It should be slippery commute for motorists Tuesday afternoon and evening as a clipper system arriving in the area around midday is expected to bring between 1 and 4 inches of snow to the Hudson Valley, according to the National Weather Service. A Winter Weather Advisory is in effect from 10 a.m. to 6 p.m. Tuesday for Northern Westchester, Rockland and Putnam, where 2 to 4 inches of snow is expected.