On Thursday morning, June 11, a cluster of thunderstorms raced through southeast Nebraska into southwest Iowa. While it brought heavy rain and lightning to Omaha, just 30 miles south of Omaha, it brought all kinds of significant weather.
The worst of the damage began in Cass County and continued through southwest Iowa. Within this broad swath, winds exceeding 80 mph at times brought substantial tree damage to a region already hit hard by severe storms this season.
The storms also brought hail up to 3" in central Page County. Then, significant flash flooding occurred in Sidney, Shenandoah, and Essex.
In the days following the storms, the National Weather Service offices in Omaha/Valley and Des Moines have been surveying the damage to determine whether tornadoes or straight-line winds caused it. The findings, released Sunday afternoon, determined that eight tornadoes occurred in the storms. Six of those were rated EF-1 with winds as high as 110 mph. Two were rated EF-0.
The tornadoes began just east of Weeping Water in Cass County, where a farm building had its walls collapse. This tornado was rated a high-end EF-1 with winds up to 100 mph. An EF-0 tornado hit the creekbed of South Cedar Creek, where tree damage was observed.
Farther east, another EF-1 tornado developed north of Union. Extensive tree damage was noted at a residence and the East Union Cemetery. Meteorologist Joseph Meyer visited the cemetery and spoke with the president of the East Union Cemetery.
In Iowa, an EF-0 hit southwest Mills County in the bluffs northwest of Tabor. Tree damage was noted in this area.
The strongest tornado of the day happened in Fremont County, just west of Thurman. At a home just west of I-29, a roof was lifted off. This tornado was rated a high-end EF-1 with winds up to 110 mph, which is borderline EF-2 intensity.
As the storms continued into Montgomery and Page Counties, 80-90 mph winds caused extensive damage to trees, power lines, and outbuildings. Within this intense core of winds, several tornadoes occurred in the Villisca vicinity.
One of these, an EF-1, began over Viking Lake and continued east. At one home, the roof was damaged. Grain bins were thrown a mile away, landing at the interchange of US-34 and US-71. This tornado had estimated wind speeds up to 105 mph.
Southwest of Villisca, an EF-1 tornado crossed over northern Page County, twisting trees along a 7-mile path. A final EF-1 occurred between Villisca and Hepburn, where a farm outbuilding lost a wall.
The National Weather Service in Des Moines is still surveying damage in Adams County and near Corning. This story will be updated when those results are released.
