38 votes

A rare “Polar Express” winter pattern is forecast over the United States and Canada, following a Polar Vortex split

8 comments

  1. [2]
    patience_limited
    Link
    From the article: I've posted from this source for the excellent graphics and animations so you can see the full magnitude and impacts of this weather anomaly. North American winter will have...

    From the article:

    The recent Stratospheric Warming event is starting to impact global weather development. We already see colder air entering North America, but now a Polar Vortex split is forecast at lower levels of the stratosphere. This will bring a “Polar Express” weather pattern across the United States and Canada deep into the month, with multiple waves of cold air.

    A “Polar Express” pattern is essentially a sequence of consecutive cold air events, with possible brief breaks. This usually requires a Polar Vortex core to provide a steady northerly flow over North America.

    I've posted from this source for the excellent graphics and animations so you can see the full magnitude and impacts of this weather anomaly. North American winter will have extra seriousness for at least the next month, while Europe gets some temperature moderation and loss of snowfall.

    I'm waiting for the shrill bleats of "this freeze means climate change isn't real, let's burn more oil" in the U.S. Meanwhile, I'm expecting another two feet of snow locally next week. Time for a mental health thread post.

    22 votes
    1. clem
      Link Parent
      Thanks for sharing (and for your comment explaining why it's interesting). It's refreshing to read a detailed article about the weather explained thoroughly so a regular person like me can...

      Thanks for sharing (and for your comment explaining why it's interesting). It's refreshing to read a detailed article about the weather explained thoroughly so a regular person like me can understand it. Also very nice to see a website designed for readability rather than optimizing ads and collecting my data!

      6 votes
  2. secretfire
    Link
    Oh cool, the regularly scheduled super rare once-in-a-generation weather event, haven't seen one of those in a few weeks.

    Oh cool, the regularly scheduled super rare once-in-a-generation weather event, haven't seen one of those in a few weeks.

    15 votes
  3. [4]
    thearctic
    Link
    As far as I understand, the general principle that ties this to global warming is that, when the temperature difference between cold air and warm air is sufficiently large, they have trouble...

    As far as I understand, the general principle that ties this to global warming is that, when the temperature difference between cold air and warm air is sufficiently large, they have trouble mixing because of the difference in density. As very cold air warms a bit, it can better mix with warm air, which can cause these cold snaps.

    With all the mild winters we've been getting recently, the snow's been nice though.

    7 votes
    1. [2]
      clem
      Link Parent
      It has been nice, but it sure caught me off guard. I had quite a bit to finish up before winter, but I was busy with Thanksgiving, and then--bam, everything was covered in snow. I'll catch up, but...

      It has been nice, but it sure caught me off guard. I had quite a bit to finish up before winter, but I was busy with Thanksgiving, and then--bam, everything was covered in snow. I'll catch up, but a lot of stuff is much slower when it's cold and snowy. And some of the stuff I've left outside will suffer a bit more sitting out all winter. But so it goes! I'm enjoying it anyway, and have mostly gotten used to the cold.

      4 votes
      1. patience_limited
        (edited )
        Link Parent
        I got caught without snow tires (delayed delivery), even anticipating the usual Thanksgiving lake effect snowstorm where I live. So I'm grumpy about this to begin with. And I'm thinner-skinned...

        I got caught without snow tires (delayed delivery), even anticipating the usual Thanksgiving lake effect snowstorm where I live. So I'm grumpy about this to begin with. And I'm thinner-skinned than I used to be where cold weather is concerned - still figuring out how many extra layers I need on any given sub-zero day. For extra seasonal joy, I've added cold-induced urticaria to the autoimmune disease symptom list.

        What do you do when the place you love is trying to kill you, that's a question a lot of people are going to ask about climate change stresses.

        2 votes
    2. patience_limited
      Link Parent
      Snow is nice until you get half a meter in a week and the sand trucks and plows can't keep up. The roads turn to ice rinks, and even very experienced drivers wind up in the ditches. Airports shut...

      Snow is nice until you get half a meter in a week and the sand trucks and plows can't keep up. The roads turn to ice rinks, and even very experienced drivers wind up in the ditches.

      Airports shut down, grocery store shelves and cases start to empty, and people start having trouble paying their heating bills. Farmers where I live will lose perennial trees and vines that can't tolerate extended time at temperatures below -20 °C. It takes years to come back from that, if the farms survive (considering that the Trump administration has already politicized agricultural disaster relief and denied/delayed the payments for the catastrophic late spring frost, it's gotten less likely they'll make it).

      4 votes
  4. lackofaname
    Link
    Ahhh, it's been hard to ignore the colder than normal snaps where I am. I've almost subconsciously been waiting for the temp to raise again; this feels more like what I'd expect for Jan/Feb. But...

    Ahhh, it's been hard to ignore the colder than normal snaps where I am. I've almost subconsciously been waiting for the temp to raise again; this feels more like what I'd expect for Jan/Feb. But then another cold wave comes.

    The figures in the post are so interesting and clear, I had no clue the polar vortex could split! And mentally, at least I can prepare myself for a miserable rest of December instead of expecting relief any time soon.

    1 vote