I'm just back from vacation and have been reading with interest the various reports over the last couple of weeks, particularly with regard to snow conditions. Joe Coha and I went in to Sam Mack Meadow over the July 4 weekend and I can add a story or two to the reports.
It seems that conditions are changing incredibly quickly. We went over Tioga Pass Friday evening, hours after its opening and, like others, were stunned by Tuolumne Marshes and frozen Tenaya Lake (which had substantially unfrozen by Tuesday). The Big Pine Creek parking lot was little more than half full, amazing for a July 4 weekend. The snow levels must have put a lot of people off. Hiking in the north fork trail saw snow at around 9500 feet and the creek crossing to head up the hill towards the Meadow was decidedly interesting. We ended up throwing our packs over, after dismantling all the attached hardware (unlike Kai et al, we'd anticipated lots of snow and had ice axes, crampons and snow shoes tied on - my pack weighed a ton with nothing inside it!), and then leaping over ourselves.
From the other side of this creek it was solid snow. From a collapsed portion around the banks of the creek running through the Meadow, we could see that the depth was around 4-6 feet. "Welcome to summer in the Sierras" said Joe, as we snow-camped with a freezing wind blowing over the Meadow.
We'd intended to try Winchell and/or Gayley but did neither, for different reasons. Winchell was first on the list, but in our efforts to get on to the Palisade Glacier I misread my too-large-scale 15 minute map and ended up ascending where I thought the contours should have been descending, ending at a cliff face that I would have been comfortable on had it been rock, but not with softening snow. Since the walk around took us right by Gayley we decided to do this instead.
Fate was against us here. As we got closer to Glacier Notch between Gayley and Sill we saw recent massive rockfall evidence. Two huge boulders had landed in the snow and skidded some distance down, while further up was a large amount of smaller debris. The only way to skirt this was to go to the Sill side of the ascent, but this was very close to a steep wall of snow with a dangerous-looking sag mark just above it. Not wanting to be the victims of either rock fall or avalanche we bailed.
The next objective was to try to go up the U-notch for the hell of it. Unlike Jim Curl, I couldn't even reach the bergschrund. In the heat the snow was softened so much that every step saw me sinking up to my thighs on the last 100 feet or so. I vaguely considered putting on snowshoes and heading up, but any hesitation I had was removed when a couloir further west let loose and avalanched. This was not a healthy place to be.
We ended up doing the "grand tour", circling around to Sam Mack Lake (which was frozen over, although starting to thaw at the edges) and then down the steep bank back to the Meadow.
Tiring of the wintry conditions, and the need for me to be back early on Tuesday, saw us pack up Monday and head lower, for a beautiful campsite between first and second lakes (highly recommended). On the way we dumped our packs and walked up to check out fourth and fifth lakes in all their winter splendour. The snow had prevented us from bagging peaks, but had provided us with glorious scenery.