A double-barreled storm will aim at California with drenching rain while areas farther north are hit with more snow and ice from Wednesday to Friday.
While the storm will bring beneficial moisture to the region, it will also cause travel disruptions to heavily-populated areas along the Pacific coast.
Storm has potential to bring heavy rain to California
A few inches of rain are likely to fall on central and northern California, especially along the west-facing slopes of the Coast Range and the Sierra Nevada. However, some rain will push southward and soak part of Southern California before the week draws to a close.
Enough rain will fall to cause excess water on the roads, including along the major California highways such as Interstate 5, I-10, I-15 and I-80. In some cases, flash and urban flooding can occur. Motorists should also be on the lookout for debris on the secondary roads in the hilly terrain. Enough rain can fall to cause mudslides, especially in areas recently charred by wildfires.
It is the second part of the double-barreled storm that will send some rain into Southern California, according to AccuWeather Senior Meteorologist Jim Andrews.
"The bulk of the rain will swing through Southern California from late Thursday to Friday," Andrews said.
"Part of the Los Angeles basin may receive an inch of rain from the storm," according to AccuWeather Senior Meteorologist Dan Pydynowski.
Rain will even reach the desert areas, including Palm Springs, California, with some showers in store for Las Vegas and Phoenix prior to the end of the week.
Snow levels will likely surge to above pass levels, including along I-80 at Donner Pass, California, during the bulk of the storm. The very beginning and end of the storm could bring a small amount of snow and slippery travel during Tuesday and Tuesday night and on Friday.
Farther north, the storm has a much colder scenario in store.
Snow and ice to cause travel disruptions in Oregon, southern Washington
"The northern Sierra Nevada and southern Cascades can expect 2-3 feet of snow for the high country from Wednesday to Thursday," Pydynowski said.
Slippery travel due to a couple of inches of snow and ice can occur in Portland, Oregon, as cold air is funneled westward through the Columbia Gorge.
"Travel along much of the I-5 corridor in Oregon to southern Washington will be slippery," Pydynowski said.
For now it appears the wintry precipitation will remain just south of Seattle. However, a slight jog could bring snow and ice farther north. Many areas east of the Cascades from Oregon to southern Washington can expect slippery travel due to snow and ice during Wednesday to Thursday.
The storm will deliver more drought relief to stricken areas of the West. Much of California and the Southwestern states continue to struggle with long-term drought with the worst conditions gripping central and Southern California.