Flash Flood Warning 16, NWS Sioux Falls, SD

896 
WGUS73 KFSD 080158
FFSFSD

Flash Flood Statement
National Weather Service Sioux Falls SD
858 PM CDT Mon Sep 7 2026

SDC023-080400-
/O.CON.KFSD.FF.W.0016.000000T0000Z-260908T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Charles Mix SD-
858 PM CDT Mon Sep 7 2026

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 11 PM CDT THIS EVENING
FOR SOUTHEASTERN CHARLES MIX COUNTY...

At 858 PM CDT, Doppler radar indicated thunderstorms producing heavy
rain across the warned area. Between 3 and 5 inches of rain have
fallen. The expected rainfall rate is 1 to 3 inches in 2 hours. Flash
flooding is ongoing or expected to begin shortly.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Radar indicated.

IMPACT...Flash flooding of small creeks and streams, urban areas,
         highways, streets and underpasses as well as other poor
         drainage and low-lying areas.

Some locations that will experience flash flooding include...
  Wagner, Marty, Dante and Yankton Sioux Tribal Nation.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.

Be aware of your surroundings and do not drive on flooded roads.

Please report observed flooding to local emergency services or law
enforcement and request they pass this information to the National
Weather Service when you can do so safely.

&&

LAT...LON 4301 9850 4301 9849 4310 9839 4312 9835
      4314 9826 4311 9821 4300 9813 4297 9814
      4292 9823 4290 9834 4290 9835 4293 9842
      4293 9844 4294 9845 4295 9847 4298 9849
      4299 9850

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL RATE...1-3 INCHES IN 2 HOURS

$$

Dux

960 
WGUS73 KFSD 080348
FFSFSD

Flash Flood Statement
National Weather Service Sioux Falls SD
1048 PM CDT Mon Sep 7 2026

SDC023-080358-
/O.CAN.KFSD.FF.W.0016.000000T0000Z-260908T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Charles Mix SD-
1048 PM CDT Mon Sep 7 2026

...FLASH FLOOD WARNING IS CANCELLED FOR SOUTHEASTERN CHARLES MIX
COUNTY...

The heavy rain has ended. Flood waters are receding in the area.
Flooding is no longer expected to pose a threat but stream rises will
continue to be possible into Tuesday morning. Please continue to heed
remaining road closures and report any flooding or washed out roads
to local officials.

&&

LAT...LON 4301 9850 4301 9849 4310 9839 4312 9835
      4314 9826 4311 9821 4300 9813 4297 9814
      4292 9823 4290 9834 4290 9835 4293 9842
      4293 9844 4294 9845 4295 9847 4298 9849
      4299 9850

$$

Dux

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