In reply to rodw:
Lochnagar can be very fickle conditions-wise. Due to the large plateau any wind with a westerly component usually results in much of the main sector becoming swamped in powder, which apart from creating very arduous and insecure climbing can obviously insulate the turf etc. A true northerly can create very nice mixed conditions in the southern sector - buttresses rimed and powder mostly blown off. Winds with an easterly component create better mixed conditions in the main sector. A large build up and plenty of thaw-freeze is required for good nick in the gullies although lean and very cold can give good sport in Raeburn's.
I agree there's usually something climbable but it's a long way for a consolation route...