Rain and Snow Returns This Weekend as Series of Storms Lashes Northwest

December 3,2015

Strong and locally damaging winds impacted the Northwest for the second time in about two weeks on Thursday. After a bit of a lull for Friday, more storminess is forecast to return this weekend.
(MORE: 1 Million Lose Power in Destructive Northwest Storm)
At least a few wind gusts exceeded 100 mph from this most recent Northwest wind event.

Wind Gusts

On Thursday, Mount Lincoln in the Sierra of California reported a gust to 106 mph at 2:20 p.m. PST, with sustained winds as high as 74 mph earlier in the afternoon. Squaw Peak in southern Oregon recorded a wind gust of 107 mph just after 8:30 a.m. PST, with sustained winds of 80 mph an hour earlier.
Typically windy spots along the Oregon coast also reported strong wind gusts, with Mount Hebo clocking a 72-mph gust just after 9 a.m. PST Thursday.
The greater Reno area had reported just over 5,000 power outages around midday Thursday, most of the power had been restored by Thursday evening. A semi truck flipped over about 5 miles east of town, where local authorities believed high winds were the cause.
Winds were strong enough to partially blow off a metal roof from a structure near Montague, California. In Brookings, Oregon, the National Weather Service relayed reports of down fences, blown in window panes and other minor damage.
Aside from the wind, much needed rain fell across portions of central and northern California. San Francisco International Airport reported 0.20 inches of rain on Thursday.
Through early Friday, additional rain and snowfall is expected, but winds will continue to diminish.

Forecast: Some Precipitation Lingers

Some ice and snow will persist across interior parts of Oregon and Washington into early Friday.

Thursday Night's Forecast

Across northern California, much needed precipitation, falling in the form of rain across the lower elevations, is likely. Snow will move into the northern Sierra Nevada through early Friday. Locally heavy snowfall rates of 1 to 2 inches per hour could impact Donner Pass on I-80.

Heavier Rain Possible Over the Weekend

Although conditions should gradually improve during the day Friday with just a bit of light precipitation across the Northwest, the next round of active weather may return as soon as Saturday.
The current thinking is that some locally heavy rain may reach western Washington and the coast of Oregon on Saturday. Snow is also possible in the mountains.
Precipitation could continue into Sunday, although the heaviest of rain is expected to fall early in the weekend. Even more rain may move into parts of the Northwest early next week as the stormy pattern continues.

Forecast Rain and Snow Through Sunday

When all is said and done, a swath of 3 to 5 inches of rain is possible from the northern coast of California, to the Oregon coast and much of western Washington.
Locally heavier rainfall totals will be possible along the immediate coast and in higher elevations.

Unsettled Atmospheric Setup

An active pattern is likely to prevail through the first week of December, especially once a stubborn cutoff area of low pressure over the central U.S. ejects eastward through Thursday.
That cutoff low, which spawned both Winter Storm Cara and Winter Storm Delphi, has led to a stagnant weather pattern across the Northwest in recent days.
Now that it's moving out, several ripples of energy in the upper atmosphere will be able to dive from the northeastern Pacific Ocean across the Northwest and pivot through the region relatively quickly.

A look at the upper level pattern across the northern Pacific Ocean and western North America.

As often is the case with storm systems in the region, particularly in the cool season, this means strong winds and locally heavy precipitation favor coastal areas. While some snow is still expected across the mountains, precipitation totals will be fairly limited due to the speed of the storm systems, ultimately limiting the snowfall potential.
The jet stream pattern may support more storminess into next week, but it is far too early to get into specifics.
For the latest information on this complex setup, regularly check back to weather.com for updates.

Storm Reports: Heavy Icing Tuesday Night, Wednesday

The first in the series of impactful weather systems arrived in the region Tuesday night into early Wednesday.
Freezing rain accumulations of a half inch thick were reported near Skamania, Washington. In Oregon, Troutdale saw ice accumulations of up to one quarter inch thick.
Ice and snow in eastern Oregon from the storm forced school cancellations in Hermiston, Pendleton, Umatilla, Boardman, Milton-Freewater and elsewhere, The Associated Press reported. Icy roads in the Columbia River Gorge also closed or delayed schools on both sides of the Oregon-Washington line.
MORE: Northwest Powerful Wind Storm, Nov. 18, 2015