It is a term that we use a lot in the summertime, and we’ve certainly had to get used to it lately. Since late June, a massive “heat dome” has encompassed nearly two-thirds of the continental United States.
While these weather events are a normal occurrence this time of year, the latest one over the last few days has broken quite a few records.
First, let’s talk about what exactly a “heat dome” is. This weather phenomena occurs when a certain set of conditions align, setting the stage for extreme heat to develop over a large geographical area.
These conditions occur when the jet stream, a river of fast-moving air that typically flows across the northern United States or southern Canada this time of year, begins to ridge northward. At the same time, the air pressure builds across areas south of the jetstream in the upper-levels of the atmosphere. Since the pressure is high, well above the ground, it forces the air toward the ground in a sinking fashion. Typically, this type of air movement will squash any chances for large areas of rain to develop, as storm clouds need rising air.