Snow Depth Days
of the Northeast: 2014-2015

The season in review

November saw the first big storm of the season, Penacook had a 10 inches with wet snow that brought extensive damage to trees and power distribution. We lost the main shade tree in our back yard, a Norway Maple the previous owners planted for some quick shade.

December was much milder and quieter, with the largest event bringing only 1.5". Snow cover held on through the 24th, so Christmas was not white. Activity picked up a bit in January, snow cover returned on the 3rd with the first of several small events. The "Blizzard of 2015" wasn't here, we had only 8.5", but much greater snowfalls weren't far away.

A cold January brought 7 days of sub-zero low temperatures and 9 more from 0-10 days. January 2014 had 6, and except for the common -11.2°F in both years, 2015 was colder.

A cold February brought 12 more sub-zero lows and 11 0-10 days (including three days with 0.1°F lows).

March brought 2 more sub-zero lows and 4 0-10 days. Relief, but with the high temperature for the month being only 55.7, it was still cold.

How cold was February really?

Comparing February to past Februaries shows that 2015's was really, really cold. In fact, the month was very similar to February 1934, the coldest month by far in New Hampshire's record. Until now.

Here are the extreme low and high temperatures for February in my records:

Yearmin
low
max
low
min
high
max
high
2004-7.930.921.453.1
2005 0.130.319.255.3
2006 0.737.219.459.2
2007-1.826.414.044.8
2008-7.933.121.647.7
2009-0.633.815.956.9
2010 8.837.826.947.1
2011-8.433.417.860.5
2012 9.230.319.252.6
2013 4.732.219.451.4
2014-5.929.021.651.4
2015-16.619.4 7.037.5

2015 wins in all four cases vs. the second most extreme:

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
Collinsville CT 6.8 23 2.1 2 16.8 97 31.3 529 10.3 440 0 11
Fairhaven MA 2.2 1 0.3 0 23.2 89 35.8 509 18.9 325
Marlboro MA 4.1 13 1 0 37.7 147 45.9 806.5 6 494 0.2 15
Pepperell MA 10.8 35 1.5 19 40.4 171 52 812 8.1 547 0.6 20
Poland Spring ME 17.1 49 6 52 38.9 209 29.3 702 2.7 510 2.8 17
Bow NH 15.5 57 3.8 83 24.1 160 47.4 723 6.6 652 2.3 114
Bristol NH 13.3 38.5 10.6 183.5 21.6 205.5 36.5 636 4.9 444 4.2 12.3
Penacook NH 12.7 38.5 3.8 53 20.4 134 37.2 567 4.1 410 1.5 12.5
Mt. Mansfield VT 1.2 0 31.7 149 25 777 33 1468 42.6 2039 21.7 2582 19.3 2371

2014-2015 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
Collinsville CT 67.3 1102 16.4
Fairhaven MA 80.4 924 11.5
Marlboro MA 94.9 1475.5 15.5
Pepperell MA 113.4 1604 14.1
Poland Spring ME 96.8 1539 15.9
Bow NH 99.7 1789 17.9
Bristol NH 91.1 1519.8 16.7
Penacook NH 79.7 1215 15.2
Mt. Mansfield VT 174.5 9386 53.8

Contributors

Name Location
Dennis Bollea Fairhaven MA
Wayne Cotterly Poland Spring ME
Paul Hansen Marlboro MA
Jim Hilt Bow NH
Andrew Plona Collinsville CT
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: 2015 December 31
Ric Werme

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