YOSEMITE VALLEY — November is a magical month in Yosemite Valley.The wall-to-wall people are gone. There are no traffic jams and half hour delays. And — thanks to October rains — the Merced River is flowing more like mid-August than it is in the waning days of autumn.I avoid Yosemite Valley like the plague in the spring and summer except as a starting point to hike out of the granite carved valley.