Alert archive / South Dakota / Severe Thunderstorm Warnings in 2026
Severe Thunderstorm Warning 71, NWS Sioux Falls, SD
NWS Sioux Falls, SD issued this severe thunderstorm warning at May 24, 2026, 10:36 PM CDT for McCook County, Minnehaha County, South Dakota. It was in force for 39 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, 10:36 PM CDT (03:36 UTC)
- Expired
- May 24, 2026, 11:15 PM CDT
- In force
- 39 min
- Issued by
- NWS Sioux Falls, SD
- Area
- Storm-based polygon
- Hail
- 1.5 in
- Wind
- 50.0 mph
Counties McCook County, SD, Minnehaha County, SD
The radar
The Sioux Falls radar (KFSD), 25 km from the middle of the area, began a volume at 03:36 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 24, 11:11 PM CDT | HAIL 1 | Wall Lake, SD | Report from 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 35 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 24, 4:53 PM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
The nearest sounding before it
Aberdeen, SD (KABR), launched 00:00Z, 3.6 hours before the alert went out and 185 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
- 29 J/kg
- Mixed-layer CIN
- -28 J/kg
- Mixed-layer LCL
- 3042 m above ground
- 0-6 km bulk shear
- 30 kt
- 0-1 km storm-relative helicity
- 48 m²/s²
- 0-3 km storm-relative helicity
- 115 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.1
The text
As transmitted.
899
WUUS53 KFSD 250336
SVRFSD
SDC087-099-250415-
/O.NEW.KFSD.SV.W.0071.260525T0336Z-260525T0415Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Sioux Falls SD
1036 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...
* Until 1115 PM CDT.
* At 1035 PM CDT, a severe thunderstorm was located over Lake
Vermillion State Recreation Area, moving east at 20 mph.
HAZARD...Ping pong ball size hail.
SOURCE...Radar indicated.
IMPACT...People and animals outdoors will be injured. Expect
damage to roofs, siding, windows, and vehicles.
* This severe thunderstorm will be near...
Hartford, Wall Lake, and Humboldt around 1040 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 4350 9686 4350 9705 4353 9727 4363 9728
4369 9687
TIME...MOT...LOC 0335Z 266DEG 18KT 4357 9715
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.50 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...<50 MPH
$$
Samet2 follow-up statements
093
WWUS53 KFSD 250356
SVSFSD
Severe Weather Statement
National Weather Service Sioux Falls SD
1056 PM CDT Sun May 24 2026
SDC087-250405-
/O.CAN.KFSD.SV.W.0071.000000T0000Z-260525T0415Z/
McCook SD-
1056 PM CDT Sun May 24 2026
...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN MCCOOK COUNTY IS
CANCELLED...
The severe thunderstorm which prompted the warning has moved out of
the warned area. Therefore, the warning has been cancelled.
&&
LAT...LON 4350 9686 4350 9705 4351 9713 4357 9714
4365 9713 4369 9687
TIME...MOT...LOC 0355Z 267DEG 18KT 4357 9701
$$
SDC099-250415-
/O.CON.KFSD.SV.W.0071.000000T0000Z-260525T0415Z/
Minnehaha SD-
1056 PM CDT Sun May 24 2026
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1115 PM CDT
FOR SOUTHWESTERN MINNEHAHA COUNTY...
At 1055 PM CDT, a severe thunderstorm was located near Wall Lake, or
8 miles east of Lake Vermillion State Recreation Area, moving east at
20 mph.
HAZARD...Half dollar size hail.
SOURCE...Radar indicated.
IMPACT...Damage to vehicles is expected.
Locations impacted include...
Hartford and Wall Lake.
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 9686 4350 9705 4351 9713 4357 9714
4365 9713 4369 9687
TIME...MOT...LOC 0355Z 267DEG 18KT 4357 9701
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.25 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...<50 MPH
$$
Samet094
WWUS53 KFSD 250410
SVSFSD
Severe Weather Statement
National Weather Service Sioux Falls SD
1110 PM CDT Sun May 24 2026
SDC099-250419-
/O.EXP.KFSD.SV.W.0071.000000T0000Z-260525T0415Z/
Minnehaha SD-
1110 PM CDT Sun May 24 2026
...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN MINNEHAHA COUNTY
WILL EXPIRE AT 1115 PM CDT...
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning will be allowed to expire. However, small
hail and heavy rain are still possible with this thunderstorm.
To report severe weather, contact your nearest law enforcement
agency. They will relay your report to the National Weather Service
Sioux Falls.
&&
LAT...LON 4350 9686 4350 9705 4351 9713 4357 9714
4365 9713 4369 9687
TIME...MOT...LOC 0409Z 266DEG 18KT 4357 9691
$$
SametWhat 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, 6:34 PM CDT, 4 hours 2 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, 6:34 PM CDT, 4 hours 2 minutes before
Area Forecast Discussion National Weather Service Sioux Falls SD 634 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 /00Z TAFS THROUGH 00Z TUESDAY/... Issued at 634 PM CDT Sun May 24 2026 Showers and thunderstorms have developed across the area late this afternoon. The storms currently extend along a line approximately from KMML down through about KAGZ. Some of these storms are produce large hail and strong winds. These storms will continue to track to the east and look to make it through the KFSD terminal area. A little uncertainty remains for KSUX as drier air my prevent storms from making it KSUX but did include a PROB30 group anyway. Should see thunderstorms chances wane towards midnight or so. After that, quiet conditions and southerly winds will persist through the night. Winds will turn southeasterly for the day tomorrow with gusts up to 20-25 knots. There could be additional storm that develop after the TAF period ends. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...None. MN...None. IA...None. NE...None. && DISCUSSION...Dux AVIATION...Meyers
Hazardous weather outlook, May 24, 12:27 PM CDT, 10 hours 9 minutes 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, 7:24 PM CDT, 3 hours 12 minutes before
Preliminary Local Storm Report
National Weather Service Sioux Falls SD
724 PM CDT Sun May 24 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0718 PM Hail 5 SSW Chandler 43.87N 95.99W
05/24/2026 M1.25 Inch Murray MN Trained Spotter
&&
MMLocal storm report, May 24, 7:50 PM CDT, 2 hours 46 minutes before
Preliminary Local Storm Report
National Weather Service Sioux Falls SD
750 PM CDT Sun May 24 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0747 PM Hail 4 N Utica 43.03N 97.50W
05/24/2026 E1.00 Inch Yankton SD Emergency Mngr
&&
MMLocal storm report, May 24, 8:07 PM CDT, 2 hours 29 minutes before
Preliminary Local Storm Report
National Weather Service Sioux Falls SD
807 PM CDT Sun May 24 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0801 PM Hail 3 ESE Menno 43.22N 97.51W
05/24/2026 E1.50 Inch Hutchinson SD Public
&&
MMLocal storm report, May 24, 8:33 PM CDT, 2 hours 3 minutes before
Preliminary Local Storm Report
National Weather Service Sioux Falls SD
833 PM CDT Sun May 24 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0810 PM Hail 5 WSW Mayfield 43.05N 97.40W
05/24/2026 E1.50 Inch Yankton SD Law Enforcement
&&
MMLocal storm report, May 24, 9:40 PM CDT, 56 minutes before
Preliminary Local Storm Report
National Weather Service Sioux Falls SD
940 PM CDT Sun May 24 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0905 PM Hail Freeman 43.35N 97.43W
05/24/2026 M1.50 Inch Hutchinson SD Public
Freeman Fire Rescue reported pea to
Ping-Pong ball sized hail in Freeman. Time
was estimated via radar.
&&
IGLocal storm report, May 24, 9:54 PM CDT, 42 minutes before
Preliminary Local Storm Report
National Weather Service Sioux Falls SD
954 PM CDT Sun May 24 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0905 PM Hail Freeman 43.35N 97.43W
05/24/2026 E2.00 Inch Hutchinson SD Public
Received a photo of 2 inch hail in Freeman
via social media. Timing was estimated from
radar.
&&
IGThe office that day
Everything else NWS Sioux Falls, SD issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 24, 7:13 PM CDT | Severe Thunderstorm Warning | FSD | Bon Homme, Yankton | 47 min |
| May 24, 7:39 PM CDT | Severe Thunderstorm Warning | FSD | Moody | 51 min |
| May 24, 7:57 PM CDT | Severe Thunderstorm Warning | FSD | Yankton | 48 min |
| May 24, 8:01 PM CDT | Severe Thunderstorm Warning | FSD | Hutchinson, Turner | 44 min |
| May 24, 8:37 PM CDT | Severe Thunderstorm Warning | FSD | Clay, Turner, Yankton | 38 min |
| May 24, 8:41 PM CDT | Severe Thunderstorm Warning | FSD | Hutchinson, Turner | 49 min |
| May 24, 9:24 PM CDT | Severe Thunderstorm Warning | FSD | Lincoln, Minnehaha, Turner | 51 min |
| May 24, 10:04 PM CDT | Severe Thunderstorm Warning | FSD | McCook | 41 min |
| May 24, 10:10 PM CDT | Severe Thunderstorm Warning | FSD | Lincoln, Minnehaha, Turner | 50 min |
| May 24, 10:42 PM CDT | Severe Thunderstorm Warning | FSD | Lincoln | 48 min |
| May 24, 11:29 PM CDT | Flash Flood Warning | FSD | Minnehaha | 72 min |
| May 24, 11:29 PM CDT | Severe Thunderstorm Warning | FSD | Lincoln, Minnehaha | 46 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.