Alert archive / Iowa / Severe Thunderstorm Warnings in 2026
Severe Thunderstorm Warning 8, NWS Sioux Falls, SD
NWS Sioux Falls, SD issued this severe thunderstorm warning at Apr 13, 2026, 6:05 PM CDT for 4 counties in Iowa. It was in force for 40 min. 15 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
- Apr 13, 2026, 6:05 PM CDT (23:05 UTC)
- Expired
- Apr 13, 2026, 6:45 PM CDT
- In force
- 40 min
- Issued by
- NWS Sioux Falls, SD
- Area
- Storm-based polygon
- Hail
- 1.25 in
- Wind
- 60.0 mph
Counties Cherokee County, IA, O'Brien County, IA, Plymouth County, IA, Sioux County, IA
The radar
The Sioux Falls radar (KFSD), 102 km from the middle of the area, began a volume at 23:09 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 |
|---|---|---|---|
| Apr 13, 6:08 PM CDT | HAIL 1.75 | 4 Se Granville, IA | |
| Apr 13, 6:08 PM CDT | HAIL 1.75 | 4 Se Granville, IA | |
| Apr 13, 6:28 PM CDT | HAIL 1 | Primghar, IA | |
| Apr 13, 6:28 PM CDT | HAIL 1 | Primghar, IA | |
| Apr 13, 6:30 PM CDT | TORNADO | 2 Ne Archer, IA | Corrects time of previous tornado report from 2 NE Archer. Start of brief tornado which tracked generally north and northwest for around 5 minutes. Track was through open fields with no visible damage. Location and track derived from eyewitness photos and vide |
| Apr 13, 6:34 PM CDT | HAIL 1.75 | 3 Nne Archer, IA | Social media report with picture of estimated hail size. |
| Apr 13, 6:34 PM CDT | HAIL 1.75 | 3 Nne Archer, IA | Social media report with picture of estimated hail size. |
| Apr 13, 6:40 PM CDT | HAIL 1 | 3 S Sanborn, IA | Report from mPING: Quarter (1.00 in.). |
| Apr 13, 6:40 PM CDT | HAIL 1 | 3 S Sanborn, IA | Report from mPING: Quarter (1.00 in.). |
| Apr 13, 6:40 PM CDT | HAIL 1.5 | Sanborn, IA | Report from mPING: Ping Pong Ball (1.50 in.). |
| Apr 13, 6:40 PM CDT | HAIL 1.5 | Sanborn, IA | Report from mPING: Ping Pong Ball (1.50 in.). |
| Apr 13, 6:41 PM CDT | HAIL 1.25 | Sanborn, IA | |
| Apr 13, 6:41 PM CDT | HAIL 1.25 | Sanborn, IA | |
| Apr 13, 6:44 PM CDT | HAIL 1.5 | Sanborn, IA | |
| Apr 13, 6:44 PM CDT | HAIL 1.5 | Sanborn, IA |
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 14 storm reports to this severe thunderstorm warning; the first came 3 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 |
|---|---|---|---|
| Apr 13, 4:39 PM CDT | Severe Thunderstorm Watch | SPC | 5 hr |
The nearest sounding before it
Minneapolis, MN (KMPX), launched 12:00Z, 11.1 hours before the alert went out and 267 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
- 8 J/kg
- Mixed-layer CIN
- -259 J/kg
- Mixed-layer LCL
- 1506 m above ground
- 0-6 km bulk shear
- 45 kt
- 0-1 km storm-relative helicity
- 124 m²/s²
- 0-3 km storm-relative helicity
- 229 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
215
WUUS53 KFSD 132305
SVRFSD
IAC035-141-149-167-132345-
/O.NEW.KFSD.SV.W.0008.260413T2305Z-260413T2345Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Sioux Falls SD
605 PM CDT Mon Apr 13 2026
The National Weather Service in Sioux Falls has issued a
* Severe Thunderstorm Warning for...
Northwestern Cherokee County in northwestern Iowa...
Southeastern Sioux County in northwestern Iowa...
Northeastern Plymouth County in northwestern Iowa...
Western O'Brien County in northwestern Iowa...
* Until 645 PM CDT.
* At 604 PM CDT, a severe thunderstorm was located near Granville, or
12 miles southeast of Orange City, moving north at 30 mph.
HAZARD...60 mph wind gusts and half dollar size hail.
SOURCE...Radar indicated.
IMPACT...Hail damage to vehicles is expected. Expect wind damage
to roofs, siding, and trees.
* This severe thunderstorm will be near...
Paullina and Granville around 610 PM CDT.
Hospers and Archer around 615 PM CDT.
Primghar around 620 PM CDT.
Other locations in the path of this severe thunderstorm include
Sheldon and Sanborn.
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 4285 9570 4286 9595 4325 9588 4326 9550
TIME...MOT...LOC 2304Z 198DEG 28KT 4292 9583
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.25 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
IG1 follow-up statement
617
WWUS53 KFSD 132324
SVSFSD
Severe Weather Statement
National Weather Service Sioux Falls SD
624 PM CDT Mon Apr 13 2026
IAC035-149-167-132334-
/O.CAN.KFSD.SV.W.0008.000000T0000Z-260413T2345Z/
Cherokee IA-Sioux IA-Plymouth IA-
624 PM CDT Mon Apr 13 2026
...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN CHEROKEE...
SOUTHEASTERN SIOUX AND NORTHEASTERN PLYMOUTH COUNTIES IS CANCELLED...
The severe thunderstorm which prompted the warning has moved out of
the warned area. Therefore, the warning has been cancelled.
A Severe Thunderstorm Watch remains in effect until 1000 PM CDT for
northwestern Iowa.
&&
LAT...LON 4297 9564 4298 9585 4325 9586 4326 9550
TIME...MOT...LOC 2324Z 197DEG 31KT 4306 9573
$$
IAC141-132345-
/O.CON.KFSD.SV.W.0008.000000T0000Z-260413T2345Z/
O'Brien IA-
624 PM CDT Mon Apr 13 2026
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 645 PM CDT
FOR WESTERN O'BRIEN COUNTY...
At 624 PM CDT, a severe thunderstorm was located near Archer, or 10
miles southeast of Sheldon, moving north at 35 mph.
HAZARD...60 mph wind gusts and half dollar size hail.
SOURCE...Radar indicated.
IMPACT...Hail damage to vehicles is expected. Expect wind damage to
roofs, siding, and trees.
Locations impacted include...
Sheldon, Sanborn, Primghar and Archer.
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 4297 9564 4298 9585 4325 9586 4326 9550
TIME...MOT...LOC 2324Z 197DEG 31KT 4306 9573
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.25 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
IGWhat 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 Apr 13, 2:50 PM CDT, 3 hours 15 minutes earlier. Its key messages:
- Thunderstorms return this afternoon and evening. Scattered strong to severe storms expected - greatest risk for southwestern Minnesota into adjacent areas of South Dakota and northwest Iowa. Timing of greatest concern is 4 to 9 PM.
- Main hazards are large hail greater than 2 inches in diameter and wind gusts to 70 mph. A tornado or two are also possible. Have a severe weather plan and multiple ways to receive warnings.
- Periodic chances (20-60%) for showers and thunderstorms continue this week. Details remain uncertain at this time.
Area forecast discussion, Apr 13, 2:50 PM CDT, 3 hours 15 minutes before
Area Forecast Discussion National Weather Service Sioux Falls SD 250 PM CDT Mon Apr 13 2026 .KEY MESSAGES... - Thunderstorms return this afternoon and evening. Scattered strong to severe storms expected - greatest risk for southwestern Minnesota into adjacent areas of South Dakota and northwest Iowa. Timing of greatest concern is 4 to 9 PM. - Main hazards are large hail greater than 2 inches in diameter and wind gusts to 70 mph. A tornado or two are also possible. Have a severe weather plan and multiple ways to receive warnings. - Periodic chances (20-60%) for showers and thunderstorms continue this week. Details remain uncertain at this time. && .DISCUSSION... Issued at 238 PM CDT Mon Apr 13 2026 Scattered thunderstorms are set to develop over the next few hours, bringing the potential for a few severe storms with large hail, damaging winds, and perhaps a tornado or two. As of 2 pm, a surface low is located over northern Nebraska with a warm front extending northeast of it across far southeastern South Dakota into northwest Iowa. Dew points in the 60s have been gradually spreading northward, and these higher dew points are expected to reach the I-90 corridor over the next couple of hours. This boundary will be the focus of initial storm development, with these storms having access to 35-50 kts of effective bulk shear and 1500-2000 J/kg of MLCAPE. There are questions though on how much some high clouds have limited the area from reaching full heating potential, but if a storm can get going then steep mid level lapse rates of 7.5-8.5 degrees C/km and mostly straight, elongated hodographs will favor large hail to around 2 inches in diameter or larger. The secondary threat will be damaging wind gusts up to 70 mph. If a storm can get rooted to the aforementioned surface warm front, then a tornado or two will also be possible. Can't rule out a strong tornado either, primarily over southwest Minnesota. As the low pressure system drift across the area, a few additional showers and storms look to develop farther south across northwest Iowa (down to about IA Highway-3, or just north of US Highway-20) within the warm sector around sunset. These storms could also be on the strong to severe side, with an isolated instance of quarter sized hail and 60 mph as the threats. Showers and storms will exit off to our east by the mid evening hours, leaving mostly quiet conditions in its wake. A few showers may develop in central South Dakota prior to daybreak Tuesday, but dry air should win out and prevent most if not all of this from reaching the ground. Patchy fog will also be possible by early Tuesday morning across portions of northwest Iowa and southwest Minnesota as winds turn light and variable overnight and ample moisture remains in place. Temperatures tonight drop mainly in the 40s, though some 50s are possible in our easternmost areas. Low chances for showers continue into the day on Tuesday, but activity is expected to remain spotty at best as rain continues to battle a dry sub cloud layer. Highs will range from the 60s northwest to 70s southeast. Rain chances look to increase Tuesday night into Wednesday as two shortwave troughs impact our area. The best chances of rain and storms look to be over northwest Iowa and adjacent areas of Nebraska, South Dakota, and Minnesota. At this time, severe weather looks unlikely with this system as the better instability looks to be off to our south and east. Rain and storms exit off to our east by Wednesday night, leading to a dry Thursday. Winds look to increase on Thursday especially west of I-29 closer to a deepening surface low, and winds may take on a southwesterly component especially in south central South Dakota. This could lead to another day with higher fire danger as temperatures will be warm and relative humidity values drop to 25% or below mainly along and west of the James River. Still some uncertainty into how breezy the winds will be, so keep up to date with the latest forecast. Not too much time to look into the extended forecast given the near term severe weather threat, but guidance is in fairly good agreement that the western trough will begin to move into our area by the end of the work week/early weekend. This could bring more rain and storms to our area on Friday and then colder weather into Saturday as guidance indicates a stronger push of cold air advection behind this system. && .AVIATION /18Z TAFS THROUGH 18Z TUESDAY/... Issued at 1241 PM CDT Mon Apr 13 2026 Isolated to widely scattered showers and storms are expected to develop this afternoon, especially east of I-29 into southern Minnesota and northern Iowa. Enough confidence to at least include a PROB30 group for thunderstorms at KFSD, but it looks like storms should stay largely east of KSUX and KHON. Storms will be capable of large hail and damaging winds. Showers and storms will quickly push off to our east this evening, leading to quieter conditions overnight. Some patchy fog is possible mainly over portions of northwest Iowa and southwest Minnesota Tuesday morning. A frontal system will move across the area today, changing winds from a more southerly direction to a more northerly direction as we head into the evening hours. Winds turn mainly light and variable overnight and stay fairly light through the end of the period. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...None. MN...None. IA...None. NE...None. && DISCUSSION...Samet AVIATION...Samet
Hazardous weather outlook, Apr 13, 3:56 PM CDT, 2 hours 9 minutes before
Hazardous Weather Outlook National Weather Service Sioux Falls SD 356 PM CDT Mon Apr 13 2026 IAZ001>003-012>014-020>022-031-032-MNZ071-072-080-081-089-090-097- 098-NEZ013-014-SDZ038>040-050-052>071-142100- 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- 356 PM CDT Mon Apr 13 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. Scattered strong to severe thunderstorms expected Monday afternoon and evening. Some storms may produce large hail 2 inches in diameter and damaging wind gusts up to 70 mph. A tornado or two cannot be ruled out. Greatest risk of storms is north of I-90 between 4 and 10 PM. .DAYS TWO THROUGH SEVEN...Tuesday through Sunday. More widespread chances for showers and thunderstorms exists for Tuesday afternoon into Wednesday. This more active pattern continues into the weekend. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time.
In the hours before
Local storm report, Apr 13, 3:39 PM CDT, 2 hours 26 minutes before
Preliminary Local Storm Report
National Weather Service Sioux Falls SD
339 PM CDT Mon Apr 13 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0332 PM Hail Tripp 43.23N 97.97W
04/13/2026 E0.75 Inch Hutchinson SD Public
Report from mPING: Dime (0.75 in.).
&&
TRMLocal storm report, Apr 13, 4:29 PM CDT, 1 hour 36 minutes before
Preliminary Local Storm Report
National Weather Service Sioux Falls SD
429 PM CDT Mon Apr 13 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0400 PM Hail 4 NW Olivet 43.29N 97.73W
04/13/2026 E1.00 Inch Hutchinson SD Public
&&
TRMLocal storm report, Apr 13, 4:44 PM CDT, 1 hour 21 minutes before
Preliminary Local Storm Report
National Weather Service Sioux Falls SD
444 PM CDT Mon Apr 13 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0416 PM Hail 5 NNE Olivet 43.31N 97.63W
04/13/2026 M1.00 Inch Hutchinson SD Public
&&
TRMLocal storm report, Apr 13, 5:23 PM CDT, 42 minutes before
Preliminary Local Storm Report
National Weather Service Sioux Falls SD
523 PM CDT Mon Apr 13 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0440 PM Hail 3 S Freeman 43.31N 97.44W
04/13/2026 E1.25 Inch Hutchinson SD Public
&&
TRMLocal storm report, Apr 13, 5:30 PM CDT, 35 minutes before
Preliminary Local Storm Report
National Weather Service Sioux Falls SD
530 PM CDT Mon Apr 13 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0523 PM Hail Moville 42.49N 96.07W
04/13/2026 E0.50 Inch Woodbury IA Public
&&
TRMLocal storm report, Apr 13, 6:03 PM CDT, 2 minutes before
Preliminary Local Storm Report
National Weather Service Sioux Falls SD
603 PM CDT Mon Apr 13 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0551 PM Hail Ashton 43.31N 95.79W
04/13/2026 E0.50 Inch Osceola IA Public
Report from mPING: Half-inch (0.50 in.).
&&
TRMThe office that day
Everything else NWS Sioux Falls, SD issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 13, 5:26 PM CDT | Severe Thunderstorm Warning | FSD | Plymouth, Sioux, Woodbury | 49 min |
| Apr 13, 5:56 PM CDT | Severe Thunderstorm Warning | FSD | Cherokee, Plymouth | 29 min |
| Apr 13, 6:30 PM CDT | Severe Thunderstorm Warning | FSD | Dickinson, Osceola | 45 min |
| Apr 13, 6:45 PM CDT | Severe Thunderstorm Warning | FSD | O'Brien, Osceola | 45 min |
| Apr 13, 6:53 PM CDT | Severe Thunderstorm Warning | FSD | Cherokee, Clay, O'Brien | 52 min |
Nearby
Severe 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.