Alert archive / South Dakota / Severe Thunderstorm Warnings in 2026

Severe Thunderstorm Warning 282, NWS Sioux Falls, SD

September 7, 2026Bon Homme County, Yankton County, South Dakota

NWS Sioux Falls, SD issued this severe thunderstorm warning at Sep 7, 2026, 10:48 PM CDT for Bon Homme County, Yankton County, South Dakota. It was in force for 27 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Sep 7, 2026, 10:48 PM CDT (03:48 UTC)
Expired
Sep 7, 2026, 11:15 PM CDT
In force
27 min
Issued by
NWS Sioux Falls, SD
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Bon Homme County, SD, Yankton County, SD

The radar

The Sioux Falls radar (KFSD), 99 km from the middle of the area, began a volume at 03:52 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Sep 7, 7:07 PM CDTSevere Thunderstorm WatchSPC7 hr

The nearest sounding before it

Aberdeen, SD (KABR), launched 00:00Z, 3.8 hours before the alert went out and 220 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.

Skew-T log-pSkew-T log-p diagram, Aberdeen, SD at 00:00Z on 2026-09-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 397 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Aberdeen, SD at 00:00Z on 2026-09-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 211 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
397 J/kg
Mixed-layer CIN
-311 J/kg
Mixed-layer LCL
920 m above ground
0-6 km bulk shear
44 kt
0-1 km storm-relative helicity
211 m²/s²
0-3 km storm-relative helicity
260 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.4

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Sioux Falls, SD wrote its last area forecast discussion before this severe thunderstorm warning went out at Sep 7, 10:42 PM CDT, 6 minutes earlier.

Area forecast discussion, Sep 7, 10:42 PM CDT, 6 minutes before
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Hazardous weather outlook, Sep 7, 2:34 PM CDT, 8 hours 14 minutes before
Hazardous Weather Outlook
National Weather Service Sioux Falls SD
234 PM CDT Mon Sep 7 2026

IAZ001>003-012>014-020>022-031-032-MNZ071-072-080-081-089-090-097-
098-NEZ013-014-SDZ038>040-050-052>071-081945-
Lyon-Osceola-Dickinson-Sioux-O'Brien-Clay-Plymouth-Cherokee-
Buena Vista-Woodbury-Ida-Lincoln-Murray-Cottonwood-Nobles-Jackson-
Pipestone-Rock-Dixon-Dakota-Beadle-Kingsbury-Brookings-Gregory-
Jerauld-Sanborn-Miner-Lake-Moody-Brule-Aurora-Davison-Hanson-McCook-
Minnehaha-Charles Mix-Douglas-Hutchinson-Turner-Bon Homme-Yankton-
Union-
234 PM CDT Mon Sep 7 2026

This Hazardous Weather Outlook is for northwest Iowa, west central
Iowa, southwest Minnesota, northeast Nebraska, central South
Dakota, east central South Dakota, south central South Dakota and
southeast South Dakota.

.DAY ONE...This afternoon and tonight.

Isolated strong to severe thunderstorms are possible near and west
of the James River late this afternoon and early this evening.
Confidence is low in development, but if something can develop an
isolated tornado, hail to ping pong ball and wind gusts to 70 mph are
possible.

Additional strong to severe storms will be possible from roughly 8 pm
to 2 am near and east of the James River. The main threat from these
storms will be half dollar hail and 60 mph winds.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

A couple strong storms may be possible for northwestern Iowa into
eastern Nebraska and southern Minnesota Tuesday afternoon and
evening.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed.

In the hours before

Local storm report, Sep 7, 7:14 PM CDT, 3 hours 34 minutes before
Preliminary Local Storm Report
National Weather Service Sioux Falls SD
714 PM CDT Mon Sep 7 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0653 PM     Hail             2 N Lake Andes          43.19N 98.54W
09/07/2026  M1.25 Inch       Charles Mix        SD   Trained Spotter

&&

Dux
Local storm report, Sep 7, 8:18 PM CDT, 2 hours 30 minutes before
Preliminary Local Storm Report
National Weather Service Sioux Falls SD
818 PM CDT Mon Sep 7 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0742 PM     Tstm Wnd Dmg     1 WSW Marty             42.99N 98.44W
09/07/2026                   Charles Mix        SD   Public

            mPING report of 3 inch branches down. Time
            estimated from radar.

&&

MM
Local storm report, Sep 7, 8:25 PM CDT, 2 hours 23 minutes before
Preliminary Local Storm Report
National Weather Service Sioux Falls SD
825 PM CDT Mon Sep 7 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0805 PM     Tstm Wnd Gst     Wagner                  43.08N 98.30W
09/07/2026  M56 MPH          Charles Mix        SD   Mesonet

            Personal weather station reported a 56 mph
            gust.

&&

MM
Local storm report, Sep 7, 8:45 PM CDT, 2 hours 3 minutes before
Preliminary Local Storm Report
National Weather Service Sioux Falls SD
845 PM CDT Mon Sep 7 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0836 PM     Tstm Wnd Gst     4 SSE Dante             42.98N 98.17W
09/07/2026  M61 MPH          Charles Mix        SD   Mesonet

            Personal weather station measured a 61 mph
            gust.

&&

MM
Local storm report, Sep 7, 10:35 PM CDT, 13 minutes before
Preliminary Local Storm Report
National Weather Service Sioux Falls SD
1035 PM CDT Mon Sep 7 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1015 PM     Tstm Wnd Gst     3 E Avon                43.01N 98.00W
09/07/2026  M51 MPH          Bon Homme          SD   Mesonet

            Mesonet station AVMS2 Avon 3E (SD Mesonet).

&&

MM
Local storm report, Sep 7, 10:44 PM CDT, 4 minutes before
Preliminary Local Storm Report
National Weather Service Sioux Falls SD
1044 PM CDT Mon Sep 7 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1011 PM     Tstm Wnd Gst     4 NE Dante              43.08N 98.13W
09/07/2026  M53 MPH          Charles Mix        SD   Mesonet

            Personal weather station measured a 53 mph
            wind gust. Time estimated from radar.

&&

MM

The office that day

Everything else NWS Sioux Falls, SD issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 7, 7:37 PM CDTTornado WarningFSDCharles Mix, Gregory38 min
Sep 7, 8:07 PM CDTFlash Flood WarningFSDCharles Mix3 hr
Sep 7, 8:14 PM CDTSevere Thunderstorm WarningFSDBon Homme, Charles Mix46 min
Sep 7, 8:24 PM CDTTornado WarningFSDBon Homme, Charles Mix36 min
Sep 7, 8:42 PM CDTSevere Thunderstorm Warning Considerable damage threatFSDBon Homme, Hutchinson48 min
Sep 7, 9:28 PM CDTSevere Thunderstorm WarningFSDBon Homme, Yankton21 min
Sep 7, 10:20 PM CDTSevere Thunderstorm WarningFSDBon Homme, Charles Mix, Douglas, Hutchinson40 min
Sep 7, 11:12 PM CDTSevere Thunderstorm Warning Considerable damage threatFSDYankton48 min
Sep 7, 11:19 PM CDTSevere Thunderstorm WarningFSDDouglas, Hutchinson41 min
Sep 7, 11:21 PM CDTSevere Thunderstorm WarningFSDCharles Mix, Douglas39 min
Sep 7, 11:42 PM CDTSevere Thunderstorm WarningFSDLincoln, Minnehaha48 min
Sep 7, 11:55 PM CDTSevere Thunderstorm WarningFSDAurora, Charles Mix, Davison, Douglas, Hanson, Hutchinson and 1 more50 min

Nearby

Severe Thunderstorm Warnings in South Dakota, 2026Every severe thunderstorm warning in 2026

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.