Some forecasters attributed the recent warm weather to a “heat dome”. This sounds like a technical term, but the expression is not used in scientific circles and some question whether it should be used at all.
Loosely speaking, a heat dome occurs when a stationary mass of high-pressure air forms over a region. This has a doming effect, blocking more warm air from rising, which raises pressure and temperature further.
A 2016 Guardian piece discussed how the term “heat dome” was starting to be used by American forecasters describing extreme conditions. One science editor complained that the new term was employed “with a kind of breathlessness that implies there is something unusual and catastrophic going on”. Others thought that it was helpful in describing the mechanism causing especially high temperatures.
In 2019 the Met Office described “heat dome” as “not a meteorological term that is recognised professionally”. But the expression took off, particularly in media discussions of the June 2021 Pacific north-west heatwave. In 2022 the American Meteorological Society added “heat dome” to its glossary of terms.
Technically correct or not, “heat dome” is here to stay. A recent paper by the American Meteorological Society argues that the best course for meteorologists would be to agree a rigorous definition and get the media to use it correctly.
