Alert archive / Iowa / Tornado Warnings in 2021
Tornado Warning 3, NWS Sioux Falls, SD
NWS Sioux Falls, SD issued this tornado warning at Aug 8, 2021, 5:26 PM CDT for Clay County, Dickinson County, O'Brien County, Iowa. It was in force for 49 min. No storm report in the archive falls inside the area while it was in force.
The area
The outline as issued.
The facts
- Issued
- Aug 8, 2021, 5:26 PM CDT (22:26 UTC)
- Expired
- Aug 8, 2021, 6:15 PM CDT
- In force
- 49 min
- Issued by
- NWS Sioux Falls, SD
- Area
- Storm-based polygon
- Tornado
- Radar indicated
- Hail
- 1.0 in
Counties Clay County, IA, Dickinson County, IA, O'Brien County, IA
The radar
The Sioux Falls radar (KFSD), 120 km from the middle of the area, began a volume at 22:29 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.
The nearest sounding before it
Omaha, NE (KOAX), launched 12:00Z, 10.4 hours before the alert went out and 225 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
- 1480 m above ground
- 0-6 km bulk shear
- 11 kt
- 0-1 km storm-relative helicity
- 50 m²/s²
- 0-3 km storm-relative helicity
- 109 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
943
WFUS53 KFSD 082226
TORFSD
IAC041-059-141-082315-
/O.NEW.KFSD.TO.W.0003.210808T2226Z-210808T2315Z/
BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Sioux Falls SD
526 PM CDT Sun Aug 8 2021
The National Weather Service in Sioux Falls has issued a
* Tornado Warning for...
Southwestern Dickinson County in northwestern Iowa...
Northwestern Clay County in northwestern Iowa...
Northeastern O'Brien County in northwestern Iowa...
* Until 615 PM CDT.
* At 525 PM CDT, a severe thunderstorm capable of producing a tornado
was located 8 miles north of Everly, or 14 miles northwest of
Spencer In Clay County, moving southeast at 20 mph.
HAZARD...Tornado and quarter size hail.
SOURCE...Weather spotters reported funnel cloud.
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...
Everly and Spencer In Clay County.
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 4306 9540 4326 9543 4326 9539 4328 9539
4332 9531 4313 9506
TIME...MOT...LOC 2225Z 326DEG 18KT 4328 9537
TORNADO...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
$$
Kalin2 follow-up statements
045
WWUS53 KFSD 082250
SVSFSD
Severe Weather Statement
National Weather Service Sioux Falls SD
550 PM CDT Sun Aug 8 2021
IAC059-141-082259-
/O.CAN.KFSD.TO.W.0003.000000T0000Z-210808T2315Z/
Dickinson IA-O'Brien IA-
550 PM CDT Sun Aug 8 2021
...THE TORNADO WARNING FOR SOUTHWESTERN DICKINSON AND NORTHEASTERN
O'BRIEN COUNTIES IS CANCELLED...
The tornadic thunderstorm which prompted the warning has moved out
of the warned area. Therefore, the warning has been cancelled.
LAT...LON 4308 9533 4316 9539 4319 9539 4326 9528
4326 9523 4313 9506 4313 9509
TIME...MOT...LOC 2249Z 322DEG 19KT 4318 9525
$$
IAC041-082315-
/O.CON.KFSD.TO.W.0003.000000T0000Z-210808T2315Z/
Clay IA-
550 PM CDT Sun Aug 8 2021
...A TORNADO WARNING REMAINS IN EFFECT UNTIL 615 PM CDT FOR
NORTHWESTERN CLAY COUNTY...
At 549 PM CDT, a severe thunderstorm capable of producing a tornado
was located near Everly, or near Spencer In Clay County, moving
southeast at 20 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...
Spencer In Clay County and Everly.
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 4308 9533 4316 9539 4319 9539 4326 9528
4326 9523 4313 9506 4313 9509
TIME...MOT...LOC 2249Z 322DEG 19KT 4318 9525
TORNADO...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
$$
Kalin752
WWUS53 KFSD 082315
SVSFSD
Severe Weather Statement
National Weather Service Sioux Falls SD
615 PM CDT Sun Aug 8 2021
IAC041-082325-
/O.EXP.KFSD.TO.W.0003.000000T0000Z-210808T2315Z/
Clay IA-
615 PM CDT Sun Aug 8 2021
...THE TORNADO WARNING FOR NORTHWESTERN CLAY COUNTY HAS EXPIRED...
The storm which prompted the warning has weakened below severe
limits, and no longer appears capable of producing a tornado.
Therefore, the warning has been allowed to expire. However heavy
rain is still possible with this thunderstorm.
LAT...LON 4308 9533 4316 9539 4319 9539 4326 9528
4326 9523 4313 9506 4313 9509
TIME...MOT...LOC 2315Z 325DEG 16KT 4309 9516
$$
SGThe office that day
Everything else NWS Sioux Falls, SD issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 8, 4:10 PM CDT | Severe Thunderstorm Warning | FSD | Osceola | 50 min |
| Aug 8, 4:29 PM CDT | Tornado Warning | FSD | Osceola | 31 min |
| Aug 8, 4:50 PM CDT | Severe Thunderstorm Warning | FSD | Clay, Dickinson, O'Brien, Osceola | 55 min |
| Aug 8, 6:31 PM CDT | Tornado Warning | FSD | Buena Vista, Clay | 44 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.