Alert archive / South Dakota / Severe Thunderstorm Warnings in 2026

Severe Thunderstorm Warning 39, NWS Sioux Falls, SD

May 17, 20265 counties in South Dakota

NWS Sioux Falls, SD issued this severe thunderstorm warning at May 17, 2026, 3:28 PM CDT for 5 counties in South Dakota. It was in force for 47 min. 19 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: May 17, 2026, 3:28 PM CDT (20:28 UTC)
Expired: May 17, 2026, 4:15 PM CDT
In force: 47 min
Issued by: NWS Sioux Falls, SD
Area: Storm-based polygon
Damage threat: Destructive
Hail: 1.5 in
Wind: 80.0 mph

Counties Bon Homme County, SD, Clay County, SD, Hutchinson County, SD, Turner County, SD, Yankton County, SD

The radar

The Sioux Falls radar (KFSD), 76 km from the middle of the area, began a volume at 20:29 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.

What was reported inside it

Time	Report	Where	Remark
May 17, 3:36 PM CDT	HAIL 1	3 E Menno, SD	Corrects time of previous hail report from 3 E Menno. Via mping. Time estimated via radar.
May 17, 3:36 PM CDT	HAIL 1	3 E Menno, SD	Corrects time of previous hail report from 3 E Menno. Via mping. Time estimated via radar.
May 17, 3:36 PM CDT	HAIL 1.75	6 Ese Menno, SD	Photo of roughly golf ball size hail. Time estimated via radar.
May 17, 3:36 PM CDT	HAIL 1.75	6 Ese Menno, SD	Photo of roughly golf ball size hail. Time estimated via radar.
May 17, 3:37 PM CDT	TSTM WND DMG	6 E Menno, SD	Large garage door on outbuilding bowed in. Time estimated from radar.
May 17, 3:37 PM CDT	TSTM WND DMG	6 E Menno, SD	Large garage door on outbuilding bowed in. Time estimated from radar.
May 17, 3:38 PM CDT	TSTM WND GST 81	7 Ese Menno, SD	Mesonet station MNMS2 Menno 7ESE (SD Mesonet).
May 17, 3:38 PM CDT	TSTM WND GST 81	7 Ese Menno, SD	Mesonet station MNMS2 Menno 7ESE (SD Mesonet).
May 17, 3:39 PM CDT	TSTM WND DMG	8 S Freeman, SD	Damage to large road signs near intersection of Hwy 18/81.
May 17, 3:39 PM CDT	TSTM WND DMG	8 S Freeman, SD	Damage to large road signs near intersection of Hwy 18/81.
May 17, 3:42 PM CDT	TSTM WND GST 82	5 S Freeman, SD	Mesonet station 163 SD RWIS Freeman.
May 17, 3:42 PM CDT	TSTM WND GST 82	5 S Freeman, SD	Mesonet station 163 SD RWIS Freeman.
May 17, 3:44 PM CDT	HAIL 1	7 N Mayfield, SD	Via mping. Time estimated via radar.
May 17, 3:44 PM CDT	HAIL 1	7 N Mayfield, SD	Via mping. Time estimated via radar.
May 17, 3:47 PM CDT	TSTM WND GST 60	9 W Hurley, SD	Spotter estimated 50-60 mph winds along with half dollar size hail.
May 17, 3:47 PM CDT	TSTM WND GST 60	9 W Hurley, SD	Spotter estimated 50-60 mph winds along with half dollar size hail.
May 17, 4:06 PM CDT	TORNADO	2 W Davis, SD	Video via social media of brief gustnado. Location estimated.
May 17, 4:09 PM CDT	TSTM WND DMG	3 E Parker, SD	Power poles snapped and irrigation pivots flipped near the intersection of 276th St and 456th Ave. Time estimated from radar.
May 17, 4:09 PM CDT	TSTM WND DMG	3 E Parker, SD	Power poles snapped and irrigation pivots flipped near the intersection of 276th St and 456th Ave. Time estimated from radar.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

Did it verify

Verified. The Iowa Environmental Mesonet's Cow matched 9 storm reports to this severe thunderstorm warning; the first came 8 minutes after it went out.

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.

Issued	Product	Office	Lasted
May 17, 1:42 PM CDT	Tornado Watch	SPC	8 hr

The nearest sounding before it

Aberdeen, SD (KABR), launched 12:00Z, 8.5 hours before the alert went out and 212 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 2103 m above ground
0-6 km bulk shear: 54 kt
0-1 km storm-relative helicity: 372 m²/s²
0-3 km storm-relative helicity: 379 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

882 
WUUS53 KFSD 172028
SVRFSD
SDC009-027-067-125-135-172115-
/O.NEW.KFSD.SV.W.0039.260517T2028Z-260517T2115Z/

BULLETIN - EAS ACTIVATION REQUESTED
Severe Thunderstorm Warning
National Weather Service Sioux Falls SD
328 PM CDT Sun May 17 2026

The National Weather Service in Sioux Falls has issued a

* Severe Thunderstorm Warning for...
  Northwestern Clay County in southeastern South Dakota...
  Northeastern Bon Homme County in southeastern South Dakota...
  Yankton County in southeastern South Dakota...
  Turner County in southeastern South Dakota...
  Southeastern Hutchinson County in southeastern South Dakota...

* Until 415 PM CDT.

* At 328 PM CDT, a severe thunderstorm was located over Menno, or 20
  miles northeast of Tyndall, moving east at 45 mph.

  HAZARD...80 mph wind gusts and ping pong ball size hail.

  SOURCE...Radar indicated.

  IMPACT...Flying debris will be dangerous to those caught without 
           shelter. Mobile homes will be heavily damaged. Expect 
           considerable damage to roofs, windows, and vehicles. 
           Extensive tree damage and power outages are likely.

* This severe thunderstorm will be near...
  Freeman around 335 PM CDT.

Other locations in the path of this severe thunderstorm include
Parker, Marion and Hurley.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

This is a potentially deadly storm. Seek shelter in an interior room
on the lowest floor of a well-built structure. Abandon vehicles in
search of a more substantial permanent structure. Stay away from
windows.

A Tornado Watch remains in effect until 1000 PM CDT for southeastern
South Dakota.

&&

LAT...LON 4292 9767 4328 9771 4350 9713 4302 9691
TIME...MOT...LOC 2028Z 249DEG 39KT 4322 9760 

THUNDERSTORM DAMAGE THREAT...DESTRUCTIVE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.50 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...80 MPH

$$

Weisser

3 follow-up statements

785 
WWUS53 KFSD 172037
SVSFSD

Severe Weather Statement
National Weather Service Sioux Falls SD
337 PM CDT Sun May 17 2026

SDC009-027-067-125-135-172115-
/O.CON.KFSD.SV.W.0039.000000T0000Z-260517T2115Z/
Clay SD-Bon Homme SD-Yankton SD-Turner SD-Hutchinson SD-
337 PM CDT Sun May 17 2026

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 415 PM CDT
FOR NORTHWESTERN CLAY...NORTHEASTERN BON HOMME...YANKTON...TURNER AND
SOUTHEASTERN HUTCHINSON COUNTIES...

At 336 PM CDT, a severe thunderstorm was located 7 miles east of
Menno, or 20 miles southwest of Parker, moving east at 50 mph.

HAZARD...80 mph wind gusts and golf ball size hail.

SOURCE...Radar indicated.

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be heavily damaged. Expect 
         considerable damage to roofs, windows, and vehicles. 
         Extensive tree damage and power outages are likely.

Locations impacted include...
  Viborg, Hurley and Centerville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Tornado Watch remains in effect until 1000 PM CDT for southeastern
South Dakota.

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

This is a potentially deadly storm. Seek shelter in an interior room
on the lowest floor of a well-built structure. Abandon vehicles in
search of a more substantial permanent structure. Stay away from
windows.

&&

LAT...LON 4292 9767 4328 9771 4350 9713 4302 9691
TIME...MOT...LOC 2036Z 264DEG 42KT 4320 9744 

TORNADO...POSSIBLE
THUNDERSTORM DAMAGE THREAT...DESTRUCTIVE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...80 MPH

$$

Weisser

482 
WWUS53 KFSD 172101
SVSFSD

Severe Weather Statement
National Weather Service Sioux Falls SD
401 PM CDT Sun May 17 2026

SDC009-067-135-172111-
/O.CAN.KFSD.SV.W.0039.000000T0000Z-260517T2115Z/
Bon Homme SD-Yankton SD-Hutchinson SD-
401 PM CDT Sun May 17 2026

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN BON HOMME...
YANKTON AND SOUTHEASTERN HUTCHINSON COUNTIES IS CANCELLED...

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

A Tornado Watch remains in effect until 1000 PM CDT for southeastern
South Dakota.

&&

LAT...LON 4316 9717 4317 9739 4340 9741 4350 9713
      4302 9691 4299 9717
TIME...MOT...LOC 2101Z 249DEG 39KT 4330 9709 

$$

SDC027-125-172115-
/O.CON.KFSD.SV.W.0039.000000T0000Z-260517T2115Z/
Clay SD-Turner SD-
401 PM CDT Sun May 17 2026

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 415 PM CDT
FOR NORTHWESTERN CLAY AND TURNER COUNTIES...

At 401 PM CDT, a severe thunderstorm was located over Hurley, or 7
miles south of Parker, moving east at 45 mph.

HAZARD...80 mph wind gusts and golf ball size hail.

SOURCE...Radar indicated.

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be heavily damaged. Expect 
         considerable damage to roofs, windows, and vehicles. 
         Extensive tree damage and power outages are likely.

Locations impacted include...
Parker, Centerville, Marion, Viborg, Irene, Hurley, and Wakonda.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Tornado Watch remains in effect until 1000 PM CDT for southeastern
South Dakota.

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

This is a potentially deadly storm. Seek shelter in an interior room
on the lowest floor of a well-built structure. Abandon vehicles in
search of a more substantial permanent structure. Stay away from
windows.

&&

LAT...LON 4316 9717 4317 9739 4340 9741 4350 9713
      4302 9691 4299 9717
TIME...MOT...LOC 2101Z 249DEG 39KT 4330 9709 

TORNADO...POSSIBLE
THUNDERSTORM DAMAGE THREAT...DESTRUCTIVE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...80 MPH

$$

Weisser

707 
WWUS53 KFSD 172108
SVSFSD

Severe Weather Statement
National Weather Service Sioux Falls SD
408 PM CDT Sun May 17 2026

SDC027-125-172118-
/O.EXP.KFSD.SV.W.0039.000000T0000Z-260517T2115Z/
Clay SD-Turner SD-
408 PM CDT Sun May 17 2026

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN CLAY AND TURNER
COUNTIES WILL EXPIRE AT 415 PM CDT...

The storm which prompted the warning has moved out of the area.
Therefore, the warning will be allowed to expire.  However, small
hail, gusty winds and heavy rain are still possible with this
thunderstorm.

A Tornado Watch remains in effect until 1000 PM CDT for southeastern
South Dakota.

&&

LAT...LON 4316 9717 4317 9739 4340 9741 4350 9713
      4302 9691 4299 9717
TIME...MOT...LOC 2108Z 268DEG 35KT 4328 9702 

$$

Weisser

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 May 17, 1:20 PM CDT, 2 hours 8 minutes earlier. Its key messages:

There is high confidence that severe thunderstorms will develop this afternoon and evening, producing large hail, destructive straight-line winds, and a few tornadoes. An Enhanced Risk (level 3 of 5) of severe storms is in place.
A transitioning storm mode will shift hazards from large hail and tornadoes initially, to widespread wind damage as an intense line of storms tracks east of Interstate 29 this evening.
A lower risk of severe weather exists late Monday afternoon and evening, mainly over northwest IA, before quieter weather moves in for the mid-week period.

Area forecast discussion, May 17, 1:20 PM CDT, 2 hours 8 minutes before

Area Forecast Discussion
National Weather Service Sioux Falls SD
Issued by National Weather Service Lincoln IL
120 PM CDT Sun May 17 2026

.KEY MESSAGES...

- There is high confidence that severe thunderstorms will
  develop this afternoon and evening, producing large hail,
  destructive straight-line winds, and a few tornadoes. An
  Enhanced Risk (level 3 of 5) of severe storms is in place.

- A transitioning storm mode will shift hazards from large hail
  and tornadoes initially, to widespread wind damage as an
  intense line of storms tracks east of Interstate 29 this
  evening.

- A lower risk of severe weather exists late Monday afternoon
  and evening, mainly over northwest IA, before quieter weather
  moves in for the mid-week period.

&&

.DISCUSSION...
Issued at 120 PM CDT Sun May 17 2026

The short-term convective outlook presents a highly volatile
spring severe weather setup. Latest surface analysis shows a
complex pattern, anchored by a strong 994 mb low over northwest
KS. An inverted trough extended north of the low through
central SD, while a well-defined warm front stretched northeast
of the low into east central NE. A weaker low was also noted in
north central NE. Visible satellite imagery revealed stable
wave clouds advancing northeast over far northeast NE and
extreme SE SD, ahead of the advancing warm front. Regional
radar imagery showed a complex of strong to severe storms over
north central NE. This storm complex is forecast by short range
guidance to continue tracking east this afternoon, intensifying
as interacts with the richer low- level moisture pool near and
south of the warm front.

Moderate to strong instability will be in place over the
southern to eastern CWA by late afternoon with MLCAPE nearing
3000 J/kg. In addition, deep layer shear will increase to around
50 kt, coincident with a mid level speed max ejecting from the
deep upper trough to our west. As the system evolves over the
next several hours, it appears the ingredients for a significant
severe weather event will be most favored over the southern to
eastern CWA. Ahead of the main convective line, some CAMs show
supercell development along the northward advancing warm front.
These storms would present a risk of very large hail (2"+) and
tornadoes. Given the amount of low level SRH/curved hodographs
present, a couple strong tornadoes are possible. The convective
cluster currently entering our far southwest CWA should
strengthen as it shifts east, with an initial hail and tornado
threat transitioning to a damaging straight line wind threat
(70+ MPH) as it grows upscale into a squall line/QLCS. Some
line-embedded QLCS tornadoes are possible, especially for any
line segments that become oriented north/south or
northwest/southeast, given southwesterly 0-3 km shear vectors.
Timing from latest high-res guidance suggests this activity
exits to the east of our CWA late this evening.

Precipitation amounts will vary significantly based on convective
tracks, though NBM guidance and HREF probability match mean
fields project a widespread 0.50 to 1.50 inches of rainfall,
particularly across northwest Iowa and southwest Minnesota. On
Monday, the cold front finally pushes into the area. Instability
and shear are forecast to be much lower than today, however,
there will be a conditional risk of severe storms over the
eastern CWA during the late afternoon to evening, if the airmass
can destabilize sufficiently ahead of the front. SPC's Day 2
outlook indicates as Marginal Risk (level 1 of 5), for our MN
and IA counties.

Behind the departing upper wave, quasi-zonal flow sets up for
Tuesday and Wednesday, yielding quiet conditions and seasonally
cool high temperatures moderating from the upper 50s Tuesday to
mid-upper 60s Wednesday.

The next upper wave moves in for the Thursday to Friday period,
however Gulf moisture remains cutoff ahead of this system.
Evaluating the ECMWF Extreme Forecast Index (EFI) reveals no
significant climatological anomalies for precipitation or wind
across the upper Midwest during this period, reinforcing the
the idea of a low-impact system for our area. The current
forecast sticks closely to the NBM consensus, maintaining broad
20-30 percent probabilities for light rain for late Thursday
into Saturday.

By late this week and especially this weekend, temperatures
will embark on a steady upward trajectory, as the mid level flow
backs west, then southwest. The Climate Prediction Center (CPC)
6-10 day outlook favors above-normal temperatures across the
Northern Plains and Upper Midwest, which supports blended
guidance high temperatures reaching well into the 80s on
Sunday.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1248 PM CDT Sun May 17 2026

Showers and storms move through the region this afternoon into
tonight. Intermittent MVFR/IFR conditions will be possible throughout
this timeframe, especially in heavier rain. TSRA was included at
least in PROB30 groups, but is expected to be the dominant weather
type at times. Widespread MVFR/IFR cigs setting in overnight for much
of Monday.

&&

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

&&

DISCUSSION...ILX/25
AVIATION...DYE

Hazardous weather outlook, May 17, 1:29 PM CDT, 1 hour 59 minutes before

Hazardous Weather Outlook
National Weather Service Sioux Falls SD
Issued by National Weather Service Lincoln IL
129 PM CDT Sun May 17 2026

IAZ001>003-012>014-020>022-031-032-MNZ071-072-080-081-089-090-097-
098-NEZ013-014-SDZ038>040-050-052>071-181830-
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-
129 PM CDT Sun May 17 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.

A significant severe weather event is possible this afternoon and
evening. Very large hail, damaging wind gusts, and tornadoes are all
possible. If you have outdoor plans know where your nearest shelter
is located. Please ensure you have multiple ways to receive warnings.
Have a plan to take shelter and act immediately if your area comes
under a severe weather warning.

.DAYS TWO THROUGH SEVEN...Monday through Saturday.

Strong to severe storms are possible again Monday afternoon and
evening, particularly over northwest Iowa and southwest Minnesota.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will likely be needed this afternoon and evening.

In the hours before

Local storm report, May 17, 3:11 PM CDT, 17 minutes before

Preliminary Local Storm Report
National Weather Service Sioux Falls SD
311 PM CDT Sun May 17 2026

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

0248 PM     Tstm Wnd Gst     1 S Wagner              43.07N 98.30W
05/17/2026  M67 MPH          Charles Mix        SD   AWOS

            AWOS station KAGZ Wagner.

&&

ak

Local storm report, May 17, 3:13 PM CDT, 15 minutes before

Preliminary Local Storm Report
National Weather Service Sioux Falls SD
313 PM CDT Sun May 17 2026

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

0250 PM     Tstm Wnd Gst     3 S Corsica             43.38N 98.41W
05/17/2026  M62 MPH          Douglas            SD   Mesonet

            Mesonet station 304 SD RWIS Corsica.

&&

ak

Local storm report, May 17, 3:15 PM CDT, 13 minutes before

Preliminary Local Storm Report
National Weather Service Sioux Falls SD
315 PM CDT Sun May 17 2026

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

0250 PM     Tstm Wnd Dmg     3 N Dante               43.08N 98.19W
05/17/2026                   Charles Mix        SD   Emergency Mngr

            Mobile trailer flipped, dismantled, and
            moved about 60 ft. Pickup truck tipped on
            its side. Time estimated from radar.

&&

PR

Local storm report, May 17, 3:18 PM CDT, 10 minutes before

Preliminary Local Storm Report
National Weather Service Sioux Falls SD
318 PM CDT Sun May 17 2026

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

0300 PM     Tstm Wnd Gst     4 E Avon                43.00N 97.97W
05/17/2026  M66 MPH          Bon Homme          SD   Public

            Via personal weather station. Exact time
            estimated via radar.

&&

ak

Local storm report, May 17, 3:23 PM CDT, 5 minutes before

Preliminary Local Storm Report
National Weather Service Sioux Falls SD
323 PM CDT Sun May 17 2026

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

0258 PM     Tstm Wnd Gst     3 E Avon                43.01N 98.00W
05/17/2026  M74 MPH          Bon Homme          SD   Mesonet

            Mesonet station AVMS2 Avon 3E (SD Mesonet).

&&

ak

Local storm report, May 17, 3:28 PM CDT, 0 minutes before

Preliminary Local Storm Report
National Weather Service Sioux Falls SD
328 PM CDT Sun May 17 2026

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

0316 PM     Tstm Wnd Gst     2 WNW Scotland          43.16N 97.76W
05/17/2026  M60 MPH          Bon Homme          SD   Public

            Via personal weather station.

&&

ak

The office that day

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

Issued	Product	Office	Counties	Lasted
May 17, 1:10 AM CDT	Flash Flood Warning	FSD	Union	4 hr
May 17, 1:09 PM CDT	Severe Thunderstorm Warning	FSD	Gregory	51 min
May 17, 2:10 PM CDT	Severe Thunderstorm Warning	FSD	Charles Mix, Gregory	50 min
May 17, 2:15 PM CDT	Severe Thunderstorm Warning Considerable damage threat	FSD	Aurora, Brule, Charles Mix, Douglas	45 min
May 17, 2:49 PM CDT	Severe Thunderstorm Warning Considerable damage threat	FSD	Bon Homme, Hutchinson, Yankton	41 min
May 17, 2:50 PM CDT	Tornado Warning	FSD	Bon Homme, Charles Mix, Hutchinson	40 min
May 17, 3:23 PM CDT	Tornado Warning	FSD	Hutchinson, Turner, Yankton	52 min
May 17, 3:35 PM CDT	Tornado Warning	FSD	Hutchinson, Turner	28 min
May 17, 3:59 PM CDT	Severe Thunderstorm Warning Destructive damage threat	FSD	Lincoln, Turner	46 min
May 17, 4:18 PM CDT	Severe Thunderstorm Warning Considerable damage threat	FSD	Lincoln, Minnehaha, Turner	42 min
May 17, 4:27 PM CDT	Tornado Warning	FSD	Lincoln, Minnehaha	48 min
May 17, 4:56 PM CDT	Severe Thunderstorm Warning Considerable damage threat	FSD	Minnehaha	49 min

Nearby

Severe Thunderstorm Warnings in South Dakota, 2026 Every 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.