Northern Sierra Nevada sees wettest fall in 30 years
California’s northern Sierra Nevada mountain range, home to some of the state’s largest reservoirs, had the wettest first two months of the water year since 1984, the National Weather Service said Tuesday.
Between October and November, the eight measuring stations along the northern range received an average of 18 inches of precipitation, or about 200% above average for the first two months of the state’s water year, said meteorologist Eric Kurth of the National Weather Service in Sacramento.
That amount of snow and rain in two months has only been seen 11 times in the region since record keeping began, Kurth said, and nearly every time the northern Sierra Nevada ended the water year with above average rainfall.
“I wasn’t expecting to see such a strong correlation. We are early, it’s certainly not a guarantee,” Kurth said. “But it’s interesting how many times that early wet start has led to a wet ending.”
The lone exception was 1984-85, which also happens to be the last time there was this much precipitation in the northern Sierra Nevada, Kurth said.
The heavy precipitation came mostly in October, when storms soaked Northern California. The Sierra Nevada’s eight-station index recorded more than 12 inches of precipitation, or about four times the average for October, Kurth said.
While the milestone may be a good omen for the water year ahead, it’s also highlighted more short-term, positive impacts on California.
On Nov. 3, the U.S. Drought Monitor reported that about a quarter of California was out of drought conditions, the best outlook the state has had since spring 2013, when 64% of the state was considered in “moderate drought” or worse.
The U.S. Drought Monitor relies heavily on precipitation levels and soil moisture to assess conditions, state water officials said. For that reason, an unusually wet October, such as the one Northern California experienced, would show some areas as having escaped drought.
In the meantime, much of the Southland remains parched as the state enters a sixth year of drought.
The southern Sierra Nevada range has received about 88% of its average precipitation for the first two months of the water year while the central region has received about 139%, according to the latest data available from the Department of Water Resources.