EUGENE, Ore. -- It was a rainy start to Thursday morning, mainly east of Interstate 5. This precipitation also brought snowfall to the passes overnight.
Thursday: Rain. Snow level 5,500 ft, rising to 6,000 ft. Highs in low 50s
Friday: Rain mainly north and along coast, Showers to south. Snow level 6,000 ft. Highs in mid to upper 50s
Saturday: Rain. Snow level 5,000 ft, dropping to 5,000 ft. Highs in upper 40s
Sunday: Isolated showers. Snow level 4,000 ft, dropping to 3,500 ft. Highs in mid 40s
Monday: Partly sunny w/ slight chance. Highs in mid 40s
Tuesday: Partly sunny w/ slight chance. Highs in low 40s
Wednesday: Mostly cloudy w/ slight chance. Highs in low 40s
Shower coverage is expected to increase throughout the morning and persist through late afternoon. This evening, the atmospheric river will shift to the north, lightening precipitation across Lane and Douglas counties.
Snow levels are also expected to increase throughout the day, as mild, subtropical air moves into the Pacific Northwest. By this afternoon, the snow level will be around 6,500 feet, which is above mountain passes.
Heavy rain looks to stall Thursday night across southwest Washington and the northern Oregon coast. The atmospheric river will slowly shift southward on Friday with the axis of heaviest rain extending form the central Oregon coast to the Washington Cascades.
This where things get tricky. The further north the "river" stays, the less precipitation we will see. This currently looks like the most likely senerio at this time. But if the "river" drifts more south, Eugene will see more significant rain on Friday. Roseburg either way looks relatively dry on Friday.
Friday night the atmospheric river will shift back north as it becomes more north-south oriented. This will bring more widespread rain on Saturday as the front moves inland. This is when the heaviest rain will move into southwestern Oregon.
The "river" will move east of the Cascades on Saturday night, bringing cooler air back into the region. This will allow snow levels to return below the passes. This cooler air could also lead to some instability on Sunday with more convective showers and the off chance of a thunderstorm.
Rainfall totals from Thursday morning through Sunday are 5 to 7 inches along the coast, 5 to 10 inches in the Coast Range, 2 to 4 inches in the Willamette Valley and the Cascade foothills, and 1 to 2 inches in the Umpqua Basin. There is a Flood Watch for parts of Lane, Linn, and Benton counties due to the rain threat. Rivers with the highest threat of flooding are the Siletz River, Luckiamute River, Coquille River, and Siuslaw River.
Another concern is strong winds Thursday afternoon through Friday afternoon along the coastline. There is a high wind warning for the length of the Oregon coastline, where gusts up to 60 mph are possible. Breezy conditions are also expected in the interior valleys, with gusts up to 35 mph.
Following this storm system, there will be some weak high pressure entering the region. This will give us a brief break from the wet weather. Despite that, an active pattern looks to remain with more rain at times next week.
For more information, visit the KEZI 9 News StormTracker 9 weather page.