Hail, Plymouth
- When
- May 31, 10:30 PM CST to 10:33 PM CST
- Where
- Plymouth County, 0.86 mi SE of Hinton
- Measured
- 1.5 in hail
- Reported by
- Social Media
- Coordinates
- 42.620, -96.290
A trough lifted through the western High Plains as a weak convergence boundary drifted eastward into southeast South Dakota during the late afternoon. Near the boundary, a diurnally destabilized air mass focused convective development in a fairly weak shear environment across the lower James River Valley.
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Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS FSD wrote it up.
A trough lifted through the western High Plains as a weak convergence boundary drifted eastward into southeast South Dakota during the late afternoon. Near the boundary, a diurnally destabilized air mass focused convective development in a fairly weak shear environment across the lower James River Valley. Thunderstorms largely produced large hail up to ping-pong ball size during periods of stronger updrafts within the storm clusters. Shear concentrated in lower levels and storm interactions combined to produce several brief tornadoes in southeast South Dakota. Storms weakened as they headed into northwest Iowa during the evening but still produced some hail up to ping-pong ball size and strong thunderstorm winds.
The local office's own words before the first event, 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 the first event at May 31, 5:55 PM CST, 4 hours 35 minutes earlier. Its key messages:
Area Forecast Discussion National Weather Service Sioux Falls SD Issued by National Weather Service Rapid City SD 655 PM CDT Sun May 31 2026 .KEY MESSAGES... - Isolated to scattered thunderstorms should develop late this afternoon into early evening. Large hail up to half dollar and damaging winds to 60 mph would be the main hazards. A Level 1 of 5 risk for severe storms covers most of the area for this threat. - Similar to today, a conditional Level 1 of 5 risk for severe storms covers the forecast area Monday afternoon. The chance of development looks lower than today, but if a storm can form, large hail and isolated damaging winds could occur. - High chances (50-80%) for rain will persist through the bulk of next week. However, severe storm chances continue to look low (near 5% or less) through next week. The better chances for rainfall appear to be Wednesday in central SD and Wednesday night into Thursday area wide. && .DISCUSSION... Issued at 1235 PM CDT Sun May 31 2026 An active pattern is expected over the next several days, although severe weather appears to remain a minor threat. Patchy heavy rain may play the bigger role with each event. For this afternoon and tonight, a small corridor of low level convergence and lift will focus near and just east of the James Valley. Clouds have cleared through early afternoon and temperatures have risen a touch. Along with this temperature rise is a turn in the surface winds to a more south to southwest direction vs. southeast. This is what is aiding in this low level convergence. The latest model soundings indicate something around 1500-2000 J/kg CAPE but weak, disorganized shear. This suggests severe weather should remain limited, but maybe a cell merger or two could produce a couple of updrafts strong enough to support hail to half dollar and wind gusts to 60 mph. Stronger storms will likely drift east or northeast at about 15 mph, so fairly slow moving. With this slower storm motion in mind, will need to keep an eye on the locally heavy rain potential. A handful of the latest hi-res models are showing small areas of 1-3" of rain with this development. One area to keep a closer eye on will be parts of Western Lake county, Northeast McCook and western Minnehaha where 1-3" of rain fell late last night. The question becomes what will drive development; will it be diurnal heating, which would allow updrafts to start developing around 19- 21z, or will it be the weak wave which moves into the area closer to 0-3z this evening. The latest HRRR and Nam output agree with the later start times, with the Nam indicating a stronger cap and less development, while the RRFS and RAP kick off development a little sooner with weaker capping. With the clearing that we are seeing in central SD towards the James Valley we may see some development by mid to late afternoon as destabilization is more likely. Suspect some development between about 5-6pm. One last thing to watch out for, if we can get mid to late afternoon development, the LFC are marginally low and a weak convergent boundary should be in parts of south central and southeast SD, so an isolated funnel or two will be possible. While a marginal risk for severe weather is in place for Monday, confidence in the chances of development are very low. A capping inversion may win out and for now CAPE values only running around 1000 J/kg with continued weak shear, albeit a little bit better than today. Another wave moves through Tuesday but weak shear and weak instability suggest if anything can develop severe weather is very unlikely. Wednesday into Thursday looks like the better chance for more clouds and better rainfall chances. Broad southerly warm advection looks to bring in some weak elevated instability as low pressure tracks east through ND. For now not anticipating all day rainfall but should see off and on chances Wednesday and Thursday as this low tracks by to the north. Friday into Sunday will see periodic weaker waves move through the area with a continuation of relatively weak flow aloft. This continued weaker shear environment should keep severe weather threats very limited. && .AVIATION...(For the 00Z TAFS Through 00Z Monday Evening) Issued At 651 PM CDT Sun May 31 2026 Isolated showers and thunderstorms will continue to be possible across the area through the early evening hours. Low stratus is expected to develop tonight over southwest Minnesota and eastern South Dakota, especially near and east of I-29. Highest confidence location for this MVFR to IFR stratus regarding the TAF sites will be at KFSD. Winds will turn light through the overnight hours, and this could also result in fog, though confidence is a bit lower in development. Additional showers and storms may develop Monday afternoon, but low confidence in development and location of these storms preclude mention in the TAFs at this time. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...None. MN...None. IA...None. NE...None. && DISCUSSION...08 AVIATION...13
Hazardous Weather Outlook National Weather Service Sioux Falls SD 133 PM CDT Sun May 31 2026 IAZ001>003-012>014-020>022-031-032-MNZ071-072-080-081-089-090-097- 098-NEZ013-014-SDZ038>040-050-052>071-011845- 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- 133 PM CDT Sun May 31 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 Level 1 of 5 risk for severe storms is in place for late this afternoon and evening. Isolated to scattered thunderstorms should develop late this afternoon between the James River and I-29, then progress eastward through the evening. A very isolated stronger storm could produce hail to half dollar and wind gusts to 60 mph. Locally heavier rain will also be possible with small swaths of one to three inches of rainfall. .DAYS TWO THROUGH SEVEN...Monday through Saturday. There is a low chance for storms again Monday afternoon. Similar to today, confidence in storm development is low. However, if storms can develop, isolated damaging winds and large hail would be the main threats. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time.
Preliminary Local Storm Report
National Weather Service Sioux Falls SD
740 PM CDT Sun May 31 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0733 PM Hail 4 SW Hurley 43.24N 97.15W
05/31/2026 E1.00 Inch Turner SD Fire Dept/Rescue
&&
TRMPreliminary Local Storm Report
National Weather Service Sioux Falls SD
805 PM CDT Sun May 31 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0754 PM Hail 2 WNW Davis 43.27N 97.04W
05/31/2026 E1.00 Inch Turner SD Public
&&
TRMPreliminary Local Storm Report
National Weather Service Sioux Falls SD
818 PM CDT Sun May 31 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0817 PM Hail Wakonda 43.01N 97.11W
05/31/2026 E0.88 Inch Clay SD Trained Spotter
&&
TRMPreliminary Local Storm Report
National Weather Service Sioux Falls SD
823 PM CDT Sun May 31 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0811 PM Tornado 4 W Wall Lake 43.53N 97.03W
05/31/2026 Minnehaha SD NWS Employee
Radar confirmed tonado.
&&
TRMPreliminary Local Storm Report
National Weather Service Sioux Falls SD
847 PM CDT Sun May 31 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0845 PM Hail Davis 43.26N 97.00W
05/31/2026 E1.00 Inch Turner SD Emergency Mngr
&&
TRMPreliminary Local Storm Report
National Weather Service Sioux Falls SD
858 PM CDT Sun May 31 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0854 PM Tornado 5 NE Centerville 43.17N 96.89W
05/31/2026 Lincoln SD Storm Chaser
Tornado observed from chaser live feed.
&&
TRMThe Sioux Falls radar (KFSD), 113 km away, was scanning. The volume nearest the first event began at 04:30 UTC.
2 hail, 1 thunderstorm wind. Local standard time, as filed.
Several tree limbs from 3 to 4 inches in diameter were broken down by strong thunderstorm wind gusts.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Iowa in 2026Every state in 2026This day in weather historyWarnings in Iowa, May 2026
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 1344138, 1344139, 1345402.