Heavy rain will soon hit the increasingly parched West

Several rounds of heavy rain and mountain snow will soon hit an increasingly parched West, the result of a meaningful change in the weather pattern evolving across the United States.

The first of several storms will begin pushing into the region from the Pacific Ocean late Saturday into Sunday, initially focusing on Northern California and parts of Oregon. By Monday, a potent low-pressure center will come ashore somewhere around the San Francisco Bay Area, blanketing the state in widespread precipitation and gusty winds.

Stormy conditions will continue beyond the first storm and also spread across the rest of the western United States through mid or late week.

Additional storm centers will probably come ashore midweek and beyond. Thereafter, some shifts in location are possible but the pattern may still favor additional rounds of activity targeting the west.

Since this storm comes amid a dry streak, initial flood concerns are low. But they will build with time around the Bay Area, and heavy rain over burn scars in Southern California could be concerning early in the week.

Storm arrives this weekend

Increasingly widespread areas of showers will push into the Oregon-California border region by later Saturday. It will probably become a steadier rain into the night, especially for coastal regions of Northern California.

It has recently been drier than normal during what is usually the wet season – places like San Francisco and Sacramento have seen barely a drop following a rainy first week of 2026.

On Sunday, 1 to 2 inches may fall from near or just north of San Francisco to the Oregon border. This could be enough to spark some isolated flash flooding concerns and will begin to saturate soils.

When the heaviest rains are expected

As the storm center crashes ashore near San Francisco on Monday, widespread – occasionally heavy – rain and snow overtakes the whole of California to open the workweek. Some thunder and small hail are possible, too.

“From Saturday evening to next Friday, 3-5 inches of rain is expected across the interior while 4-6 inches of rain is expected across the coastal mountain ranges,” wrote the National Weather Service forecast office in the Bay Area. “The bulk of this rain will fall in the Sunday to Wednesday time frame.”

Strong wind gusts of 40 mph or greater are also probable – advisories or other alerts may be issued at the storm peak for wind damage potential, especially around and south of San Francisco and Monterey.

The Bay Area Weather Service office has said the flooding concerns start out low, but increase with each day as rainfall saturates the soil.

Across the Southland, concern for heavy rain is amplified by risk to burn scar regions, including those from historic fires a little over a year ago in and around Los Angeles. An atmospheric river pushed along by the storm system will boost the potential for rainfall rates in excess of 0.5 inches per hour on Monday. Debris flows are possible if rain hits a significant scar. Flash flooding may also become a broader concern.

In the Sierra Nevada, 1 to 3 feet of snow is also probable on Monday, perhaps leading to the need for chains on vehicles, and maybe halting traffic for a time during the most intense activity. Heavy snow will also fall at the resort level in Southern California.

Stormy conditions remain

Much of the winter so far has been a story of dry, relatively warm high-pressure conditions for the western United States while there have been big, cold dips in the jet stream over the East.

Expect that pattern to now be flipped for some time.

Additional waves of storminess are a good bet after the first round that begins this weekend.

A second consolidated storm system may emerge late Tuesday into Wednesday as it spins near California’s coast on its glide eastward. Like the predecessor system, the follow-up storm could deliver another several inches of rain and multiple feet of high mountain snow.

A similar atmospheric steering pattern is currently favored among weather forecast models for the next seven to 10 days, leaving the door open for more waves of precipitation. By later month, the wettest conditions compared to normal may be in the Pacific Northwest, with drier weather returning to the south.

Given the warm and dry first two-thirds of winter, especially in ski country, the change is more than welcome.

Moisture needed despite full reservoirs in California

California remains drought-free, but it’s on its own across the western states. Much of this is thanks to relatively frequent rains in the state over recent years, leaving most reservoirs with above-average water levels. Given a few rounds of heavy snow around Christmas, parts of the Sierra are also near normal for snowfall.

Precipitation is more critical east of California, across the Great Basin and into the Rockies, where drought continues to be widespread. In Colorado, where the snowpack is the worst on record at this point in the season, moisture from the Southern California atmospheric river is slated to arrive by Monday night or Tuesday.

Once rain and mountain snow shift east into these regions, near- and above-average precipitation is expected from several storms for about a week or 10 days as well.