California snowpack falls well below average in January. Will back-to-back Sierra storms help?
California’s snowpack is “behind the 8-ball” but water officials are hopeful that a pair of storms sweeping through Northern California starting Friday will boost storage in the Sierra Nevada, which dipped well below average following a significantly dry January.
The latest figures from the state Department of Water Resources show the Sierra snowpack remains below average for this time of year. As of Friday morning, the statewide snow-water equivalent — the amount of water stored in snow — measured 10.5 inches. That’s just 65% of normal for Jan. 31 and 40% of the average expected by April 1, when snowpack typically peaks.
DWR’s Snow Survey Manager Andy Reising said the Sierra, which accounts for a third of the state’s water needs, lost ground after January’s lack of storms.
“We’ve had a very dry January,” he said Friday following the second seasonal survey at Phillips Station, “And it has hurt our snowpack by not adding to it. So we’re behind the 8-ball throughout the state, on average.”
California snowpack breakdown
Statewide, the snowpack was at 108% of normal at the start of January, but the absence of major storms since has driven it down to 65%. As of Friday, it stood at just 40% of the expected April 1 total.
The northern Sierra, which includes the Trinity and Cascade mountains north of Lake Tahoe, reported the highest snow levels. The region’s snow-water equivalent measured 14.6 inches on Jan. 31, or 89% of normal for the date. That’s a decline from Jan. 2, when it was 15.9 inches, or 161% of normal.
“Despite a good start to the snowpack in the Northern Sierra in November and December, we can look back as recently as 2013 and 2021 to show how quickly conditions can change for the drier,” said Karla Nemeth, DWR’s director. “California missed out on critical snow-building storms in January. ... For each day it’s not snowing or raining, we are not keeping up with what we need.”
The central Sierra, covering areas around Tahoe and Yosemite, saw a slight snow-water increase over the month, rising to 10.2 inches — about 58% of normal for Jan. 31 and just 36% of the expected April 1 peak.
The southern Sierra remains the driest, with only 6.7 inches of snow-water equivalent, down a half-inch from the beginning of the month. That represents just 47% of normal for this time of year and only 29% of the April 1 average.
Still, at the manual survey spot not far from Echo Summit, snow-water levels held steady, with Friday’s manual measurement recording 8 inches of snow-water equivalent in 22.5 inches of snow.
“The snowpack has consolidated a little bit and a little bit has melted off,” Reising said as fresh snow began falling from the first of two storms. “So again, 9 inches (last month). Now, we’re at 8 inches, so essentially unchanged in this location.”
Reising noted that current snow levels were tracking similar to last year, when a series of late winter storms helped bolster the pack. Water officials are hoping the latest atmospheric river storms will do the same before the two or three remaining surveys, the next being on Feb. 28.
“We had good storms in November and December, which built the snowpack to a statewide average of 108%,” Reising said. “Then we had a dry January, which dropped our average all the way down to 65%.”
But, as snow fell on Phillips Station for the first time in nearly four weeks, Reising said “this year is a prime example of how much the conditions can change within a year.”
Warmer storms could limit gains
The storms hitting the region could improve conditions, but officials warn they are warmer than usual. That means more rain at lower elevations and less snow accumulation, potentially reducing the long-term water storage benefits.
But it was a far cry from the 2022-23 water season when a parade of cold atmospheric river storms created the deepest snowpack recorded across the Sierra Nevada within the last 40 years. Just like last year, the warmer storms could hinder significant water storage even with reservoirs across the state remaining high.
Lake Oroville, the largest state-controlled reservoir critical to bringing water to the southern two-thirds of the state, was 75% capacity, which was 126% of its historical average. Other reservoirs in the region — including Lake Shasta’s federal supply — were running at or above their historical averages. Only Folsom Lake, which has seen an increase in outflows into the American River over the past couple of days, was low; Friday’s capacity was just 37% or 80% of its historical average, as water managers made room ahead of the storms.
Just like last year, Reising said the final snowpack comes down to what Mother Nature has in store for the critical second half of the season.
“We were chased out of here in March last year,” he said. “That was a prime example of how much conditions can shift within a season.”
While forecasters are uncertain about how much snow these storms will bring, Reising said, “a good six, seven, eight days of precipitation” would be a boost for the snowpack.
One certainty, however, is that Southern California will remain much drier than the northern half of the state despite its recent rains.
“We’ll have to wait and see what that will be,” he told reporters. “We’ll definitely need more storms throughout the next several months to make up for the very dry January experienced, particularly in the central and southern part of the state.”
This story was originally published January 31, 2025 at 1:51 PM.
