Alert archive / South Dakota / Tornado Warnings in 2026

Tornado Warning 40, NWS Sioux Falls, SD

September 7, 2026Bon Homme County, Charles Mix County, South Dakota

NWS Sioux Falls, SD issued this tornado warning at Sep 7, 2026, 8:24 PM CDT for Bon Homme County, Charles Mix County, South Dakota. It was in force for 36 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
Sep 7, 2026, 8:24 PM CDT (01:24 UTC)
Expired
Sep 7, 2026, 9:00 PM CDT
In force
36 min
Issued by
NWS Sioux Falls, SD
Area
Storm-based polygon
Tornado
Radar indicated
Hail
1.0 in

Counties Bon Homme County, SD, Charles Mix County, SD

The radar

The Sioux Falls radar (KFSD), 134 km from the middle of the area, began a volume at 01:25 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.

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this tornado warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

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, 1.4 hours before the alert went out and 222 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

The text

As transmitted.

710 
WFUS53 KFSD 080124
TORFSD
SDC009-023-080200-
/O.NEW.KFSD.TO.W.0040.260908T0124Z-260908T0200Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Sioux Falls SD
824 PM CDT Mon Sep 7 2026

The National Weather Service in Sioux Falls has issued a

* Tornado Warning for...
  Southeastern Charles Mix County in south central South Dakota...
  West central Bon Homme County in southeastern South Dakota...

* Until 900 PM CDT.

* At 824 PM CDT, a severe thunderstorm capable of producing a tornado
  was located near Verdel, or 16 miles west of Tyndall, moving east
  at 30 mph.

  HAZARD...Tornado and quarter size hail.

  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.

* This tornadic thunderstorm will remain over mainly rural areas of
  southeastern Charles Mix and west central Bon Homme Counties.

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 4288 9820 4292 9824 4301 9795 4287 9789
TIME...MOT...LOC 0124Z 257DEG 28KT 4291 9818 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...1.00 IN

$$

AP
2 follow-up statements
513 
WWUS53 KFSD 080145
SVSFSD

Severe Weather Statement
National Weather Service Sioux Falls SD
845 PM CDT Mon Sep 7 2026

SDC023-080154-
/O.CAN.KFSD.TO.W.0040.000000T0000Z-260908T0200Z/
Charles Mix SD-
845 PM CDT Mon Sep 7 2026

...THE TORNADO WARNING FOR SOUTHEASTERN CHARLES MIX COUNTY IS
CANCELLED...

The tornadic thunderstorm which prompted the warning has moved out 
of the warned area. Therefore, the warning has been cancelled.

A Severe Thunderstorm Watch remains in effect until 200 AM CDT for
south central and southeastern South Dakota.

&&

LAT...LON 4290 9808 4295 9811 4297 9809 4301 9797
      4301 9795 4294 9791 4289 9790
TIME...MOT...LOC 0144Z 244DEG 12KT 4294 9806 

$$

SDC009-080200-
/O.CON.KFSD.TO.W.0040.000000T0000Z-260908T0200Z/
Bon Homme SD-
845 PM CDT Mon Sep 7 2026

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 900 PM CDT FOR WEST
CENTRAL BON HOMME COUNTY...

At 844 PM CDT, a severe thunderstorm capable of producing a tornado
was located near Avon, or 10 miles west of Tyndall, moving northeast
at 15 mph.

HAZARD...Tornado and quarter size hail.

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.

This tornadic thunderstorm will remain over mainly rural areas of
west central Bon Homme 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 4290 9808 4295 9811 4297 9809 4301 9797
      4301 9795 4294 9791 4289 9790
TIME...MOT...LOC 0144Z 244DEG 12KT 4294 9806 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...1.00 IN

$$

AP
906 
WWUS53 KFSD 080156
SVSFSD

Severe Weather Statement
National Weather Service Sioux Falls SD
856 PM CDT Mon Sep 7 2026

SDC009-080205-
/O.EXP.KFSD.TO.W.0040.000000T0000Z-260908T0200Z/
Bon Homme SD-
856 PM CDT Mon Sep 7 2026

...THE TORNADO WARNING FOR WEST CENTRAL BON HOMME COUNTY WILL EXPIRE
AT 900 PM CDT...

The storm which prompted the warning has weakened below severe
limits, and no longer appears capable of producing a tornado.
Therefore, the warning will be allowed to expire.  However, gusty
winds are still possible with this thunderstorm.

A Severe Thunderstorm Watch remains in effect until 200 AM CDT for
south central and southeastern South Dakota.

Remember, a Severe Thunderstorm Warning still remains in effect for
Bon Homme and southern Hutchinson counties. 

&&

LAT...LON 4290 9808 4295 9811 4297 9809 4301 9797
      4301 9795 4294 9791 4289 9790
TIME...MOT...LOC 0155Z 257DEG 28KT 4296 9796 

$$

AP

What forecasters said that day

The local office's own words before this tornado 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 tornado warning went out at Sep 7, 6:33 PM CDT, 1 hour 51 minutes earlier. Its key messages:

  • A couple of supercells will be possible west of the James River late this afternoon through early evening. IF a storm can develop, a tornado or two, ping pong ball sized hail and wind gusts to 70 mph are all possible.
  • Additional scattered and possibly severe storms are possible from late evening into the early overnight hours. The main threats will be half dollar sized hail and wind gusts to 65 mph.
  • Quiet but continued warm conditions are expected for the rest of the work week with the next better chance for precipitation Saturday night into Sunday.
Area forecast discussion, Sep 7, 6:33 PM CDT, 1 hour 51 minutes before
Area Forecast Discussion
National Weather Service Sioux Falls SD
633 PM CDT Mon Sep 7 2026

.KEY MESSAGES...

- A couple of supercells will be possible west of the James
  River late this afternoon through early evening. IF a storm
  can develop, a tornado or two, ping pong ball sized hail and
  wind gusts to 70 mph are all possible.

- Additional scattered and possibly severe storms are possible
  from late evening into the early overnight hours. The main
  threats will be half dollar sized hail and wind gusts to 65
  mph.

- Quiet but continued warm conditions are expected for the rest
  of the work week with the next better chance for
  precipitation Saturday night into Sunday.

&&

.DISCUSSION...
Issued at 103 PM CDT Mon Sep 7 2026

Elevated showers and thunderstorms will continue to move
northeast through central SD into the afternoon. Locally heavy
rain and wind gusts to 50 mph will be the main threats.

Otherwise, showers and thunderstorms will likely be hard to
come by this afternoon as strong capping is in place. The
exception may be in central SD closer to increasing southwest
flow aloft and slightly stronger surface heating. If these
storms can develop, CAPE around 2000 J/kg as well as about 40
knots of deep layer shear as well as decent turning from
southeast to southwest in the lowest km. This will support all
modes of severe weather with an isolated tornado, hail to ping
pong ball and wind gusts to 70 mph. Unless the models are
completely incorrect in handling the capping inversion, the
chance for this very late afternoon and early evening convection
will be confined to areas west of the James River. One other
negative is the ongoing convection in central SD, which appears
to be taking a bite out of the daytime heating.

Farther east the threat will be more likely from about 8 pm to 2 am
as storms could become more rooted in a stronger LLJ with increasing
southwest flow aloft. This lay lead to a cluster of stronger
updrafts with half dollar sized hail, wind gusts to 60 mph and
pockets of heavy rain the main threats.

Instability lingers through late tonight into early Tuesday
morning as upper level support slowly moves through. Confidence
is low on additional stronger convection, but with potentially
1000-1500 J/kg of instability some isolated stronger storms will
be possible. For now the threat of heavy rain like the past
couple of days looks pretty low as storms should be more
progressive.

Instability is slow to shift southeast through the day on Tuesday
and should result in additional showers and potentially stronger
thunderstorms Tuesday afternoon. The better chance for this will
likely be south of a Yankton to Jackson MN line, with the better
chance from about 3 pm to 8 pm.

A stronger westerly jet aloft settles into the area Wednesday into
Thursday, with a fast moving trough expected to move through
Thursday night into Friday. This pattern should support dry
conditions on Wednesday and Thursday with a chance for showers and
thunderstorms late Thursday night, but more into Friday. Depending
upon the timing of the front with this wave on Friday, highs could
climb into the 90s in a few locations before a fairly strong shot of
cooler air moves in for next weekend where highs in the 70s are more
likely. Saturday night into Sunday will see a decent chance for
showers and thunderstorms as models are fairly agreeable with a wave
moving through, just not so much with the exact timing.

&&

.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 633 PM CDT Mon Sep 7 2026

Latest radar and satellite imagery shows remaining showers in and
around KBKX pushing off to the northeast early this evening. At the
same time, thunderstorms are developing southwest of KAGZ. These
thunderstorms will continue to push off to the northeast through the
rest of the evening hours. Will watch convective trends but the
coverage of thunderstorms could also increase as well. Have kept
PROB30/TEMPO groups in KFSD and KSUX's TAFs through most of the
overnight hours. Lowered ceilings and visibilities are expected
within the storms, potentially down to MVFR levels. Some of these
storms could be strong to severe with large hail and damaging winds
as the main hazards. Chances for storms looks to wane into tomorrow
morning though showers may persist through the morning and into the
afternoon timeframe. A cold front will be pushing through the
forecast area tomorrow, turning winds to out of the northwest in its
wake. This same front looks to develop another round of
thunderstorms across northwest Iowa towards the end of the period
tomorrow afternoon.

&&

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...None.
MN...None.
IA...None.
NE...None.

&&

DISCUSSION...08
AVIATION...Meyers
Hazardous weather outlook, Sep 7, 2:34 PM CDT, 5 hours 50 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, 1 hour 10 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, 6 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

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, 8:42 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, 10:48 PM CDTSevere Thunderstorm WarningFSDBon Homme, Yankton27 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

Tornado Warnings in South Dakota, 2026Every tornado warning in 2026Tornadoes 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.