If you want to ski in early December it is always going to be a little chancey. Book your air, don't worry about the hotel until the last minute, because if you are going to ski SLC, the best choice, there will be plenty of rooms no worry. If it turns out to be a terrible year, then you can simply cancel and reschedule at the last minute for $150 on Delta.
I always jot down a few notes after my trips.
12/3/06 - ONLY 40" base but skied just fine. Want to know the truth about how the Bird skis on a 40" base, check out these pictures from post after early Dec 06.
SNOWBIRD IS AMAZING!!!! Scroll down and look at all the 40" base pictures in that thread.
Scroll to bottom to see snowfall that resulted in those pics http://www.alta.com/pages/snowhistory_past.php?pastseason=20062007
Looking at these snowfall total number, i think you need 100" of snowfall to produce a 40" base to make it worthwhile. Much of the hill will be open then, with a few rocks to watch out for.
12/7/07 2nd worst start in 42 yrs. Only had a 30" base befure until it started snowing 5pm day before, they reported 7" but there was 24" new off Wildcat and Collins. Snowed all day.
12/8/07 Snowbasin - only Needles open, but new snow made it all nice with gullies skiable
12/9/07 - 12" fresh on Gadzoom.
For that 07 trip, I was oh so close to canceling it, but we had a 4 ft falling as we came in that made our trip very, very nice. From my personal experience, I would say if you have a 40" base at Snowbird/Alta you will be happy with your early season trip, 30" is too low. Don't schedule the 1st weekend, but the 2nd weekend, better yet the 3rd weekend. A 3 ft snow will change everything.
The same thing happened happened at Aspen in 08 for our 2nd week of December trip. It was slim pickings but a last minute big storm made the skiing just fine. But I wouldn't schedule Co. before Xmas. I did because I had freq flyer tickets I used for my group and the room were much cheaper. But I am 4 for 4 with good conditions in December. 2 SLC, 1 Aspen, 1 Zermatt. There is something very, very enjoyable about getting that first trip in before xmas!!! Plus freq flyer tixs are much easier and rooms are cheaper (except for SLC where they are always cheap).
Now Check out the Alta Snowfall History http://www.alta.com/pages/snowhistory.php#pastseasons
Also, if this is your only trip of the year, then December is a dumb choice. Best is January/Feb. Here we sit waiting for winter, it's oh so nice to be packing that ski bag in December, instead of waiting another month, after the holidays. March i don't trust, because warm weather and sunny days ruins everything quickly. We have this same thread every year and the last couple have been nailbiters!!
Edited by SnowbirdDevotee - 10/1/10 at 8:04am