I-80 westbound closed to semis over Donner Summit — and a new Sierra advisory runs Sunday into Monday

Interstate 80 westbound over Donner Summit is closed to all tractor-semitrailer combinations from the Nevada state line to 4.7 miles west of Kingvale, according to Caltrans on Nov. 14 — a truck-only closure carried in the agency's highway report as of 3:01 p.m. Pacific on Saturday, advising every westbound combination to use an alternate route. The same report lists no restriction for eastbound Interstate 80 in the Sierra, so the pass is moving traffic again — just not westbound semis.

The closure is the tail of the season's first big Sierra storm, the one CDLWire's Thursday edition tracked as winter storm warnings with up to 12 inches above 6,000 feet on Interstate 80 and Highway 50. The snow arrived Friday afternoon, and it closed the road outright. The Reno Gazette Journal, updated at 4:25 p.m. on Nov. 13, reported traffic stopped in both directions over Donner Summit after multiple spinouts, with eastbound traffic held at Kingvale near the Placer County line and westbound traffic held at Truckee. Chains or four-wheel-drive vehicles with snow tires were required in both directions just before the closure, westbound traffic from Reno was being screened about 5 miles west of Reno, and eastbound vehicles were being checked at Applegate.

By Saturday the interstate had reopened to passenger traffic, but the freight restriction held through the day. Caltrans' late-morning report still required chains on all vehicles except four-wheel-drive vehicles with snow tires on all four wheels from Truckee to west of Kingvale westbound, with westbound trucks screened at Mogul, west of Reno, and required to stop at the brake check area west of Nyack; by the 3:01 p.m. report, the westbound truck closure was the only Sierra restriction left on Interstate 80. The alternate Sierra crossing is under controls of its own: chains are required on all vehicles except four-wheel-drive vehicles with snow tires on all four wheels on U.S. Highway 50 from Twin Bridges to Meyers, over Echo Summit, in the same Caltrans report.

The break is short, and the next round already carries a formal advisory. The National Weather Service in Sacramento issued a Winter Weather Advisory at 10:55 a.m. Pacific on Saturday, Nov. 14, in effect from 4:00 p.m. Sunday to 10:00 p.m. Pacific on Monday for the northern Sierra above 6,000 feet — including Interstate 80, Highway 50, State Route 4 and State Route 108 — and the Southern Cascades above 6,000 feet, including Lassen National Park. The advisory calls for total snow accumulations of 2 to 6 inches, with up to 14 inches near Lassen Park, and winds gusting as high as 40 mph. Snow levels start at 6,500 to 7,500 feet on Sunday and drop to around 5,000 to 6,000 feet on Monday, with the heaviest snow expected late Sunday night into Monday morning, and the hazardous conditions set to hit Sunday evening travelers and both Monday commutes.

The Weather Service's Saturday-afternoon forecast discussion puts the Sunday-Monday system a step below the one that just closed the pass — "not as impactful as recent system" — with the widespread precipitation ending by Monday afternoon and showers lingering in the mountains through Monday night. What follows it is the larger concern. After a lull on Tuesday, a colder, wetter system arrives late Tuesday night, and the discussion puts the probability of at least 12 inches of snow above 5,000 feet at around 70 to 100% from Wednesday through Thursday night, with a 40 to 70% chance of 2 feet, accumulating snow above 4,000 feet and potentially lower. Those are forecast probabilities, not a warning — no watch or warning for the midweek system has been issued yet — but they describe a stronger storm than either of the two in front of it.

For drivers, Saturday evening's position is specific. A westbound combination cannot cross Donner Summit at all under the current Caltrans report, and the agency names no reopening time — the restriction stands until a later report lifts it, so check the Caltrans highway report or QuickMap before rolling rather than assuming the morning's status still holds. Eastbound is unrestricted in the current report, but chain controls on this corridor have gone on, tightened and turned into a full closure inside a single afternoon once already this weekend. U.S. 50 is not a free detour: it is chained over Echo Summit. And any Sierra crossing planned for Sunday evening or Monday now sits inside a posted advisory window, with the midweek system behind it forecast to be the strongest of the three. Carry chains, and treat Sunday before 4:00 p.m. Pacific as the cleanest crossing window the Sierra is offering this week.