Weather more typical of December than October will prevail over much of the East on Friday, although mild air will linger along the Gulf Coast and in Florida. Scattered morning showers will dampen the eastern Carolinas. A cold rain will fall from the Ohio Valley to southern New England. Patchy snow will occur over the higher elevations from West Virginia to the Catskill Mountains, with additional snow expected Saturday. The wet snow will cling to the leaf-clad trees, causing limbs to break and subsequent power failures. Dry and warm October weather will prevail from the Rockies to the Southwest, where temperatures will peak near 90 degrees in parts of Southern California. Elsewhere, showers will spread inland across the Pacific Northwest. FOCUS: DANGER IN THE RAIN The first widespread rain since last spring occurred early this week, over southern California. The initial raindrops of the storm settled the dust and made commuting more challenging for motorists around Los Angeles. About 140 collisions were reported on Los Angeles County roads from 6 a.m. to 9 a.m. on Tuesday compared with 60 collisions the week earlier in the same period. When light rain falls on roads after many days of dry weather, asphalt and concrete can become very slippery. The build-up of oil on roads during a lengthy rainless period can be substantial. When rain eventually falls, water beads up on the oil, since oil and water do not readily bond together. Such a surface can be surprisingly slippery. 