In a few past discussions I've noted that we have not had an across-the-board bad snow year in North America since 1991-92, fairly impressive since there were 4 of them in the 16 years through that season. 2011-12 does not make the cut on an equal region rated basis either mainly because 2 regions (Pacific Northwest and western Canada) had excellent seasons well above average. 1980-81, 1986-87 and 1991-92 stand out because no regions were above average, similar to 1981-82 and 2010-11 being the only seasons with no regions being below average.
1976-77 is still prominent despite being a huge season in the East because it was so extreme in the West. All 7 western regions were bad and for 5 of them it was the lowest overall season in 40+ years.
Unlike last year 2011-12 comes out differently if you weight by skier visits (I'm using 15 million for the natural snowfall relevant Northeast). The 2 highest regions for visits (the other being Front Range Colorado) are also the 2 with the worst snowfall. So by skier visit weighting 2011-12 comes out similar to 1986-87 and 1991-92 with only 1980-81 and 1976-77 being worse.
Details on the low snow regions:
Only 1979-80 was as low for snowfall, and given the March meltdown I think there's a case for 2011-12 being qualitatively the worst ever season for the Northeast.
Northern and Central Colorado
By snowfall 2011-12 is the worst, but there are a lot more areas with complete season data now than in 1976-77 and 1980-81. There's quite of bit of monthly data for those seasons, and comparing those I would say that 2011-12 was about the same as 1980-81 with 1976-77 being not quite as bad. During the latter 2 seasons the early season drought persisted through most of January but March snowfall was actually above average compared to the record low this year.
With Sierra volatility there have been 7 lower snow years than 2011-12. But since half the snow came in March qualitatively it was the 3rd worst behind 1976-77 and 1990-91 (more total snow but 3/4 of it in March).
1976-77 was clearly the worst but 2011-12 is similar to about 6 other seasons next in line. For slowest start through mid-January 2011-12 was probably 3rd worst behind only 1980-81 also.
Southern and Western Colorado
3 seasons were much worse and another 3 similar to 2011-12. The Southwest was the only region with decent December snow in 2011, so qualitatively those areas may have had better overall skiing than the raw numbers would indicate. I include Aspen and Crested Butte in this region but they were much worse than the areas farther south and more comparable to the areas farther east along I-70.
The U.S. Northern Rockies were overall close to average, though most areas were below average offset by a few near the Canadian border that were far above average.