If considering a trip to Yosemite, remember that the snowpack is around 65% of normal. This means early running out of water for the falls. I would expect them to be basically dry by the end of July. On the other hand, it usually means the Tioga Road will open sooner than normal, giving access to the wonderful high country. If planning a trip, best to check on conditions just before you go. As far as the big chain controversy goes, I have been to Yosemite a zillion times in all seasons. I have never needed chains. But I always carried them... To be unprepared is very foolish indeed.