Snowfall is highly variable from year to year around southern New England, and, for that matter, all of New England. There is about a 100-inch range between the highest and lowest snow totals in the record books for much of New England, including Worcester and Boston.
Think about that for a moment: The difference between a year with little snow and one with a lot of snow is nearly 8 feet.
Massive Swings in Accumulation Are the Norm
In Worcester, there are an equal number of years where snowfall was under 30 inches and above 100 inches, and in Boston, we find 8 years with snowfall over 80 inches and 5 years where snowfall was under 15 inches. The average snowfall at Logan Airport is a few inches over 40, but increases to the mid 60s when you arrive at the Worcester hills, where the region often sees 20 percent more or less than those average numbers.
The chart below shows how much snow has fallen in Boston since the late 1800s. Notice how highly variable it is ó this is what makes forecasting the total seasonal snowfall so difficult.
Global Fluctuations Are the Key
The reason behind the range is, of course, the highly variable track of storms and the amount of cold air present during them each winter. Snowfall tends to cluster in extremes. There are snowy months and not-so-snowy months. There have been many Decembers with under an inch of snow in Boston and still many others with over 18 inches. Each year brings about wild swings in snowfall and makes predictions quite difficult.
How Much Snow Will We Get This Winter?
Last winter, we all know snowfall was very low from November to the middle of January. The snowiest period during that time was actually around Thanksgiving. It wasn't until the third week of January when the snow came, and then it didn't stop for 6 weeks. However, the snow and precipitation in general also shut down rather rapidly with drought conditions showing up by May.
This December will also likely have less snow than average, but this doesn't mean a repeat of last winter. Typically, we see 8-14 inches of snow across the region in December.
Here, you can see how snowfall typically stacks up in an average season:
The big factor at play this winter is El Nino, which tends to bring less snow and fewer arctic outbreaks to the area. El Nino also tends to peak in December and then lose its influence as winter progresses. Many El Nino years have the bulk of their snowfall later in January and February, similar to last season, but significantly less overall.
El Nino and other factors such as the Arctic Oscillation and North Atlantic Oscillation are raising the odds of a year with less snow than average.
The maps below show how much snow typically falls across the region, and what I am expecting this year:
The idea is snowfall should be near or under average ó and not above. This is my best estimate on snowfall putting all the factors together. These types of forecasts donít have a high degree of accuracy because I am attempting to forecast for a very small area. My expertise lies in short- and medium-range forecasting, but I still like dabbling in the longer range stuff as well.
Last winter, while eastern Massachusetts, southern New Hampshire and coastal Maine had enormous amounts of snow, the inland and northern areas had average and even below average snowfall.
Two storms tracking 50 or 100 miles in one direction or another can raise or lower snowfall totals by a foot or more, and an El Nino lasting a bit longer or not as long as forecast can also change predictions and the ultimate outcome.
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