Blowing Snow Climatology

First a note on the late winter cold snap that is unfolding at the moment.  Fairbanks dropped to -46°F yesterday morning and -48°F this morning, a remarkable intensity of cold for this late in the winter.  This morning's low temperature is in fact the coldest observed this late in winter since 1956, and few events can rival it.  Here are the most notable cold readings at similar dates in the 1930-present Fairbanks history, with the 1932 and 1964 events surely being the most anomalous:

Feb 20-28, 1932   -50°F or colder for 9 consecutive nights

Feb 23, 1933   -49°F

Feb 26, 1954  -50°F

March 1, 1956  -49°F; -45°F on the 8th

March 15, 1964  -46°F

Two more nights of intense cold are possible before the current chill eases.

Looking back at the past couple of weeks, there were two episodes of sustained blowing snow, which is very uncommon in the sheltered Fairbanks bowl.  Last Thursday the airport reported blowing snow for 15 straight hours, which appears to be the second longest uninterrupted duration of blowing snow observations since hourly observations began in 1948.  The record is 17 straight hours exactly 15 years earlier, in late February 2011.

Then on Tuesday another 8 hours of blowing snow was reported as the cold air moved in after the snowfall.  That takes this winter's total to 25 hours, including a brief episode in January, and the historical data shows this is close to a record - see below.

The pronounced drop-off in blowing snow from the mid-1970s through 2005 is very striking, and at first glance it's tempting to ascribe this to changes in observational practice.  However, the PDO may again be a plausible explanation, as the PDO flipped positive in 1976.  There does seem to be a correspondence between heightened frequency of blowing snow and the most negative PDO periods of 1950-1956, 1970-1975, 2008-2013, and 2021-present.

It's also interesting to observe that blowing snow is easily most common (least uncommon) in the month of February, both in terms of total number of hours and number of unique days and years when it occurs - see below.

I would welcome suggestions for why February is particularly favored for blowing snow, because the wind is not significantly higher than earlier winter months; the frequency of strong breezes (e.g. 15 knots) is barely any higher than December.

Without being an expert on snow pack properties and the physics of blowing snow, I'd suggest that the return of significant solar warming in February may be a key factor, allowing the snowpack to warm from its midwinter lows.  As for March, the stronger winds might be expected to produce still more blowing snow, but by that time the sun is often warm enough to melt the snowpack surface, forming a hard crust, and the frequency of blowing snow drops back again.  March also tends to be the driest of the winter months, so there's less new snow to blow around.