'Pineapple Express' Triggers Floods in California, NASA Animation Shows
Get the world’s most fascinating discoveries delivered straight to your inbox.
You are now subscribed
Your newsletter sign-up was successful
Want to add more newsletters?
Delivered Daily
Daily Newsletter
Sign up for the latest discoveries, groundbreaking research and fascinating breakthroughs that impact you and the wider world direct to your inbox.
Once a week
Life's Little Mysteries
Feed your curiosity with an exclusive mystery every week, solved with science and delivered direct to your inbox before it's seen anywhere else.
Once a week
How It Works
Sign up to our free science & technology newsletter for your weekly fix of fascinating articles, quick quizzes, amazing images, and more
Delivered daily
Space.com Newsletter
Breaking space news, the latest updates on rocket launches, skywatching events and more!
Once a month
Watch This Space
Sign up to our monthly entertainment newsletter to keep up with all our coverage of the latest sci-fi and space movies, tv shows, games and books.
Once a week
Night Sky This Week
Discover this week's must-see night sky events, moon phases, and stunning astrophotos. Sign up for our skywatching newsletter and explore the universe with us!
Join the club
Get full access to premium articles, exclusive features and a growing list of member rewards.
A different kind of river has been winding over California in recent weeks: NASA satellites spied a so-called atmospheric river passing over the state, bringing with it a deluge of stormy weather that has been flooding the West Coast.
For about a week, California and other parts of the western U.S. have been hit with rain and snow, causing severe flooding of rivers and valleys. According to NASA, the cause of the precipitation is known as an atmospheric river, a jet stream of moist air that can stretch tens to hundreds of miles wide.
The storm system can carry as much water vapor as 15 times the Mississippi River's flow, according to the National Oceanic and Atmospheric Administration (NOAA). An atmospheric river, also known as a "pineapple express" because the storm system often begins in the tropical Pacific, can bring 30 to 50 percent of the western U.S.' annual rainfall, NOAA estimates.
A NASA animation shows the atmospheric river's rainfall over California and the West Coast from Jan. 7 to Jan. 10, as measured by satellites every 30 minutes. Bright white spots in the animation show where rainfall has been heaviest. For instance, 15 feet (4.6 meters) of snow fell on California's Mammoth Mountain, according to the National Weather Service.
"San Francisco has seen more rain in the first two weeks of 2017 than it did in the entire year of 2013," NASA officials wrote in a post about the atmospheric river event.
The heavy rain and snow have caused mudslides and floods, and have killed at least five people, The Weather Channel reported. California's iconic drive-through tree, the Pioneer Cabin Tree in Calaveras Big Trees State Park, was toppled by the severe storms. Meteorologists predict that the storms will continue through the week.
The U.S. West Coast is not the only area to be hit by atmospheric rivers; a similar jet stream was found over Antarctica. This storm system moves from the Indian Ocean to East Antarctica, bringing snow and moisture to the dry continent.
Get the world’s most fascinating discoveries delivered straight to your inbox.
Original article on Live Science.


