Alert archive / South Dakota / Severe Thunderstorm Warnings in 2026

Severe Thunderstorm Warning 59, NWS Sioux Falls, SD

May 24, 2026McCook County, Minnehaha County, Turner County, South Dakota

NWS Sioux Falls, SD issued this severe thunderstorm warning at May 24, 2026, 6:28 PM CDT for McCook County, Minnehaha County, Turner County, South Dakota. It was in force for 47 min. 1 report 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 24, 2026, 6:28 PM CDT (23:28 UTC)
Expired
May 24, 2026, 7:15 PM CDT
In force
47 min
Issued by
NWS Sioux Falls, SD
Area
Storm-based polygon
Hail
1.5 in
Wind
60.0 mph

Counties McCook County, SD, Minnehaha County, SD, Turner County, SD

The radar

The Sioux Falls radar (KFSD), 38 km from the middle of the area, began a volume at 23:30 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

TimeReportWhereRemark
May 24, 6:35 PM CDTHAIL 1.55 E Canistota, SDReport via social media, time estimated by 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 one storm report to this severe thunderstorm warning; the first came 7 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.

IssuedProductOfficeLasted
May 24, 4:53 PM CDTSevere Thunderstorm WatchSPC6 hr

The nearest sounding before it

Minneapolis, MN (KMPX), launched 12:00Z, 11.5 hours before the alert went out and 322 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, Minneapolis, MN at 12:00Z on 2026-05-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Minneapolis, MN at 12:00Z on 2026-05-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 61 square meters per square second.193958Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1333 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
61 m²/s²
0-3 km storm-relative helicity
92 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

007 
WUUS53 KFSD 242328
SVRFSD
SDC087-099-125-250015-
/O.NEW.KFSD.SV.W.0059.260524T2328Z-260525T0015Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Sioux Falls SD
628 PM CDT Sun May 24 2026

The National Weather Service in Sioux Falls has issued a

* Severe Thunderstorm Warning for...
  Southwestern Minnehaha County in southeastern South Dakota...
  Southeastern McCook County in southeastern South Dakota...
  Northeastern Turner County in southeastern South Dakota...

* Until 715 PM CDT.

* At 627 PM CDT, a severe thunderstorm was located over Lake
  Vermillion State Recreation Area, moving east at 10 mph.

  HAZARD...Ping pong ball size hail and 60 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...People and animals outdoors will be injured. Expect hail 
           damage to roofs, siding, windows, and vehicles. Expect 
           wind damage to roofs, siding, and trees.

* This severe thunderstorm will be near...
  Lake Vermillion State Recreation Area and Humboldt around 635 PM 
  CDT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

To report severe weather, contact your nearest law enforcement
agency. They will send your report to the National Weather Service
office in Sioux Falls.

&&

LAT...LON 4349 9735 4365 9730 4365 9697 4341 9703
TIME...MOT...LOC 2327Z 276DEG 8KT 4358 9721 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.50 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Samet
2 follow-up statements
828 
WWUS53 KFSD 242346
SVSFSD

Severe Weather Statement
National Weather Service Sioux Falls SD
646 PM CDT Sun May 24 2026

SDC125-242355-
/O.CAN.KFSD.SV.W.0059.000000T0000Z-260525T0015Z/
Turner SD-
646 PM CDT Sun May 24 2026

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN TURNER COUNTY IS
CANCELLED...

The severe 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 1100 PM CDT for
southeastern South Dakota.

&&

LAT...LON 4350 9701 4351 9719 4365 9726 4365 9697
TIME...MOT...LOC 2345Z 253DEG 13KT 4360 9715 

$$

SDC087-099-250015-
/O.CON.KFSD.SV.W.0059.000000T0000Z-260525T0015Z/
Minnehaha SD-McCook SD-
646 PM CDT Sun May 24 2026

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 715 PM CDT
FOR SOUTHWESTERN MINNEHAHA AND SOUTHEASTERN MCCOOK COUNTIES...

At 645 PM CDT, a severe thunderstorm was located over Lake Vermillion
State Recreation Area, moving east at 15 mph.

HAZARD...Ping pong ball size hail and 60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...People and animals outdoors will be injured. Expect hail 
         damage to roofs, siding, windows, and vehicles. Expect wind 
         damage to roofs, siding, and trees.

Locations impacted include...
  Humboldt.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

To report severe weather contact your nearest law enforcement agency.
They will send your report to the National Weather Service office in
Sioux Falls.

&&

LAT...LON 4350 9701 4351 9719 4365 9726 4365 9697
TIME...MOT...LOC 2345Z 253DEG 13KT 4360 9715 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.50 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Samet
825 
WWUS53 KFSD 250006
SVSFSD

Severe Weather Statement
National Weather Service Sioux Falls SD
706 PM CDT Sun May 24 2026

SDC087-099-250016-
/O.EXP.KFSD.SV.W.0059.000000T0000Z-260525T0015Z/
Minnehaha SD-McCook SD-
706 PM CDT Sun May 24 2026

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN MINNEHAHA AND
SOUTHEASTERN MCCOOK COUNTIES WILL EXPIRE AT 715 PM CDT...

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 will be allowed to expire.  However, small
hail and gusty winds are still possible with this thunderstorm.

A Severe Thunderstorm Watch remains in effect until 1100 PM CDT for
southeastern South Dakota.

To report severe weather, contact your nearest law enforcement
agency. They will relay your report to the National Weather Service
Sioux Falls.

&&

LAT...LON 4350 9701 4351 9719 4365 9726 4365 9697
TIME...MOT...LOC 0006Z 276DEG 8KT 4360 9709 

$$

Samet

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 24, 12:18 PM CDT, 6 hours 10 minutes earlier. Its key messages:

  • Isolated to scattered thunderstorms possible during the late afternoon through early overnight hours (5pm-11pm) east of Highway 281. Primary risks of 2 inch hail and 65 mph winds.
  • Isolated to scattered thunderstorms may redevelop Monday evening into Monday night over NW Iowa and NE Nebraska. Non- zero severe weather risks may bring gusty winds and hail.
  • Temperatures remain 10+ degrees above normal into mid-week, but expect a slight cooldown back to normals by next weekend.
  • Rain risks return Friday into next weekend (20-40%), however severe weather chances are very low.
Area forecast discussion, May 24, 12:18 PM CDT, 6 hours 10 minutes before
Area Forecast Discussion
National Weather Service Sioux Falls SD
1218 PM CDT Sun May 24 2026

.KEY MESSAGES...

- Isolated to scattered thunderstorms possible during the late
  afternoon through early overnight hours (5pm-11pm) east of
  Highway 281. Primary risks of 2 inch hail and 65 mph winds.

- Isolated to scattered thunderstorms may redevelop Monday
  evening into Monday night over NW Iowa and NE Nebraska. Non-
  zero severe weather risks may bring gusty winds and hail.

- Temperatures remain 10+ degrees above normal into mid-week,
  but expect a slight cooldown back to normals by next weekend.

- Rain risks return Friday into next weekend (20-40%), however
  severe weather chances are very low.

&&

.DISCUSSION...
Issued at 1211 PM CDT Sun May 24 2026

THIS AFTERNOON/EVENING: Temperatures continue to rise towards and
into the 80s this afternoon. Initial mid-lvl vorticity tracking
across South Dakota this morning will keep a narrow channel AC
focused along the Ridge and Minnesota River valley early this
afternoon. Increasing southwesterly surface flow will continue
to pull modest boundary layer moisture northward, but some of
the high-res CAMs are overdoing current moisture at mid-day.
Nevertheless, we should eventually see more consistent
mid/upr-50 dew points arrive by late afternoon. The arrival of
slightly enhanced mid-lvl lapse rates will push MLCAPE values
towards the 1500-2200 J/KG layer by late afternoon. The main
question will then become "where does initiation occur?". Some
preference today for a weak area of surface convergence and low-
lvl jet convergence towards the Highway 14 corridor and into
the Minnesota River valley after 4pm. With inhibition weakened
further south towards the MO River, additional
isolated/scattered development could take place by early evening
further west along a weak dry line near the James River valley,
but this development is much less certain and more conditional
based on weaker convergence. It's the arrival of mid-lvl
vorticity in the 00-03Z window that may help development further
develop and linger into the early overnight hours before low-
lvl flow veers and pushes convection eastward.

Regarding hazards, the increase in effective shear towards the
30-40 knot mark support a few supercells, with analogs
suggesting 1.5-2" hail potential. A few wind gusts to 60-70 mph
may be possible given steep low-lvl lapse rates, but only
modest DCAPE. The tornado risk remains very low. The west-east
slow storm movement through the Highway 14 corridor this evening
could lead lead to minor flash flood risks with HREF PMM data
suggesting 1-2" per hour rates. Storm risks lower quickly after
midnight with a quiet remaining overnight forecast.

MEMORIAL DAY: Even warmer temperatures are expected for Memorial day
as winds remain southwesterly. Highs are expected to rise into the
upper 80s to lower 90s. One thing to note will be a rise in
afternoon dewpoints towards the lower 60s that may push heat index
values into the 90s. Will also need to monitor the potential for
isolated convection to form Monday evening across portions of north
central/northwestern Iowa into northeastern Nebraska, given the
slightly dirty mid-lvl flow remaining in the Plains. Several CAMS
(more NAM based), all suggest low-end development by late afternoon
to early evening, potentially driven by weak low-lvl convergence on
the developing LLJ. Shear remains rather weak but instability and
mid-lvl lapse rates of more than sufficient. Could see a few
stronger storms with localized downburst winds and severe hail if
trigger mechanism can be determined.  This activity may quickly
weaken after sunset, but continue to drift north into the overnight
hours.

TUESDAY-THURSDAY: The middle of the week favors dry and mild
conditions as a mid-lvl ridge builds through the Plains and extends
northward into Central Canada.  Residing under the ridge of this
quasi-blocking pattern would suggest very weak flow aloft, a slight
influence from east southeasterly surface winds, and dry conditions
with afternoon CU.

FRIDAY-SUNDAY: A broad mid-lvl ridge over the CONUS remains in place
through next weekend.  However, we begin to see eastward shifts in
the the dominant surface high over the Great Lakes, allowing a
better channel of low-lvl moisture to move through the Mid/Upr MO
river valley. What develops is a nearly daily low (20-40%) risk for
shower and thunderstorms, mostly within the peak diurnal timeframe.
Shear and instability in this pattern will be quite weak, so non-
severe thunderstorms are favored.  Temperatures are also favored to
drop closer to seasonal average in the middle to upper 70s.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1155 AM CDT Sun May 24 2026

VFR conditions will persist into the evening and overnight
hours. Limited mid-lvl AC deck will slide east northeast this
afternoon as a CU field begins to develop. Eventually this CU
may mature into a few thunderstorms by very late afternoon and
evening. Initial focus may be in SW Minnesota, with a lower
risk near the MO river near Yankton. Winds remain southwesterly,
gusting to 20 knots at times this afternoon.

This activity will be very widely scattered, with the greatest
concentration along the Ridge into SW Minnesota into the early
overnight hours. A breezy southerly wind is anticipated all
night.

Clouds will clear from west to east overnight with VFR
conditions persistent into Monday morning.

&&

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

&&

DISCUSSION...Dux
AVIATION...Dux
Hazardous weather outlook, May 24, 12:27 PM CDT, 6 hours 1 minute before
Hazardous Weather Outlook
National Weather Service Sioux Falls SD
1227 PM CDT Sun May 24 2026

IAZ001>003-012>014-020>022-031-032-MNZ071-072-080-081-089-090-097-
098-NEZ013-014-SDZ039-040-054>056-060>062-065>071-251730-
Lyon-Osceola-Dickinson-Sioux-O'Brien-Clay-Plymouth-Cherokee-
Buena Vista-Woodbury-Ida-Lincoln-Murray-Cottonwood-Nobles-Jackson-
Pipestone-Rock-Dixon-Dakota-Kingsbury-Brookings-Miner-Lake-Moody-
Hanson-McCook-Minnehaha-Hutchinson-Turner-Bon Homme-Yankton-Union-
1227 PM CDT Sun May 24 2026

This Hazardous Weather Outlook is for northwest Iowa, west central
Iowa, southwest Minnesota, northeast Nebraska, east central South
Dakota and southeast South Dakota.

.DAY ONE...This afternoon and tonight.

Isolated to scattered strong to severe storms are possible after 5pm
this afternoon and may continue through 11pm. The primary threats
will be large hail up to 2 inch hail and 65 mph wind gusts.

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

Scattered thunderstorms may again be possible Monday evening and
overnight. While the risks for severe weather are low, a storm or two
could produce marginally severe hail around 1 inch and brief 50 mph
wind gusts.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed after 5pm and continuing through
11pm.

SDZ038-050-052-053-057>059-063-064-251730-
Beadle-Gregory-Jerauld-Sanborn-Brule-Aurora-Davison-Charles Mix-
Douglas-
1227 PM CDT Sun May 24 2026

This Hazardous Weather Outlook is for central South Dakota, east
central South Dakota, south central South Dakota and southeast
South Dakota.

.DAY ONE...This afternoon and tonight.

Hazardous weather is not expected at this time.

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

Additional showers and thunderstorms will be possible on Monday
mainly east of I-29.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

In the hours before

Local storm report, May 24, 5:18 PM CDT, 1 hour 10 minutes before
Preliminary Local Storm Report
National Weather Service Sioux Falls SD
518 PM CDT Sun May 24 2026

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

0511 PM     Hail             6 WSW Tripp             43.18N 98.07W
05/24/2026  E1.00 Inch       Hutchinson         SD   Storm Chaser

&&

MM
Local storm report, May 24, 5:28 PM CDT, 1 hour before
Preliminary Local Storm Report
National Weather Service Sioux Falls SD
528 PM CDT Sun May 24 2026

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

0526 PM     Hail             Tripp                   43.23N 97.97W
05/24/2026  M1.25 Inch       Hutchinson         SD   Law Enforcement

            Sheriff reported half dollar size hail.

&&

MM
Local storm report, May 24, 5:39 PM CDT, 49 minutes before
Preliminary Local Storm Report
National Weather Service Sioux Falls SD
539 PM CDT Sun May 24 2026

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

0520 PM     Hail             Pipestone               44.00N 96.31W
05/24/2026  E1.00 Inch       Pipestone          MN   Emergency Mngr

            Most of the hail was dime to nickel sized. A
            few quarters were mixed in.

&&

MM
Local storm report, May 24, 5:47 PM CDT, 41 minutes before
Preliminary Local Storm Report
National Weather Service Sioux Falls SD
547 PM CDT Sun May 24 2026

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

0540 PM     Hail             3 ENE Tripp             43.24N 97.90W
05/24/2026  E1.75 Inch       Hutchinson         SD   Storm Chaser

&&

MM
Local storm report, May 24, 6:16 PM CDT, 12 minutes before
Preliminary Local Storm Report
National Weather Service Sioux Falls SD
616 PM CDT Sun May 24 2026

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

0555 PM     Hail             7 E Tripp               43.22N 97.83W
05/24/2026  E2.00 Inch       Hutchinson         SD   Storm Chaser

&&

MM
Local storm report, May 24, 6:20 PM CDT, 8 minutes before
Preliminary Local Storm Report
National Weather Service Sioux Falls SD
620 PM CDT Sun May 24 2026

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

0558 PM     Hail             6 NW Scotland           43.21N 97.78W
05/24/2026  E1.75 Inch       Hutchinson         SD   Storm Chaser

&&

MM

The office that day

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

IssuedProductOfficeCountiesLasted
May 24, 4:39 PM CDTSevere Thunderstorm WarningFSDBon Homme, Charles Mix, Douglas, Hutchinson51 min
May 24, 5:21 PM CDTSevere Thunderstorm WarningFSDBon Homme, Hutchinson39 min
May 24, 5:57 PM CDTSevere Thunderstorm WarningFSDBon Homme, Hutchinson48 min
May 24, 6:36 PM CDTSevere Thunderstorm Warning Considerable damage threatFSDBon Homme, Hutchinson, Yankton39 min

Nearby

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