Severe Thunderstorm Warning 280, NWS Sioux Falls, SD

584 
WWUS53 KFSD 080242
SVSFSD

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

SDC009-135-080300-
/O.CON.KFSD.SV.W.0280.000000T0000Z-260908T0300Z/
Bon Homme SD-Yankton SD-
942 PM CDT Mon Sep 7 2026

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1000 PM CDT
FOR NORTHEASTERN BON HOMME AND WEST CENTRAL YANKTON COUNTIES...

At 942 PM CDT, a severe thunderstorm was located near Scotland, or 12
miles northeast of Tyndall, moving northeast at 20 mph.

HAZARD...60 mph wind gusts and penny size hail.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

This severe thunderstorm will remain over mainly rural areas of
northeastern Bon Homme and west central Yankton Counties, including
the following locations... Lesterville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4299 9769 4314 9779 4317 9763 4302 9756
      4300 9766
TIME...MOT...LOC 0242Z 244DEG 19KT 4310 9766 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

AP

285 
WWUS53 KFSD 080249
SVSFSD

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

SDC009-135-080259-
/O.CAN.KFSD.SV.W.0280.000000T0000Z-260908T0300Z/
Bon Homme SD-Yankton SD-
949 PM CDT Mon Sep 7 2026

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN BON HOMME AND
WEST CENTRAL YANKTON 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.

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

&&

LAT...LON 4299 9769 4314 9779 4317 9763 4302 9756
      4300 9766
TIME...MOT...LOC 0247Z 244DEG 19KT 4312 9761 

$$

AP

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
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.

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

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

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

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