It happens every year like clockwork. Once the leaves and pine cones drop and the nights grow cold, winter sports enthusiasts begin to focus on weather forecasts and the first hints of a storm on the horizon.
Currently, near-average sea surface-water temperatures in the Pacific Ocean indicate a high likelihood for ENSO-neutral conditions during winter 2020. The absence of warmer- or cooler-than-normal ocean temperatures in the Pacific (El Niño and La Niña) removes two key indicators that meteorologists use to create extended seasonal weather forecasts. Other atmospheric and oceanic oscillations are likely to have greater influence this year.
Weather forecasting gets better all the time, but in my opinion these months-long seasonal predictions are a bit of an overreach.
The Climate Prediction Center (a branch of National Oceanic and Atmospheric Administration) is predicting above average temperatures and drier than normal precipitation in central California this winter. With an eye on that forecast, scientists are also predicting the likely development of drought conditions in this region through January.
Priya Hutner explores some of the local lore on winter weather predictions.
Weather forecasting gets better all the time, but in my opinion these months-long seasonal predictions are a bit of an overreach. A significant portion of winter precipitation in the Tahoe Sierra is delivered by a half dozen or more atmospheric rivers — if we get hit by most of them, snowfall will be abundant; if too many miss us, resorts will be relying on snowmaking to cover the slopes.
41 feet in 2018-19
Last winter, the Tahoe Sierra was running just about average for snowfall and precipitation through the end of January 2019. But February opened with a barrage of cold, potent storms that never seemed to stop. The Central Sierra Snow Laboratory near Donner Pass was buried with 221 inches that February — more than 18 feet — exponentially above the month’s average of 73 inches. Impressive, yes, but keep in mind that two years before, 273 inches fell in January 2017, setting new January and any month snowfall records at the Snow Lab.
When the skies finally cleared, resorts had set new snowfall records for the month. Totals ranged from 267 inches (22 feet) at Sugar Bowl to Homewood Mountain Resort with a mind-boggling 328 inches (27 feet) in just 28 days — about a foot a day. February 2019 still failed to overtake the current California monthly snowfall record of 390 inches (32.5 feet) measured at Tamarack south of Lake Tahoe during January 1911. For the winter of 2019, the final tally at the Snow Lab was 493 inches (41 feet). That puts last winter at about No. 40 since 1878. The ranking is an estimate because of missing data and tied years for snowfall.
Precipitation, however, is a more critical metric than snow and that category was exceptional last year. Characterized by intense snowstorms and prolonged periods of generally wet and often gloomy weather, the winter of 2019 resulted in an impressive amount of precipitation (rain plus snow water equivalent). The water year ended on Sept. 30 and Randall Osterhuber, lead scientist at the Central Sierra Snow Lab, reported 87 inches of precipitation measured there. That ranks 2019 at No. 6 for precipitation since 1871. Comparing again to 2017 — the wettest winter ever recorded in the central Sierra — 2019’s hefty precipitation total at the Snow Lab was still 33 inches shy of 2017. If you’re a local who has lived in the Tahoe area since 1982, you have experienced eight of the Top 10 wettest years in recorded history.
Epic water years
Winter 2019 tied with 1958 and 1965 for total precipitation. All three of these epic water years were defined by extraordinary episodic weather events. February 2019 was discussed above. For the winter of 1964-65, the season opened with torrential rain in December. An arctic airmass moved into Northern California on Dec. 14 and tapped into an atmospheric river 500 miles wide that extended to Hawaii. When the warm, moist air collided with the polar air, widespread rain inundated Northern California.
Downieville was soaked with nearly 34 inches of rain in less than two weeks. In the northern Sierra, where freezing levels rose to 9,000 feet, rainfall totals ranged from 20 to 25 inches in five days. In the Mattole River basin on the north coast of California, nearly 50 inches of rain fell from Dec. 19 to 23, with 15 inches measured in just 24 hours. Rivers throughout the north state set new record flow peaks accompanied by devastating flooding. Botanic and geomorphic evidence indicated that it was California’s worst flood since the year 1600, with a recurrence interval that exceeded 100 years — 24 people were killed and damage was estimated at $240 million.
During the winter of 1957-58, a strong El Niño event in the Pacific Ocean influenced prevailing weather patterns. Much of California received above-average precipitation and the Tahoe Sierra was no exception. Frequent storms lashed the region with wind, rain and snow. Cold storms in March generated a rash of severe thunderstorms and unprecedented tornado activity in the lower elevations. The U.S. Weather Bureau reported that the winter of 1958 was the wettest season in 90 years.
As April approached, Californians were hoping for an early spring. Sierra ski resorts were boasting a bountiful snowpack and resort managers were praying for good weather during the traditionally busy Easter vacation. Unfortunately, the worst storm of the season barreled in just in time for the lucrative holiday. Massive snow slides stopped all train, truck and automobile traffic trying to get through the mountains. Highway 40 over Donner Pass was closed for five consecutive days by the storm. A dozen avalanches near River Ranch Lodge on State Route 89 closed the road for nearly a week. The precipitation gage at Soda Springs was completely buried by the heavy snowfall, but at nearby Norden, 10 feet of snow fell in five days. On April 4, upper-elevation snow depths exceeded 27 feet.
Tahoe Sierra resorts took the brunt of the powerful spring storm. At Squaw Valley, construction crews preparing for the upcoming 1960 Winter Olympics were shut down by the intense weather. Olympic planners had been hoping for a mild winter so that construction could continue on the installations, but their optimism dimmed in the relentless onslaught. Donner Summit Lodge at Soda Springs reported an estimated 1,500 people stranded there by snowdrifts. Sugar Bowl ski area on Donner Summit was hardest hit. An avalanche wiped out three towers on the Mt. Lincoln chair lift, closing it for the season. Ski racers slated to compete there in the Far West Ski Association Divisional Alpine Championships on April 12 and 13 had a long hike to the starting line at the top of Mount Lincoln.