Snow and Water levels 2011

[Wandering Daisy]

I think you are putting too much faith in the sensor data. You say that there has been a lot of melting in April. I would instead look at the basin averages of "measured" snow survey data and percents of average. Although all the data is not yet in, the 5 basins (34 data points)San Joaquin drainage was 158% normal and May 1 192% normal. The 2 basin Tulare River drainage (15 data points) was 124% normal April 1 compared to 171% normal May 1. The 4 basin Sacramento River Basin (35 data points) was 156% normal April 1 and 216% normal May 1. This data does NOT tell me that a lot of melting has happened in April, compared to normal. Also look at the California-Nevada river guidance plots. Only 2 rivers are at or above monitor stage, none at flood stage. The melt has only begun. The Merced at Pohono is not that high yet.

After all the hoop-a-loo last spring about high snow I simply decided to go out and see for myself, and yes, there was a lot of snow end of June, but it did not stop me from going out. But I agree that playing with the data is fun! CDEC is good use of our tax dollars. Lets pray the fools do not cut its funding.

[Cross Country]

Having experienced this kind of stuff many times I must I agree with the general consensus except the phrase " extremely dangerous is probably UNDERSTATED. Please everyone be very cautious.

[rlown]

in fact, if you look at some of the sensors, the WC numbers are actually increasing.

Maybe, we can just say there will still be a lot of snow and runoff this year? and be done with it.. Expect it, and plan for it.

Just tell me when the lakes at 10,500 will ice out. You'd be a king!

[oldranger]

Russ,

I'd guess about August 3 for the lake you are really interested in.

Mike

[Electra]

August 8th!

I brought up 1995 because that was a BIG year but melt below 10k was mostly complete throughout the range by mid-july like most 'normal' years but above 10k it lingered into August and anything above 10,500 stayed covered for most of August. From what little data i have seen and the weather patterns this winter, it seems similar. Deep base with heavy water content = late melt up high most likely. I have a short early june trip planned and a longer mid july trip planned and will report in detail what I find....

[tim]

There might well be a big difference below and above 10000ft if the forecast weather pattern for the next two weeks continues through May - the nighttime freezing level looks to be consistently around 8000ft or so (with daytime highs in Yosemite Valley mid 70s - sounds beautiful). Just based on a quick look at the day/night temperature ranges (25-30 degrees appears typical), it seems that (subject to a bit of variation due to cloud cover, etc.) the daytime high in Yosemite Valley needs to get to ~85 before it is above freezing overnight at ~10000ft.

It does also seem from the CDEC data that the Yosemite-Tahoe region has received more snow and is slower to melt out so far this year, compared to further south. I note that Cedar Grove is already open (anyone been there yet?) and the Mineral King road is expect to be open for Memorial Day weekend: http://www.nps.gov/seki/planyourvisit/r ... itions.htm" onclick="window.open(this.href);return false;

[RoguePhotonic]

I note that Cedar Grove is already open (anyone been there yet?)

I might be headed there this weekend so i'll let you know what it's like.

Even further South around Kennedy Meadows the snow does not start until about 8000 feet.

[tim]

I might be headed there this weekend so i'll let you know what it's like.

We might see you there (again - we met at Iva Bell Hot Springs last August when I was hiking with my twins).

[RoguePhotonic]

Really? You were the one I talked to in the evening with the kids as I scouted out the springs? I didn't know that was you.

If I do go I don't know what my plans will be because the friend I am going with is really out of shape so we will probably just do some easy day hikes.

[kpeter]

WD, you were right about the automated gauges. I went back to the drawing boards and just analyzed data from the May 1 manual reads--which tell a somewhat wetter story.

A lot of stations have not reported yet, but I was able to find 7 stations that had reported, that represented a variety of elevations and latitudes, and that had complete data for all our comparison years. (The stations were: Vernon Lake, Tenaya Lake, Dana Meadows, Pioneer Basin, Blackcap Basin, Crabtree Meadow, and Cottonwood Pass. All comparisons across years are May 1 to May 1.)

Overall, the total water content of these 7 stations is very close to 1998 and 2006. 1995 was substantially wetter, while 1993 was drier. 2010 (last year) was much drier.

While it is nice to know that 1998, 2006, and 2011 are almost identical in May 1 snowpack in typical backpacking terrain, it unfortunately doesn't tell us very much about how late the season might be.

Remember that 1998 melted out three weeks later than 2006 with exactly the same May 1 water content. This could still wind up being a normal year if the next six weeks are warm like 2006, or it could be a very late year if the temps are cool like 1998.

Best Odds: If we split the difference between our "sister years" of 2006 and 1998 we will be about 10 days behind an average year, or 4-5 days behind last year.

Factoids:
1. Vernon Lake is wet this year! With 40" it is wetter than in any of the comparison years.

2. Blackcap Basin is drier than any of the comparison years (not counting 2010.)

3. Pioneer Basin is as wet as 1995. That bodes poorly for me, since I had wanted to cross it in late July.