The south fork of the Nooksack River could start to flood near the Saxon Road bridge around 10 a.m. Sunday morning, March 16, according to a flood warning issued by the National Weather Service.
Flood stage is at 8 feet for that area. Due to 2 to 3 inches of rainfall in 24 hours in the North Cascades, the river was at 6.4 feet as of 4 a.m., according to the warning.
Nearby low-lying farms could be inundated, and water could cover the road in some places, including Highway 9, north of Acme.
Moderate to heavy rain was expected to continue Sunday, with another 1 to 2 inches of rain falling in the mountains. Other parts of the Nooksack could also flood if the heavy rain continues.
The weather service warned drivers not to try to drive through flooded areas as that is the most common cause of flood-related deaths in Washington.
The river is expected to fall to below flood level by Sunday afternoon. A flood watch remains in effect for parts of Whatcom County through Monday afternoon.
The service also issued a winter storm warning for eastern parts of Whatcom County. Mount Baker was expected to get 6 to 12 inches of snow, and areas of Mount Baker Highway could get periods of heavy snow.
The winter storm warning is in effect until midnight Sunday.