Alert archive / South Dakota / Severe Thunderstorm Warnings in 2026
Severe Thunderstorm Warning 202, NWS Sioux Falls, SD
NWS Sioux Falls, SD issued this severe thunderstorm warning at Jul 25, 2026, 8:42 PM CDT for 5 counties in South Dakota; Sioux County, Iowa. It was in force for 48 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
- Jul 25, 2026, 8:42 PM CDT (01:42 UTC)
- Expired
- Jul 25, 2026, 9:30 PM CDT
- In force
- 48 min
- Issued by
- NWS Sioux Falls, SD
- Area
- Storm-based polygon
- Damage threat
- Considerable
- Hail
- 0.75 in
- Wind
- 70.0 mph
Counties Sioux County, IA, Clay County, SD, Lincoln County, SD, Turner County, SD, Union County, SD, Yankton County, SD
The radar
The Sioux Falls radar (KFSD), 58 km from the middle of the area, began a volume at 01:42 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.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Jul 25, 3:36 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jul 25, 7:58 PM CDT | Severe Thunderstorm Watch | SPC | 4 hr |
The nearest sounding before it
Aberdeen, SD (KABR), launched 00:00Z, 1.7 hours before the alert went out and 238 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
- 4963 J/kg
- Mixed-layer CIN
- -115 J/kg
- Mixed-layer LCL
- 1465 m above ground
- 0-6 km bulk shear
- 36 kt
- 0-1 km storm-relative helicity
- 100 m²/s²
- 0-3 km storm-relative helicity
- 155 m²/s²
- Significant tornado parameter
- 1.8
- Supercell composite
- 17.3
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 Jul 25, 6:22 PM CDT, 2 hours 20 minutes earlier. Its key messages:
- Increased confidence in severe storm chances this evening and early overnight. Damaging winds to 75 to 85 mph are possible. Hail will be a secondary threat, possibly to the size of quarters.
- Extreme Heat Warning through Sunday. Heat index values as high as 115 degrees
- While details are uncertain and confidence remains low, if storms develop Sunday evening into Sunday night, some may be strong to severe with damaging winds, isolated large hail and locally heavy rain possible.
- Still a good chance for highs in the 90s next week in most locations. Additional heat headlines are possible.
Area forecast discussion, Jul 25, 6:22 PM CDT, 2 hours 20 minutes before
Area Forecast Discussion
National Weather Service Sioux Falls SD
622 PM CDT Sat Jul 25 2026
.KEY MESSAGES...
- Increased confidence in severe storm chances this evening and
early overnight. Damaging winds to 75 to 85 mph are possible.
Hail will be a secondary threat, possibly to the size of
quarters.
- Extreme Heat Warning through Sunday. Heat index values as high
as 115 degrees
- While details are uncertain and confidence remains low, if
storms develop Sunday evening into Sunday night, some may be
strong to severe with damaging winds, isolated large hail and
locally heavy rain possible.
- Still a good chance for highs in the 90s next week in most
locations. Additional heat headlines are possible.
&&
.DISCUSSION...
Issued at 117 PM CDT Sat Jul 25 2026
Heat:
Not much change as dew points in the upper 60s to mid 70s provide
the area with an oppressive environment. As temperatures rise into
the 90s today and Sunday, heat indices will jump to between 100-110
degrees in most locations. The hottest conditions continue to look
to be along the James and Missouri River valleys.
For now Monday through Wednesday should see highs generally in the
90s but with a bit less humidity. This will keep the heat index in
the 90s as well. Will have to keep an eye on the dew points trends
as a few more degrees of moisture will push heat indices above 100.
A wave moving through on Wednesday will likely bring slightly cooler
air into the area so the second half of the week may not be quite as
hot.
Thunderstorms:
Overall a capping inversion will be in place for the area through
the afternoon, so development is not expected. One exception may be
in and around Gregory/Charles Mix counties where model soundings
hint at possibly breaking the cap. If this can happen, an isolated
storm with the potential for wind gusts around 70 mph are possible.
CAPE values only running about 500-1500 J/kg with fairly weak shear,
but with a very dry subcloud layer. Otherwise, development should
take place west of the area and move in after about 6-8 pm. This
cluster of storms will likely be a bit pulsy, but with better
instability and still a fairly significant sub cloud dry layer wind
gusts to 75 mph will be likely with the potential for a cold pool to
develop. Hail to the size of quarters will also be possible, but
wind will be the main threat. Many of the latest 12z models are
jumping on this wind threat and the HRRR has been very consistent
bringing this wind threat right down I-90 this evening.
Some lingering showers are possible from midnight into early Sunday
morning, but are not expected to be severe and may even have trouble
reaching the ground with a significant dry layer below. Still a lot
of question marks regarding the severe threat tomorrow afternoon and
tomorrow night. For now a significant amount of dry air in the low
to mid levels should provide enough capping to avoid afternoon
thunderstorm development. If a storm could develop, 2000 J/kg CAPE,
30-40 knots of deep layer shear and a significant dry layer in the
lower levels would support wind gusts to 75 mph and hail to the size
of half dollars. Otherwise during the later evening and overnight
hours the models are really backing off on any potential for the
area and keeping the isolated to scattered activity to the northeast.
A wave will move through the area Wednesday into Thursday morning
and be the next chance for showers and thunderstorms. This will be
the next threat for possible severe storms. The main threat for
showers and thunderstorms should come on Thursday.
&&
.AVIATION /00Z TAFS THROUGH 00Z MONDAY/...
Issued at 616 PM CDT Sat Jul 25 2026
Scattered convection will continue to develop and move east this
evening. High winds will pose the greatest risks, with potential
for 60+ mph winds moving through the area.
This convection will likely arrive into Huron by 00Z, with
potential for convection to reach FSD around 02Z. MVFR ceilings
are expected in convection, though there remains a high degrees
of uncertainty on if storms will reach the airport.
Sioux City poses even more uncertainty, with most guidance
suggesting convection weakens by time it arrives. At a minimum,
shower activity may continue into Sunday morning.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...Extreme Heat Warning until 8 PM CDT Sunday for SDZ038>040-050-
052>071.
MN...Extreme Heat Warning until 8 PM CDT Sunday for MNZ071-072-080-
081-089-090-097-098.
IA...Extreme Heat Warning until 8 PM CDT Sunday for IAZ001>003-
012>014-020>022-031-032.
NE...Extreme Heat Warning until 8 PM CDT Sunday for NEZ013-014.
&&
DISCUSSION...08
AVIATION...DuxHazardous weather outlook, Jul 25, 5:25 PM CDT, 3 hours 17 minutes before
Hazardous Weather Outlook National Weather Service Sioux Falls SD 525 PM CDT Sat Jul 25 2026 IAZ001>003-012>014-020>022-031-032-MNZ071-072-080-081-089-090-097- 098-NEZ013-014-SDZ071-262230- Lyon-Osceola-Dickinson-Sioux-O'Brien-Clay-Plymouth-Cherokee- Buena Vista-Woodbury-Ida-Lincoln-Murray-Cottonwood-Nobles-Jackson- Pipestone-Rock-Dixon-Dakota-Union- 525 PM CDT Sat Jul 25 2026 This Hazardous Weather Outlook is for northwest Iowa, west central Iowa, southwest Minnesota, northeast Nebraska and southeast South Dakota. .DAY ONE...Tonight. Heat index values between 100 and 110 will continue this evening. Scattered thunderstorms may approach after dark. These storms may be in a weakening phase, but could still bring 60 to 70 mph winds as they move through. .DAYS TWO THROUGH SEVEN...Sunday through Friday. Heat index readings will again climb between 100 to 110 degrees Sunday afternoon and evening. While uncertain, isolated to scattered thunderstorms may redevelop Sunday late afternoon and evening. Large hail and 70 mph winds may be possible. .SPOTTER INFORMATION STATEMENT... Spotter activation may be needed after 10pm. SDZ038>040-050-052>070-262230- Beadle-Kingsbury-Brookings-Gregory-Jerauld-Sanborn-Miner-Lake-Moody- Brule-Aurora-Davison-Hanson-McCook-Minnehaha-Charles Mix-Douglas- Hutchinson-Turner-Lincoln-Bon Homme-Yankton-Clay- 525 PM CDT Sat Jul 25 2026 This Hazardous Weather Outlook is for central South Dakota, east central South Dakota, south central South Dakota and southeast South Dakota. .DAY ONE...Tonight. Scattered severe storms will try to develop and move eastward this evening and into the early overnight hours. Hail risks of ping pong ball size, and straight line winds of 75 mph or greater will be possible. Heat index values as high as 110 degrees will continue this evening. .DAYS TWO THROUGH SEVEN...Sunday through Friday. Heat index readings will again climb between 100 to 110 degrees Sunday afternoon and evening. While uncertain, isolated to scattered thunderstorms may redevelop Sunday late afternoon and evening. Large hail and 70 mph winds may be possible. .SPOTTER INFORMATION STATEMENT... Spotter activation will be needed through 12am.
In the hours before
Local storm report, Jul 25, 7:29 PM CDT, 1 hour 13 minutes before
Preliminary Local Storm Report
National Weather Service Sioux Falls SD
729 PM CDT Sat Jul 25 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0724 PM Tstm Wnd Gst 1 SSW Parkston 43.38N 98.00W
07/25/2026 M65 MPH Hutchinson SD Mesonet
Personal weather station.
&&
TRMLocal storm report, Jul 25, 7:33 PM CDT, 1 hour 9 minutes before
Preliminary Local Storm Report
National Weather Service Sioux Falls SD
733 PM CDT Sat Jul 25 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0719 PM Tstm Wnd Gst 3 E Cavour 44.37N 97.98W
07/25/2026 M69 MPH Beadle SD Mesonet
Mesonet station 211 SD RWIS Cavour.
&&
TRMLocal storm report, Jul 25, 7:44 PM CDT, 58 minutes before
Preliminary Local Storm Report
National Weather Service Sioux Falls SD
744 PM CDT Sat Jul 25 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0737 PM Tstm Wnd Gst 8 ESE Parkston 43.35N 97.83W
07/25/2026 M66 MPH Hutchinson SD Mesonet
Personal weather station.
&&
TRMLocal storm report, Jul 25, 8:04 PM CDT, 38 minutes before
Preliminary Local Storm Report
National Weather Service Sioux Falls SD
804 PM CDT Sat Jul 25 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0800 PM Tstm Wnd Gst 5 ESE Salem 43.70N 97.31W
07/25/2026 M58 MPH McCook SD Mesonet
Personal weather station.
&&
TRMLocal storm report, Jul 25, 8:18 PM CDT, 24 minutes before
Preliminary Local Storm Report
National Weather Service Sioux Falls SD
818 PM CDT Sat Jul 25 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0805 PM Tstm Wnd Gst Canistota 43.60N 97.29W
07/25/2026 E65 MPH McCook SD Trained Spotter
Wind gusts estimated at 65 mph bent an 8
inch diameter young tree at a 45 degree
angle. No damage and no hail, but heavy
rainfall.
&&
TRMLocal storm report, Jul 25, 8:32 PM CDT, 10 minutes before
Preliminary Local Storm Report
National Weather Service Sioux Falls SD
832 PM CDT Sat Jul 25 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0818 PM Tstm Wnd Gst 6 NNE Monroe 43.56N 97.16W
07/25/2026 M58 MPH McCook SD Mesonet
Personal weather station.
&&
TRMThe office that day
Everything else NWS Sioux Falls, SD issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 25, 7:06 PM CDT | Severe Thunderstorm Warning | FSD | Davison, Douglas, Hutchinson | 39 min |
| Jul 25, 7:23 PM CDT | Severe Thunderstorm Warning | FSD | Beadle, Kingsbury, Miner, Sanborn | 52 min |
| Jul 25, 7:23 PM CDT | Severe Thunderstorm Warning | FSD | Hanson, Hutchinson, McCook | 37 min |
| Jul 25, 7:29 PM CDT | Severe Thunderstorm Warning | FSD | Davison, Hanson, Lake, McCook, Miner, Sanborn | 46 min |
| Jul 25, 8:04 PM CDT | Severe Thunderstorm Warning | FSD | Hutchinson, Lincoln, McCook, Minnehaha, Turner | 41 min |
| Jul 25, 8:33 PM CDT | Severe Thunderstorm Warning | FSD | Lincoln, Minnehaha, Turner | 42 min |
| Jul 25, 8:53 PM CDT | Severe Thunderstorm Warning | FSD | Lincoln, Minnehaha | 37 min |
| Jul 25, 9:09 PM CDT | Severe Thunderstorm Warning | FSD | Clay, Lincoln, Union | 51 min |
| Jul 25, 9:26 PM CDT | Severe Thunderstorm Warning | FSD | Lincoln, Union | 34 min |
| Jul 25, 9:49 PM CDT | Severe Thunderstorm Warning | FSD | Union | 41 min |
| Jul 26, 12:39 PM CDT | Heat Advisory | FSD | Bon Homme, Charles Mix, Clay, Douglas, Gregory, Hutchinson and 4 more | 31 hr |
| Jul 25, 9:53 PM CDT | Severe Thunderstorm Warning | FSD | Clay, Dickinson, Lyon, O'Brien, Osceola, Sioux | 37 min |
Nearby
Severe Thunderstorm Warnings in South Dakota, 2026Severe Thunderstorm Warnings in Iowa, 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.