24 Jul 2010, 7:13pm
Climate and Weather Forestry education
by admin

No Trend In Southern Sierra Snowfall Since 1916

A recent study shows that snowfall in the southern Sierra Nevada has not trended up or down since snow measurements began in 1916.

The study is:

John R. Christy and Justin J. Hnilo. 2010. Changes in Snowfall in the Southern Sierra Nevada of California Since 1916. Energy & Environment, Vol. 21, No. 3, 2010

and the full text is [here]. A quote from the Conclusions:

With the available data from six mid-elevation stations in the Southern Sierra region of California we reconstructed annual snowfall totals for 36 missing years of the Huntington Lake record to complete the time series (1916–2009). The standard error of the missing years is calculated to be ±36 cm, or 6% of the 94-year annual mean of 624 cm in the most robust estimation method (though we utilized the average of six methods which reduces the standard error further.)

The results of both the annual and spring snowfall time series indicate no remarkable changes for the 1916–2009 period in the basins drained by the Merced, San Joaquin, Kings and Kaweah Rivers. In the six reconstructions the range of trend results varied only slightly from -0.3% to +0.6 % decade-1. With a consensus trend of only +0.5 cm (+0.08%) decade-1 ±13.1 cm decade-1 there is high confidence in the “no-significant-trend” result. The corroborating information on temperature trends (Christy et al. 2006), stream flow, precipitation and shorter period snow water equivalent trends presented here are consistent with “no-significant-trend” in So. Sierra snowfall near 2000m elevation since 1916.

Kudos to Christy and Hnilo. Well done.

I have, however, a great temptation to say “been there, done that.” In 2008 I did a study [here] of maximum winter snowpack in the Snake River watershed, which drains 108,000 square miles in parts of six U.S. states.

Christy and Hnilo examined the snowfall records for stations in the southern Sierras from Mariposa County in the north to Kern County in the south, a much smaller area.

They used six snotel stations that met “a minimal set of standards (consistent observations for at least 35 years)”. I used the 20 longest, continuously measured snotel records from 3 US Army Corps of Engineers databases containing 745 snotel records from the Snake River watershed. Of those 20 selected, the shortest record was 75 years long. I did not “reconstruct” any records.

But we found the same thing: no significant trend in snowpack or snowfall (not exactly the same things, but pretty close).

Christy and Hnilo got their researched published in a peer-reviewed journal. I did not even make the attempt, but instead self-published online at W.I.S.E. [here]. They probably got paid to do their research. I did not.

But none of that is important. What matters is that the information is finally coming out. No trend in snow.

Snow alarmists are requested to please stop ringing the alarm bells; there is nothing to get panicked about.



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