The weather headlines may have subsided for the past week or so, but the Storm King is back on a rampage this week. Multiple feet of snow are expected in the highest elevations with 8 to 10 inches of precipitation (water) likely along the Sierra Crest. On Mt. Shasta’s upper mountain another 10 feet of snow is coming.
This satellite image on Feb. 6 depicts the long fetch of water vapor being transported to the Pacific Coast by a strong Atmospheric River. Depending on duration and intensity, weather systems like this can dump 20 to 40 inches of water in some locations over the course of a week or more. Heavy rain and high snow levels make them the #1 cause of winter flooding in the West. They can have the same impact as a major hurricane or strong tropical storm.
The good news for those of us suffering from shovel fatigue is that due to the subtropical origin of this approaching Atmospheric River freezing levels will be primarily above 7,500 feet and the bulk of the moisture this week will fall as rain in Truckee and Lake Tahoe communities. Today NWS forecasters had us lake level people pegged for 8 to 10 inches of wet snow, but luckily for us in Carnelian Bay it has been mostly “snain” — rain and melting snow — that requires minimal management. Just 500 feet higher heavy snow is falling.
As yet another Atmospheric River surges into the West Coast flood watches and warning flags are flying over the California Sierra. Again today high winds have blown down some Tahoe resort operations on the upper slopes where the best quality snow lies.
Hydrologists and weather forecasters are keeping a close eye on freezing levels this week as they watch to see how the snowpack absorbs the torrential rain expected. Streams and rivers are already running high due to the antecedent wet conditions.
Severe weather this winter has hindered mountain ops at some resorts, particularly those located along the Sierra Crest where volatile storm dynamics are much more impactful than in other areas. Ridge gusts alone have exceeded 125 mph in recent storms — tough conditions to run a chairlift or perform avalanche control. But when conditions clear, the skiing and riding has been stellar as here at Alpine Meadows last week.
Surface reservoirs in much of the West have rebounded to healthy levels, but underground aquifers in California have yet to show the bump expected from the near record levels of moisture this winter. Ground water supplies in the Sierra and Western Nevada should do well as the massive mountain snowpack begins to melt this spring.
Despite the much improved conditions, it seems likely that California’s governor Jerry Brown will be reluctant to declare the drought entirely over as he wants aggressive water conservation to become the norm in this heavily populated, drought prone state.
For the first half of this winter the Northern Sierra has been trailing only two seasons that received greater early precipitation — 1996-97 & 1955-56 — both major flood years. We’ve been close to severe flood levels already this winter, but the Truckee River has crested just shy of causing significant damage. So far.
Here's where we're at: By Jan. 31, 1997, 59.4 inches of precipitation were measured across the Northern Sierra. By the same day in 1956, nearly 56 inches had been tallied. They are the two wettest starts to a winter since 1922. As of early today (Feb. 6), 2017 is around 58 inches for the season.
In Feb.1997, precipitation rates fell off a cliff so we’ll probably outpace that exceptional year after this week’s moisture is measured. In Feb.1956, the N.S. Index averaged a solid 10 inches of precipitation so the race for #1 wettest in the first 5 months of a Water Year is still on! (2017 versus 1956).
FYI: Neither 1956 nor 1997 made it to the Top 10 wettest seasons at Donner Pass.
CLICK HERE<< TO SIGN UP FOR YOUR FREE TAHOE NUGGETS.
CLICK HERE << TO VIEW MOST RECENT NUGGETS.
CLICK HERE<< TO READ SIERRA STORIES ARTICLES.
VISIT THESTORMKING.COM FOR ARCHIVED NUGGETS & MUCH MORE!
***ALL TAHOE NUGGET PHOTOS ARE AVAILABLE AS PRINTS FOR FRAMING.