Monday, April 5, 2021

Rare Snow Onslaught

Winter is putting on a remarkable final act in Fairbanks-land, with extraordinarily heavy snowfall in the past several days - especially for the time of year - and very unusual cold.

First, the cold: the high of only 11°F on the first of the month in Fairbanks was the lowest daily maximum temperature in April since the remarkable events of 2013.  Today has seen similar temperatures, but it felt even colder with a very stiff breeze.  And still colder conditions are on the way; the National Weather Service is going for just 4°F on Friday, which would be the coldest daytime high on record for so late in the season (1930-present).

As for snow, Fairbanks is up to 16.7" in the first 4 days of the month, which already makes this the snowiest April since 1948.  The two-day total of 13.2" marks the first time on record that more than a foot has fallen in a two-day period in April.


Late winter and spring are typically the driest time of year in Fairbanks, so it's really noteworthy that 1.2" of liquid equivalent precipitation fell in the two-day period.  There have only been 4 other events in 90 years when more than 1" fell in two days between late January and late May, i.e. during a period spanning one-third of the year.  Three of these involved a rare snow onslaught like the current event, bucking the seasonal normal:

- March 23-25, 1963: 20" of snow in 3 days, snow depth went from 18" to 35"

- Feb 11-13, 1966: 35" of snow in 3 days, snow depth went from 20" to 52"

- March 23-25, 1991: 21" of snow in 3 days, snow depth went from 39" to 54"

1966 and 1991 were the only winters since the 1930s that saw a snow depth above 50".  Last night's snow depth measurement came in at 40", which is the greatest since 1993.

It's also worth noting that this event produced the most two-day precipitation to fall as snow since the March 1991 event; so it's been 30 years since a snowstorm of this character occurred in Fairbanks - at any time of year.  (Late September 2015 saw more than a foot of heavy wet snow, but about half the total precipitation fell as rain.)

Here's the webcam view from the University of Fairbanks this afternoon: not very spring-like.


  1. Late season cold-snow-thick ice can create flooding issues when it eventually warms up. Might be a bad year for some folks that live near low valleys and rivers.


    1. Yes indeed, a dynamic breakup is now much more likely. It's hard to imagine an uneventful melt season.

  2. Is this event an 80 year event?? Or is recent weather is so dissimilar to known patterns that it is really not possible to say that. At least until we can look back at this event several years from now.

    1. Very difficult to say, because recurrence interval depends strongly on exactly what the "event" is - plus this time of year has such rapid change that outliers are more difficult to describe statistically. The two-day snowfall was the highest on record for April, but in terms of cold the event was on par with a few other spring cold snaps.