Throughout the next several days, a dip in the jet stream will set up over the eastern Pacific, allowing moisture to flow into California, Oregon and Washington.
In addition, two different storm systems are poised to develop over the Pacific and drench the West Coast later this week, providing the parched region with beneficial rainfall.
(MORE: Record Driest Year in California, Parts of Oregon)
The Return of the Rain and Mountain Snow
The first system arrives on the West Coast Wednesday.
By Thursday, the initial low pressure system continues to push east, bringing rain to eastern Oregon, southern Idaho, and much of Nevada and Utah. In higher elevations, snow will fall throughout the Sierra Nevada east into the Rocky Mountains.
On Friday, a second and potentially more potent system pushes toward the California coast.
This system will bring rain as far south as Los Angeles, which is already running 6 inches below normal rainfall this year, on top of an 11.33-inch deficit from 2013. For the combined 2013-14 period to date, only 18 percent of normal rainfall has fallen. While 2 to 4 inches of rain may fall in L.A. during this second storm system, it will still not be enough to get rid of the drought. The foothills in Southern California could see heavier rain amounts of up to 6 inches, making recent burn areas vulnerable to debris flows and mudslides.
Beneficial snowfall will blanket the Sierra Nevada late this week with totals of 2 to 3 feet possible in the higher elevations. But again, the amounts aren't likely to be enough to bolster the snowpack – currently only 30 to 50 percent of average – to seasonal norms.
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