Heat Wave Due To “Exceptionally Strong” Air Mass

Photos: Alex E. Proimos

Photos: Alex E. Proimos

Today has been the coolest day all week in the Northeast of the US.  The Midwest, Northeast and Southern parts of the country have been experiencing consecutive days of high temperatures and humidity which have contributed to many deaths throughout the country. What is the cause of this cantankerous heat and is it an indication of future affects of global warming? The National Geographic reports:

A stubborn high-pressure system is the culprit behind the dangerously high heat wave that’s been baking much of the U.S., experts say.

The high-pressure system—a large area of dense air—is being held in place by upper-level winds known as the jet stream. Within the system, dense air sinks and becomes warmer, and since warm air can hold more moisture than cooler air, there’s also very high humidity. (Learn more about Earth’s atmosphere.)

Stationary high-pressure systems aren’t unusual during the summer, according to Eli Jacks, a meteorologist at the National Weather Service headquarters in Silver Spring, Maryland.

But what sets this system apart is its size and strength.

“It’s exceptionally strong and very wide, covering thousands of miles from border to border and from the Rocky Mountains to the East Coast,” Jacks said.

[Continues at National Geographic]