Heavy rains forecast for the North Cascade Mountains beginning Monday are expected to significantly raise the Nooksack River level at Ferndale by Wednesday. A strong warm front is approaching from the west bringing with it a lot of moisture according National Weather Service (NWS) Seattle office forecasters.
“Locally heavy rain is expected on the southwest slopes of the north Cascades Monday afternoon. It appears that the heaviest rain will occur Monday night, where local amounts of up to 7.5 inches on the north Cascades could fall during the 24-hour period ending at 4 AM PST, Tuesday,” forecasters said in this morning’s forecast area discussion.
As a result of the heavy rain in the mountains, the Nooksack River level at Ferndale is currently forecast to crest at about 19.5 feet, within the official “minor flood stage” range of 18 to 20.5 feet.
Once the river level passes the 15-foot mark, the following roads can be expected to be impacted by water and debris over the roadway.
- Barrett and Paradise Roads
- Ferndale Road, both north of Slater Road and north of Marine Drive
- Marine Drive between Rural Avenue and Lummi Shore Drive
As the river level approaches the 18-foot mark, the potential for floodwaters to encroach onto Slater Road increases.
Drivers should be alert to the dangers from floodwaters and debris on roadways and the possibilities for road closures due to flooding.
The most recent river flooding event and subsequent road closures were the result of the river level cresting at just beyond the 18-foot mark.
The same weather system will also bring rain to the Ferndale area and 24-hour rainfall totals are expected to be up to a half an inch.
In addition to the rains, strong winds are expected in the northern interior areas (e.g. Ferndale) on Monday, NWS forecasters say.
It looks like wind speeds will probably reach advisory criterion over parts of the coast and northwest interior.
A Wind Advisory will probably need to be issued with the afternoon forecast package. The current forecast indicates that the strongest winds will occur during the day, Monday, but the latest guidance shows that it will be Monday night. Gusts could also reach 50-55 mph in a few places such as Whidbey Island.
River level forecasts can change frequently and people with property near the river or driving on low-lying roads near the river are advised to stay updated with the latest Nooksack River Level Forecast for the Ferndale area.