Heat dome

A heat dome is a weather phenomenon consisting of extreme heat that is caused when the atmosphere traps hot air as if bounded by a lid or cap. Heat domes happen when strong high pressure atmospheric conditions remain stationary for an unusual amount of time, preventing convection and precipitation and keeping hot air “trapped” within a region. This can be caused by multiple factors, including sea surface temperature anomalies and the influence of a La Niña. The upper air weather patterns are slow to move, referred to by meteorologists as an Omega block.