How a Heat Dome Creates Dangerous, Record-Breaking Temperatures

The atmospheric heat dome that is causing record temperatures in parts of the Northeast arrived earlier than usual, is situated farther north and is the strongest in several decades, according to weather experts.

Heat domes usually form in the South and Southwest during the summer and are rarely seen in the Northeast in mid-June. 

“It is out of the ordinary and is unusual to see this type of intense high,” said Paul Pastelok, senior meteorologist at AccuWeather. 

A heat dome is an area of high pressure that traps hot air below it. Such a system also diverts jet-stream winds that might bring down the temperature. Heat domes can remain stationary for days until conditions change and the high-pressure system moves on.