Boreal opened briefly with 2 runs in mid-October, only to suspend operations on Friday. A storm blew across the Donner Summit on Sunday, leaving the first signs of real snow and giving hope for Thanksgiving week skiing.
Boreal reported 8-12 inches of fresh power and will re-open on Tuesday. A handful of resorts will open Thanksgiving week, with the rest following in December.

Updated 11/12:

Heavenly: Nov. 19 (15″ base)
Kirkwood: Dec. 18 (32″ base)
Sierra at Tahoe: Nov. 27 (14-18″ base)

Alpine Meadows: Dec. 10 (11-15″” base)
Boreal: Nov. 9 (8-10″ base)
Dodge Ridge: Nov. 27
Donner Ski Ranch: Dec. 18
Granlibakken Resort: TBD
Homewood: Dec. 18
Northstar at Tahoe: Nov. 20
Soda Springs: Dec. 18
Squaw Valley USA: Nov. 20 (3-14″ base)
Sugarbowl: Nov. 25 (5-8″ base)
Northstar at Tahoe: Nov. 19 (5-13″ base)
Tahoe Donner: Dec. 10
Diamond Peak: Dec.16
Mt. Rose: Mid-November

All dates are based on snowfall and could change. Check with the resort before you go.