And if we examine the winter with the last big snow (2010-11) a bit further, we find that it was not a particularly good snowfall winter either, thanks in part to a lot of very small events and one larger melty one.
So, in reality, we’re now three years removed from experiencing a snow season worth talking about. Perhaps getting that all-time record snow record (56.1 inches) in 2009-10 wasn’t a good thing?
As Jason noted on Monday, we’ve had 6 snow accumulation events (0.1”+ snow) on the winter, yet D.C.’s official snowfall total is an abysmal 1.5”.
That brings us out to an average snow event of just one-quarter inch. Dusting central.
First, let’s start with some good news. If you take an average of the last 30 winters before this one, we can expect about 6.2 accumulating snow events per winter. With at least a handful of weeks left, we’re already there this season! Overperformer?!
Of those seasons with six or more accumulation events, this one is running well below the lowest in terms of average snow amount per event. 1988-89 was closest to our current average, averaging 0.71 inches per event for the 8 events. This biggest “storm” that winter produced 1.2 inches.
This season still has several weeks to go at the least, but even if the next event is a 4 inch snowstorm, we’d only barely get past that 1988-89 mark. A 5 inch snowstorm would catapult us past 2010-11’s similarly pathetic 0.8 inch event average — 12 accumulation events that year, with only Commutageddon being of real note.
If we’re able to hold an event average below 1 inch, it would be the first time in history we’ve had three seasons with that distinction in a row.
The lowest seasonal event averages, 0.1 inch in 1972-73 and 1997-98, both consisted of only one accumulation event. 1926-27 has the closest average to this year (so far) with 0.46 inch per event, out of five events, though the max was more than five times higher this year’s 0.4 inches at 2.2 inches.
Half of the National Airport winters (34 of 68, including this one) have brought what I’ll call “warning snow.” Warnings for snow begin at the 5 inch mark over a 12 hour period, though it can also be verified by 7 inches over 24 hours, or via a mix of hazardous ice and snow. Here, warning snow is a 5 inch snowstorm.
Despite our historic lack of a 2 inch or greater snowstorm, stretches such as the current one without warning snow are not uncommon.
Two others of similar or longer length occurred during the 2000s. At National, there have even been two stretches with 4 winters in a row that did not feature warning snow. One came back in the late 1940s into early 1950s.
Overall, in the last 30 winters D.C. has averaged 0.8 warning events a year, though they tend to clump and come in multiples for years that have them. Snowy 2009-10 had 4. 1960-61 leads the group since the mid-1940s with 5 such events.
Though it might seem hopeless as a snow lover, we’ve still got some prime snowstorm climatology ahead — cough Presidents’ Day 2003 — for good snow. We also can “expect” about five and a half inches on average, from tomorrow through the rest of the season.
Can we get it done before the clock runs out?