SOUTH LAKE TAHOE, Calif. — Weather officials have gone back 20 years and haven’t seen a storm materialize in October like the one headed for the Tahoe Basin.

The National Weather Service in Reno on Thursday afternoon issued a winter storm watch along with a flood watch due to heavy snow expected in the High Sierra and for soaking rains that could lead to debris flow events like landslides.

“At this time … {A} Significant atmospheric river still on track late weekend into early next week with heavy rain and mountain snow looking almost certain,” the service said in its forecast discussion Friday morning.

The flood watch is in effect from 5 a.m. Sunday, Oct. 24, through 11 a.m. Monday, Oct. 25. The winter weather watch goes into effect at 11 a.m. Sunday and lasts through Monday evening.

Up to 3 feet of snow, and possibly more in localized areas, are forecast above 8,000 feet where winds could reach triple digits.

The service said travel during the advisories will be difficult over mountain passes. Snow levels are forecast to start above 9,000 feet Saturday night before lowering to 6,000 on Monday.

Debris flows, ash flows, rock falls, and tree falls are possible, especially on or near burn scars and steep terrain, including the Tamarack and Caldor fire areas.

“Rises on small creeks and streams are expected, equipment in and near river and creek channels should be moved to safety,” the service said. “Rock falls in canyons and ponding of water on roads will create hazardous driving conditions, especially along Interstate 80 between Truckee and Reno. Localized urban flooding is also possible.”