The Sierra had the most snow in October since at least 1945. These storms also dumped substantial snow in Utah. Thus Mammoth, Kirkwood, Brian Head and Utah's Cottonwood Canyons were in full operation with excellent conditions for Thanksgiving. November snowfall was well below average throughout the West until a strong last week, so skiing is still limited in other regions.
California: The October storms centered on Mammoth, which has had 109 inches of snow (82 in October) and is now 100% open on a 4-6 foot base with excellent conditions.
Kirkwood has received 121 inches and is 70% open, and Squaw has had 85 at 8,200 ft. and 38 at 6,200 ft and is 40% open. Alpine Meadows, Heavenly and Northstar are all about half open.
Alpine Meadows, Boreal, Sugar Bowl and Sierra-at-Tahoe were open at least on weekends since Halloween. The Sierra was refreshed with over a foot of snow last weekend.
See Current California Ski Conditions for more details on Southern California and Mammoth. Arizona Snowbowl is in full operation, very rare for November.
Pacific Northwest: November storms had fairly high snow levels and thus have been mostly rain in the ski areas. Whistler has had 47 inches snowfall and is 15% open. Mt. Baker (8% open) and Mt. Bachelor (18% open) are the only other areas open.
Canadian Rockies and Interior B.C.: Lake Louise is 11% open on snowmaking and 25 inches snowfall, and Sunshine is 50% open. Big White and Silver Star are 35% open and Sun Peaks 65%.
U. S. Northern Rockies: Targhee has had 74 inches snowfall and is 75% open. Big Mountain has had 54 inches and is 19% open. Big Sky is 20% open.
Utah: 4-8 feet of snow fell in October. Alta, Snowbird, Brighton, and Solitude and Snowbird are all 90+% open with 6 foot bases and excellent conditions after another 3 feet last week.
Season snowfalls: Alta 182, Brighton 156, Snowbird 166, Snowbasin 88, Brian Head 152.
Park City is 39% open and The Canyons 20% on about half the snowfall of the Cottonwood Canyon areas.
Northern and Central Colorado: After a slow start these areas got 2-3 feet last week. Breckenridge is 14% open on 66 inches snowfall, Copper 33% on 61 snowfall, Keystone 25% on 55 snowfall, Loveland 23% on 61 snowfall,
Steamboat 30% on 68 snowfall, Vail 15% on 68 snowfall, and Winter Park 12% on 66 snowfall.
Southern and Western Colorado: Wolf Creek is 100% open on 97 inches of season snowfall, 3 feet last week. Durango is 25% open on 67 inches snowfall, and Telluride is 30% open.
These areas are somewhat ahead of schedule on the early season Southwest storm track. Further north Aspen/Snowmass is 20% open and Crested Butte 24%.
Northeast: November 9 was Killington's opening day, same as last season, and the East continued to struggle with frequent rain in November. Season snowfall has been a paltry 11 inches at Jay and 8 at Sugarbush.
Current percents open: Jay 2%, Killington 10%, Okemo 20%, Stowe 6%, Sugarbush 6%, Stratton 14%, Sunday River 9%, Sugarbush 7%, Hunter 7%, Mt. St. aAnne 5%, Tremblant 12%.
I strongly recommend checking First Tracks Online Ski Magazine No-Bull Ski Reports for up to date information in this region, where both weather and surface conditions can change so rapidly.