The March Sierra Nevada Snow Survey
"With all the media
hype about the huge winter let’s put it into perspective. Many of the High
Sierra March 1 snow surveys from 2017 were the largest ever measured on the
date. The 2019 measurements have averaged just about 60% of those measured
in 2017. In 2017 March snowfall was lackluster so peak snowpack April 1 was
less then the record years of ‘69 and ‘83. What happens this month will be
decisive as to how the snow year actually ends up but as of now the High
Sierra is a bit over half of what it was in 2017." - John Ditti, California State Snow Surveyor.
Thomas
Re: The March Sierra Nevada Snow Survey
The winter record ever measured at mid-elevation (about 7000 ft) was over 90 feet! in the 1890's. This was likely quite accurately measured for the Donner area due to both the massive commercial ice business on Donner Lk as well as the nearby railroad. It precedes the current office of Snow Survey, but it wasn't necessarily an uncommon depth back then. John Muir got his idea of Sierra glaciation from extant glaciers on Merced Pk, which were already long gone when I was born. In fact, that was the world record for annual snowfall until modern remote monitoring equipment was installed in southern coastal Alaska. But 90 ft at 7000 was probably less that what fell higher up, where it wasn't measured. Max snow depth typically accumulates around 9000 ft. Drifts can be far deeper. Single month averages don't tell the whole story. But this is one March that is probably just too avalanche-prone for realistic backcountry ski travel.
Re: The March Sierra Nevada Snow Survey
How do they get the snow to fill out a survey form? North Dakota snow can't do it...
Re: The March Sierra Nevada Snow Survey
It sounds like we are at 'average' annual snow fall in the Sierra for up to this date...which as Drew points out, is dependent on what one wishes to consider 'average'.
Re: The March Sierra Nevada Snow Survey
Snow levels allegedly peaked during the "little ice age" of the 1700's. Then the Industrial Revolution came and started gradually raising global temp, though nowhere near the rate as now. But when I was growing up in the Sierra there were still lots of cirque glaciers around. Now just a few. And heavy snow years seemed a lot snowier than now. This particular year would just be average, not heavy snowfall like it seems after a decade of drought more often than not. But it will probably be a bad mosquito season until August.
Re: The March Sierra Nevada Snow Survey
The National Weather Service just posted a hydrologic outlook, predicting flooding this year in the Cascades and Sierra Nevada from snowmelt.
RISK OF CALIFORNIA FLOODING DURING THE SNOWMELT SEASON IS ELEVATED
THIS YEAR FOR MUCH OF THE CASCADES AND SIERRA NEVADA. FLOOD
CONVEYANCE SYSTEMS BELOW MAJOR RESERVOIRS IN THE SAN JOAQUIN WILL
BE UNDER ADDITIONAL STRESS THROUGHOUT THE SPRING. FLOODING
ANYWHERE IN THE STATE COULD ALSO RESULT FROM HEAVY RAINFALL, OR
THE COMBINATION OF RAIN AND SNOWMELT AT ANY TIME DURING THE
SPRING. REFER TO THE LONG RANGE OUTLOOK PRODUCT FOR FLOOD
EXCEEDANCE PROBABILITIES AT PARTICULAR LOCATIONS FOR THE MARCH
THROUGH MAY PERIOD. FOR SHORT TERM HYDROLOGIC FORECASTS AND
GENERAL WATER RESOURCE INFORMATION, PLEASE SEE THE CNRFC HOMEPAGE
AT: HTTP://WWW.CNRFC.NOAA.GOV.
https://forecast.weather.gov/showsig...6#.XIHGs3dFyUk
Re: The March Sierra Nevada Snow Survey
We've had a LOT of rain, so the ground at the lower elevations is soaked. Most of the storms this year have come from the northwest, rather than the southwest, so they are colder with much less moisture. So the snowpack will have less water. But, because the lower elevation ground is so saturated from all the rain, it can't absorb any more water.. so the runoff will be greater. It all depends on whether it stays cold, with the snow melting slower, or if it warms up...
Re: The March Sierra Nevada Snow Survey
Our problem is all the snow sitting on top of ground that's frozen three feet down. All the melt is going to have to run off. The few waterfalls in the region should be spectacular though!
Kent in SD
Re: The March Sierra Nevada Snow Survey
Now most of the Sierra Nevada is at around 150% of average snowpack, including the higher portions in the southern part of the range. That equates to potential avalanches presently, a lot dangerous stream runoff in June, and an especially bad skeeter season in July. After that, we might be treated to "Spring" bloom and fall color simultaneously in the parts of the high country around Sept. But I've seen considerably heavier snow years numerous times in the past. What I still need to research is snow conditions in Wyoming, because I'm headed to the Wind River Range first, in August.
Re: The March Sierra Nevada Snow Survey
I was just reading an article on Mamomoth Lakes area and some places snow packed to 50' (don't shoot me, but that's what it said)....it sounds rather incredible, but I have a feeling that this may cause some serious floods....certainly massive runoff. Hmmm, avalanches might be part of the equation. I think it would be good idea to take a kayak along, eh ?
Les