Tuesday, January 23, 2024

Cold Snap Begins

A significant cold snap is getting under way for interior and northern Alaska, and computer models show it deepening and intensifying in the coming days.  Here's the latest ECMWF ensemble mean 500mb height anomaly forecast for Saturday afternoon, showing a deep trough with a very cold Arctic air mass parked over Alaska:

By this weekend the air aloft will be much colder than what's currently in place, even though surface temperatures dropped into the -40s in many eastern interior locations this morning.  The initial round of cold has been generated by surface-based cooling (clear skies, calm winds) with a strong inversion: here's the 3am sounding from Fairbanks today.

The cooperative observer at North Pole 1N reported an impressive -49°F this morning, while Fort Yukon dropped to -50°F.  -48°F was measured over in Eagle, and Chicken saw -52°F.  It looks like these numbers will be exceeded without difficulty over the next week.

If we do end up with a historically significant cold spell, it will be quite unusual for an El Niño winter; Rick Thoman notes the possibility of the longest winter cold spell during El Niño since January 1973.  That was a good one: 15 consecutive days with -40° or lower in Fairbanks.


  1. Clouds moved over Fairbanks today so we saw some warming. We can deal with cold as long as electricity keeps flowing. The other issue is deteriorating air quality. Both Fairbanks and North Pole have a new Stage 2 alert. https://dec.alaska.gov/air/anpms/communities/fbks-pm2-5-curtail-alert/ At night with a flashlight visible ice crystals from power plants, vehicles, and heat sources can be seen floating about. We breathe that air and it's not good.

    1. The GFS model outlook calls for cold until ~February 6th. A couple more weeks with little change, but we know how all that can itself change.

    2. It's been some time since we had ice fog in Fairbanks. It's not bad yet...bad is barely seeing the next street light ahead.

  2. Bad ice fog is not seeing across the intersection! That happened all the time growing up here in the 70s-80s.