Thursday, November 16, 2023

A Few Notes

A few comments on various topics.  First, the snow onslaught in Anchorage: the recent 10-day total of 38" amounts to the 3rd highest on record.  Last year's December snow was even a bit greater, and the top event was back in February 1996.

It's really remarkable to see such a large amount of snow at the airport - where there is typically less snow than across most of the area - and in back-to-back years.  With La Niña last winter and El Niño this winter, we can't pin the blame on similar climate forcing, so perhaps it's just "luck of the draw".

Second, the Tanana River at Nenana froze up last week on Wednesday the 8th.  The scene is suitably wintry today:

But the mighty Yukon River hasn't frozen over at Dawson yet; here's the latest video from the webcam:

The situation at Dawson looks about the same as last year at this time:

Long-time readers will recall discussion of the lack of a proper freeze-up all winter long at Dawson in some recent years:

This autumn has certainly been on the warm side of normal in Dawson, but it's not breaking records for lack of freezing potential: here's a chart of accumulated freezing degree days (accumulated temperature differential below 32°F):

This is from the reliably-reporting "LRP" site in Dawson, not the airport, where many observations are missing.  The city does have a much longer history of climate observations, of course, but it seems there are some discrepancies between the different climate sites that would affect any long-term trend analysis.

And finally, I'll highlight the remarkable lack of sea ice along Alaska's west coast at this time, related to persistent southerly winds and warmth.  Rick Thoman posted a graphic to illustrate:

"Sea ice concentration analysis for Wednesday and the same date last year from the National Weather Service Alaska Region Sea Ice Program. Much less ice in the southern Chukchi and Bering Seas currently than this date last year. November 15 and effectively no ice in Kotzebue Sound is especially shocking, even by recent norms."

Here's a longer archive of November 15 analyses, from 2021 (top) to 2018 (bottom):


  1. Richard, I've been reading about the AI vs WX forecasting topic. Do you have any comments so far?

  2. Hi Gary, there's tremendous buzz in the industry about this. Yes, I'll pen some comments about the situation in a blog post soon. I don't anticipate a dramatic improvement in forecast accuracy because of these developments (at least not yet), but behind the scenes the weather business is going to see some major changes.

    1. Autoregressive back to the future: