Snow Depth Days
of the Northeast: 2015-2016

The season in review

The 2015/2016 snow season could almost be named The Year without a Winter thanks to warm weather into February and lack of snowfall throughout the season. Concord got off to the second latest start in its history, with the first measurable snow fall on Dec 29th. The storm brought only 4.9" of snow, and that was the biggest snowfall of the season! That was also the deepest snow of the season, but was nearly equaled by 4.5" depths on a couple days in February.

Penacook isn't really in a snow shadow, but is in the Merrimack Valley. As a result, I don't get snow until the entire air column saturates. Storms that bring snow to places like Boston often are too far away from Penacook to bring us as much snow. A closer storm often doesn't pick up as much water from the Atlantic as a coastal hugging storm does. Overall, I had the least amount of snow of everyone tracked here.

As for temperatures, the core of the season was a subzero stretch for February 12-15 which had lows of -2.4°F, -12.2°F, -13.5°F, and -8.2°F. Those were the only subzero temperatures of the entire season, only five other days went below 10°. On the other hand, in December, January, and February there were eight, one, and seven days above 50°F. That February day got up to 62.3°F!

All that brought two interesting events. Forsythia had started blooming in southern NH before the cold wave, and the buds were about to bloom here. The cold killed all the blossoms and most of the buds. Several other flower species were harmed, especially in Massachusetts.

An unofficial early sign of spring is when the Red Sox equipment truck leaves Fenway just before the start of spring training. It left this year on February 10th - I and others had trouble with this because we felt winter hadn't started!

The rest of the winter continued with the woeful snowfall and snow depths. Low temperatures in March and April hovered around freezing, so real spring conditions were slow to develop.

As for Snow Depth Days, low snowfall and above average temperatures can lead to low SDD counts, and the only redeeming event of the season was to set several new minima in my records, most notably least snowfall (22.5") and least SDDs (146), the old minima were 43.0" and 170.

Paul Venditti summarized the differences between last season and this one with this in his February report:

Note that the Winter (1 Dec-29 Feb) temperature departure was plus 5.5 F°. Last winter's three month departure was minus 4.3 F°!

Note also that February last year averaged 12.6 F°, or 16.6 F° colder than this February!

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 0 12.5 46 14.4 72 3.2 4 4.4 5
Marlboro MA 1.2 4 8.4 26.5 16.2 77.5 4.7 6 6.5 9.5
Pepperell MA 3.3 7 7 63 17.7 92 6.5 2 8.7 8
Poland Spring ME 0.6 1 5.3 13 10.8 128 14 87 4 3 4.4 4
Bow NH 4.8 12 9.5 130 12.5 156.5 3.8 13 4.4 7
Bristol NH 5.9 15.3 7.9 161 10.1 54 1.7 1 3.4 2.4
Penacook NH 4.9 14 5.6 70.5 7.7 58 1.5 1 2.8 2
Mt. Mansfield VT 3 8 8.6 55 15 80 26.9 574 16.9 741 10.9 909 15.9 896 5.6 388

2015-2016 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
Quotient
Fairhaven MA 35 127 3.6
Marlboro MA 37 123.5 3.3
Pepperell MA 43.2 172 4.0
Poland Spring ME 39.1 236 6.0
Bow NH 35 318.5 9.1
Bristol NH 29 233.7 8.1
Penacook NH 22.5 145.5 6.5
Mt. Mansfield VT 102.8 3651 35.5

Contributors

Name Location
Dennis Bollea Fairhaven MA
Wayne Cotterly Poland Spring ME
Steve Gunn Bristol NH
Paul Hansen Marlboro MA
Jim Hilt Bow NH
Chris Seeber Charlestown RI
Paul Venditti Pepperell MA
Ric Werme Penacook NH

Credits

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.

Musings

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: 2016 June 18
Ric Werme

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