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.

Thunderstorm Wind in MILLS, IOWA
From 16-JUN-17 19:15:00 to 16-JUN-17 19:15:00 (CST-6)
Location: PACIFIC CITY
Magnitude: 65.00 EG
Reported by: Trained Spotter

Large trees were blown down along with windows in a house were broken by the damaging winds.

Thunderstorm Wind in FREMONT, IOWA
From 16-JUN-17 19:35:00 to 16-JUN-17 19:35:00 (CST-6)
Location: THURMAN
Magnitude: 65.00 EG
Reported by: Trained Spotter

Very large trees southwest of Thurman were blown down by damaging winds.  Th trees were blocking a road.

Thunderstorm Wind in POTTAWATTAMIE, IOWA
From 16-JUN-17 19:38:00 to 16-JUN-17 19:38:00 (CST-6)
Location: OAKLAND
Magnitude: 65.00 EG
Property damage: 0.00K
Reported by: Public

Trees were blown down across a road from damaging thunderstorm winds.

Thunderstorm Wind in FREMONT, IOWA
From 16-JUN-17 19:49:00 to 16-JUN-17 19:49:00 (CST-6)
Location: THURMAN
Magnitude: 52.00 EG
Reported by: Trained Spotter

Several trees were blown down by damaging thunderstorm winds.

Thunderstorm Wind in MONTGOMERY, IOWA
From 16-JUN-17 20:05:00 to 16-JUN-17 20:05:00 (CST-6)
Location: GRANT
Magnitude: 56.00 EG
Reported by: Emergency Manager

Trees and power lines were blown down by damaging thunderstorm winds near Grant.

Thunderstorm Wind in POTTAWATTAMIE, IOWA
From 16-JUN-17 07:20:00 to 16-JUN-17 17:20:00 (CST-6)
Location: MINDEN
Magnitude: 61.00 EG
Reported by: Emergency Manager

Parts of a roof on a Menards warehouse distribution center collapsed due to damaging thunderstorm winds. Time is estimated from radar data.

Thunderstorm Wind in HARRISON, IOWA
From 16-JUN-17 18:40:00 to 16-JUN-17 18:40:00 (CST-6)
Location: LITTLE SIOUX
Magnitude: 52.00 EG
Reported by: COOP Observer

Winds of 60 mph were estimated by a Cooperative Weather Observer near Little Sioux.

Thunderstorm Wind in SHELBY, IOWA
From 16-JUN-17 19:35:00 to 16-JUN-17 19:35:00 (CST-6)
Location: CORLEY
Magnitude: 54.00 MG
Reported by: AWOS

Winds gusted to 62 mph at the AWOS weather station at Harlan Airport.

Thunderstorm Wind in HARRISON, IOWA
From 16-JUN-17 18:55:00 to 16-JUN-17 18:55:00 (CST-6)
Location: WOODBINE
Magnitude: 70.00 EG
Reported by: Emergency Manager

A roof was blown off an industrial building along with widespread tree damage in and west of the town of Woodbine.

Thunderstorm Wind in POTTAWATTAMIE, IOWA
From 16-JUN-17 19:00:00 to 16-JUN-17 19:00:00 (CST-6)
Location: LAKE MANAWA
Magnitude: 61.00 EG
Reported by: Public

A roof of a home was damaged from a 5 inch limb that was blown into the roof.

Tornado in MILLS, IOWA
From 16-JUN-17 19:11:00 to 16-JUN-17 19:13:00 (CST-6)
Location: FOLSOM
Tornado F-scale: EF1
Reported by: NWS Storm Survey

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.

Tornado in MILLS, IOWA
From 16-JUN-17 19:10:00 to 16-JUN-17 19:18:00 (CST-6)
Location: PACIFIC CITY
Tornado F-scale: EF1
Reported by: NWS Storm Survey

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.