Alert archive / Minnesota / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 125, NWS Sioux Falls, SD
NWS Sioux Falls, SD issued this severe thunderstorm warning at Aug 28, 2021, 5:34 PM CDT for Rock County, Minnesota; Lyon County, Iowa. It was in force for 17 min. 2 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
- Aug 28, 2021, 5:34 PM CDT (22:34 UTC)
- Expired
- Aug 28, 2021, 5:51 PM CDT
- In force
- 17 min
- Issued by
- NWS Sioux Falls, SD
- Area
- Storm-based polygon
- Hail
- 1.25 in
- Wind
- 60.0 mph
Counties Lyon County, IA, Rock County, MN
The radar
The Sioux Falls radar (KFSD), 39 km from the middle of the area, began a volume at 22:36 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 28, 5:38 PM CDT | HAIL 1 | Hills, MN | DELAYED REPORT. MOST OF THE HAIL WAS DIMES OR SMALLER, BUT THERE WERE A FEW QUARTER-SIZED HAIL STONES. |
| Aug 28, 5:40 PM CDT | TSTM WND DMG | Hills, MN | DELAYED REPORT. TREES REPORTED DOWN, DIAMETER OF THE TRUNKS WAS 2-3 FEET. A POWER LINE WAS KNOCKED DOWN AS WELL, RESULTING IN POWER OUTAGE OF ABOUT 3 HOURS. |
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 28, 3:44 PM CDT | Tornado Watch | SPC | 5 hr |
| Aug 28, 3:57 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
The nearest sounding before it
Aberdeen, SD (KABR), launched 12:00Z, 10.6 hours before the alert went out and 224 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
- 9 J/kg
- Mixed-layer CIN
- -334 J/kg
- Mixed-layer LCL
- 1540 m above ground
- 0-6 km bulk shear
- 61 kt
- 0-1 km storm-relative helicity
- 25 m²/s²
- 0-3 km storm-relative helicity
- 558 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.9
The text
As transmitted.
899
WUUS53 KFSD 282234
SVRFSD
IAC119-MNC133-282315-
/O.NEW.KFSD.SV.W.0125.210828T2234Z-210828T2315Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Sioux Falls SD
534 PM CDT Sat Aug 28 2021
The National Weather Service in Sioux Falls has issued a
* Severe Thunderstorm Warning for...
North central Lyon County in northwestern Iowa...
Southern Rock County in southwestern Minnesota...
* Until 615 PM CDT.
* At 534 PM CDT, a severe thunderstorm was located near Larchwood, or
13 miles west of Rock Rapids, moving northeast at 30 mph.
HAZARD...60 mph wind gusts and half dollar size hail.
SOURCE...Radar indicated.
IMPACT...Hail damage to vehicles is expected. Expect wind damage
to roofs, siding, and trees.
* This severe thunderstorm will be near...
Hills around 540 PM CDT.
Beaver Creek around 550 PM CDT.
Luverne around 605 PM CDT.
Blue Mounds State Park around 610 PM CDT.
Other locations impacted by this severe thunderstorm include Steen.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
A Tornado Watch remains in effect until 900 PM CDT for southwestern
Minnesota.
For your protection move to an interior room on the lowest floor of a
building.
A Tornado Watch remains in effect until 900 PM CDT for southwestern
Minnesota.
&&
LAT...LON 4375 9624 4360 9605 4359 9605 4346 9642
4351 9645
TIME...MOT...LOC 2234Z 230DEG 26KT 4350 9642
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.25 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
APT1 follow-up statement
513
WWUS53 KFSD 282251
SVSFSD
Severe Weather Statement
National Weather Service Sioux Falls SD
551 PM CDT Sat Aug 28 2021
IAC119-MNC133-282300-
/O.CAN.KFSD.SV.W.0125.000000T0000Z-210828T2315Z/
Lyon IA-Rock MN-
551 PM CDT Sat Aug 28 2021
...THE SEVERE THUNDERSTORM WARNING FOR NORTH CENTRAL LYON AND
SOUTHERN ROCK COUNTIES IS CANCELLED...
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning has been cancelled. However gusty winds are
still possible with this thunderstorm.
A Tornado Watch remains in effect until 900 PM CDT for southwestern
Minnesota.
A Severe Thunderstorm Watch remains in effect until 900 PM CDT for
northwestern Iowa.
LAT...LON 4375 9624 4360 9605 4359 9605 4346 9642
4351 9645
TIME...MOT...LOC 2250Z 230DEG 26KT 4358 9629
$$
APTThe office that day
Everything else NWS Sioux Falls, SD issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 28, 4:45 PM CDT | Tornado Warning | FSD | Rock | 30 min |
| Aug 28, 4:49 PM CDT | Severe Thunderstorm Warning | FSD | Nobles, Rock | 41 min |
| Aug 28, 5:00 PM CDT | Severe Thunderstorm Warning | FSD | Nobles, Rock | 45 min |
| Aug 28, 5:06 PM CDT | Tornado Warning | FSD | Murray, Nobles, Pipestone, Rock | 24 min |
| Aug 28, 5:24 PM CDT | Tornado Warning | FSD | Nobles | 36 min |
| Aug 28, 5:26 PM CDT | Severe Thunderstorm Warning | FSD | Cottonwood, Jackson, Murray, Nobles, Pipestone, Rock | 34 min |
| Aug 28, 5:26 PM CDT | Tornado Warning | FSD | Cottonwood, Murray | 34 min |
| Aug 28, 5:29 PM CDT | Severe Thunderstorm Warning | FSD | Cottonwood, Jackson, Murray, Nobles, Pipestone, Rock | 31 min |
| Aug 28, 5:43 PM CDT | Tornado Warning | FSD | Cottonwood, Murray | 32 min |
| Aug 28, 5:45 PM CDT | Severe Thunderstorm Warning | FSD | Cottonwood, Jackson, Murray, Nobles | 45 min |
| Aug 28, 5:49 PM CDT | Tornado Warning | FSD | Cottonwood, Jackson, Murray, Nobles | 26 min |
| Aug 28, 6:01 PM CDT | Tornado Warning | FSD | Cottonwood | 30 min |
| Aug 28, 6:15 PM CDT | Severe Thunderstorm Warning | FSD | Pipestone, Rock | 45 min |
| Aug 28, 6:53 PM CDT | Severe Thunderstorm Warning | FSD | Rock | 52 min |
| Aug 28, 4:23 PM CDT | Severe Thunderstorm Warning | FSD | Lyon, Sioux | 37 min |
| Aug 28, 4:39 PM CDT | Tornado Warning | FSD | Lyon | 36 min |
| Aug 28, 6:44 PM CDT | Severe Thunderstorm Warning | FSD | Lyon | 46 min |
Nearby
Severe Thunderstorm Warnings in Minnesota, 2021Severe Thunderstorm Warnings in Iowa, 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.