‘Atmospheric River’ aimed at U.S., First one of the cold season, What it means for you

A unique weather situation is shaping up for late October. Here’s what an atmospheric river means and why it matters.

An “atmospheric river” has been dubbed such by the field of meteorology and is a hundreds of miles long and a few hundred miles wide swath of very high moisture content in the atmosphere. It is a very long and wide stream of Pacific air moisture.

Atmospheric rivers eventually hit the U.S. and usually cause large areas of heavy rain, or occasionally extreme precipitation events.

The forecast animation below shows you the total combined water vapor in the air. The orange, red and purple colors signify very high amounts of water vapor through the atmosphere, from the ground to the top of the atmosphere. Water vapor eventually turns into precipitation. Notice I’ve switched t