Record Warmth Blankets Alberta

Extreme warmth associated with a powerful western high pressure ridge and conditions related to climate change has broken temperature records across Western Canada during recent days.

On December 9, the southern Alberta cities of Lethbridge and Grand Prairie saw temperatures rising to record highs of 14 C or 57 degrees Fahrenheit. Meanwhile, Calgary experienced 15.4 C temperatures (60 degrees F) — which shattered the previous record of 14.4 C that had stood for 127 years. Four other cities in southern Alberta also saw record warm temperatures on Saturday.

For context, temperatures for this region typically range between -1 to -13 C this time of year.

(The first 11 days of December show far above average temperatures for most of Western North America and the Arctic. Image source: Global and Regional Climate Anomalies.)

The primary feature driving such extreme temperatures is a power high pressure ridge that has been anchored in place during November and December. The ridge has been drawing warm air north and generating unusually warm weather for regions from the U.S. West through central and western Canada and on up into the Northwest Territories and Alaska.

Very slow reformation of sea ice in the Chukchi and Bering Seas is a likely contributing factor to the ridge. A physical feature associated with human-caused climate change. La Nina is likely also enabling the synoptic transfer of heat into both the Arctic and the North American West through a very pronounced Rossby type wave pattern in the Jet Stream. But present Arctic warmth in the range of 3-5 C above climatological averages is well beyond 20th Century norms during La Nina years. It is instead primarily an upshot of polar amplification — where human-forced warming due to greenhouse gas emissions generates more warming at the poles than in the lower latitudes. So climate change related factors are also influencing this overall warmer than normal pattern.

(Above freezing temperatures aren’t typical for Alberta this time of year. But the region was blanketed by 40-60 degree [F] highs on Saturday. That’s 9 to 27 degrees [F] above average. Image source: Earth Nullschool.)

As a result, places like Calgary haven’t received any snowfall so far this year during December. A situation that is likely to continue for at least the next five days as warmer than normal conditions are expected to persist.

December is typically a rather snowy month for Calgary — receiving 8 days of snow during a normal year. But this year isn’t really that normal and the climate, with global temperatures exceeding 1 C above 1880s averages, isn’t normal anymore either.


Hat tip to Dobby

Leave a comment


  1. Andy_in_SD

     /  December 12, 2017

    I had spent time in Red Deer, Alberta (pretty rough oil town back then) in the early 80’s. December / January. It was bitterly cold, the kind that burns your lungs if you inhale too fast.

    The lack of snow is an issue if it continues through the winter. If so, we can expect drought next year, as well as fires.

    In central Europe, relatives let me know it went from -1C to 18C the next day. Again, this will impact soil moisture next year. Plants will also misfire with extended high temp situations in the winter.

    • I’m thinking we’ll have more northern fire issues this year if the present western ridge remains strong. However, some models (see below) show ridge shifting into Central U.S. This would accelerate U.S. drought but give the NWT a bit of a respite.

  2. So longer range predictions do show Alberta cooling, but at serious cost of pretty extreme polar warming. Note that this model also shows the ridge shifting into the Central U.S. which would be rather bad for the present drought situation there. As noted in the post, please add grain of salt for long range forecasts of this kind.

  3. miles h

     /  December 12, 2017

    a little good news… World Bank is to stop funding upstream oil…

  4. Jeremy in Wales

     /  December 12, 2017

    Tell Calgary they can have their snow back, 5 days and I have had enough!

    • Hah. Yeah, about that… Looks like US will experience a bit warm up next week if the longer term models are correct. Grain of salt needed…

  5. Dobby

     /  December 13, 2017

    Thanks for this post about my area Robert, very much appreciated. I live in Calgary, AB.

    We haven’t really had a proper winter here all through the recent California drought of 2012-2017, because like California, we also spent a lot of time under the same ridging pattern that affected California, the same one we’re under again now. I’ve had perennials try and come up in mid January in recent years, which is quite the thing to see when you grew up here and expect to be bundled up at that time of year in a parka with scarves and mitts in temperatures of -30C. That would be a proper winter here, not +10C for extended periods of time in January or February, and even warmer sometimes.

    It’s felt like being one of the people on the front lines of a changing climate, while others elsewhere thought this was only all just being imagined by computer models. No, it’s here, it’s real.

    In recent past years, when the ridge does give way to a short cold snap for a week or so, it has often built right back in again afterward, and then stayed for another month until abating once again for just another short week. Confused plants really hate that. We’ve even had bears coming out of hibernation before it was actually spring. Then they have nothing to eat, which is an example of adaptation problems in the flora and fauna when the climate shifts so dramatically and quickly like it has here.

    We’ll have to see what the rest of this winter brings for us after our projected slight cool down in a few weeks time. It really has been surreal these past several years living up north here, yet being under the “ridiculously resilient ridge.” They’re going to have to start adding reoccurring to that infamous alliteration now too.

    Thanks again for your fabulous coverage of the effects of climate change in our neighborhood Robert. Really well done sir.

    • Got to say that I really appreciate the local-based testimony and observations here. You’re in a region that’s experiencing some of the strongest impacts of human-forced climate change. You’re experiencing this stuff first hand. That’s something we all need to hear, IMO.

  6. Dobby

     /  December 13, 2017

    Hey, I just noticed the hat tip Robert. After reading here for several years now, what an honor. Shucks. 🙂

  7. Loni

     /  December 13, 2017

    I’m tryin’ to imagine what a homeless winter is going to look like.


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