An Atmospheric River is not a term you commonly hear in Louisiana but more so on the west coast.

It can be described as a river in the sky. The river is made up of water vapor and the amount of it can be equivalent to the average flow of water at the mouth of the Mississippi River!

Atmospheric rivers move inland and sweep over Mountains, causing the water vapor to rise. The water vapor then cools, creating heavy rain and/or snow.

These atmospheric rivers can be 250-300 miles wide and account for 30-50% of annual precipitation on the west coast of the United States.

Weak atmospheric rivers can bring beneficial rain or snow, but the more powerful ones can cause extremely heavy rainfall and devastating floods.