• Skip to primary navigation
  • Skip to main content
  • Skip to primary sidebar

Weatherboy

Weatherboy Weather News, Maps, RADAR, Satellite, and Forecasts.

  • Local
  • Earth Science News
  • RADAR
  • Current Warnings
  • Satellite
  • Current Maps
  • Forecast Maps
  • Video

Atmospheric River to Dump 5-10 Feet of Snow in California

by Weatherboy Team Meteorologist - January 25, 2021

Extremely heavy snow of 5-10' or more is possible over the next week in portions of California as an atmospheric river event unfolds. Image: pivotalweather.com
Extremely heavy snow of 5-10′ or more is possible over the next week in portions of California as an atmospheric river event unfolds. Image: pivotalweather.com

An “atmospheric river” phenomena is forecast to bring an incredible amount of moisture to California in the coming days; over the next week, several inches of rain are expected to fall over lower elevations while 5-10 feet of snow will fall over the mountainous terrain.




An atmospheric river refers to a narrow stream of concentrated moisture in the atmosphere. The most common atmospheric river event is nick-named “Pineapple Express”; in this type of situation, a robust stream of moisture near the Hawaiian islands flows north and east into western North America, dropping copious amounts of rain and snow as it interacts with the terrain there.

The American GFS forecast model shows a stream of moisture from north of Hawaii heading into California as part of an atmospheric river event. Image: tropicaltidbits.com
The American GFS forecast model shows a stream of moisture from north of Hawaii heading into California as part of an atmospheric river event. Image: tropicaltidbits.com

 

These long, narrow atmospheric rivers help transport moisture from the tropics, in water vapor form, to areas far from the tropics. The liquid equivalent of these moisture plumes could be comparable to the water flowing through the mouth of the Mississippi River, according to NOAA.




On average, 30-50% of annual precipitation on the U.S. West Coast occurs from a few atmospheric river events. In addition to replenishing water supplies, they can also create problems associated with heavy precipitation: flooding, rock/mud slides, and avalanche dangers.

NOAA continues to study how atmospheric rivers evolve over the western U.S.. Image: NOAA
NOAA continues to study how atmospheric rivers evolve over the western U.S.. Image: NOAA

 

As the stream of water vapor hits the mountain ranges over the U.S. west coast, the air rises, cools, and condenses the moisture out of it. This condensed moisture falls out of the sky as heavy rain, heavy snow, or both.




A significant atmospheric river event is expected to unfold in the coming days, with the worst arriving Wednesday and Thursday.  With bad weather arriving, the National Weather Service has issued hundreds of watches and advisories across California, Nevada, Oregon, Idaho, Utah, and Arizona. In addition to heavy snow and rain, freezing conditions harmful to agriculture, damaging winds,  and rough surf are also possible across large portions of California.

Numerous advisories have been issued by the National Weather Service ahead of this week's rough weather forecast. Image: weatherboy.com
Numerous advisories have been issued by the National Weather Service ahead of this week’s rough weather forecast. Image: weatherboy.com

Primary Sidebar

Sponsored Ad

Search

Latest News

  • Hurricane Season Starts with New System in the Gulf; Could Become Tropical Storm Arlene
  • USGS Scientists Monitoring Volcano for Signs of Eruption
  • Swirl of Clouds Causes Concern Near Florida Day Before Hurricane Season Starts
  • People Report Shaking as Earthquake Strikes New Hampshire
  • Smoke from Nova Scotia Fires Invade New Jersey; Prompts Air Quality Alert
  • Multiple Earthquakes Shake Kentucky & Tennessee, Not Far from New Madrid Seismic Zone
  • May Ends on a Very Dry Note in the Northeast; Philadelphia About to Break Record
  • Carnival Sunshine Cruise Ship Sails into East Coast Storm, Creating Injuries & Damage On-Board
About | Careers | Contact | Contests
Terms | Privacy | Ad Choices
Weatherboy is a (R) Registered Trademark of isarithm LLC, All Rights Reserved.
All content herein is Copyright by Isarithm LLC 1997-2022