Alert archive / Iowa / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 112, NWS Sioux Falls, SD
NWS Sioux Falls, SD issued this severe thunderstorm warning at Aug 27, 2021, 12:34 AM CDT for Plymouth County, Sioux County, Iowa; Lincoln County, Union County, South Dakota. It was in force for 41 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
- Aug 27, 2021, 12:34 AM CDT (05:34 UTC)
- Expired
- Aug 27, 2021, 1:15 AM CDT
- In force
- 41 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 Plymouth County, IA, Sioux County, IA, Lincoln County, SD, Union County, SD
The radar
The Sioux Falls radar (KFSD), 71 km from the middle of the area, began a volume at 05:35 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 |
|---|---|---|---|
| Aug 27, 1:05 AM CDT | HAIL 1 | 3 S Rock Valley, IA | SPOTTER REPORTS HEAVY RAIN, GREEN SNAPPED CORN, DEAD BIRDS, HOLES IN SIDING AND APPROXIMATELY QUARTER SIZED HAIL. |
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 |
|---|---|---|---|
| Aug 26, 8:03 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
The nearest sounding before it
Omaha, NE (KOAX), launched 00:00Z, 5.6 hours before the alert went out and 185 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
- 5342 J/kg
- Mixed-layer CIN
- -16 J/kg
- Mixed-layer LCL
- 1163 m above ground
- 0-6 km bulk shear
- 27 kt
- 0-1 km storm-relative helicity
- 111 m²/s²
- 0-3 km storm-relative helicity
- 199 m²/s²
- Significant tornado parameter
- 3.8
- Supercell composite
- 24.0
The text
As transmitted.
824
WUUS53 KFSD 270534
SVRFSD
IAC149-167-SDC083-127-270615-
/O.NEW.KFSD.SV.W.0112.210827T0534Z-210827T0615Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Sioux Falls SD
1234 AM CDT Fri Aug 27 2021
The National Weather Service in Sioux Falls has issued a
* Severe Thunderstorm Warning for...
Sioux County in northwestern Iowa...
Northern Plymouth County in northwestern Iowa...
Southern Lincoln County in southeastern South Dakota...
Northern Union County in southeastern South Dakota...
* Until 115 AM CDT.
* At 1233 AM CDT, severe thunderstorms were located along a line
extending from near Newton Hills State Park to near Alcester to 6
miles west of Akron, moving east at 40 mph.
HAZARD...70 mph wind gusts.
SOURCE...Radar indicated.
IMPACT...Expect considerable tree damage. Damage is likely to
mobile homes, roofs, and outbuildings.
* Severe thunderstorms will be near...
Hawarden around 1240 AM CDT.
Fairview around 1245 AM CDT.
Hudson around 1250 AM CDT.
Other locations in the path of these severe thunderstorms include
Ireton, Rock Valley, Craig, Sioux Center, Maurice, Struble, Le Mars,
Orange City, Hull, Alton and Boyden.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
Torrential rainfall is occurring with these storms, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.
&&
LAT...LON 4280 9679 4303 9678 4323 9682 4326 9596
4302 9591 4275 9603
TIME...MOT...LOC 0533Z 270DEG 34KT 4319 9665 4303 9657 4283 9668
TORNADO...POSSIBLE
THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...70 MPH
$$
SG1 follow-up statement
646
WWUS53 KFSD 270553
SVSFSD
Severe Weather Statement
National Weather Service Sioux Falls SD
1253 AM CDT Fri Aug 27 2021
IAC149-167-SDC083-127-270615-
/O.CON.KFSD.SV.W.0112.000000T0000Z-210827T0615Z/
Sioux IA-Plymouth IA-Lincoln SD-Union SD-
1253 AM CDT Fri Aug 27 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 115 AM CDT
FOR SIOUX...NORTHERN PLYMOUTH...SOUTHEASTERN LINCOLN AND NORTHEASTERN
UNION COUNTIES...
At 1253 AM CDT, severe thunderstorms were located along a line
extending from near Rock Valley to near Ireton to 6 miles east of
Akron, moving east at 40 mph.
HAZARD...70 mph wind gusts.
SOURCE...Radar indicated.
IMPACT...Expect considerable tree damage. Damage is likely to mobile
homes, roofs, and outbuildings.
Locations impacted include...
Sioux Center, Maurice, Struble, Le Mars, Orange City, Hull, Alton
and Boyden.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
Torrential rainfall is occurring with these storms, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.
&&
LAT...LON 4279 9660 4301 9648 4324 9652 4326 9596
4302 9591 4275 9603
TIME...MOT...LOC 0553Z 270DEG 34KT 4319 9639 4303 9631 4283 9642
TORNADO...POSSIBLE
THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...70 MPH
$$
SGThe office that day
Everything else NWS Sioux Falls, SD issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 27, 12:17 AM CDT | Severe Thunderstorm Warning | FSD | Lyon, Sioux | 28 min |
| Aug 27, 1:04 AM CDT | Tornado Warning | FSD | Sioux | 26 min |
| Aug 27, 1:09 AM CDT | Severe Thunderstorm Warning | FSD | Cherokee, Lyon, O'Brien, Osceola, Plymouth, Sioux | 51 min |
| Aug 27, 1:25 AM CDT | Severe Thunderstorm Warning | FSD | Cherokee, Ida, Plymouth, Woodbury | 50 min |
| Aug 27, 1:52 AM CDT | Severe Thunderstorm Warning | FSD | Buena Vista, Cherokee, Clay, Dickinson, O'Brien, Osceola | 68 min |
| Aug 27, 2:00 AM CDT | Severe Thunderstorm Warning | FSD | Buena Vista | 60 min |
| Aug 26, 11:05 PM CDT | Severe Thunderstorm Warning | FSD | Hutchinson, Turner, Yankton | 25 min |
| Aug 27, 12:08 AM CDT | Severe Thunderstorm Warning | FSD | Clay, Lincoln, Turner, Union | 37 min |
Nearby
Severe Thunderstorm Warnings in Iowa, 2021Severe Thunderstorm Warnings in South Dakota, 2021Every 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.