With the polar vortex up to Halloween tricks, Alaska’s largest city is surfing toward November on a wave of weather historically more like early September than late October.

It has left some wondering about a climatological reorientation as Minnesota – the state that wants to rebrand itself “North” – shivered in the cold.

The midday temperature in International Falls on Tuesday was 27 degrees, which left that city on the southern edge of Canada’s border 26 degrees colder than the biggest U.S. city north of the Canadian border.

Temperatures in Minneapolis, Minnesota’s largest city, were forecast to dip to 22 degrees Tuesday night while the mercury was expected to stay above freezing in Alaska’s largest city with a forecast for temperatures in the mid-30s to lower 40s. 

How unusual is this?

An Anchorage-area resident for most of his adult life, 63-year-old Doug O’Harra can’t remember a year in which Halloween wasn’t marked by either frozen ground or turf lost beneath a blanket of snow, though he concedes it is possible that might have happened sometimes in the past four decades.

“Memory is a leaky drybag with frayed seams,” O’harra admitted. National Weather Service records, however, aren’t.

The daily, climate “normal” temperature for Anchorage is usually at freezing by mid-October and falling fast. By Halloween, with daylight down to just a titch over eight and a half hours in length and the northern nights already long, the historic, normal, daytime high barely creeps above freezing to top out at 32.7 degrees while the nighttime low plunges to 21.3 degrees. 

Not this year.

A record was set on Monday when the city’s high temperature hit 54 degrees – two degrees warmer than the previous record set in 2013 and 20 degrees above normal. The nighttime low of 42 degrees was 19 degrees above normal, according to the weather service. 

Alaska climate trends over the last 42 years echo this weather report, according to the Alaska Climate Research Center, although the changes are not nearly as extreme except on the state’s North Slope where autumn temperatures in Utqiagvik (Barrow) are up a staggering 18 degrees.

Anchorage autumns have warmed by only 3.6 degrees, but that’s significantly above the average, annual, year-round warming of 2.1 degrees since 1976.

Swirls, swirls, swirls….

What is going on at the moment and has been happening with some regularity in the last several years is a ripple in the stream of air spinning around the globe.

Instead of northern hemisphere weather wirling neatly in a circle around the north pole, the polar vortex has been wobbling and kicking off pressure ridges in the atmosphere that can seriously mess up weather normal.

When a high-pressure ridge forms over the West Coast of North America, east-bound weather headed across the central Pacific Ocean is funneled north in the form of the aptly named “Pineapple Express,” “an atmospheric river…bringing warm and moist air all the way from Hawaii to Alaska” as the weather service describes it.

Meanwhile, behind the ridge to the east in the American Heartland,  cold, Arctic air gets sucked down through central Canada into the Midwest in a pattern oddly reminiscent of the Wisconsin Glacial Episode an estimated 50,000 to 150,000 years ago. 

The legendary “frozen tundra of Lambeau Field” in Green Bay, Wisc. was getting some of that frigid air this week. MIT climatologist Judah Cohen, the director of seasonal forecasting at Atmospheric and Environmental Research and an authority on the polar vortex suspects a winter-long pattern could be developing.

“…If you are a regular reader of the blog and/or my research then you are already familiar with my arguments that Arctic amplification, which not only includes amplified Arctic warming but low sea ice extent and high snow cover extent in the fall, is favorable for high pressure in the Arctic and downstream troughing and cold temperatures at least regionally across the northern hemisphere (NH) continents,” he wrote Monday.

Arctic sea ice is now at a record low, according to the National Snow and Ice Data Center, and October snow cover in the northern hemisphere is, in Cohen’s words, “relatively extensive.” He’s predicting this global-warming related phenomenon could, strangely enough, again put the big freeze on the Midwest.

“Based on my observational analysis,” Cohen wrote, the developing picture “favors high pressure in the Arctic with downstream troughing and cold temperatures across the continents.  So, if you are considering Arctic predictors in your winter forecast, I would say that they are quite bullish for severe winter weather at least regionally (in the Heartland) and possibly on even larger scales if the stratospheric polar vortex gets involved.

“…In many ways this upcoming winter forecast is a good proxy or symbolic of the current debate whether accelerated Arctic warming is contributing to colder mid-latitude winters.  The dynamical models clearly say no.  I believe observational analysis says yes, and it will be interesting to see if this winter is consistent with the modeling or observational/empirical analysis.

Short term v long term

“Of course, one winter alone does not prove a theory or analysis but rather is one data point in a series or collection of data points,” Cohen added.

Only time will tell whether Cohen or the models are right, but the pattern is of interest to Alaska because the changes that bring winter cold to the Midwest bring the opposite to the 49th state.

At the moment, Cohen – like a lot of other climatologists – is watching “sea surface temperatures…well above normal around Alaska and the eastern North Pacific” which “favors, ridging over Alaska and the eastern North Pacific but I see mixed signals where the main axis of the ridging sets up.  If it is along the West Coast like 2013/14 and 2014/15 the cold is focused in the central and eastern North America, but if it is offshore like 2017/18 then the cold is focused more in western and central North America.”

He also admits he is operating outside the scientific mainstream on this one.

“Of course, the dynamical models don’t agree with me and say ignore all that is going on in the extratropics,” he writes. “All that is important is that the Arctic is warm and if anything, that the warm anomalies will spread to the lower latitudes.”

In either of those scenarios, Alaska heats up, but in a land where just a few degrees shift in temperature can mean the difference between lots of rains and lots and lots of snow. Cohen is predicting normal or above normal pretty much through November.

He also sees possibilities for increased snowfall in Alaska. Whether that will come at all elevations is anyone’s guess. The problem is again a matter of a few degrees.

The weather service’s forecast for the week in Anchorage calls for temperatures above freezing with rain or showers almost every day.  But at elevation to the south at Turnagain Pass on the Kenai Peninsula, the prediction is for near-freezing conditions with snow.

To the north where the early-season snow at Hatcher Pass in the Talkeetna Mountains has been a delight to skiers, on the other hand, the prediction is temperatures will warm up just enough to set the precipitation to flipflopping between rain and snow.

That is how the week started. It rained at Hatcher Sunday night into Monday morning, but the precipitation than turned to snow and a reported 10 inches had fallen by Tuesday evening.

The good news for those who love winter sports is that coastal Alaska can get a lot of snow in temperatures at or even just above freezing. The bad news for those who love winter sports in coastal Alaska is that the weather now regularly goes Seattle like in any month.










11 replies »

  1. This time of year, there is only so much cold air to go around. When it is warm up here, it is generally cold in other places. That works until February, when it is cold everywhere. How about a -43.6 F in Peters Sinks, UT yesterday? Apparently set a low temp record for anywhere in the Lower 48 in October. I wouldn’t be getting rid of your cold weather gear quite yet. Other data point is that there are over 200 days of a quiet sun (no sunspots) so far in 2019. Dress warmly. Cheers –

  2. For the doubters:

    Another Ice Age a’coming..
    Upside-down “rivers” of warm ocean water may be one of the causes of Antarctica’s ice shelves breaking up, leading to a rise in sea levels. But a new study suggests an increase in sea ice may lead to a much more devastating change in the Earth’s climate — another ice age.

    Using computer simulations, the research suggests that an increase in sea ice could significantly alter the circulation of the ocean, ultimately leading to a reverse greenhouse effect as carbon dioxide levels in the ocean increase and levels in the air decrease.

    “One key question in the field is still what caused the Earth to periodically cycle in and out of ice ages,” University of Chicago professor and the study’s co-author, Malte Jansen, said in a statement. “We are pretty confident that the carbon balance between the atmosphere and ocean must have changed, but we don’t quite know how or why.”
    A new study by UChicago scientists show how an increase in Antarctic sea ice could trigger a chain of events leading to an ice age. Image courtesy of Yvonne Firing

    A new study by UChicago scientists show how an increase in Antarctic sea ice could trigger a chain of events leading to an ice age. Image courtesy of Yvonne Firing

    The last major ice age ended at the end of the Pleistocene era, about 2.5 million years ago, as glaciers have periodically grown and then gotten smaller. Researchers believe that changes to the Earth’s orbit may be partly responsible for some of the Earth’s cooling, but additional factors have likely played a part, Jensen added.

    “The most plausible explanation is that there was some change in how carbon was divided between the atmosphere and the ocean,” Jansen continued. “There’s no shortage of ideas about how this happens, but it’s not quite clear how they all fit together.”

    • Very interesting!

      At the bottom of the FoxNews article, linked at the bottom of Bryan’s comment above, is a link to the original paper, on Nature Geoscience.

      Global cooling linked to increased glacial carbon storage via changes in Antarctic sea ice

      Others doubt that even mild weather-pattern fluctuations, such as we are experiencing now and have good records of over the last century or 2, are predominately about CO2, pro or con … much less big-time climate-change.

      (CO2 is pretty small potatoes, greenhouse-wise, and the greenhouse mechanism itself is but one of numerous ways the climate could be affected … but in what looks more like politics than science, it has become the only mechanism that can be discussed, without inviting abuse.)

      But what we have here in this report, is a project to explain not just weather-patterns, but actual large-scale climate shifts & transitions, in terms of the currently dominant carbon dioxide greenhouse gas mechanism. Without arguing about the role of CO2.

      On the Nature Geosciences page for this paper, is a prominent “Code availability” offer to download “MITgcm”, which is the Global Circulation (or Climate) Model software, on which this simulation was performed. The paper author will provide the code that was developed to run the particular simulation that is the subject of this report.

      The download contains about 1,000 files and is 162.5 megabytes. It might have to be compiled … it could be intended for Linux, so beware. In the files-manifest we see a substantial number of PDFs, which are going to be Documentation, Manuals, Guides, Instructions, etc.

      Having those PDFs to peruse – short of knowing how to deploy the GCM itself, much less perform research with it – could be worth the price of the download (zero), for average curious people.

      A decade to two back, there were a number of different GCM packages, each produced by different schools or labs. Each was basically the private & closely-guarded Kingdom of its respective (public tax-supported) research entity. Today, a number of research centers are in the advanced stages of making the models Open Source and available to all. MIT is a leading such example.

      Cool stuff!

      • Ted, just be sure to send your check for your Carbon Credit$ to:
        Al Gore’s Amazing Internet
        c/o “An Inconvenient Truth”
        Warming Way
        Fire Island, MA

      • I suppose you’re right Bryan. Lot of other people tell me that too. “Did you get that carbon-check off to Al Gore yet??” One day the dog ate my check book. Then, I was going to … but I couldn’t find a pen. Now, there’s another little delay … waiting for hell to freeze over.

  3. Another bunk winter on the horizon for S.C.
    20 degrees above normal and raining into November…
    The snow up in Hatcher’s will get “glazed” by this rain and any additional snowfall will be added to that “icy” layer in the base.
    This phenomenon is the main reason for avalanches since each additional snowfall is on top of that icy base that never allows full “consolidation” until spring.
    Be careful in the hills this winter since AK has a climate more like New England and less like the “Arctic”.

  4. As long as there is enough snow by late-winter to make a good base on the Iditarod trail, all is not lost!

    Of course, the trail sprawls across several different regions of South Central and Western Alaska, and conditions can vary.

    It’s worth mentioning that the Iditarod was first set up & got it’s start, near the end of a pronounced cool-spell that culminated in fears of an impending new Ice Age. Some did suggest that Anchorage & environs might not always be a relialble snow-sports venue…

    Those who got their start in the North during the 1970s, have base-line memories of an especially Alaskan Alaska.

    When the first nuclear submarine the Nautilus crossed the Arctic Ocean (1958), the ice was thin and open water was common. For years, it and other new nuke boats could pretty much surface at will, during the summers.

    But as we moved into the ’70s, ice grew back in, became perennial and got thicker, and there were few leads & openings. In the early nuke-years, sailors had a great time playing with polar bears, practicing ice-diving and other Arctic skills, and helping gather science data. No more, as we got further into the Big Chill … immediately preceding the current warm-spell.

  5. I woke up and thought I was late at getting the garden started, except when I looked we still had about a foot left of our two feet of snow from earlier. Maybe this way I will get a chance to locate a few more buried items instead of having to wait for break up. I’ll take the 11 in Alaska.

    My gosh, I can remember seeing a Ford pickup sitting up on a jersey wall like a teedee totter down in Denver in the middle of the 25 one time when the roads were bad. I never knew those Fords could jump like that. Simply Amazing…..

  6. Thank you Craig for spotting the true culprits (Pineapple Express, el Nino, la Nina) and NOT focusing on that nonsense “Global Warming”:
    The Pineapple Express is a non-technical term for a meteorological phenomenon characterized by a strong and persistent flow of moisture and associated with heavy precipitation from the WARM waters adjacent to the Hawaiian Islands and extending to any location along the Pacific coast of North America to include ALASKA.

    • Guess “Global Warming” only happens in specific locations.. Quick everybody, move to Denver to keep from dying in 11yrs.
      DENVER (CBS4) – Denver Weather: More Snow, Record Cold, Winter Storm Warning In Effect. The second arctic front to slam into Colorado in just two days arrived earlier than expected Tuesday. It produced heavy snow for the morning commute, slowing the drive down big time and contributing to many accidents across the Front Range.
      Most locations will see 6 to 12 inches of total snowfall (on top of what accumulated on Monday!).

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