Good Start to the Rainy Season in California, Oregon, Washington; More Rain This Week

Linda Lam
Published: October 23,2016
A pattern change in late October usually signals the beginning of the rainy season in portions of the West, and this year is no different. Beneficial rainfall has already occurred, making a positive impact in some areas experiencing drought, and a wet pattern looks to be developing in the week ahead.
Rain returns to the forecast in the West to start the week. Then, another area of low pressure may approach the California coast late in the week, bringing more wet weather to an area that desperately needs it.

Wet Forecast For Last Full Week of October

An unsettled pattern is developing to start this week. Chances for rain increase into Monday for the Pacific Northwest and northern California, as a strong low pressure system approaches the region.

Current Satellite

Rainfall is generally expected to be light through Monday with most locations receiving less than an inch. Portions of northwestern California and western Oregon, however, may receive up to three inches of total rainfall.
(MAPS: Weekly Planner)

Five Day Forecast

Another low pressure system may impact the Pacific Northwest Wednesday, bringing another round of mainly light rain to the region.
(FORECAST: Los Angeles | Sacramento, California | Portland, Oregon | Seattle)

Rainfall and Snowfall Forecast

Late this week, a third low pressure system is expected to approach the West Coast and may bring significant rain farther south into central and southern California. A few thunderstorms are even possible with this late-week system. If moderate to heavy rain does develop in southern California, there will be the risk of mudslides and debris flows on recent burn areas.
There is currently some uncertainty on timing and strength of this potential system given that it is still a few days away, so be sure to check back to weather.com for forecast updates.

Drought Improvement

A series of low pressure systems brought much-needed rainfall to the Pacific Northwest about a week ago. Damaging winds were also observed in Oregon and Washington last weekend.
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, 7.77 percent of the state is not experiencing at least abnormally dry conditions, which is the most since March 2013.

Drought conditions across the West as of October 18, 2016 (data from droughtmonitor.unl.edu).

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. 18, only 7.91 percent was still experiencing dry conditions.
(MORE: Is Seattle's Rainy Reputation Deserved?)
Seattle has already received over 7 inches of rainfall in October. On average, Seattle sees about 5 days per year with an inch or more of rainfall and, from Oct. 13 through Oct. 20, they have seen 3 days with at least an inch of rain.

There was good news for Oregon, too. On Oct. 11, the entire state was experiencing dry conditions and, as of Oct. 18, almost a third 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.
(MORE: Los Angeles Rain Causes Traffic Problems)
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 last week. Unfortunately, most of the region has remained dry so far.
Hopefully this pattern of low pressure systems moving into the West Coast will persist as we head through fall and into this winter. Snowfall, in particular, is important in the Sierra as far as the water supply for California. However, rain is also needed and is helpful in at least moistening the soil to help prevent wildfires at this time of year.
MORE: California Fires, September 2016 (PHOTOS)