Have you ever heard of an atmospheric river? This weather phenomenon may not be as well-known as hurricanes or tornadoes, but it can have a significant impact on weather patterns and cause severe flooding in certain areas. In this article, we’ll explain what an atmospheric river is and how it works.
What is an Atmospheric River?
An atmospheric river is a narrow band of water vapor that extends from the tropics to higher latitudes. These “rivers in the sky” can transport massive amounts of moisture, often equivalent to several times the flow of the Mississippi River. Atmospheric rivers are responsible for delivering a significant portion of the precipitation that falls in the western United States.
How Do Atmospheric Rivers Work?
Atmospheric rivers are formed when a low-pressure system draws in moist air from the tropics. The warm, moist air rises and condenses as it moves up the slope of the mountains, producing precipitation in the form of rain or snow. The moisture in the atmospheric river can be carried for thousands of miles, and the river can be as narrow as 250 miles or as wide as 600 miles.
Impact of Atmospheric Rivers
Atmospheric rivers can have both positive and negative impacts. They are a critical source of water for many areas in the western United States, particularly California, where they can provide up to 50% of the state’s water supply. However, when atmospheric rivers bring too much moisture too quickly, they can cause severe flooding and landslides.
In January 2017, an atmospheric river brought heavy rain and flooding to California, causing damage and leading to evacuations in several communities. In February 2019, another atmospheric river brought heavy snow and rain to the Sierra Nevada Mountains, providing much-needed water for the drought-stricken state but also causing widespread flooding and travel disruptions.
Atmospheric rivers are an important weather phenomenon that can have significant impacts on weather patterns and the water supply in many areas. While they are a critical source of water for some regions, they can also cause severe flooding and landslides when they bring too much moisture too quickly. By understanding what an atmospheric river is and how it works, we can better prepare for its impact and mitigate its effects.
