Snowpack records falling, but not yet a ‘historic’ winter
TAHOE CITY, Calif. — The Lake Tahoe Basin has experienced, what has felt like, nonstop snow in January, leading people to call this a historic winter. While snowfall records have fallen this season at Truckee-Tahoe, the region still needs quite a bit more snow to match the best January on record and also winter as a whole.
Snowfall measurements vary around the basin, depending the path of the storms and the location the measurement was taken. The National Weather Service in Reno has an average snowfall in the Tahoe Area for the first 19 days of January at 84 inches.
The Natural Resource Conservation Service, which collects measurements from several SNOTEL sites around the basin show a snow depth of 96 inches at the Palisades site, 104 inches at the Ebbetts Pass site and 105 inches at the Mt. Rose site.
The UC Davis Central Sierra Snow Lab, which is located on Donner Pass, said in a Facebook post on Tuesday, Jan. 17, that they’ve measured 165 inches of new snowfall.
“There are records falling, which is crazy because it’s not even the end of the month,” said Bryan Allegretto, Northern CA/NV Forecaster for OpenSnow.
It is important to note that these records are for a four-month period, so the basin can’t claim it’s the snowiest winter ever, which was 2017.
“It’s not the snowiest season ever because we’re not even halfway through, we’re about 39% through with the ski season,” Allegretto said. “We have a lot more winter to go before we can claim any seasonal records and we’re not even close to those.”
He went on to say daily records only go back to 1970, and within that period, the basin beat the 1994-95 four month record.
“Looking back, I don’t think we’ve had anything like that since 1951-52. It’s probably more than a 52-year record, it’s probably more like a 70-year October to January record,” Allegretto said.
NRCS won’t be conducting another snowpack survey until the end of January but Jeff Anderson, state hydrologist, went out to manually take measurements during the second week of the month and various SNOTEL sites around the basin also remotely send in hourly updates.
“We’re at record territory for this time of the winter, not compared to the end of the biggest winters, but we’re definitely on the trajectory if the storms continue, to register one of the biggest winters ever,” Anderson said.
Central Sierra Snow Lab said in a Thursday post on Facebook that the season snow total so far is 356.5 inches.
One thing that has made this winter unique is that the majority of the precipitation this year has been snow rather than rain.
“When we see tons of water, tons of big storms like this in this short amount of time, it usually is a lot more atmospheric rivers and rain. We actually had a lot less rain than is usual for a storm that is this wet,” Allegretto said. “Our snowfall average is running a lot higher versus normal. The storms have actually been pretty cold outside of those rain storms so we’re over 200% for a lot of ski areas and for the snow lab.
“We’ve been running at over 200% since December, so it just keeps coming, it just keeps staying around that 200% number,” Allegretto added.
For the rain that has fallen, it’s been absorbed into the snow rather than into the ground, which increases snowpack numbers because water content within snowpack is the main statistic that’s looked at when measuring snowpack. As of Jan. 19, the snow lab has the snowpack listed at 195% of average.
So, both snowpack and snowfall records for the four-month period have been beaten.
“If we look at the average of [SNOTEL sites around the basin] there’s 32 inches of water content in the snowpack. We can look at just 2017, that was the last really big year, that year maxed out at 54.7 inches of water content average of the basin,” Anderson said. “The thing that’s really impressive to me is that we are about 8.5 inches of snow-water ahead of where we were on this date in 2017.”
So, while the basin is more than half-way to beating that record, the storm patterns have to continue throughout the rest of the winter. Anderson said a good atmospheric river can increase snow-water content by about 3-3.5 inches, so the basin is two atmospheric rivers ahead of 2017.
The next highest record is 1983 which topped out at 60.9 inches of snow-water.
So, can the basin beat that record? Maybe.
“The other data point that’s pretty cool is that right now if it wasn’t to snow another flake or rain another drop for the rest of the winter, we’re already 111% of the median peak that happens in the spring, so we already have an above-normal winter,” Anderson said.
There is about two weeks of clear weather ahead but temperatures are expected to remain cold during that period.
“I think we could possibly be below average, at least through the end of February. I think we’ll have some big weeks. The first week of February could be a big week, but then we’ll be below average again, maybe for the rest of February,” Allegretto said.
He did say that La Nina seasons tend to be bookend seasons, so big storms at the beginning and end of the seasons. So, he is expecting some bigger storms at the end of the season.
As for the snow that’s already there, Allegretto said because of below average temperatures, “that snow is not going anywhere.”
Fingers crossed for a big rest of the season, and if we’re lucky, some Fourth of July skiing.
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