A line of intense supercell thunderstorms developed over northeast Nebraska during the afternoon hours of Friday, June 16. These storms progressed toward the south and east through the evening, progressively morphing into a sweeping line of storms with embedded areas of both supercells and intense bow echoes.
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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.
A line of intense supercell thunderstorms developed over northeast Nebraska during the afternoon hours of Friday, June 16. These storms progressed toward the south and east through the evening, progressively morphing into a sweeping line of storms with embedded areas of both supercells and intense bow echoes. While the entire line produced widespread reports of wind damage and hail across a large portion of southwest Iowa and eastern Nebraska, the most intense activity produced hurricane-force winds of 80-110 mph, hail larger than golf balls, and several tornadoes. Damage was reported in several counties across southwest Iowa and eastern Nebraska, with significant damage to homes impacted by tornadoes and widespread, substantial tree and crop damage.
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 Jun 16, 6:44 AM CST, 36 minutes earlier.
Area Forecast Discussion National Weather Service Omaha/Valley NE 744 AM CDT Fri Jun 16 2017 .SHORT TERM...(Today through Sunday) Issued at 320 AM CDT Fri Jun 16 2017 Main concerns in the short term are chances for thunderstorms, the severe potential with them and the timing this afternoon/evening. The following features of interest were noted in the 00Z upper air charts. A jet max of around 125 kts (satellite derived wind) was just of the coast of WA/OR. Winds of up to 75 knots extended out ahead of this max as far east as MT. At 500 mb, the flow was fairly zonal from the Pacific Northwest into the northern and central Plains with no height falls. Warm temperatures at 700 mb were noted from KS southwest into the Four Corners region and Mexico. At 850 mb, Dewpoints were in the teens C, with the highest noted at KTOP with 18 C. The KOAX sounding had steep low and mid level lapse rates, with a 700 mb temperature of only 8 degrees C and a PW of 1.29 inches. Surface analysis early this morning was somewhat contaminated due to leftover outflow from storms last evening and early this morning, but only a few were lingering in southwest IA as of 08Z. Dewpoints were quite variable with some 50s in northeast NE and generally 60s elsewhere in the area. Expect southerly low level flow to increase today as low pressure develops to the west. Expect low pressure to be over north central NE by early afternoon with a warm front curving from the low toward northern IA and a trough/weak cold front extending down into northwest KS. Using a combination of the convection allowing mesoscale models and both the 00Z and 06Z runs of the NAM, have POPs increasing as the afternoon progresses with highest values across northeast NE. The 04Z run of the experimental HRRR did not develop much prior to 23Z but that seems to late based on some other output, including the 00Z NSSL WRF. Storms that develop will be in a favorable environment for severe weather (MUCAPE values of 2000-4000 J/kg and 0-6 km bulk shear values of 30-50 kts). Storms that develop may initially be discrete with all modes of severe weather possible, but will trend toward wind and hail potential as a one or more MCS clusters congeal and track southeast through the evening. Have mentioned large hail and damaging winds for some areas in grids. Generally have POPs decreasing to slight chance in southeast NE and southwest IA after midnight, but some showers/ storms could move into northeast NE from the west late. Will have some chance of thunderstorms mentioned on Saturday, but I suspect the main threat of severe will be east and south of our area if the current expected timing of the cold front ends up being correct. Cooler and drier air will build in behind that front from Saturday night into Sunday night. Some showers/t-storms will try to develop Sunday with the cold air aloft, but mainly from eastern SD toward northern IA. Highs Sunday should reach the mid and upper 70s north and lower 80s south. .LONG TERM...(Sunday night through Thursday) Issued at 320 AM CDT Fri Jun 16 2017 Main mid tropospheric features at the start of this period will be a closed low over western Ontario, brisk northwest flow from MT into the mid Missouri Valley, a ridge over western Canada and an anticyclone over the southwest US. Through mid week, that high pressure ridge aloft should build/expand, with a general flow deamplification from the Pacific Northwest into the northern and central Plains. Later in the week, a longwave trough should progress southeast across the northern Rockies and southern Canada. This should result in highs next week ranging mostly from the mid 80s to lower 90s (possibly just 80s by Thursday) with lows Monday in the mid 50s to around 60s, but mainly from the lower 60s to lower 70s Tuesday through Thursday. There will be some intermittent chances for precipitation, but timing those is expected to be difficult with the northwest flow. && .AVIATION...(For the 12Z TAFS through 12Z Saturday morning) Issued at 739 AM CDT Fri Jun 16 2017 VFR conditions with mid and high clouds today and outside of thunderstorms. Thunderstorms are forecast to develop later this afternoon as surface low pressure moves into the area at KOFK...spreading southeast toward KOMA and KLNK in the evening. Exact timing can be refined, however honed in on the 22 to 02Z time period. Instability is fairly high and soundings support gusty winds...thus did include variable wind gusts with the storms later today. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...None. IA...None. && SHORT TERM...Miller LONG TERM...Miller AVIATION...Zapotocny
Hazardous Weather Outlook National Weather Service Omaha/Valley NE 420 AM CDT Fri Jun 16 2017 IAZ043-055-056-069-079-080-090-091-NEZ011-012-015>018-030>034- 042>045-050>053-065>068-078-088>093-162330- 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- 420 AM CDT Fri Jun 16 2017 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHWEST IOWA...WEST CENTRAL IOWA...EAST CENTRAL NEBRASKA...NORTHEAST NEBRASKA AND SOUTHEAST NEBRASKA. .DAY ONE...TODAY AND TONIGHT There is an enhanced risk for severe thunderstorms this afternoon and evening, mainly from around 4 pm to midnight, and mainly from northeast Nebraska into east central Nebraska and western Iowa. Large hail and damaging winds would be the primary hazards. The atmosphere is expected to become very unstable again today. A frontal boundary, pushed east by an upper level impulse, will be the primary focus for thunderstorms development in the early to mid afternoon across northeast Nebraska. Storms should continue to develop along that front through the evening as it moves east and southeast across the rest of eastern Nebraska and southwest Iowa. The severe threat is expected to diminish after midnight. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY Thunderstorms will be possible Saturday into Saturday night. Some severe storms may occur, with the highest chances in southeast Nebraska and southwest Iowa. There should be intermittent chances for thunderstorms for at least parts of the area from Tuesday afternoon through Thursday. .SPOTTER INFORMATION STATEMENT... Spotter activation may be needed in parts of the area this afternoon and evening.
The Omaha radar (KOAX), 78 km away, was scanning. The volume nearest the first event began at 13:19 UTC.
10 thunderstorm wind, 2 tornado. Local standard time, as filed.
Parts of a roof on a Menards warehouse distribution center collapsed due to damaging thunderstorm winds. Time is estimated from radar data.
Winds of 60 mph were estimated by a Cooperative Weather Observer near Little Sioux.
A roof was blown off an industrial building along with widespread tree damage in and west of the town of Woodbine.
A roof of a home was damaged from a 5 inch limb that was blown into the roof.
This is a continuation of the EF-2 tornado that went through Sarpy County, Nebraska. The tornado started on the Missouri River about 1/2 mile north of US Highway 34. The tornado proceeded southeast causing occasional tree damage until near the US 34/I-29 interchange , there was significant roof damage to several businesses. After crossing I-29, the tornado struck a trailer campground, blowing over or damaging trailers. The tornado then continued for another mile eastward, producing minor tree damage prior to dissipating.
This is a continuation of the tornado that struck Offutt Air Force Base in Sarpy County, Nebraska. The tornado crossed the Missouri River just east of a water treatment plant in Bellevue, Nebraska. The tornado continued moving southeast into rural, river bottom land in Iowa and then struck a farmstead on Gaston Avenue in Mills County. Several outbuildings and barns were damaged or destroyed. The farm home suffered roof damage. The tornado continued southeast and then tipped over a center pivot irrigation system before dissipating.
Large trees were blown down along with windows in a house were broken by the damaging winds.
Very large trees southwest of Thurman were blown down by damaging winds. Th trees were blocking a road.
Winds gusted to 62 mph at the AWOS weather station at Harlan Airport.
Trees were blown down across a road from damaging thunderstorm winds.
Several trees were blown down by damaging thunderstorm winds.
Trees and power lines were blown down by damaging thunderstorm winds near Grant.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Iowa in 2017Every state in 2017This day in weather historyThe tornado archive for Iowa, 2017Warnings in Iowa, June 2017
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: 709064, 709092, 709067, 709070, 709464, 709465, 709080, 709087, 709093, 709089, 709090, 709091.