Expert: Upcoming storm could deliver much-needed boost to Sierra snowpack
February 28, 2018
If the storm forecasted to hit the Tahoe Basin through the weekend delivers, it would provide a much-needed boost to this winter's below-average snowpack in the Sierra.
Though Monday's storm brought 6 – 14 inches of new snow to area ski resorts, it did not do much for the overall snowpack throughout the basin.
"The storm was more of a skiers' storm because it was super light powder with just 5 percent water content. That's more like what Utah sees than what Tahoe typically sees," said Jeff Anderson, hydrologist for the Natural Resources Conservation Service (NRCS). "There was not a lot of water in it, which we need for our water supply."
The Sierra's snowpack stores a third of California's water supply, which will gradually melt off in the spring into the state's managed reservoirs.
The storm bumped the snowpack in the Tahoe Basin up from 27 percent of the median water content for this time of year to 30 percent on Tuesday. NRCS measures snowpack by water content due to the variability of snow depth; there is a median amount for everyday of the winter based off a 30-year period between 1981 and 2010.
"It's a bit of a bump, but it didn't solve the fact that we have pretty low snowpack," said Anderson.
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But if the storm scheduled to hit Tahoe from Wednesday to Saturday morning comes through, that could change.
The National Weather Service is calling for 1-3 feet of snow accumulation at 6,000 feet and 3-5 feet above 7,000 feet. Temperatures will hover between 20-35 degrees.
"I looked at the Tahoe Basin and applied what's forecasted for precipitation through the weekend, and if that happens we might see a bump of up to 20 percent from this one storm," said Anderson. "These atmospheric rivers are really what builds our snowpack."
The last atmospheric river to hit the area was in November.
"That one was super warm. It only put snow up above 8,000 feet," explained Anderson. "This storm is ideal because it's coming in cold enough that it's going to build a pretty significant amount of snow even at lake level and in all the valleys."
Coupled with another storm front that might hit the basin around March 7, next month could have the makings of a "Miracle March," said Anderson.
"1991 is a great example of that. Snowpack went from 20 percent of normal to about 80 percent of normal in just one month."