Winter Weather Targets Cascades as Series of Storms Cross Southern Oregon

MEDFORD, Ore. (Jan. 4, 2026) — A series of weather systems moving across northern California and southern Oregon is expected to bring periods of rain and mountain snow through midweek, with the greatest impacts focused on higher elevations in the Cascades, forecasters said.

A persistent upper-level trough will guide weather conditions through Monday. A weak cold front moving through the region Sunday evening is forecast to bring another round of light to moderate precipitation. Colder air behind the front is expected to lower snow levels to between 3,500 and 4,000 feet by Monday morning.

With precipitation continuing into Monday, additional snowfall is expected at Cascade mountain passes and along Sawyers Bar Road west of Etna. Forecasters said 1 to 2 inches of snow could reach Interstate 5 near Siskiyou Summit or between Weed and Dunsmuir, as well as portions of highways 89 and 97. While accumulation on highways may be limited due to relatively warm road surfaces and lingering moisture, slick conditions could develop during snow showers.

The upper trough is expected to split on Monday, sending a cutoff low southward and allowing for a brief lull in weather activity Tuesday morning. Isolated showers may linger, but a new cold front is forecast to arrive later Tuesday, bringing afternoon showers to the coast and the Cascades. Precipitation is then expected to spread inland through Wednesday and Thursday.

Snowfall in the Cascades remains the primary concern midweek. Forecast totals range from 8 to 16 inches between elevations of 4,500 and 5,500 feet, including major Cascade passes and Willamette Pass. Higher elevations and ridgelines could see 16 to 24 inches of snow. These amounts meet advisory-level winter weather criteria, though forecasters cautioned that snow levels have been trending higher in recent model runs, which could affect timing and totals.

East of the Cascades, snowfall of 4 to 8 inches is forecast for eastern Cascade foothills, with 3 to 6 inches expected across east-side terrain. Basin floors are expected to receive an inch or less. West of the Cascades, snow levels are forecast to drop to around 2,500 feet early Thursday as precipitation tapers off. Under current projections, Interstate 5 at Siskiyou Summit could see up to an inch of snow, with a few isolated snow showers possible around the Mount Shasta area.

After the midweek system exits, conditions are expected to stabilize. Forecast models show precipitation diminishing through Thursday as a Pacific ridge builds over the region. While some ensemble guidance suggests brief disturbances could flatten the ridge, overall chances for precipitation remain low, with coastal areas seeing a 10% to 20% chance of rain and inland areas holding at single-digit probabilities from Friday through Sunday.