It’s looking to be an El Niño-dominated winter across much of the U.S., as the truly impressive event this year makes forecasters more confident that the climate phenomenon’s impacts will show up this coming season. In its monthly update of the seasonal outlook, National Oceanic and Atmospheric Administration forecasters on Thursday held steadyMore
The Pacific Northwest is set to be hit by a string of storms over the next week, beginning with several hours of high winds Thursday afternoon, along with freezing rain in some areas and snow at higher elevations.
While that snow is a welcome sight after last year’s pitiful winter snowpack, this early season snowfall doesn’t guarantee a good outcome for the cold season as a whole.
The spate of storms set to impact the region is the result of a low-pressure system in the Gulf of Alaska and a high-energy jet stream trained on the Pacific Northwest that is bringing with it those high winds and rain, Brian Hurley, a meteorologist with the National Weather Service’s Weather Prediction Center, said.
That setup “just keeps generating new systems coming through,” he said.
A frontal system will move through the area over the weekend, potentially leading to a brief respite by late Sunday. But “by the time we get to Monday, another system is knocking on the door,” Hurley said.
This continuous train of storms is very much a contrast to the high-pressure area parked over the West last winter and much of the first half of the year that has several western states on track to see their warmest year on record.
One of the main concerns for Thursday are the high winds that will rush over western parts of the region for a few hours in the afternoon.
“This is going to be a kind of brief, but powerful event,” Josh Smith, a meteorologist at the National Weather Service office in Seattle, said.
The Pacific Northwest is known for its large trees, which can be felled by such wind events, leading to power outages. Branches torn away from trees could also litter roads and muck up the evening commute in the area.
Freezing rain is also a travel concern, particularly in mountain passes, which allow winds to rush through and bring colder air to lower elevations. As rain falls on chilled surfaces, it can freeze, and “you can get really dangerous travelling conditions,” Smith said.
Higher elevations, particularly in the Cascades, should see several inches (and potentially more than a foot) of snow — a welcome sight after last winter’s record low snowpack in many areas, which led to a so-called “wet drought” in the region.
Some of that snow will stick around and help to build up this year’s snowpack, but “even though we’re getting quite a bit of snow now, it doesn’t mean” that it won’t be below-normal by the end of the season, Smith said. This is because in El Niño years, as this one is, it is common for the Pacific Northwest to see snow early on, but for that to taper off come January and February, he said.
During the winter months, the El Niño-fueled storm activity tends to shift further south, impacting Southern California and other parts of the southern tier of the U.S.
Any rains and snow from this El Niño would be welcome in California, mired in four years of record-breaking drought. Already some parts of the central Sierra Nevada range have measured above-normal snowpacks.
But while those rains and snows could help the state begin to dig out of its significant precipitation deficit, any intense storms could also lead to flash floods and mudslides, something state officials have already begun preparing for.