Sunday, May 19, 2013
Weather is highly variable from place to place and of all the weather variables snow is one of the least consistent. Depending on where you are in New England this winter your total snow thus far could be within an inch of normal or as much as 66% below normal. It is becoming more evident that the winter of 2012-2013 is not going to be a blockbuster snowy one. However, depending on where you are snowfall for this winter might end up being right on track.
Back in October when I was thinking about how much snow we would end up with in Portland, I forecast around 55 inches of snow would fall or about 10% less than normal. So far, Portland has seen 35 inches of snow almost exactly what the average would predict. Contrast this with Boston, one of the least snowy places in New England this year. They have yet to break the 10 inch mark of total snowfall and they are nearly 70% below normal on snowfall. There are several factors that have thus far contributed to a low snow year along coastal southern New England.
One of the biggest reasons for the huge difference is that warmer ocean air turned two or three snow making storms into rainy ones. Our snowy December was a rainy wet one to the south. Since the start of the year snowfall has been much less than normal in all of New England. While January is our coldest month it also produces significant snowfall. This January the cold came, but not the snow. Too much dry air from Canada kept the moisture to our south and out to sea. The only reason our snow totals are not looking lower is that we had a very snowy December.
Some of you might wonder what the rest of winter will bring in terms of snowfall. If we get deep into February without a major storm the odds rapidly grow that we won't have a major storm the rest of winter. The reason for this is that persistence is a very powerful tool in forecasting. Persistence is the idea that once patterns take hold they are difficult to dislodge. Last summer when the drought began across the Mid-West it was unlikely it would break until the winter or following spring.
Two winters ago when New England saw many places with close to 100 inches of snow the pattern got "stuck" in a snowy regime. During the winter of 2011-2012, a warm and dry pattern locked in place starting in November and lasted all winter. I would argue that last winter's pattern is still somewhat in place, having only broken for the December snow and cold of January. February and March have provided some of Maine's biggest snow storms. Across ski country February 15th to March 21st brings some of the largest snow totals of the winter. It can certainly still snow a lot more this winter, but the window of time is going to begin to run out quite soon.
David Epstein has been a meteorologist for more than 25 years. He spent 16 years in Boston and currently freelances at WGME13 in Portland.
In 2006, David founded GrowingWisdom.com, a business producing educational and marketing videos for the green industry. He currently is a professor at Framingham State College, teaches Jan Plan at Colby College and owns Bloomscapes Inc., a landscape design business.
David authored "Gardens Of New England" and his work has been published in Grolier's Science Annual for 10 years. He lives in South Natick, Mass., and has a summer home in Harpswell.