High Sierra Topix

The melt has really begun the last couple days. Yesterday at Agnew Pass the temperature ranged from 31 (low) to 68 (high), and today so far it as been 32 (low) and 64 (high). We are reaching the point where the water can't refreeze at night.

The auto gauge (for what it is worth) shows Agnew Pass going from 73" to 64" of snow depth from 8am to 2pm today alone.

Tomorrow is forecast to be 5 degrees warmer in Bishop than it was today--up to 90. The 10 day forecast shows slight cooling by Sunday then returning to this pattern.

I think it is safe to say that this year is already not shaping up to be another 1998.

Wow! The Blackcap Basin Sensor went berserk this am. Indicates about a 6" increase in water content!

Hope this doesn't indicate an end its value for the remainder of the snowpack season.

mike

for some reason, some of the WC's on the auto sensors go up on the melt. Probably just a sign that it's melting, but I'm not a hydrologist like some here..

oldranger wrote:Wow! The Blackcap Basin Sensor went berserk this am. Indicates about a 6" increase in water content!

The Blackcap temperature gauge is out, too.

I've noticed that kind of thing with the automatic sensors. You have convinced me to prefer the water content data, but the snow depth gauges don't seem to go crazy like this. I wonder if the water content is the best data to use prior to the melt, but if depth is more reliable after the melt begins?

In any case, Blackcap's snow height was 166 towards the end of March and is down to 103 today.

Bishop pass snow height was 130 towards the end of March is down to 83 today.

Here is a good website on snow sensors. I am not sure these are the kind used for CDEC data. There are also sensors that use electrical conductivity. At any rate, ALL sensors are an indirect measurement and subject to accuracy limits and errors.

http://www.id.nrcs.usda.gov/snow/recrea ... h_faq.html" onclick="window.open(this.href);return false;

I think it is safe to say that weather stations require maintenance. I am not a hydrologist, but I do take care of 6 weather stations in the Central Valley as part of my job. I notice from time to time CDEC stations will cease to give readings, or show erratic spikes that could not be reliable data. High winds, heavy snow, battery problems, electronic failure, lightning, solar power, mechanical stress- These stations are subjected to all sorts of factors, aren't they!? I am sometimes surprised the system works as well as it does.
Back to the original subject: it is looking more and more to me(with the warmer weather) that parts of the eastern and southern Sierra will be somewhat accessible by Memorial Day. Unfortunately, the lakes are not as plentiful, and the rivers and creeks will be running high. For us back country fisherman, it seems that late in the summer and fall will be better conditions this year....

richlong8 wrote:I notice from time to time CDEC stations will cease to give readings, or show erratic spikes that could not be reliable data. High winds, heavy snow, battery problems, electronic failure, lightning, solar power, mechanical stress- These stations are subjected to all sorts of factors, aren't they!? I am sometimes surprised the system works as well as it does.

Very true. I know for a fact that the CDEC TES station got struck by lightning a couple years back, only because I emailed CDEC to see when the station would come back online.

It also started to read erratic snow depth this year, when the snow got deeper than the station was tall. When it's snowing, the depth sensor reads 249.

Still fun to watch, and very glad the sensors exist.

Here's a few photos from our trip to Cedar Grove this weekend (May 6-8). Really fun car camping trip and very quiet and beautiful this time of year (Sentinel campsite was less than half full on Saturday night). The river and waterfalls were running high, but there was still lots of snow, starting around 6000ft under the trees (not so obvious from the photos) - Grant Grove had a lot of near continuous coverage. We didn't get all the way to Mist Falls, but the switchbacks up to Paradise Valley were supposedly under 4ft of snow. Not clear how easy it was to get up to Bubbs Creek, but we met some guys coming back with ice axes who apparently had been up there for a few days. Beautiful weather, at least on Friday and Saturday (74 degrees in the Canyon) though it turned to cold showery rain by Sunday morning.

kpeter wrote:The melt has really begun the last couple days. Yesterday at Agnew Pass the temperature ranged from 31 (low) to 68 (high), and today so far it as been 32 (low) and 64 (high). We are reaching the point where the water can't refreeze at night.

The auto gauge (for what it is worth) shows Agnew Pass going from 73" to 64" of snow depth from 8am to 2pm today alone.

Tomorrow is forecast to be 5 degrees warmer in Bishop than it was today--up to 90. The 10 day forecast shows slight cooling by Sunday then returning to this pattern.

I think it is safe to say that this year is already not shaping up to be another 1998.

3 or 4 warm days...then a week of sub-normal temperatures...and the weekend forecast is for record low temperatures (snow at the higher elevations).

I'm not counting my snowmelt until it's melted. Or something like that.

Guys, I'll admit I know very little about how such information is compiled (probably should as I work in water quality, but thats another story), but this was in todays Fresno Bee. The writer notes that recent data released by the DWR indicates a very high water content this year, but he was doubtful about the numbers so he did his own research. After he had compiled his numbers, he called the DWR and they verified his numbers. He reported the top 5 years of water content on 1 April as follows.

82/83 - 227%
68/69 - 224%
94/95 - 180%
10/11 - 171%
97/98 - 160%

Again, I know nothing about how these numbers came about. One sensor out of Fresno or is it a compilation of many? Got me.

Regardless and as previously mentioned, it will melt when it melts and I don't think you have to be an expert to figure out the streams are going to be running high early on whenever that may be. Heck, they already are and there's alot of snow still to melt.