With a deep trough and cold air aloft, light snow continued on and off last night and for much of today in Fairbanks-land, and it has actually been piling up on the higher hills outside of town. Remarkably, the SNOTEL instrument on Munson Ridge (3100' elevation) has reported a gain of more than an inch of liquid equivalent in the snowpack, and a 7" increase in snow depth, since Saturday.
The current snow water equivalent of 18.6" is a new all-time record for the Munson Ridge site, with data back to October 1980; the previous record was 18.4" at the start of April 1991. For the month of May, it's a record by a larger margin (previously 17.1" in early May 2018).
Consider this: the 18.6" of water now on the ground at Munson Ridge is equivalent to the annual precipitation in Fairbanks' wettest year of record (last year, 18.74"). It's all going to be coming downstream in a matter of weeks.
Down at valley-level it has been too warm for additional snow accumulation today, but yesterday's official total of 1.2" is the largest snowfall this late in the season in Fairbanks since 1992.
The number of hours of snow falling is very unusual too: 25 hourly observations reported snow falling (sometimes mixing with rain) yesterday and today, and only 3 other years have managed this feat after the first week of May: 1992 (90 hours), 1964 (44 hours), and 1966 (30 hours after accounting for the 3-hourly spacing of obs at that time).
Here's this morning's 4am AKDT balloon sounding from Fairbanks, showing the steep lapse rate that has made it easy to produce recurring snow showers.
Here's the 500mb analysis from the same time, courtesy of Environment Canada.
The recent snow in Fairbanks arrived in small packages...localized and periodic squalls rather than a single event. It would snow or rain some, quit, then another small cell of precipitation would pass over the area generally from the SW. Local radar captured the event quite well.
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