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April 1 Bulletin 120 percentages

Posted: Thu May 26, 2016 7:47 am
by ERIC
I've noticed that many of our members cite historical April 1 snow water content percentages as a comparative indicator of early access conditions. While useful, I do want to point out 1) that the focus on April 1 data we see in the news is primarily meaningful to predicting downstream water supply, and 2) melt variability from year to year is high between April and May and for that reason I find comparative May 1 Bulletin 120 percentages to be more useful with respect to early season access conditions info sought by most, although YMMV.

Just my 2-cents.

Re: April 1 Bulletin 120 percentages

Posted: Thu May 26, 2016 9:50 am
by Wandering Daisy
Agreed. But a lot of information, such as the historical opening dates of Tioga on the Yosemite web site, look like they are based on the April 1 statistic. I have also noticed a few comparisons to 2011. 2011 was an unusually high and late lingering snow year. This year snow will definitely melt earlier. As for river crossings, peak flow coincides with peak melt, which may not necessarily be different in a 200% snow year vs a 100% snow year. The high water just lasts longer in higher snow years. My main concern this year for early trips is high water, not snow as such.

The only way to really evaluate snow conditions is to go out and give it a try. I still enjoy my trips even if I have to retreat from snow conditions that are unexpected.

Reporting your early season trip conditions here really helps everyone too.

Re: April 1 Bulletin 120 percentages

Posted: Thu May 26, 2016 10:22 am
by ERIC
Wandering Daisy wrote:The only way to really evaluate snow conditions is to go out and give it a try. I still enjoy my trips even if I have to retreat from snow conditions that are unexpected.

Reporting your early season trip conditions here really helps everyone too.
Definitely agree with this.