What are heat domes – the phenomenon driving record US temperatures?
Al Jazeera
Last year, the US saw the most number of heatwaves since 1936 and it is now bracing for an unusually hot June.
More than 75 million people across the United States, especially in the Midwest and East Coast, are living amid extreme heat alerts even before the first official day of summer this Thursday.
Much of the US Midwest has been witnessing scorching heat with temperatures expected to surpass 37.8 degrees Celsius (100 degrees Fahrenheit), with meteorologists saying the extreme heat is caused by excessive humidity and domes of hot air in the atmosphere. Weather scientists describe the phenomenon as heat domes.
So what is a “heat dome” and how is it connected to a heatwave?
A heat dome is a weather phenomenon where a high-pressure area is formed in the atmosphere, which traps hot air beneath like a lid traps air in a pot.
The pressure pushes air down into a hotter, dome-shaped mass and prevents the milder weather systems from moving through.