The problem with Jackson is steep ungroomed terrain with predominantly SE exposure. Bob Peters and I debated this issue at some length last year http://forums.epicski.com/archive/in...p?t-38275.html
, but it has since occurred to me that the perfect demonstration of the effect of exposure is at my favorite mountain Snowbird.
I am Snowbird every year for 4 days between March 4 and March 17. Mineral Basin and Little Cloud are matching terrain pods with comparable terrain and altitude but opposite exposures (north wrapping around to west in Little Cloud, south wrapping around to east for Mineral Basin). Mineral Basin opened in 2000, and for the first 5 years weather was sunny and off-trail conditions in most of Mineral were crap. The only runs we would ski out there we would traverse at least to Powder Paradise and usually all the way to the Bookends, which are tilted slightly northeast. This year I got lucky with cool weather and a substantial dump overnight on March 13. I racked up 5 sweet powder runs in the first 1 1/2 hours in Mineral Basin. But that's one year out of 6.
At Jackson nearly the entire mountain is as badly exposed as Mineral Basin. You can argue that Utah is warmer than Wyoming, but Mineral's elevation is 9,600 - 11,000 while 3/4 of Jackson's terrain is lower than 8,500. The bottom line on Jackson: don't advance book for any later than mid-February. I was there President's weekend 1995, and as soon as the sun came out the snow turned heavy. I went to Jackson in late January this past season, and it finally lived up to its billing.