Turning Wintry

Snow has been on the ground in Fairbanks since late last week, and at this point it is unlikely to melt out, despite a warm forecast for Halloween.  (Temperatures are expected to get above freezing in the next couple of days, which is unusual for the time of year, but not extreme - it was 48°F on Halloween 4 years ago.)

Other than the great chinook and "brown Christmas" events of 1934, the latest date in the year with at least two inches of snow on the ground that subsequently melted out in Fairbanks was October 26 in 1940.  So if two inches of snow is observed at the end of October, it's almost certainly safe to remain there until spring.

Here's the history of snowpack onset date in Fairbanks; this year's presumed date of October 24 is not unusual.  1934 and 1992 were the two big outliers.

Temperatures have been dropping off statewide since I posted about "lack of cold" on the 18th, driven by rather strong troughing from the Bering Sea to the Gulf of Alaska:

Interestingly, Utqiaġvik yesterday dropped to -10°F, and the daily average temperature was below 0°F for the first time in October since 2018, and before that since 2002.  Until the mid-1990s, a daily mean temperature below 0°F in October wasn't at all unusual, occurring in more years than not, but this is only the fifth such day since 1996.

Looking back at autumn in Utqiaġvik, it's interesting to observe how little unusual warmth there has been in comparison to the past decade.  It looks like the October and September-October averages will be the coolest since 2015, but of course that's still well above the normal of the 20th century.