The west coast of the US, from Oregon to the mountains of California and the golf courses of Phoenix, has received near-record levels of snowfall this week in what authorities are calling a “once-in-a-generation” event.
California’s mountainous regions have received so much snow — more than 40 feet of snow since the start of the season — that entire cities have closed due to being virtually cut off from the rest of the state. The Governor has declared a state of emergency in 13 counties due to the unusual snowfall.
Portland, Oregon’s largest city, saw its second snowiest day on record with nearly a foot of snow, while further south in Arizona, suburban Phoenix received a dusting of snow.
“This rain and snow bucked the trend, and it’s very unexpected,” said Ryan Maue, a meteorologist and former chief scientist for the National Oceanic and Atmospheric Administration. “It’s like once in a generation.”
The effects of the storms can be seen throughout the region. In California, extreme weather has left thousands without power, closed Yosemite and Joshua Tree National Parks and triggered avalanches. In Lake Tahoe, an avalanche struck an apartment building, forcing residents to evacuate. No one was injured in the 200-yard-wide snowslide, the local sheriff’s office sayingbut “it gobbled up the bottom two floors of the building.”
Officials at Sierra Nevada tourist destinations have urged visitors to stay home rather than risk travel as the roads remain dangerous.
Yosemite National Park, which broke a 54-year-old daily snowfall record, has closed indefinitely.
Although the storms have overwhelmed the state, they have helped alleviate California’s devastating drought. The entire state was going through a drought three months ago but now, according to the US Drought Monitormore than half the state is out of drought.
Bianca Feldkircher, a meteorologist with the National Weather Service, said a persistent blocking pattern over the Pacific Ocean plus cold air migrating south from the Arctic have created the conditions for widespread snowfall along the West Coast.
“Not only were you getting significant snowfall in areas that already see snow, but you were also seeing snowfall at lower elevations in southern California, which is very rare,” Feldkircher said.
For example, the March 1 forecast warned of snowfall in parts of Phoenix, which Feldkircher said is “super unusual” for this time of year. And last week, Portland recorded abnormally high snowfall rates, recording nearly 11 inches (28 cm), the second snowiest day in the city’s history.
When it comes to human-induced climate change, meteorologists say it’s challenging to pin down what role it’s playing in the West Coast’s peculiar winter season.
But increasingly extreme weather is expected as global temperatures rise. “Heat produces humidity, humidity produces storms, and heat and humidity come together to produce even more severe storms,” Feldkircher said.
Forecasting technology continues to improve. Much better, even soon you will be able to forecast extreme events more accurately. “In the near future, I don’t think the weather will cause problems with our weather forecasting capabilities,” Maue said.
Although many regions struggled with challenging winter conditions, some are welcoming much-needed moisture.
The recent precipitation is a boon to ameliorate the drought that has persisted in the Southwest.
California tends to go from rags to riches to bounty to rags when it comes to rain, Maue said. “That’s why, from a policy standpoint, you need to be able to have water regulations, reservoirs, and water supplies that can last through multi-year droughts.”