Most major Northstate roads are well cleared of snow Thursday morning, but Wednesday was a reminder that winter conditions have arrived. Interstate 5 was closed near the Oregon border in both directions Wednesday afternoon after snowfall made the roads slick and several big rigs jackknifed on both sides of the freeway. The westbound lane of Highway 44 was closed early Wednesday afternoon after 2 big rigs jackknifed just east of Viola. A collision with injuries between a big rig and a passenger car led to a closure of Highway 89 near Snowman’s Hill in Siskiyou County.