Snowmaking in the Northeast often begins in October, but it is usually difficult to expand open terrain over the next month. Rain is frequent enough in November that it is rare for anyone to get as much as 50% open. The 2002-03 and 2018-19 seasons were conspicuous exceptions in staying cold more consistently in the early season. Natural snow was actually below average in 2002-03, but the season scores well because temperatures stayed below freezing until mid-March. Many would argue that the quality of eastern skiing is more temperature dependent than snowfall dependent.

For the Vermont areas analyzed here natural snow is a much more important part of the equation than elsewhere in the East. Off-piste glades become safely skiable on about a 40-inch base (usually attained early January through late March) and there is often ample powder skiing when it snows during this period. The scale of areas like Stowe and Mad River Glen (as well as the gladed terrain) is similar to SoCal's Mt. Baldy. But the higher average, and more important greater consistency of snowfall in Vermont results in many more powder days. The 2000-01 season, which averaged close to 400 inches in Northern Vermont and over 500 at Jay, is illustrative. The 13 Vermont weekends rated A in 2000-01 are nearly double the best seasons in Southern California and comparable to average years in Whistler or Colorado. The 2011-12 season had been the worst on this chart before 2015-16. Northern Vermont's natural snowpack was subpar but was never taken down by big midwinter rains and only collapsed during a record March heatwave. Elsewhere in the Northeast 2011-12 was comparable to the prior worst ever season in 1979-80. 2015-16 broke many of the record low snowfall records from 1979-80, and in addition was plagued with numerous rain and thaw episodes. There were no weekends with full operation on packed powder conditions in 2015-16, while all other seasons since 2000 had at least 3 such weekends.

In the late season the warmer weather and more frequent rain curtail Vermont skiing much faster than in the West. Even with the huge snowpack of 2000-01 or the big April dumps in 2007 the natural snowpack was marginal for skiing by early May. Overall this chart confirmed my gut feeling that "an average season in Vermont is comparable to a good season in Southern California," with a score of about 35 (before powder adjustment). But 35 is also the score of the worst ever seasons at Alta and Whistler. 2015-16 was the only season in Vermont comparable to a poor season in Southern California.

Other Eastern Regions
1) Snowmaking leaders with mostly intermediate runs, places like Hunter Mt., Okemo, Sunday River. Early season profile is similar to the chart. Fewer A's midseason due to half as much natural snow, more limited spring operation, average score probably around 30.
2) Upstate NY, New Hampshire and Maine areas with terrain similar to the charted Vermont group, but snowfall is typically less than 200 inches, examples Whiteface, Wildcat, Sugarloaf. Slower to get covered early, harder to keep covered with less natural snow (or wind exposure in the case of Wildcat), average score probably around 25.
3) Quebec has multiple regions. The Townships (Sutton, Orford) are the extension of Vermont's Green Mountains though at lower altitude. Snowfall around 250, probably scores 30-35. The Laurentians (Tremblant) are colder than New England but get no more than 150 inches natural snow. Likely score 25-30. The Quebec City area (St. Anne, Le Massif) is equally cold but more snow, overall 200 inch average, likely score 30-35.
4) Southern New England and mid-Atlantic areas are lower and often on the wrong side of a rain/snow divide. Average score at most areas no more than 20. Snowshoe has high altitude for the East and a bit more natural snow, probably scores at least 25.

More Snow Conditions Charts
Mammoth/Sierra Nevada
Fernie and Whistler
Utah
Colorado