Thunderstorm Wind in Lancaster County, Nebraska

Widespread severe wind gusts and straight line wind damage was observed across the entirety of Lancaster County with a line of severe thunderstorms that moved through the afternoon of July 31st. The highest measured wind gust was 92 miles per hour, recorded 1 mile southwest of Denton, Nebraska by a mesonet station. An 83 miles per hour wind gust was also measured by the Lincoln ASOS, and an 88 miles per hour wind gust was recorded by another mesonet station 4 miles northwest of Martell. Significant tree damage was reported across the county, with numerous trees blown down across the Lincoln metro. There were also several reports of structural damage, including a hotel which received roof damage near the Lincoln airport. Damages from these storms are estimated to be approximately 1.5 million dollars.

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.