Thunderstorm Wind in Sarpy County, Nebraska

A line of intense thunderstorms swept across Sarpy county, resulting in widespread significant wind damage. While the greatest measured wind gust was 80 miles per hour, recorded by a mesonet station in Papillion, narrow swaths of enhanced straight line wind damage was consistent with wind speeds closer to 100 miles per hour. One such swath impacted portions of northeast Gretna, where multiple homes had windows blown out, trees uprooted, and large portions of their roofs blown off. Most of this damage was noted around the intersection of 168th Street and Meridian Street. Additionally, numerous powerlines and traffic lights were damaged or blown down across the county. Multiple semis were also noted as being flipped off of the road, one in north Gretna off of 204th street, and another off of Highway 370 in east Gretna. Power outages lasted for several days after the storms moved through. Total damages from these storms were estimated to be around 15 million dollars, with approximately 10 million in damages to the OPPD infrastructure.

The prevailing upper-level pattern for the end of July featured a trough over the Pacific Northwest, favoring southwesterly flow over the central Great Plains. Two troughs ejected out into the north-central CONUS during this episode. The first brought two back to back nights of severe weather across portions of northeast Nebraska the night of the 28th and the 29th. The second trough moved out into the central Plains and brought the synoptic scale forcing for a historic severe wind event that impacted both Lincoln and Omaha metropolitan areas. Wind gusts as high as 100 miles per hour extended from Lancaster County northeast to the Nebraska-Iowa border, leaving behind a large swath of significant tree, powerline and structural damage. Power outages from this storm lasted for up to a week in some locations, particularly in Omaha.

This episode also featured several afternoons of excessive heat for portions of southeast Nebraska and southwest Iowa. A few instances of 110 degree heat indices were observed in a few southwest Iowa counties the afternoon of the 29th, with even more widespread excessive heat the afternoon of the 31st across much of the forecast area south of Interstate 80. Peak heat indices in this region topped out between 110 and 115 degrees before afternoon convection cooled temperatures back down.