Is Global Warming Killing Snowfall?

UPDATE: Blog reader Tom also recommends these articles (which I haven't read yet):

ORIGINAL POST:

I received a couple of questions this week from blog readers regarding the lack of snowfall lately and its relationship to Global Warming.

- Emiliano from Argentina asked about the lack of snowfall here in State College, PA during the last year, and the continued warm pattern over the Northern Hemisphere, and could it all be related to Global Warming.

- Donald, who plows snow on the west side of Boston, Massachusetts pointed out that they haven't been able to plow for 10 months (since Feb. 13). He wants to know if this has happened before, will it happen again this year, and how are El Nino and Global Warming involved?

I'll tell anyone who will listen that I'm not a Global Warming expert. AccuWeather has no official opinion on Global Warming though we do have a Global Warming blog which is trying to examine both sides of the issue. So when it comes to explaining the relationship of El Nino and other various indexes, and Global Warming, I'm not the guy to ask.

So instead what I'll do is look at the historical weather data for the last 40 years, which is probably the most time that most of us can recall. I've talked to our Forensics Folks to get ahold of some tools to look at historical snowfall for State College and Boston, because there isn't an easy way to access it on the web.

YEARLY SNOWFALL IN BOSTON, BEDFORD & STATE COLLEGE

When you graph out the yearly snowfall amounts (note - this is calendar year, not season. so the amounts themselves are not important but the trends are), you don't see much of a pattern. I've added 6-year moving average trend lines to try to smooth out the graphs. Note also that there are several years of missing data for Boston in the late 90's, which is why I added Bedford, which is to the west of the city (probably more where Donald works), and for State College in the mid 1970's. This will make the trendlines inaccurate.

The best thing I could say looking at these graphs is that there was a general decreasing trend in yearly snowfall in Boston and State College from the mid 1970's to the early 1990's, but then there was an increase in the mid 1990's and again in the mid 2000's. So technically snowfall has increased at both locations since 2003, though last winter featured abismally low totals and an early end to the season (only 9 inches from January to April here in State College), and as Donald points out, pretty much nothing in the Boston area after 2/13/06. Abismal, but I can't say how unusual that is, without pouring through the monthly data.

I guess what I'm trying to say is: Don't let one year spoil you into thinking that Global Warming is taking all your snow away. When you look at the big picture, for snowfall anyway, the last few years really aren't that different. (Snowfall is not a great predictor of Global Warming anyway because it's so exaggerated compared to rainfall, which really matters more to the earth).

For another opinion on this topic, consult Cory Pesaturo's diatribe written in February 2006 "Southern New England Snowfall: Is Something Happening To The Winters?" He has some interesting comments on whether the volatility of storms is changing, despite the trends of yearly snowfall.