More Rain, Mountain Snow Kicking Off Hopeful Rainy Season in California, Oregon, Washington Through the Weekend

Linda Lam
Published: October 27,2016
A parade of Pacific storms will march on through the weekend, bringing additional drought relief to parts of California and adding on to one of the wettest Octobers on record in the Northwest.
The next in this series of storms will slide into California with a slug of soaking rainfall into Friday. That system is tapping some mid and high level moisture from Seymour, which will stay well to the south in the eastern Pacific Ocean.

Wet Forecast For Last Full Week of October

Below is a rough timeline for the next series of Pacific systems and where they are expected to spread rain and mountain snow.

Current Radar

• Friday: California (including L.A.) wettest, Oregon, Washington, Great Basin (Some Sierra snow, California thunderstorms also).
• Saturday: Weaker disturbance brings some showers to the Northwest on Saturday. 
• Sunday: A stronger and wetter storm takes aim on Northern California and Oregon (rain, mountain snow, some t-storms also possible). Some rain also spreads to Washington, Nevada, northern Utah, and Idaho.
• Early Next Week: A weaker system may bring some additional rain to California.

(MAPS: Weekly Planner)

Five Day Forecast

The heaviest total rainfall through Sunday is likely to be over Northern California and far southwest Oregon, particularly the coastal ranges and slopes of the Siskiyous and Sierra below snow level, where over 3 inches of rainfall is likely.
A couple of inches of rain is possible along the I-80 corridor, including parts of the Bay Area and Sacramento.
Rainfall totals farther south remain somewhat uncertain. The best chance for an inch of total rain will be near Point Conception and Santa Barbara County.
If moderate to heavy rain does develop in southwestern California, there will be the risk of mudslides and debris flows on recent burn areas.
The National Weather Service has issued flash flood watches for burn areas in southwestern California, from near Monterey southward to the mountains of Los Angeles, Ventura and San Bernardino Counties, and for the Lake Tahoe region.
(FORECAST: Los Angeles | Portland, Oregon | Seattle)

Rainfall and Snowfall Forecast

Some of the higher peaks of the Sierra, Siskiyous and Cascades, not to mention the northern Rockies, may pick up over a foot of snow through the weekend.

Drought Improvement

A series of low pressure systems brought much-needed rainfall to the Pacific Northwest earlier this month. Damaging winds were also observed in Oregon and Washington the weekend of Oct. 15.
The drought monitor released on Oct. 20 showed, for the first time since early June, a small part of California that isn't analyzed as even abnormally dry, in the far northwest corner of the state. In fact, 8.96 percent of the state is not experiencing at least abnormally dry conditions as of Oct. 25, which is the most since March 2013.

Drought conditions across the West as of October 25, 2016 (data from droughtmonitor.unl.edu).

Through Tuesday, it was the third wettest October-to-date in Sacramento, second wettest October-to-date in Blue Canyon, California, and record wettest October-to-date in Eureka, California.
However, the area that needs to see rain and snow the most remains central and southern California. Portions of Southern California, including Los Angeles, did receive some rainfall in recent days.
(MORE: Los Angeles Rain Causes Traffic Problems)

A Wet October in the Northwest

There also was huge improvement in Oregon and Washington as well.
The drought monitor report for Oct. 11 showed 84.46 percent of Washington seeing at least abnormally dry conditions and, as of Oct. 25, less than a tenth (0.1) percent was still experiencing dry conditions.
(MORE: Is Seattle's Rainy Reputation Deserved?)
Seattle has already received 8.90 inches of rainfall in October through Wednesday. This ranks as the third wettest October on record in the city. The wettest October was in 2003 when 8.96 inches of rain fell.
On average, Seattle sees about 5 days per year with an inch or more of rainfall and, from Oct. 13 through Oct. 26, they had seen 4 days with at least an inch of rain.
Other parts of Washington and Oregon are also flirting with their record-wettest Octobers. Through Oct. 25, Portland, Oregon; Salem, Oregon; and Astoria, Oregon, had their wettest Octobers-to-date. Eugene, Oregon, and Medford, Oregon, had their second wettest Octobers-to-date, according to the Southeast Regional Climate Center.
On Oct. 11, the entire state of Oregon was experiencing dry conditions and, as of Oct. 25, almost half of the state, toward the coast, is now currently free of abnormally dry conditions. However, sections of central and eastern Oregon still need more rain to ease the drought.

Recap of Pacific Storms So Far This Week

On Monday, the first Pacific storm along with a separate upper-air disturbance soaked parts of Northern California and the Northwest, and brought a flare-up of thunderstorms to Southern California and the Desert Southwest.

Parts of the high country of Southern California picked up 1 to 2 inches of rain from Saturday evening through Monday evening. Over 3,400 lightning flashes were detected over Southern California Monday. Barstow, California, saw its first measurable rainfall since April 30, its fourth longest dry streak (175 days) on record, according to the National Weather Service in Las Vegas.
A second storm impacted the Northwest on Wednesday, bringing over an inch of rain to Seattle.
MORE: California Fires, September 2016 (PHOTOS)