Swells up to 20-feet will make for good surf watching along the Oregon Coast this week, like in this photograph from Heceta Head in January 2007.Ready, set, soak.
A potent storm packing tropical moisture will aim a Pacific fire hose at the Northwest starting early tomorrow morning and lasting until Wednesday night, forecasters said today.
Although the system -- which is being carried along by a 200-mph jet stream -- will dump a half foot of snow in the Cascades, snow levels will soar to 7,000 to 8,000 feet by late tomorrow afternoon, changing that snow to rain.
The blast of Pacific rain could cause rivers and streams to quickly rise, especially on the Northern Oregon and Southwest Washington coasts, said Chris Collins, a forecaster for the National Weather Service in Portland.
Tuesday's rainfall forecast.
Wednesday's rainfall forecast
Thursday's rainfall forecast"I wouldn't be surprised to see five to eight inches of rain fall on the coastal mountains,'' Collins said. "Some places could see ten inches of rain."
Heavy rain could lead to minor tidal flooding on coastal rivers such as the Nehalem, Wilson and Trask thanks to the highest tides of the month and building seas, with swells of 16 to 18 feet on Wednesday and Thursday mornings. Tidal flooding could also occur on Willapa Bay in Southwest Washington as high tides near 11 feet.
Waves and strong ebb currents will also create 20 to 22 foot seas at the Columbia River bar, leading to very rough conditions. Strong rip currents are also likely along the coast, where winds will gust to 55 to 60 mph tomorrow and Wednesday.
At 1:40 p.m. this afternoon, the weather service issued a high wind watch for the North and Central Oregon coast through tomorrow evening. Gusts to near 60 mph could rake exposed headlands and beaches, with sustained winds of 40 mph.
Urban street flooding is also a distinct possibility, forecasters said, because of storm drains choked with leaves.
Portland has had measurable rain every day this month, with 2.09 inches through noon today, about half an inch above normal. Last year at this time, rainfall was a paltry 0.22 inches.
The next wave of rain could also set off landslides and debris flows.
"Here we go again,'' said George Taylor of Applied Climate Services in Corvallis. "It looks like a pretty wet one, but these fire hose storm are really hard to predict: If you're under the fire hose, you're going to get pretty wet...but they tend to spray erratically."
A conveyor belt of moisture is set to bring heavy rain, wind and possible flooding and landslides to the Pacific Northwest.
Officials will keep a close watch on areas burned during the Gnarl Ridge fire on the Northeast flanks of Mount Hood this summer, where bare hillsides have already lead to rapid runoff and small debris flows and landslides.
Debris flow could also occur on areas burned by the Kitson fire, which burned through steeply timbered hillsides four miles Southeast of Oakridge in September.
Rain stays in the forecast into Friday, but look for a drying trend by the weekend, with partly cloudy skies and temperatures in the high 50s.
