"Atmospheric River" Flowing Into West Coast

Looks like a possible torrent, after a year of drought and non-stop wild fires. Hopefully, it brings needed relief and a not mud sliding disaster for the fire stripped hills and mounts of the west coast.

That “river” is going to hit the east cost mid-next week. We don’t need the water but it doesn’t hurt, given our drought of last year. If nothing else, we finally going to get more “seasonable” weather in New England.

Fingers crossed.


Hmm… surf sites have just picked up on the NWS forecasts. The surf sites are now projecting overhead surf for New England breaks from Wednesday on.

Returning to near “normal” for the northeast.


Atmospheric river is a term that makes no sense. No more than underground river.
We could get 4-7 feet of snow in the Sierra in the next week. After the drought this is what we need. Ten million acres of fire scars are just sacrifice areas.

Support logging and thinning to create fire resilience.

Think of oft used NWS term – jet streams – which talk about the upper level wind flows or currents. Prevailing jet stream in for the USA is west to east. Down near the equator, it is east to west, bringing the hurricanes that come across from Africa into the Carribeans.

Evidently, talk of “jet streams” and “atmospheric river” by the NWS is pretty standard. As a NWS forecast consumer, it’s not my role to tell them that their “jargon” makes no sense. Rather, I read enough forecasts and NWS discussions to understand somewhat what they are referring to and how their forecasts are going to effect me in my area.


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For those (like me) who enjoy reading NWS discussions:


Some fine and relevant reading. :slight_smile:



I have studied climatology and got paid to write about it.

I don’t need journalists from the East Coast telling me we are going to get 10 inches of rain. We may get 4-7 feet of snow at the highest elevations in the Sierra. The water equivalent is around 5-7 inches of rainfall. At lower elevations we will be getting much less than that. There are plenty of unfortunate terms used by people that are not scientists, or used for public consumption.

Wow, Sir, sorry tht you are offended (by east coast folks, journalist…?). In my link, it goes directly to NOAA/NWS site. I was just repeating the term/jargon that was being used in the NWS forecasts discussion by the NWS climatologists, meteorologists, or whatever they call themselves. Feel free to insert your correct term. I don’t care.

At any rate, I’m hoping for good rain for west coast to address its year long drought. I hope that it doesn’t come down so fast and hard that the hillsides slide out.

More important, I am getting some waves out of the meteorological event coming my way. :slight_smile:


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I respect your expertise, however, the authors are more than just “journalists.”

"Matthew Cappucci is a meteorologist for Capital Weather Gang. He earned a B.A. in atmospheric sciences from Harvard University in 2019, and has contributed to The Washington Post since he was 18. He is an avid storm chaser and adventurer, and covers all types of weather, climate science, and astronomy.

“Jason Samenow is The Washington Post’s weather editor and Capital Weather Gang’s chief meteorologist. He earned a master’s degree in atmospheric science and spent 10 years as a climate change science analyst for the U.S. government. He holds the Digital Seal of Approval from the National Weather Association.”

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The thing with atmospheric river is that the flow direction is somewhat like a fractal generated random walk. The last few storms we were supposed to get a few tenths of an inch total and we got inches in my neighborhood. Hopefully fire season is soon over. Forecast is for overhead to overhead + 4’ on Monday. I am too old for that kind of punishment but will probably find a sheltered spot to surf or maybe sit on my tailgate with a pot of tea and watch.

So, yes, I was remembering what happened last time in your area of CA. My college roommate is up in Sonoma, near where the fires have been. Several years back, the fire literally stopped a foot from his house. It was saved but the town and surrounding areas took some major washouts in the subsequent rains.

We are getting almost double overhead Wednesday into Thursday. No longer my thing either anymore. Several years ago, I was surfing 2nd Beach/Ri, next to a point of land. I easily paddled out on the rip along the point. But, when I took a turn out into open, Yikes! Not double overhead but overhead (8-10’) I surfed it and survived a couple major wipeouts which I managed to roll up from. But the upside times in the rolling foam pile were long. The scare factor was equal to the fun factor. I resolved then not to go beyond head high (6-7’ max).

I think by next weekend, it will be nice, mellow stuff for me. Whatever you do, stay safe out there.


Nevada is the driest state, and we get shadowed out of precip all the time. The local meteorologists have local radar and several predictive models to work with.

I am happy to hear the W Post meteorologists have great credentials, but even the NWS and NOAA have a hard time with precip around here. I used to deliver the WA Pst as a kid. It has been a great newspaper.

Our local NWS folks said it best when a few complained about their forecast: We’re in marketing, not production.

Whatever you want to call it, it is an unusual weather pattern, and generally a positive one for us.

Looking at San Francisco, we normally don’t get any significant rain from May through September, and about an inch in October. So far this October, we have gotten almost 2 inches in downtown and the storm coming Saturday night through Monday is expected to bring another 1-2 inches. 4 inches would be about 20% of our annual rain, which is very good given we are in a drought. In the areas this rain hits, we can call the fire season over, which is also good.

This by itself won’t take us out of a drought, we could still have a dry winter. Our wettest months are January and February, when we get almost half our annual rain (about 9" between the two months), and they are still predicting drier than normal for the winter. So we will take any rain this will give us.

These “atmospheric river” weather patterns are somewhat targeted. The area the rain hits covers maybe a 100-150 mile swath north to south. If the weather system stays in one spot, that swath will get dumped on, and north and south of it will get less or even be dry. This one thankfully sounds like it will slowly drift south, which will spread the wealth (and reduce risk of landslides some).

Oh, another negative is that the areas that had fires in last few years are at risk of land slides.

This is not expected to do anything for southern California. It wont slide that far south. Santa Barbara and south will get little to no rain. Their fire season likely will continue there for a while.

For more info on SF climate (monthly averages and the like) - check this site: Climate in San Francisco County, California

Note - for those that aren’t familiar with our weather, we have significant microclimates in this area. In the summer, there are times when it will be 60F on the coast and 100F a half hour drive inland. Drive an hour north of SF to Santa Rosa, and the annual amount of rain almost doubles. An hour south to San Jose, and it halves from SF.

So true! In New England, the saying is, “If you don’t like the weather, wait a day…” With San Francisco, it’s drive across the Bay Bridge and go another 20-30 miles. Several years ago, I stayed at a friend’s place up near Mission/Castro line in August. Nice mid 70 degrees in the City. I then drove to meet up with my college roommate in Healdsburg for a 25 plus mile loop ride to Lake Sonoma launch and back. It felt warm, got hotter and then felt like it was scorching. When we got back to Healsburg and checked the weather, the temp registered 100 degrees. We enjoyed the post ride celebration with mutliple bottles of water followed by craft ale. :slight_smile:


I believve atmospheric river is a term that is at least 30 years old.





Rain is still coming here in SF. My early prediction was low - we are at almost 4" of rain for this round (on top of the 2" we had earlier this month). I am guessing another 1-2 inches before it ends tomorrow, and then it looks like we go back to our standard dry pattern.

Minor issues around the area, such as downed trees and some roadway ponding. Likely have been or will be some slides in the areas that had fires in the last few years.