Alert archive / Iowa / Tornado Warnings in 2021
Tornado Warning 25, NWS Sioux Falls, SD
NWS Sioux Falls, SD issued this tornado warning at Dec 15, 2021, 5:15 PM CST for 4 counties in Iowa. It was in force for 30 min. 3 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, 5:15 PM CST (23:15 UTC)
- Expired
- Dec 15, 2021, 5:45 PM CST
- In force
- 30 min
- Issued by
- NWS Sioux Falls, SD
- Area
- Storm-based polygon
- Tornado
- Radar indicated
- Hail
- 0.75 in
Counties Buena Vista County, IA, Cherokee County, IA, Clay County, IA, O'Brien County, IA
The radar
The Sioux Falls radar (KFSD), 130 km from the middle of the area, began a volume at 23:15 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, 5:25 PM CST | TSTM WND DMG | 3 E Royal, IA | LARGE PINE TREE BLOW DOWN. TIME ESTIMATED FROM RADAR. |
| Dec 15, 5:31 PM CST | TSTM WND DMG | 1 Sse Spencer, IA | TREES DOWN IN TOWN. TIME ESTIMATED FROM RADAR. |
| Dec 15, 5:33 PM CST | TSTM WND GST 54 | 3 Wnw Spencer, IA |
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 207 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.
- 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
The text
As transmitted.
206
WFUS53 KFSD 152315
TORFSD
IAC021-035-041-141-152345-
/O.NEW.KFSD.TO.W.0025.211215T2315Z-211215T2345Z/
BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Sioux Falls SD
515 PM CST Wed Dec 15 2021
The National Weather Service in Sioux Falls has issued a
* Tornado Warning for...
Northeastern Cherokee County in northwestern Iowa...
Northwestern Buena Vista County in northwestern Iowa...
Western Clay County in northwestern Iowa...
Southeastern O'Brien County in northwestern Iowa...
* Until 545 PM CST.
* At 515 PM CST, a severe thunderstorm capable of producing a tornado
was located over Peterson, or 15 miles northeast of Cherokee,
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...
Royal around 525 PM CST.
Everly around 530 PM CST.
Spencer In Clay County and Fostoria around 535 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 4279 9532 4297 9561 4325 9538 4325 9500
TIME...MOT...LOC 2315Z 206DEG 61KT 4292 9534
TORNADO...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
$$
Chapman2 follow-up statements
121
WWUS53 KFSD 152328
SVSFSD
Severe Weather Statement
National Weather Service Sioux Falls SD
528 PM CST Wed Dec 15 2021
IAC021-035-141-152337-
/O.CAN.KFSD.TO.W.0025.000000T0000Z-211215T2345Z/
Cherokee IA-Buena Vista IA-O'Brien IA-
528 PM CST Wed Dec 15 2021
...THE TORNADO WARNING FOR NORTHEASTERN CHEROKEE...NORTHWESTERN BUENA
VISTA AND SOUTHEASTERN O'BRIEN COUNTIES IS CANCELLED...
The tornadic thunderstorm which prompted the warning has moved out
of the warned area. Therefore, the warning has been cancelled.
A Tornado Watch remains in effect until 800 PM CST for northwestern
Iowa.
LAT...LON 4297 9520 4304 9539 4325 9538 4325 9500
TIME...MOT...LOC 2327Z 206DEG 61KT 4311 9521
$$
IAC041-152345-
/O.CON.KFSD.TO.W.0025.000000T0000Z-211215T2345Z/
Clay IA-
528 PM CST Wed Dec 15 2021
...A TORNADO WARNING REMAINS IN EFFECT UNTIL 545 PM CST FOR WESTERN
CLAY COUNTY...
At 527 PM CST, a severe thunderstorm capable of producing a tornado
was located between Spencer and Royal, 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...
Fostoria around 535 PM CST.
Other locations impacted by this tornadic thunderstorm include
Rossie.
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 4297 9520 4304 9539 4325 9538 4325 9500
TIME...MOT...LOC 2327Z 206DEG 61KT 4311 9521
TORNADO...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
$$
Chapman304
WWUS53 KFSD 152344
SVSFSD
Severe Weather Statement
National Weather Service Sioux Falls SD
544 PM CST Wed Dec 15 2021
IAC041-152353-
/O.EXP.KFSD.TO.W.0025.000000T0000Z-211215T2345Z/
Clay IA-
544 PM CST Wed Dec 15 2021
...THE TORNADO WARNING FOR WESTERN CLAY COUNTY WILL EXPIRE AT 545 PM
CST...
The tornadic thunderstorm which prompted the warning has weakened
and moved out of the warned area. Therefore, the warning will be
allowed to expire. However, gusty winds are still possible with
this thunderstorm.
A Tornado Watch remains in effect until 800 PM CST for northwestern
Iowa along the highway 71 corridor.
LAT...LON 4297 9520 4304 9539 4325 9538 4325 9500
TIME...MOT...LOC 2343Z 204DEG 45KT 4325 9512
$$
ChapmanThe 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 | 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 | 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 | 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 | FSD | O'Brien, Sioux | 39 min |
| Dec 15, 4:56 PM CST | Severe Thunderstorm Warning | 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, 5:29 PM CST | Severe Thunderstorm Warning | FSD | Dickinson | 46 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.