heat dome

 The weather event that brought this to our attention this year occurred in Canada and north-western America where a heat dome settled for five days, causing hundreds of deaths, contributing to wildfires, and wreaking havoc on  marine life.  Mussels cooked in shallow water, the shells piling up on the beaches and crunching underfoot.  The US is now set to endure one in the Pacific north-west.

 A heat dome is created when hot air warmed by convection currents in the ocean moves towards the land and is trapped beneath a slow-moving high-pressure system that forms a lid or cap over the hot air, meaning that it settles on the land for some time.

 Heat domes appear to be occurring with much greater regularity in regions that are not equipped to deal with such unusually high temperatures.