Excessive Heat — Union, Arkansas

2025-08-19 · Union, Arkansas

Wider weather episode

A large but strong upper level ridge of high pressure expanded from the Southern Rockies/Central and Southern Plains into the Mid-Mississippi and Tennessee Valley on August 19th, with compressional warming beneath the ridge contributing to extensive warming across much of North Louisiana, Southern Arkansas, and portions of extreme Eastern Texas. Cloud cover leftover from decayed scattered showers and thunderstorms that developed across the area on the 18th also limited the extent of cooling during the overnight/early morning hours into the 19th, with temperatures only falling to near 80 degrees. This provided a head start to strong diurnal heating during the day, with afternoon temperatures climbing to well in excess of 100 degrees over these areas. When combined with the high humidity, heat indices climbed to near or in excess of 110 degrees across portions of Southern Arkansas, North Louisiana, and extreme Eastern Texas. The upper ridge retreated a bit to the west on the 20th, with afternoon temperatures falling back below 100 degrees, and heat indices below 110 degrees.

Source: NOAA Storm Events Database, event_id 1290737. Narrative written by the NWS forecast office that issued the report.