An exceptionally hot air mass that develops when high pressure aloft prevents warm air below from rising, thus trapping the warm air as if it were in a dome. The subsidence associated with the high pressure also causes further warming by compression. Heat domes are often associated with calm upper-level flow directly overhead and/or with blocking patterns. The term has been popularized by the news media as a way to explain extreme heat and/or drought events across large regions.
National Ocean and Atmospheric Administration, 2021: What is a heat dome? Accessed 5 October 2021, https://oceanservice.noaa.gov/facts/heat-dome.html.
Term edited 14 March 2022.