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

Linda Lam
Published: October 21,2016
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 into next week.
Rain will return to the forecast in the West this weekend and into early next 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 Into Next Week

An unsettled pattern is expected to develop heading into next week. Chances for rain increase late Saturday and into Sunday for the Pacific Northwest due to an approaching cold front.

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 rainfall.
Some light rain is possible as far south as the Los Angeles area Sunday into Monday due to an upper-level disturbance embedded in the southwest flow aloft.
(MAPS: Weekly Planner)

Five Day Forecast

Another cold front will move into the Pacific Northwest early in the week, bringing another round of rain to the region.
Moderate to locally heavy rainfall, however, is possible with this system in northwestern California and southwestern Oregon. Otherwise, generally light rainfall is expected and the showers will spread across the inter-mountain West as well.
Snow is also possible in portions of the Sierra above 7500 feet Monday night and into Tuesday.
(FORECAST: Los Angeles | Sacramento, California | Portland, Oregon | Seattle)

Rainfall and Snowfall Forecast

Drier conditions will take hold of much of the West midweek, as an upper-level ridge of high pressure temporarily moves into the region.
However, late next week, another low pressure system is expected to approach the West coast and may bring significant rain farther south into central and southern California.
There is currently some uncertainty on timing and strength of this potential system given that it is a week 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 last week into early this week. Damaging winds were also observed in Oregon and Washington late last week.
The drought monitor released on Oct. 20 showed for the first time since early June there is 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 early this 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)