9539
      4350 9538 4385 9511 4384 9486
TIME...MOT...LOC 2344Z 184DEG 40KT 4344 9538 4326 9489 

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

$$

Weisser

216 
WWUS53 KFSD 160009
SVSFSD

Severe Weather Statement
National Weather Service Sioux Falls SD
609 PM CST Wed Dec 15 2021

IAC059-MNC063-160018-
/O.EXP.KFSD.SV.W.0176.000000T0000Z-211216T0015Z/
Dickinson IA-Jackson MN-
609 PM CST Wed Dec 15 2021

...THE SEVERE THUNDERSTORM WARNING FOR DICKINSON AND JACKSON COUNTIES
WILL EXPIRE AT 615 PM CST...
    
The storms which prompted the warning have moved out of the area.
Therefore, the warning will be allowed to expire.  However gusty
winds are still possible with these thunderstorms.

LAT...LON 4350 9488 4350 9491 4326 9491 4326 9539
      4350 9538 4385 9511 4384 9486
TIME...MOT...LOC 0008Z 195DEG 63KT 4384 9523 4366 9474 

$$

Weisser

The office that day

Everything else NWS Sioux Falls, SD issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Dec 15, 2:56 AM CST	Dense Fog Advisory	FSD	Buena Vista, Cherokee, Clay, Dickinson, Ida, Lyon and 5 more	6 hr
Dec 15, 3:23 PM CST	Severe Thunderstorm Warning Considerable damage threat	FSD	Plymouth, Woodbury	67 min
Dec 15, 4:00 PM CST	Tornado Warning	FSD	Woodbury	45 min
Dec 15, 4:05 PM CST	Severe Thunderstorm Warning Considerable damage threat	FSD	Buena Vista, Cherokee, Ida, Plymouth, Woodbury	55 min
Dec 15, 4:17 PM CST	Tornado Warning	FSD	Plymouth, Woodbury	28 min
Dec 15, 4:26 PM CST	Severe Thunderstorm Warning Considerable damage threat	FSD	Plymouth, Woodbury	34 min
Dec 15, 4:31 PM CST	Tornado Warning	FSD	Ida, Plymouth, Woodbury	29 min
Dec 15, 4:32 PM CST	Tornado Warning	FSD	Plymouth, Woodbury	28 min
Dec 15, 4:42 PM CST	Tornado Warning	FSD	Buena Vista, Cherokee, Clay, Ida, O'Brien, Plymouth and 1 more	33 min
Dec 15, 4:51 PM CST	Severe Thunderstorm Warning Considerable damage threat	FSD	O'Brien, Sioux	39 min
Dec 15, 4:56 PM CST	Severe Thunderstorm Warning Destructive damage threat	FSD	Buena Vista, Cherokee, Clay, Ida	46 min
Dec 15, 5:08 PM CST	Tornado Warning	FSD	Buena Vista, Cherokee, Clay	37 min
Dec 15, 5:15 PM CST	Tornado Warning	FSD	Buena Vista, Cherokee, Clay, O'Brien	30 min
Dec 15, 9:01 AM CST	Dense Fog Advisory	FSD	Cottonwood, Jackson, Lincoln, Lyon, Murray, Nobles and 2 more	119 min

Nearby

Severe Thunderstorm Warnings in Iowa, 2021 Severe Thunderstorm Warnings in Minnesota, 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.