Alert archive / Iowa / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 8, NWS Sioux Falls, SD
NWS Sioux Falls, SD issued this severe thunderstorm warning at Apr 5, 2021, 10:07 PM CDT for Nobles County, Rock County, Minnesota; Lyon County, O'Brien County, Osceola County, Iowa. It was in force for 53 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
- Apr 5, 2021, 10:07 PM CDT (03:07 UTC)
- Expired
- Apr 5, 2021, 11:00 PM CDT
- In force
- 53 min
- Issued by
- NWS Sioux Falls, SD
- Area
- Storm-based polygon
- Hail
- 1.25 in
- Wind
- 60.0 mph
Counties Lyon County, IA, O'Brien County, IA, Osceola County, IA, Nobles County, MN, Rock County, MN
The radar
The Sioux Falls radar (KFSD), 75 km from the middle of the area, began a volume at 03:10 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 |
|---|---|---|---|
| Apr 5, 10:18 PM CDT | HAIL 0.75 | Ellsworth, MN | ALSO REPORTED 50 MPH WINDS WITH THE HAIL. |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
The nearest sounding before it
Omaha, NE (KOAX), launched 00:00Z, 3.1 hours before the alert went out and 226 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
- 820 J/kg
- Mixed-layer CIN
- -127 J/kg
- Mixed-layer LCL
- 2210 m above ground
- 0-6 km bulk shear
- 20 kt
- 0-1 km storm-relative helicity
- 95 m²/s²
- 0-3 km storm-relative helicity
- 170 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 1.4
The text
As transmitted.
511
WUUS53 KFSD 060307
SVRFSD
IAC119-141-143-MNC105-133-060400-
/O.NEW.KFSD.SV.W.0008.210406T0307Z-210406T0400Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Sioux Falls SD
1007 PM CDT Mon Apr 5 2021
The National Weather Service in Sioux Falls has issued a
* Severe Thunderstorm Warning for...
Eastern Lyon County in northwestern Iowa...
Osceola County in northwestern Iowa...
Northwestern O'Brien County in northwestern Iowa...
Southeastern Rock County in southwestern Minnesota...
Southern Nobles County in southwestern Minnesota...
* Until 1100 PM CDT.
* At 1007 PM CDT, a severe thunderstorm was located over Rock Rapids,
moving east at 35 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...
Ellsworth around 1015 PM CDT.
George around 1020 PM CDT.
Little Rock around 1030 PM CDT.
Sibley and Ashton around 1040 PM CDT.
Melvin around 1055 PM CDT.
Other locations impacted by this severe thunderstorm include Bigelow
and Steen.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 4320 9562 4324 9587 4326 9587 4326 9598
4331 9630 4354 9625 4356 9551
TIME...MOT...LOC 0307Z 276DEG 31KT 4344 9613
HAIL...1.25IN
WIND...60MPH
$$
SG3 follow-up statements
327
WWUS53 KFSD 060327
SVSFSD
Severe Weather Statement
National Weather Service Sioux Falls SD
1027 PM CDT Mon Apr 5 2021
MNC133-060337-
/O.CAN.KFSD.SV.W.0008.000000T0000Z-210406T0400Z/
Rock MN-
1027 PM CDT Mon Apr 5 2021
...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN ROCK COUNTY IS
CANCELLED...
The severe thunderstorm which prompted the warning has moved out of
the warned area. Therefore, the warning has been cancelled.
LAT...LON 4320 9562 4324 9587 4326 9587 4326 9598
4332 9616 4355 9604 4356 9551
TIME...MOT...LOC 0327Z 271DEG 31KT 4345 9588
$$
IAC119-141-143-MNC105-060400-
/O.CON.KFSD.SV.W.0008.000000T0000Z-210406T0400Z/
Lyon IA-Osceola IA-O'Brien IA-Nobles MN-
1027 PM CDT Mon Apr 5 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1100 PM CDT
FOR EASTERN LYON...OSCEOLA...NORTHWESTERN O'BRIEN AND SOUTHERN NOBLES
COUNTIES...
At 1027 PM CDT, a severe thunderstorm was located over Little Rock,
or 7 miles northwest of Sibley, moving east at 35 mph.
HAZARD...60 mph wind gusts and quarter size hail.
SOURCE...Radar indicated.
IMPACT...Hail damage to vehicles is expected. Expect wind damage to
roofs, siding, and trees.
This severe storm will be near...
Sibley around 1040 PM CDT.
Other locations impacted by this severe thunderstorm include Bigelow.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 4320 9562 4324 9587 4326 9587 4326 9598
4332 9616 4355 9604 4356 9551
TIME...MOT...LOC 0327Z 271DEG 31KT 4345 9588
HAIL...1.00IN
WIND...60MPH
$$
SG599
WWUS53 KFSD 060346
SVSFSD
Severe Weather Statement
National Weather Service Sioux Falls SD
1046 PM CDT Mon Apr 5 2021
IAC119-141-060355-
/O.CAN.KFSD.SV.W.0008.000000T0000Z-210406T0400Z/
Lyon IA-O'Brien IA-
1046 PM CDT Mon Apr 5 2021
...THE SEVERE THUNDERSTORM WARNING FOR EASTERN LYON AND NORTHWESTERN
O'BRIEN COUNTIES IS CANCELLED...
The severe thunderstorm which prompted the warning has moved out of
the warned area. Therefore, the warning has been cancelled.
LAT...LON 4326 9560 4325 9571 4326 9585 4356 9582
4356 9551
TIME...MOT...LOC 0345Z 276DEG 31KT 4343 9566
$$
IAC143-MNC105-060400-
/O.CON.KFSD.SV.W.0008.000000T0000Z-210406T0400Z/
Osceola IA-Nobles MN-
1046 PM CDT Mon Apr 5 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1100 PM CDT
FOR WESTERN OSCEOLA AND SOUTHEASTERN NOBLES COUNTIES...
At 1045 PM CDT, a severe thunderstorm was located near Sibley, moving
east at 35 mph.
HAZARD...60 mph wind gusts and quarter size hail.
SOURCE...Radar indicated.
IMPACT...Hail damage to vehicles is expected. Expect wind damage to
roofs, siding, and trees.
This severe thunderstorm will remain over mainly rural areas of
western Osceola and southeastern Nobles Counties, including the
following locations... Bigelow.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 4326 9560 4325 9571 4326 9585 4356 9582
4356 9551
TIME...MOT...LOC 0345Z 276DEG 31KT 4343 9566
HAIL...1.00IN
WIND...60MPH
$$
SG863
WWUS53 KFSD 060352
SVSFSD
Severe Weather Statement
National Weather Service Sioux Falls SD
1052 PM CDT Mon Apr 5 2021
IAC143-MNC105-060401-
/O.EXP.KFSD.SV.W.0008.000000T0000Z-210406T0400Z/
Osceola IA-Nobles MN-
1052 PM CDT Mon Apr 5 2021
...THE SEVERE THUNDERSTORM WARNING FOR WESTERN OSCEOLA AND
SOUTHEASTERN NOBLES COUNTIES WILL EXPIRE AT 1100 PM CDT...
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning will be allowed to expire. However gusty
winds up to 50 mph are still possible with this thunderstorm.
LAT...LON 4326 9560 4325 9571 4326 9585 4356 9582
4356 9551
TIME...MOT...LOC 0351Z 276DEG 31KT 4343 9561
$$
SGThe office that day
Everything else NWS Sioux Falls, SD issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 5, 7:39 PM CDT | Severe Thunderstorm Warning | FSD | Pipestone | 36 min |
| Apr 5, 9:27 PM CDT | Severe Thunderstorm Warning | FSD | Rock | 33 min |
| Apr 5, 9:48 PM CDT | Severe Thunderstorm Warning | FSD | Rock | 27 min |
Nearby
Severe Thunderstorm Warnings in Iowa, 2021Severe Thunderstorm Warnings in Minnesota, 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.