Tuesday, December 10, 2024

Alaska's Changing Environment

Last week UAF released an updated version of their summary report on "Alaska's Changing Environment", documenting trends and recent events across many aspects of the natural environment in Alaska.  I recommend taking a look at the latest report, which updates and extends the original 2019 publication:

https://uaf-accap.org/alaskas-changing-environment/

There's a wealth of information in the document.  Extreme events of recent years are highlighted (e.g. ex-Typhoon Merbok, landslides), and the discussion goes far beyond traditional weather and climate metrics to explore ocean and wildlife changes that I knew nothing about.

Coming back to today's weather, my late November comment about the negative PDO phase favoring colder weather in southern Alaska is being challenged in dramatic fashion, as western and southern regions have been overwhelmed by warm Pacific air in the last couple of days.  Anchorage reached 47°F last night, the highest December temperature since 2019, when it reached 51°F (the monthly record).  Nearby Merrill Field and Elmendorf AFB both reached 51°F last night, and again that's the warmest since 2019.  It was even warmer a bit farther north:


There'll be no prizes for guessing the Pacific weather pattern responsible for this: widespread low pressure across the Bering Sea and Aleution region, and a prominent ridge over western Canada.  Here are maps from 3pm AKST yesterday:




2 comments:

  1. I recall mid-January of 2009 as a negative-PDO/La Nina epic meltdown in southern Alaska, similar to what we've seen this December. That was in the midst of an otherwise cold winter. I wonder if the temps are gonna plummet at some point in the next week or so... the long range doesn't really indicate that.

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    1. Good memory, that was an incredible warm-up.
      Anchorage went from -24F on Jan 7 to 5 straight days with highs in the 40s starting on the 15th. Wild!

      No cold in sight in the next 10 days or so, but January could be a very different story.

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