FOX31 Denver

Why is California getting so much moisture and Colorado isn’t?

COLORADO SPRINGS, Colo. (KXRM) — You may have seen the pictures of the historic rain and snowfall out of California recently and you may have heard of the term “atmospheric river.” But what exactly are atmospheric rivers and how do they affect what we see in Colorado on the Front Range?

Atmospheric rivers explained

Atmospheric rivers are just as it sounds, a large river of water vapor high up in the atmosphere, and some people even describe them as “fire hoses” pointed at the West Coast. 

These “rivers of moisture” carry lots of water from the tropical regions near the equator toward the poles and are massive in size. Atmospheric rivers can be roughly 250 to 375 miles wide, which is roughly at least four back-to-back trips from Colorado Springs to Denver.

According to the National Oceanic and Atmospheric Administration, NOAA, depending on the size of the atmospheric river, can carry eight to 15 times more water than the flow of the Mississippi River. 

The large rivers of water are very common and move with the weather. They are present on Earth at any given time and multiple can occur at once.

How do they work?

As the giant band of water vapor pushes inland, the moisture gets forced upwards by the mountains. It then cools and condenses, producing heavy rain and if cold enough, snow. 

The problem we have on the Front Range with these storms is usually the opposite.

Atmospheric rivers use up all of the moisture by the time they reach us, leaving most its moisture across the West Coast.

Colorado’s Western Slope can luck out with more moisture from these storms, but because of the drying effect of the Rocky Mountains, the Front Range usually ends up dry.

Be sure to stay with the Pinpoint Weather team as we continue to track this active atmospheric river pattern and the upcoming storm to Southern Colorado.

As of Tuesday, another atmospheric river has hit the Golden State, but by Wednesday, this storm will have leftover moisture for Southern Colorado and the Front Range.