More Snow and Cold

Back on December 18, I commented that the extreme cold then affecting northwestern Canada and far eastern Alaska looked likely to shift westward in the coming weeks, and that trend has played out nicely.  Not only had Fairbanks "not seen the worst of it yet", but severe cold has now developed in southwestern and south-central Alaska.

This morning was remarkably cold for many locations across the south and southwest; here's a selection of minimum temperatures since midnight last night (click to enlarge):

The -33°F in Bethel and the -12°F in Homer are both the coldest since 2012, and the astonishing -35°F in Kenai is the coldest since February 1999.  Today's high temperature in Homer has been only +1°F, which is also the lowest since 1999.

Anchorage airport (-17°F this morning) was colder (-21°F) in 2024, but the high temperature so far today is only -6°F.  January 7, 2009 was the only day this century with a colder maximum temperature (-9°F).

As for snowfall, Anchorage received a hefty dump on Monday and Tuesday this week, with 19 inches in the two days.  This is the highest 2-day snowfall since March 2002, and the 5th highest on record (data back to 1953).  It's also a record for highest 2-day snowfall in January, the previous record being just 2 years ago; prior to that the greatest 2-day total in January was only 13.7" (in 1987).

The combination of cold and snow in the past week is extremely anomalous for Anchorage.  For instance, the temperature rose to only 18°F during the snow storm earlier this week, and that makes it the largest 2-day snow with a 2-day high temperature below 20°F; the previous was 16.6" with a high of 14°F, again in January of 2024.

Here's a scatterplot of weekly temperature and snowfall for Anchorage in winter; I've highlighted the latest week and the very analogous week in 2024.

Anchorage has had weeks in the past with either more snow or lower temperatures, but the combination of cold and snow right now is virtually outside the bounds of the historical climate, just as it was 2 years ago.

The interesting thing about the 2024/2026 similarity is that 2023-24 was a strong El Niño winter, but this winter we're in a La Niña.  As I've commented before, this winter resembles a "traditional" La Niña for Alaska, whereas 2023-24 was quite atypical for El Niño.

CPC's latest 6-10 day forecast indicates that the cold is likely to continue shifting westward in the coming days, and Southeast will likely continue to warm up as the flow orientation changes.  There's a lot of uncertainty after the middle of the month, however, and I wouldn't be at all surprised to see a new round of cold across northwestern Canada for the second half of January.