Thursday, November 21, 2013

Dark in Barrow, -50 F in Southeast Interior

Continued cooling over interior Alaska has produced the season's first reports of -50 °F today in the southeast; here are some of the colder observations:

-51 F  Bolio Lake RAWS
-50 F  Chicken COOP
-50 F  CW4591 automated station near Tok
-49 F  Marguerite Creek near Healy 13NE
-48 F  Tok #2 COOP
-47 F  Northway airport
-46 F  Tok COOP
-41 F  Eielson AFB

According to the GHCN data, it is somewhat unusual for -50 F to be reported this early in the winter in Alaska; it happens once or twice a decade on average.  The earliest observation of -50 F was on November 4, 1945, at Allakaket (-53 F).

In the far north of Alaska, the polar night has now reached Barrow, where the sun set three days ago for the last time this year.  The FAA webcam image below shows the southern horizon today at close to solar noon.




3 comments:

  1. Hi,

    Just a general question for you, if you have the time. What are the main conditions that create this tendency for such severe cold snaps (that seem to plunge down very quickly) in that Tok/Chicken/Beaver Creek area? It really seems so much worse there in that regard than the rest of interior Alaska and northern Canada. It's almost like a little slice of northeastern Siberia/Far East Russia stuck in a remote corner of North America.

    Thanks!

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    Replies
    1. Hi,

      Rick would be able to speak about this with greater insight, but I think there are two main factors that favor frequent and rather extreme cold in that part of the world: elevation and lack of wind. Tok is over 1600 feet above MSL, Chicken is at 1800', and Beaver Creek YT is over 2100'. Higher elevation means less infrared radiation from above on clear nights and hence the ability to cool more quickly and to lower levels. Lack of wind seems to be related to sheltering by the Alaska Range to the south and west, and the plateau-like terrain that doesn't favor drainage winds.

      See the following link for a post last year about the coldest place in AK:

      http://ak-wx.blogspot.com/2012/11/where-is-coldest-place-in-alaska.html

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    2. In addition to those factors, most reporting stations in that part of Alaska adjoin down sloping river drainages that channel cold descending from higher elevations...Tok, Tok and Tanana River; Chicken, Fourtymile River; Northway, Nabesna and Chisana Rivers; Beaver Creek, White River originating in Alaska.

      Not sure of the factors, but Tomtor, Yakutsk, and other nearby communities in Yakutia, Siberia share similar geographic properties. And their winter cold marginalizes ours in Alaska.

      Gary

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