The first snow-storm of the season is upon us-leading to the closure of some mountain passes. From noon onward, Sonora Pass will be closed at State Route 108. Monitor Pass at SR 89 will close at 2 p.m. while SR 120 West will close at 5 p.m. If your travels take you over the Sierra, plan to leave before the closures or take an alternate route. Those highways may not reopen until Saturday.