A pair of storms will create difficult travel across the northwestern United States early this week while Santa Ana winds whip across portions of Southern California.
Back-to-back storms will bring areas of moderate-to-heavy rain and snow from Washington and Oregon to Idaho and Montana through Tuesday.
Rain will stretch from Seattle to Portland, Oregon, on Monday.
Accumulating snow will fall from the Cascades and much of eastern Washington and Oregon to the Bitterroots and Tetons.
The milder air will send temperatures back into the 40s F in Seattle and Portland on Monday for the first time since Dec. 12 and 13, respectively.
The second storm, moving onshore during Monday night, will contain more moisture and lead to heavier rain and snow for most of the Northwest.
“Over an inch of rain may fall in some communities from Seattle to Portland, leading to areas of flash flooding, especially in poor drainage areas,” AccuWeather Meteorologist Kyle Elliott said.
Rain will even make an appearance as far south as portions of northern California, Nevada and Utah during Tuesday afternoon and Tuesday evening. In locations where temperatures will hover near or below freezing, sleet or a period of freezing rain may fall.
Those traveling along Snoqualmie and Stampede passes during Monday night and Tuesday will need to be alert for snow-packed and icy roads. Precipitation will begin in the form of snow but change over to a cold rain during Monday night and early Tuesday before changing back over to snow by Tuesday afternoon. Between 6 and 10 inches of snow can fall by the end of the event.
Temperatures will slowly climb above freezing for precipitation to change over to plain rain in and around Boise during Tuesday afternoon.
Aside from precipitation, each storm will pack strong winds, mainly across the Cascades and northern Rockies. Winds will gust between 40 and 60 mph at times. This will lead to steering difficulties, especially for high-profile vehicles.
“These strong winds will increase the risk for property damage in cities such as Billings and Great Falls, Montana and Cheyenne, Wyoming,” Elliott said.
Prior to the storm during Monday night, high pressure anchored over the Intermountain West will lead to gusty Santa Ana winds across portions of Southern California on Monday. Wind gusts will peak around 50 mph in the populated Santa Ana wind-prone areas with higher gusts along the mountaintops.
Drivers of high-profile vehicles planning to travel on roads in these wind-prone areas will be at risk of dangerous crosswinds. This includes Cajon Pass along Interstate 15.
These gusty winds will also be felt from southeastern California into southern Nevada and western Arizona.
These winds will taper off during Monday night.
Quieter weather will return to the West during the middle of the week as high pressure builds across the Rockies. This, however, will increase the Santa Ana winds once again across the Desert Southwest.