A potent atmospheric river brought heavy rainfall to the Pacific Northwest region of the United States in early December 2025, triggering widespread flooding and landslides. The deluge was caused by a narrow band of moisture originating over 7,000 miles away from near the Philippines, which was unusually far north for this type of event.
Satellite data and models provided by NASA's Goddard Earth Observing System (GEOS) showed high amounts of water vapor in the atmosphere over the Pacific Ocean, with some areas receiving more than 10 inches of rain in just a 72-hour period. This is equivalent to the average annual rainfall for much of Washington state.
The National Weather Service reported that Seattle-Tacoma International Airport set a daily record for rainfall on December 10, with 1.6 inches falling that day alone. Flooding was also ongoing on rivers such as the Skagit River and Snohomish River, which saw record or near-record flood levels.
The heavy rainfall caused numerous road closures due to flooding and mudslides, including parts of Interstate 90 in western Washington. Emergency response efforts were underway, with NASA's Disaster Response Coordination System activated to support the state's emergency operations center.
The event highlighted the impact of long-distance atmospheric rivers on regional weather patterns, particularly when moisture originates from far-off locations such as the Philippines. Such events underscore the importance of monitoring and predicting changes in atmospheric conditions to mitigate their effects on communities and infrastructure.
Satellite data and models provided by NASA's Goddard Earth Observing System (GEOS) showed high amounts of water vapor in the atmosphere over the Pacific Ocean, with some areas receiving more than 10 inches of rain in just a 72-hour period. This is equivalent to the average annual rainfall for much of Washington state.
The National Weather Service reported that Seattle-Tacoma International Airport set a daily record for rainfall on December 10, with 1.6 inches falling that day alone. Flooding was also ongoing on rivers such as the Skagit River and Snohomish River, which saw record or near-record flood levels.
The heavy rainfall caused numerous road closures due to flooding and mudslides, including parts of Interstate 90 in western Washington. Emergency response efforts were underway, with NASA's Disaster Response Coordination System activated to support the state's emergency operations center.
The event highlighted the impact of long-distance atmospheric rivers on regional weather patterns, particularly when moisture originates from far-off locations such as the Philippines. Such events underscore the importance of monitoring and predicting changes in atmospheric conditions to mitigate their effects on communities and infrastructure.
omg can u believe that 10 inches of rain fell in just 72 hrs? i mean idc how much it was but its def crazy 
i was following this on twitter all day and the pics from seattle were insane - like streets flooded up to cars 
and people having to evacuate their homes 
what a nightmare. nasa is super cool for helping with the emergency response btw 
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It's like a whole year's worth of rain just dumped on them at once. And it's not like they weren't warned or anything... the satellite data was out there months ago showing that something was up. 
Still, gotta give credit to NASA for having all those models and systems in place to help track the storm. I'm glad they were able to activate their Disaster Response Coordination System to support the state's emergency ops center. It's gonna take some time to clean up this mess, but at least everyone's safe... that's the most important thing, right? 
, this atmospheric river is INSANE! 10 inches of rain in just 72 hours? That's like a whole summer in Seattle! 
I'm surprised they didn't get hit with a tsunami or something. 
They must've been super intense. And poor Washington state, flooding everywhere... what a disaster! 
and I'm sure it was no joke for the people down there, trying to deal with flooding and mudslides and all that. 
anyway, glad NASA is on it and helping out, that's always good to see. 
We need to be way more prepared for events like this. I was in Portland during the floods last week and saw some pretty gnarly slide activity 
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. It's a good reminder to check on our neighbors and loved ones, 'specially if they're dealing with extreme weather conditions. We should all be supporting each other during these times 
. The science behind atmospheric rivers is wild, too - I love how NASA's been tracking this stuff to help predict these events 
. Maybe we can learn from it and become better at preparing for these kinds of disasters in the future? Fingers crossed!
. It just goes to show how far ahead of the curve NASA is when it comes to predicting severe weather events... super cool, right? 
. Glad NASA is involved with disaster response and all that, hope everyone stays safe 
.
. It's scary to think about the flooding and landslides that happened. I hope everyone is safe and dry now.
. I know some people might say it's not that big of a deal, but to me, it feels like we're just getting started with the effects of rising temps and extreme weather events. I've been following NASA's work on this stuff, and they seem pretty serious about it.
. It's not just about us humans; it affects so many other creatures and ecosystems too. We should be working together to find ways to mitigate these effects and make sure everyone has access to clean water and safe living spaces.
i'm living for the updates on Seattle's flood situation tho, like 1.6 inches a day?!?! that's wild! 
but at the same time, it's crazy how far that moisture came from - like 7k miles away!!! 
anyway, can't wait to see what else this winter brings 
I mean, 10 inches of rain in 72 hours? That's crazy talk! It's like the sky just decided to go all out on us 
And the roads, oh man, that's a major concern. I can imagine being stuck in traffic with water everywhere 
What really blows my mind is how far away the moisture came from – 7,000 miles? That's like trying to predict when it'll snow in Tokyo 
. and yeah, the sat data is wild 
, shows just how unpredictable our weather can be sometimes