Tuesday, February 19, 2013

Heading Into The Backstretch Of Winter

Snowfall in the latter stages of the season is fickle, often fleeting, but can be rewarding with large heapings of snowfall. Every so often, a late season bonanza of snowfall can hit the region and produce a significant, if not large amount of snowfall in the Delaware Valley. Of course, many years don't feature much of anything other than rogue coatings or maybe an inch of snow.

Over the last twenty years, the date of the average last snowfall of at least a tenth of an inch at the Airport was March 14th. We haven't had a March "last snowfall" since 2009 (the tail end of a March 1st-2nd snowstorm that brought nine inches of snow to the Airport) and four of the last five years have featured no March accumulating snows. Traces certainly occurred at spots along the way and on April 1st, 2011, a couple of inches of snow fell across the north and west suburbs from a disturbance that coated the region. However, as far as the Airport is concerned it's been since April 5th, 2006 since the last April snowfall in the city but since 1993, six years featured an measurable April snowfall -- 2006, 2004, 2003, 2000, 1997, and 1996 -- six in eleven years!

Average date of last measurable snowfall (defined as at least 0.1") plus dates of first & last snows.

Snowfall averages after March 1st dwindle quickly -- the city only averages 3.3" of snow here on out for the balance of the cold season, with 2.8" of that falling in March and the other half inch in April. March is a common "last blast" of winter -- 1993, 2007, 1962, and other years have blanketed the region with decent to hefty snows...or in 2007's case, sleet. In other years, trace amounts are more common and are typically the rule in most months of March and April.

In fact, we haven't had a year without a trace of snow in either March or April since 1946. It's been a while...although getting more than just conversational flakes floating through the sky has been a rarity the last few years.