Atmospheric Rivers Pour Down On California

California has seen some massive rainstorms in recent weeks

The downfalls have mainly been caused by long and narrow collections of water vapor traveling with the weather patterns in the sky, known as atmospheric rivers.

A study recently posted on Nature Geoscience reports that atmospheric rivers are responsible for up to 65% of the extreme rain and snowfall in Western United States. However, not uncommon to other parts of the world, they are responsible for up to 75% of extreme precipitation events globally.

An atmospheric river (AR) is a flowing column of condensed water vapor in the atmosphere responsible for producing significant levels of rain and snow, especially in the Western united States.

NOAA’s website says “These columns of vapor move with the weather, carrying an amount of water vapor roughly equivalent to the average flow of water at the mouth of the Mississippi River” and “Although atmospheric rivers come in many shapes and sizes, those that contain the largest amounts of water vapor and the strongest winds can create extreme rainfall and floods, often by stalling over watersheds vulnerable to flooding. These events can disrupt travel, induce mudslides and cause catastrophic damage to life and property. A well-known example is the “Pineapple Express,” a strong atmospheric river that is capable of bringing moisture from the tropics near Hawaii over to the U.S. West Coast.”

An article in USA Today reported that as many as 10 separate rivers have been identified in Northern California this season, where the average is between 5 and 7.

The heavy rains have caused floods and warnings across the northern and central parts of the state, with notable events building in and around San Francisco, Salinas, San JoseMonterey County, San Joaquin County, and at the dams on Lake Oroville and the South Dayton Retention Pond.

Current Flood warnings for California can be found here.


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