Uploaded October 2021 | Updated September 2026, 12 hours ago
Did you know that rivers don’t just run over land, but also through the sky?
Water vapor is constantly circulating through the atmosphere, particularly around the warm equatorial regions of our planet. Under the right conditions, it forms clouds and precipitation, and sometimes, long narrow bands of concentrated water vapor that carry huge amounts of moisture into the upper latitudes. These streams are referred to as “atmospheric rivers,” which are a primary feature in the global water cycle.
On Sunday, California and the Pacific Northwest were hit by both a large atmospheric river as well as what meteorologists call a “bomb cyclone,” which forms when air pressure drops rapidly and the storm explosively strengthens. According to NWS Seattle, the storm’s pressure dropped to 942.5 mb—the lowest pressure ever recorded off the Washington coast.
This convergence of storms brought more than half a foot of rain to parts of the Bay area in addition to strong winds, flash floods, and mud/landslides. They also bring the potential for heavy snow to higher elevations in the Sierra Nevada mountain range. The National Weather Service in Seattle and Tacoma, Wash. predict that the huge storm system may even reach Vancouver Island in southern British Columbia today.
Authorities from California, which has been plagued with wildfires and drought, warned that areas where fire has eliminated large amounts of vegetation (known as burn scars), could see debris flows of rushing mud, rocks, or vegetation that may sound like cracking, roaring, or even a freight train. They are warning residents to not attempt to cross a debris flow and to take shelter in the highest floor of their homes in case one occurs. Additionally, there are currently at least 150,000 power outages according to PowerOutage.US due to the extreme weather, and two people were killed when a tree fell on their vehicle near Seattle.
NOAA satellites are vital in providing important information about airborne moisture so we can better understand atmospheric rivers to not only make better weather forecasts, but manage water resources, and predict flood risks.
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Learn more: nesdis.noaa.gov/news/earth-orbit-atmospheric-river-hits-the-west-coast
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Video Credits:
NOAA
NASA/Goddard Space Flight Center
CIRA
Special Thank You for additional imagery to CIMSS, NASA’s SVS and NOAA’s Visualization Lab
Music Credit:
“Clouds Dispersing,” by Ariel Mann [BMI]; Universal Production Music
Did you know that rivers don’t just run over land, but also through the sky?
Water vapor is constantly circulating through the atmosphere, particularly around the warm equatorial regions of our planet. Under the right conditions, it forms clouds and precipitation, and sometimes, long narrow bands of concentrated water vapor that carry huge amounts of moisture into the upper latitudes. These streams are referred to as “atmospheric rivers,” which are a primary feature in the global water cycle.
On Sunday, California and the Pacific Northwest were hit by both a large atmospheric river as well as what meteorologists call a “bomb cyclone,” which forms when air pressure drops rapidly and the storm explosively strengthens. According to NWS Seattle, the storm’s pressure dropped to 942.5 mb—the lowest pressure ever recorded off the Washington coast.
This convergence of storms brought more than half a foot of rain to parts of the Bay area in addition to strong winds, flash floods, and mud/landslides. They also bring the potential for heavy snow to higher elevations in the Sierra Nevada mountain range. The National Weather Service in Seattle and Tacoma, Wash. predict that the huge storm system may even reach Vancouver Island in southern British Columbia today.
Authorities from California, which has been plagued with wildfires and drought, warned that areas where fire has eliminated large amounts of vegetation (known as burn scars), could see debris flows of rushing mud, rocks, or vegetation that may sound like cracking, roaring, or even a freight train. They are warning residents to not attempt to cross a debris flow and to take shelter in the highest floor of their homes in case one occurs. Additionally, there are currently at least 150,000 power outages according to PowerOutage.US due to the extreme weather, and two people were killed when a tree fell on their vehicle near Seattle.
NOAA satellites are vital in providing important information about airborne moisture so we can better understand atmospheric rivers to not only make better weather forecasts, but manage water resources, and predict flood risks.
*
*
Learn more: nesdis.noaa.gov/news/earth-orbit-atmospheric-river-hits-the-west-coast
*
*
Video Credits:
NOAA
NASA/Goddard Space Flight Center
CIRA
Special Thank You for additional imagery to CIMSS, NASA’s SVS and NOAA’s Visualization Lab
Music Credit:
“Clouds Dispersing,” by Ariel Mann [BMI]; Universal Production Music
