Rain and snow came to portions of the west coast of the United States earlier this week caused by Atmospheric Rivers and are forecast to occur this coming weekend. What are atmospheric Rivers, this document ,"What are Atmospheric Rivers" by NOAA provides some of the meteorology behind atmospheric rivers, they say in part:
Atmospheric rivers are relatively long, narrow regions in the atmosphere – like rivers in the sky – that transport most of the water vapor outside of the tropics. 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. When the atmospheric rivers make landfall, they often release this water vapor in the form of rain or snow. 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.
Take a look at this graphic that explains what an atmospheric River on the west coast USA is.
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| Obtained on December 30, 2022 from https://www.noaa.gov/stories/what-are-atmospheric-rivers |
I first got wind of the atmospheric river that occured on the west coast USA from this Washington Post article by Matthew Cappucci on December 27th, Cappucci reports in part:
The West Coast, ordinarily known for being parched and drought-stricken, is facing a barrage of atmospheric rivers — plumes of deep tropical moisture known for bringing heavy rain and snow. Parts of coastal California, including the Bay Area, are under flood watches, initial signs from the first of several atmospheric rivers set to drench the West in the days ahead.
Weather alerts — for heavy rain in the lowlands, and snow and wind in the mountains — blanket most of central and Northern California. Coastal and central Oregon and Washington are largely under flood watches and high wind warnings, with winter storm warnings in the Cascades and Columbia River Basin.
I am interested in these forecasted atmospheric rivers because I know how much the drought-stricken west coast needs rain. While I doubt that this atmospheric river event will be a drought buster, any precipitation will help. I understand that the atmospheric river event, see for example the graphic below from the Sacramento Weather Forecast Office of the National Weather Service will take place over a couple of days possibly bringing from one to nine inches depending on location:
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| Obtained on December 30, 2022 from https://www.weather.gov/sto/ |
