Snow Depth Days
of the Northeast: 2010-2011

The season in review

Last year we had an El Nino, this year a La Nina. We also have negative North Atlantic and Arctic Oscillation, like we did last year. That helped keep the storm track south through the mid-Atlantic states and their "Snowmageddon" season. (Hey, if we can't have snow, Washington DC is a good place to send it.) It also forced storms up the coast and back into Canada, so what would have been cold snaps were quite a bit warmer than they might have been.

Some of the same may happen this season, but Joe D'Aleo is looking for more snow in northern New England than last year.

Through November there was little snow. Penacook seemed to be a local maximum for a 0.8" show shower (hardly a squall) on the 27th, and there was a little in southern New England a couple weeks before. December was bare until the 23rd, when a 1" snowfall gave us a very marginal white Chrstmas. Two days later a 7.7" storm finally made it look like Christmas.

Snow continued in January, a 16.6" on the 12th and no thaw during the month made it look and feel like mid-winter. Several of the storms went south of Penacook and were crippling storms in southern New England and New York City area.

Daily/Monthly Data

The following table summarizes the snow fall and depth days from sites that are posting that data on local weather observations mail lists and a couple others. If people also prepare Web pages for daily information for their site, I'll include links to them. Cells under the "snow" column are the snowfall for the site in that month, under "SDD" are the depth days for the month.

Location October November December January February March April May
Snow SDD Snow SDD Snow SDD Snow SDD Snow SDD Snow SDD Snow SDD Snow SDD
Fairhaven MA 0.5 1
Marlboro MA 0 0 15.4 70.5 39.2 390.5
Pepperell MA 0.1 0 9.6 38 38.2 314
Poland Spring ME 0.3 0 14.9 71 29.4 333
Bow NH 0.6 0 9.1 34
Penacook NH 0.8 0.5 8.6 31 36.6 362
Charlestown RI 1.6 1 8 26 30.9 226
Woonsocket RI 0.6 0 15.7 61 38.2 375
Mt. Mansfield VT 23.1 96 8.2 120 44.5 724 35.2 1288

2010-2011 season to end of last month

The persistence quotient is lower than the ultimate value if there is still snow on the ground at the site. This data will be updated each month.

Location Snowfall Depth Days Persistence
Fairhaven MA 0.5 1 2.0
Marlboro MA 54.6 461 8.4
Pepperell MA 47.9 352 7.3
Poland Spring ME 44.6 404 9.1
Bow NH 9.7 34 3.5
Penacook NH 46 393.5 8.6
Charlestown RI 40.5 253 6.2
Woonsocket RI 54.5 436 8.0
Mt. Mansfield VT 111 2228 20.1


Name Location
Dennis Bollea Fairhaven MA
A Cadoret Woonsocket RI
Wayne Cotterly Poland Spring ME
Paul Hansen Marlboro MA
Jim Hilt Bow NH
Andrew Plona Collinsville CT
Jot Ross Ashland MA
Chris Seeber Charlestown RI
Rick Tracy Groveland MA
Paul Venditti Pepperell MA
Ric Werme Penacook NH


Jim Corbin, a meteorologist from Rhode Island, proposed the concept of both snow depth days and the persistence quotient, but he didn't have good names for them.  After a bouncing around various ideas, I came up with Depth Days.  It seems to fit into colloquial speech well, e.g. "When mired in the Depth Days of February, she thought fondly of the Dog Days of August." Of course, none of us snow lovers would ever think that. I picked Persistence Quotient while putting this page together, we'll see how it wears with time.


I think depth days is a great statistic, and I'm surprised that it is catching on slowly outside of the NE Weather Spotters mail list. I never expected that the NWS would embrace it quickly, but I had hoped that TV meteorologists would start using it, in monthly summaries, if nothing else. It would be nice if ski areas would use it, but they may not wish to if they are not likely to be #1 consistantly. (And if only one area reports depth days, it would not be a good comparative statistic.) The University of Vermont has graphs of snow depths at Stowe through many seasons.

Last update: 2011 February 3
Ric Werme

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