Western U.S. Continues to be Under the Gun for Parade of Storms

The West Coast has barely had time to dry out from the weekend and early rounds of moisture as another storm system sets up to target the region beginning late Wednesday. Here is a more detailed look at what the western U.S. should expect for the balance of the week.

Wet Start to the Week Will Continue for Much of Western U.S.

Several rounds of moisture are set to target the western third of the country this week as the parade of storms continues to roar in from the Pacific Ocean. The start of February has been a dramatic change from the last few weeks of January, a time in which the region saw unseasonably dry weather.

The moisture machine fired up late last week and has not let up since. Places such as Seattle have been dealing with sporadic snow showers, a rarity for this part of the Pacific Northwest. The early week round of rain and snow is forecast to dissipate by late Tuesday, however, another wave of precipitation is waiting on deck.

A classic Pineapple Express has been to blame for the last several days of immense moisture. This atmospheric river took aim at southern Oregon and Northern California with the most powerful bands of moisture. However, some of the rain and snow crept to the north and into Washington and British Columbia, Canada.

Widespread rainfall totals of 2 to 4 inches have been reported in the higher terrains with the hardest-hit areas recording nearly a foot of rain over the last few days. The heavy rain is predicted to linger through Tuesday, raising the risk of flash flooding, landslides, and mudslides.

Communities in southwestern Oregon, including Medford, are forecast to pick up at least a few inches of rain by the time the system wraps up. Heading to the south and the west, California cities such as Redding and Santa Rosa will see rainfall amounts of 4 to 8 inches. This equals about a month's worth of rain over a typical February.

Along with the mass amounts of moisture, the atmospheric river also ushered in milder air from the Pacific Ocean. As a result, the bulk of the moisture has been falling as rain in the Golden State. Any snow that falls on Tuesday in California will be limited to elevations above 7,000 feet. While Donner Pass on Interstate 80 may see some snow mix with the rain late Tuesday, most of the measurable snow will remain over pass level in the Sierra Nevada.

It was a different situation to the north where colder air diving down from Canada has been supporting widespread snow in Washington state. Snoqualmie Pass along Interstate 90 about an hour east of Seattle could not escape the persistent snow over the weekend. Chains were required for travel at one point over the busy pass due to the hazardous road conditions.

Snow began to fall on Sunday morning in the Seattle metro area. While the snow did not deliver significant accumulation, it was enough to force the closure of some schools on Monday. The Emerald City's hilly terrain and lack of snow removal equipment means that it does not make many flakes to cause widespread disruptions.

Details of the Next Storm System

The West Coast will see a brief drying out period on Wednesday before the next system comes ashore. You can expect the rain and the snow to begin later in the day in a zone from Northern California and up to western Washington. The colder air associated with this weather maker will increase the chances of widespread snow when compared to the preceding storm.

Snow levels in the northwestern corner of California will start at elevations of 4,000 feet at first. However, these levels will fall to about 1,000 feet across the Siskiyou Mountains by Thursday night. Rain will transition to snow across the northern Sierra throughout the day Thursday, sending 1 to 2 feet of fresh accumulation over this zone. Snow of this magnitude will undoubtedly impact travel across the mountain passes in this region by Thursday night.

Meanwhile, it will be more torrential rain for the valleys and low-lying elevations. This rain will stick around through early Friday. Most of Northern California should prepare for rainfall amounts of 1 to 2 inches. The eastern foothills nestled into the Sierra will see 2 to 4 inches of additional moisture, raising the threat of landslides and flooding.

Will Southern California See Any of This Moisture?

Southern California was left out of the first round of moisture this week but that is expected to change by the middle of the week with the second system. The Los Angeles area can count on rainfall totals of about 0.25 - 0.50 of an inch. The rain will begin to fall across the metro area on Wednesday morning with the potential of heavy rainfall at times.

After drier conditions in the afternoon and evening hours in Los Angeles on Wednesday, the sporadic rain will move in again overnight. Lighter rain showers pairing with fog will be the story on Thursday with the bands of moisture picking up in intensity overnight and into early Friday. The rain will finally ease later in the day Friday with the clouds remaining. It will be a cool stretch of days in Los Angeles with readings topping out at about the 60-degree mark and lows falling into the mid 50s.

Santa Barbara could pick up as much as an inch of rain out of this system. The rain is predicted to begin late Tuesday in the resort city with rainfall near half of an inch possible. Occasional rain showers are in the forecast throughout the day and night Wednesday with the rain anticipated to intensify again on Thursday. Another quarter of an inch of rain is the forecast for Santa Barbara overnight Thursday with the precipitation letting up later on Friday. Like Los Angeles, daily highs will struggle to break past the 60-degree mark during this time.

The surge of moisture is certainly good news for the fire-ravaged region. However, the precipitation that falls on recent burn scars will create concerns about mudslides.

Drier weather will be the story for California just in time for the weekend. However, the rain may linger across the Pacific Northwest. More details on this forecast will be available in the days to come.

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