The weather pattern that has kept the West mild, dry and mainly storm-free recently has begun to change, and storms will line up to strike the region this week.

Late Friday into Saturday, the first round of rain doused the Northwest and British Columbia coasts. Well over an inch of rain inundated some cities and towns.

The steadiest rain from this first system has tapered off, but unsettled conditions will allow spotty showers to linger in the same areas through the end of the weekend.

The next bout of rain will assail the West on Monday, with a bit of rain from the system first grazing the Northwest Coast today and tonight. Monday’s windswept rain will soak the coast from Washington to northern California, spreading southward into central California during the afternoon.

Through Monday night, northern California and western Oregon will bear the brunt of the storm. Rainfall totals of an inch or two will be common in this area, with more than 3 inches possible in spots.

The heavy rain could trigger flash flooding problems, especially in low-lying and poor drainage areas. Travelers along the I-5 corridor from central California on northward will be forced to take it slow and will face an increased risk of hydroplaning at highway speeds.

On top of reduced visibility in downpours, strong southerly winds ahead of the storm will gust to 40 mph at times, triggering flight delays and cancellations from Seattle to San Francisco.

As the storm presses inland late on Monday into Tuesday, the arrival of colder air will allow heavy snow to pile up in the Cascades and northern Sierra Nevada.

Snowfall totals in the highest peaks could be on the order of feet. At pass levels, including portions of Interstates 90 and 80, several inches of snow will make roads slippery and treacherous.

Wet weather will persist throughout the West into midweek, and rain accompanied by mountain snow will overspread much of the Intermountain West during the latter half of the week. Yet another system will set its sights on California by the end of the week as well, bringing torrents of rain and more snow in the mountains.