Excessive Heat — Fremont, Iowa

2024-07-29 · Fremont, Iowa

Event narrative

A combination of hot afternoon temperatures and high dew points brought a brief period of excessive heat during the afternoon, with heat indices up to 110 being observed in a few counties across southwest Iowa.

Wider weather episode

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.

Source: NOAA Storm Events Database, event_id 1206734. Narrative written by the NWS forecast office that issued the report.