National Weather Service (NWS) Seattle office forecasters say western Washington can expect a little break between weather systems today but wet weather returns on Sunday and continues into the middle part of next week. Heavy rains in the mountains and an rise in the snow levels will result in an increase in the Nooksack River’s level.
According to NWS forecasters,
The systems from Monday through Thursday of next week have the potential to bring locally heavy rainfall and windy conditions at times.
Extended models continue to show the potential for an atmospheric river aimed at Western Washington with the source region for the airmass from around Hawaii in the middle of next week. Snow levels will be moderately high and rainfall amounts may be heavy at times.
Confidence in the details is low at this time as the models have been inconsistent on just where the river will end up moving inland the last few runs.
There is the possibility that several rivers around the [western WA] area could reach flood stage by the middle of next week.
The Nooksack River level forecast for Ferndale as of 6:20am on December 15th shows it rising 14.5 feet between Sunday and Wednesday, cresting Wednesday morning at around the 19.5-foot mark.
19.5 feet is well within the official “Minor Flood Stage” designation and local road and property impacts can be expected.
Historically, when the river level at Ferndale exceeds 15 feet, drivers on low lying roads such as Marine Drive, Ferndale Road and Barrett/Paradise Roads can expect to encounter water and debris over the road and the possibility of road closures. When the river level exceeds 18 feet, drivers on Slater Road, east of the Nooksack River bridge, can expect to encounter water and debris over the roadway and the possibility of the road being closed.
Unseasonably warm temperatures will accompany the atmospheric river providing high temperatures in the 50s and lows in the 40s around the Ferndale area.
Local rainfall is expected to remain below a half-inch each day between Sunday and Wednesday. Winds are also expected but forecasters expect them to be less powerful than the winds that hit the Ferndale area during the past week.