Canada and the northwest of the USA: 2 meters of snow or rain?

By Arjen on 3 December 2015 · 4

November was a very good month in Canada and the northwest of North America and thanks to the storm that's still to come it will become even better! At least if we believe the reports. You can find articles about 2 meters of snowfall, while other articles tell something different. Let me try to make some things more clear for you!

  • There will be a lot of precipitation
  • The snowline will be between 900 and 1800 meters
  • Advice: stay out of the backcountry the first days and ride some powder inbounds above mid-station

Atmospheric river is the cause of the precipitation

The whát? Yes, that's exactly what I thought when I first started studying the weather in North America. The atmospheric river is a phenomenon that we don't really know in Europe. It's quite common in North America and they also call it the Pineapple Express.

The "Pineapple Express" is an airflow that travels from Hawaii to the rainy west coast of North Americafrom time to time. It looks like a river in the air, is often thousands of kilometers long, and usually hundreds of kilometers wide. The same amount of water is transported in this 'air river' as in the Amazone river in Brazil. Now that's a lot of water. When this river hits the mountains in the Pacific North West and British Columbia, it's forced to rise, cools down and the result is a lot of precipitation. To read more about the details of such a river, click here.

The atmospheric river finds its way to the north
The atmospheric river finds its way to the north

Such an atmospheric river is developing right now. You can monitor the river on the website of NOAA. You can see a preview on the map above. A yellow river in the atmosphere is finding its way towards the northwest of the USA and western Canada. And that leads to the snow maps below. If you just can't believe the amounts or if you want to zoom, go to our North American snow maps.

Black spots = the motherload
Black spots = the motherload

And huge amounts of freshies:

Lots of snow, but also lots of wind and high temperatures
Lots of snow, but also lots of wind and high temperatures

You can also see that on the maps of NOAA (snowfall in feet):

next 7 days
next 7 days

You can expect lots of precipitation the next couple of days. All thanks to the atmospheric river that's heading towards the west coast of North America.

The snow line fluctuates between 900 and 1800 meters

The pineapple express sounds pretty warm and from time to time that's exactly what it is. A low pressure area is positioned west of the coast of Canada at first. The result is a southerly current which brings warmer air. This is the scenario we'll see twice. It won't be that cold on the coast on Saturday with rain in the valleys and snow above 1000-1500 meters. In areas close to the ocean, the snow line will be higher than more inland. The snow line on Vancouver Island and Washington State can go up to the 1800 meters. We see exactly the same on Monday. It should be noted that the temperatures will rise in the West first and in the Rockies later. The wind from the southwest will be quite strong and that might cause some problems in the backcountry. My advice is not to go out in the backcountry in the Pacific Northwest and the Canadian Rockies, but to ride powder inbounds above 1500-1700 meters.

And thus? Well, this could be a great storm cycle. The atmospheric river will bring a lot of rain, but also a lot of snow above 1500 meters. Even between 1000 and 1500 meters the snow pack will grow despite the snow that occasionally will come down as rain. Next week will be great to ride powder in Canada. More and more resorts open their lifts, there's plenty of powder and it's still not too crowded. Who's in?

Stay stoked, Morris


  • Chester_Tartsnatcher
    Chester_Tartsnatcher op 3 December 2015 · 15:02
    I'm in. I'll be skiing in the Seattle area, likely Crystal Mountain.

    When a pineapple express comes in like this, what's really nice is if there's some lows spinning in from the Gulf of Alaska or North Pacific. That's what will bring the snow line down.

    See this:
  • Wolverino
    Wolverino op 4 December 2015 · 09:16
    I'm in too.
  • meteomorris
    meteomorris op 4 December 2015 · 11:32
    @Chester_Tartsnatcher thanks! You're right. But the warm sectors of the storm might push the snowline in the coastal areas up to 1500-1800 meters. Luckily the cold fronts will bring enough cold snow on top. Looks like some epic days to come! Enjoy... and ps... Pics or it didn't happen 😉
    May the powder be with you.
  • Chester_Tartsnatcher
    Chester_Tartsnatcher op 7 December 2015 · 16:40
    Snow line was down to 1100 meters Saturday and Sunday and faceshots were had!.

    You can consider them like Schoedingers Cat: since there's no pictures are they dead or alive?


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