Severe Thunderstorm Warning 74, NWS Sioux Falls, SD

575 
WWUS53 KFSD 250629
SVSFSD

Severe Weather Statement
National Weather Service Sioux Falls SD
129 AM CDT Mon May 25 2026

IAC119-167-250639-
/O.CAN.KFSD.SV.W.0074.000000T0000Z-260525T0700Z/
Lyon IA-Sioux IA-
129 AM CDT Mon May 25 2026

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN LYON AND
NORTHEASTERN SIOUX COUNTIES IS CANCELLED...

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

&&

LAT...LON 4316 9585 4332 9574 4323 9539 4299 9552
TIME...MOT...LOC 0629Z 295DEG 26KT 4322 9573 

$$

IAC141-143-250700-
/O.CON.KFSD.SV.W.0074.000000T0000Z-260525T0700Z/
Osceola IA-O'Brien IA-
129 AM CDT Mon May 25 2026

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 200 AM CDT
FOR SOUTH CENTRAL OSCEOLA AND NORTHERN O'BRIEN COUNTIES...

At 129 AM CDT, a severe thunderstorm was located near Sanborn, or
near Sheldon, moving southeast at 30 mph.

HAZARD...60 mph wind gusts and quarter size hail.

SOURCE...Radar indicated.

IMPACT...Hail damage to vehicles is expected. Expect wind damage to 
         roofs, siding, and trees.

Locations impacted include...
  Sanborn, Primghar, Melvin, Archer and Hartley.

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 4316 9585 4332 9574 4323 9539 4299 9552
TIME...MOT...LOC 0629Z 295DEG 26KT 4322 9573 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

IG

255 
WWUS53 KFSD 250651
SVSFSD

Severe Weather Statement
National Weather Service Sioux Falls SD
151 AM CDT Mon May 25 2026

IAC143-250701-
/O.CAN.KFSD.SV.W.0074.000000T0000Z-260525T0700Z/
Osceola IA-
151 AM CDT Mon May 25 2026

...THE SEVERE THUNDERSTORM WARNING FOR SOUTH CENTRAL OSCEOLA 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 4312 9564 4326 9555 4323 9539 4304 9549
TIME...MOT...LOC 0651Z 294DEG 27KT 4316 9553 

$$

IAC141-250700-
/O.CON.KFSD.SV.W.0074.000000T0000Z-260525T0700Z/
O'Brien IA-
151 AM CDT Mon May 25 2026

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 200 AM CDT
FOR NORTHEASTERN O'BRIEN COUNTY...

At 151 AM CDT, a severe thunderstorm was located over Hartley, or 16
miles east of Sheldon, moving southeast at 30 mph.

HAZARD...60 mph wind gusts and quarter size hail.

SOURCE...Radar indicated.

IMPACT...Hail damage to vehicles is expected. Expect wind damage to 
         roofs, siding, and trees.

Locations impacted include...
Hartley.

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 4312 9564 4326 9555 4323 9539 4304 9549
TIME...MOT...LOC 0651Z 294DEG 27KT 4316 9553 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

IG

212 
WWUS53 KFSD 250658
SVSFSD

Severe Weather Statement
National Weather Service Sioux Falls SD
158 AM CDT Mon May 25 2026

IAC141-250708-
/O.EXP.KFSD.SV.W.0074.000000T0000Z-260525T0700Z/
O'Brien IA-
158 AM CDT Mon May 25 2026

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN O'BRIEN COUNTY
WILL EXPIRE AT 200 AM 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 4312 9564 4326 9555 4323 9539 4304 9549
TIME...MOT...LOC 0658Z 295DEG 26KT 4314 9547 

$$

IG

Area Forecast Discussion
National Weather Service Sioux Falls SD
1050 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.

&&

.UPDATE...
Issued at 1049 PM CDT Sun May 24 2026

With ongoing severe weather across parts of the area, the next
update will out before 5 am on May 25th.

&&

.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.

&&

UPDATE...05
DISCUSSION...Dux
AVIATION...Meyers

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.

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.

&&

IG

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.

&&

IG

Preliminary Local Storm Report
National Weather Service Sioux Falls SD
1039 PM CDT Sun May 24 2026

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

0605 PM     Hail             Woodstock               44.01N 96.10W
05/24/2026  E1.25 Inch       Pipestone          MN   Trained Spotter

            A trained spotter reported half dollar sized
            hail in Woodstock, MN. Time estimated via
            radar.

&&

IG

Preliminary Local Storm Report
National Weather Service Sioux Falls SD
1136 PM CDT Sun May 24 2026

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

1130 PM     Hail             2 SW Sioux Falls        43.52N 96.76W
05/24/2026  E1.00 Inch       Minnehaha          SD   Public

            Got an mping report of Quarter sized hail in
            Sioux Falls. Time estimated via radar.

&&

IG

Preliminary Local Storm Report
National Weather Service Sioux Falls SD
1138 PM CDT Sun May 24 2026

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

1022 PM     Hail             1 SSW Harrisburg        43.42N 96.70W
05/24/2026  E1.00 Inch       Lincoln            SD   Public

            Received a public report of quarter sized
            hail near Harrisburg. Time estimated via
            radar.

&&

IG

Preliminary Local Storm Report
National Weather Service Sioux Falls SD
1152 PM CDT Sun May 24 2026

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

1140 PM     Hail             2 W Brandon             43.59N 96.62W
05/24/2026  E1.00 Inch       Minnehaha          SD   Public

            mPING Report of Quarter (1.00 in.) sized
            hail just west of Brandon. Time estimated
            via radar.

&&

IG