During the late evening hours of May 31 and into the early morning of June 1, 2026, a stalled frontal boundary draped across northeast Nebraska and western Iowa became the focal point for strong to severe thunderstorm development. The environment along the boundary featured roughly 2,000 J/kg of instability and 30 knots of deep-layer shear, which proved sufficient to organize convection.
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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 OAX wrote it up.
During the late evening hours of May 31 and into the early morning of June 1, 2026, a stalled frontal boundary draped across northeast Nebraska and western Iowa became the focal point for strong to severe thunderstorm development. The environment along the boundary featured roughly 2,000 J/kg of instability and 30 knots of deep-layer shear, which proved sufficient to organize convection. Additionally, a dry sub-cloud layer yielded approximately 1,400 J/kg of DCAPE, promoting a severe downdraft threat alongside the hail risk.
As storms initiated and pushed southward overnight, radar signatures indicated the potential for several swaths of large hail and damaging winds, particularly across western Iowa. However, because the storms primarily traversed sparsely populated areas late at night, only a handful of severe weather reports were received. Quarter-size (1.00 inch) hail was estimated near the towns of Woodbine and Avoca, Iowa. The storms also produced a measured wind gust of 63 mph and localized tree damage in Pottawattamie County, Iowa. The complex continued tracking southward, eventually decreasing in intensity and weakening below severe limits during the early morning hours.
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 Omaha, NE wrote its last area forecast discussion before the first event at May 31, 10:24 PM CST, 1 hour 43 minutes earlier. Its key messages:
Area Forecast Discussion National Weather Service Omaha/Valley NE 1124 PM CDT Sun May 31 2026 .KEY MESSAGES... - Regular chances for showers and thunderstorms continue with more thunderstorms in the forecast for this evening, especially along and east of the Missouri River. - A summer-like pattern sets up next week keeping warm and muggy weather in place with additional daily chances for showers and thunderstorms throughout the week into next weekend. && .DISCUSSION... Issued at 1104 PM CDT Sun May 31 2026 We've seen a couple isolated storms develop this evening, some along a boundary stretching south from ongoing storms in South Dakota, and a couple others around the Omaha/Council Bluffs area. Mid-level dry air is making storm development difficult, though if storms do develop there is 2000J/kg+ of CAPE, and 1400J/kg of DCAPE. Shear is modest (75m2/s2 of sfc-1km SRH), lending to observed storms not holding together long, but occasional low-to-mid level rotation was observed in the earlier cell over Douglas County. The low tornado threat is only diminishing, making primary hazards large hail and damaging winds. Storms that develop this evening should clear out by 5AM, with clearing skies Monday morning. Ridging starts to build up on Monday over our area with subsidence dampening storm potential Monday afternoon despite a shortwave moving over our area. CAMs show a few isolated storms through the afternoon, so introduced a 15-20% chance for a few isolated storms. Temperatures expected to warm into the mid-to- upper 80s during the afternoon. A more substantial shortwave triggers convection over western Nebraska during the afternoon, likely developing into an MCS through the evening. This could bring us another chance for showers and storms across our far western counties early Tuesday, though most guidance has it dissipating before it gets any farther east. We continue to see ridging amplify across the Central Plains through midweek, with a moisture plume triggering storms along the western flank of the ridge. Nightly potential for MCS development and propagation eastward appears likely, with increasing chances for storms to make it into eastern Nebraska Tuesday night and Wednesday night. Thursday the Ridge shifts far enough eastward for the moisture plume to run straight up through our area, developing storms across eastern Nebraska and western Iowa Thursday afternoon through the evening. Going into the weekend, the ridge shifts far enough eastward that that moisture plume drops southeast into Missouri, but a developing surface Low over the Dakotas triggers more chances for showers and storms Friday afternoon and evening. Through the weekend we see a baroclinic weather pattern set up with strong ridging building up to our north, and a series of two shortwave troughs moving northeast into Nebraska through the weekend. This will keep chances for showers and storms for Saturday and Sunday, while increased warm-air advection from enhanced southerly flow will warm temperatures back into the upper 80s to near 90. Extreme heat appears possible next week with ample moisture contributing to concerning heat indices. && .AVIATION /06Z TAFS THROUGH 06Z TUESDAY/... Issued at 1124 PM CDT Sun May 31 2026 Storms should stay mostly clear of the terminals for the rest of the night, though we do still have a 20% chance of a storm impacting KOMA through 07Z. Mostly clear skies expected through morning with winds becoming northwesterly by around 10Z. Winds continue to shift toward northerly then northeasterly by midday Monday with a 15-20% chance for a few isolated showers/storms Monday afternoon into the evening. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...None. IA...None. && DISCUSSION...McCoy AVIATION...McCoy
Hazardous Weather Outlook National Weather Service Omaha/Valley NE 1107 PM CDT Sun May 31 2026 IAZ043-055-056-069-079-080-090-091-NEZ011-012-015>018-030>034- 042>045-050>053-065>068-078-088>093-020415- Monona-Harrison-Shelby-Pottawattamie-Mills-Montgomery-Fremont-Page- Knox-Cedar-Thurston-Antelope-Pierce-Wayne-Boone-Madison-Stanton- Cuming-Burt-Platte-Colfax-Dodge-Washington-Butler-Saunders-Douglas- Sarpy-Seward-Lancaster-Cass-Otoe-Saline-Jefferson-Gage-Johnson- Nemaha-Pawnee-Richardson- 1107 PM CDT Sun May 31 2026 This Hazardous Weather Outlook is for southwest Iowa, west central Iowa, east central Nebraska, northeast Nebraska and southeast Nebraska. .DAY ONE...Tonight. Strong to severe storms are possible through around 3 AM. Isolated hail and strong wind gusts are the primary hazards. .DAYS TWO THROUGH SEVEN...Monday through Saturday. Additional strong to severe thunderstorms are possible across the area Monday afternoon and evening. Isolated hail and strong wind gusts are the primary hazards. Daily chances for thunderstorms continue through next week. Thunderstorms could potentially be strong to severe, though chances are low (less than 15%) at this time. .SPOTTER INFORMATION STATEMENT... Spotter activation may be needed.
Preliminary Local Storm Report
National Weather Service Omaha/Valley NE
918 PM CDT Sun May 31 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0913 PM Hail 6 SW Norfolk 41.98N 97.49W
05/31/2026 E0.25 Inch Madison NE Public
&&Preliminary Local Storm Report
National Weather Service Omaha/Valley NE
927 PM CDT Sun May 31 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0919 PM Hail 2 NW Elkhorn 41.30N 96.26W
05/31/2026 E0.25 Inch Douglas NE Public
&&Preliminary Local Storm Report
National Weather Service Omaha/Valley NE
938 PM CDT Sun May 31 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0933 PM Hail 1 NW Elkhorn 41.30N 96.25W
05/31/2026 E0.50 Inch Douglas NE Public
Report from mPING: Half-inch (0.50 in.).
&&Preliminary Local Storm Report
National Weather Service Omaha/Valley NE
1159 PM CDT Sun May 31 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1156 PM Hail Woodbine 41.74N 95.71W
05/31/2026 E1.00 Inch Harrison IA Law Enforcement
&&
mwThe Omaha radar (KOAX), 88 km away, was scanning. The volume nearest the first event began at 06:04 UTC.
2 thunderstorm wind, 1 hail. Local standard time, as filed.
Delayed report received via broadcast media, including a video showing copious amounts of hail falling. Hailstones were estimated to be at least 1 inch in diameter. Time was estimated using radar.
Delayed report of tree damage with estimated wind gusts up to 60 mph. Time estimated with radar.
Personal weather station measured wind gust of 63 mph.
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, June 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: 1339594, 1339595, 1339596.