interpretation NOHRSC for SoSHR

[stjoris]

Hi all,
I'm looking into hiking the Southern Sierra High Route(http://www.adventurealan.com/southern-s ... shr-guide/) in early June, but the current snow conditions have me a little bit worried. I've been keeping an eye on the NOHRSC data and it seems some of the south east parts are actually melting ok. What surprises me is that the higher regions on the east seem to have less snow, mt Whitney is not even covered in snow according to this data. What to make of this?

snow cover

Screen Shot 2017-05-12 at 12.53.42.png

snow depth

Screen Shot 2017-05-12 at 12.54.19.png

snow water eq.

Screen Shot 2017-05-12 at 12.54.06.png

[maverick]

What surprises me is that the higher regions on the east seem to have less snow, mt Whitney is not even covered in snow according to this data. What to make of this?

Welcome to HST!
Picture taken from just above Trail Camp was posted on Instagram by timwoo, taken 5/9/17, looks like plenty of snow to me.

[Wandering Daisy]

I think your line is mis-located. It is hard to overlay a line from a map source onto a satallite image. There are all sorts of distortions when using two different sources. I am not sure if the NOHRSC images are corrected to agree with map coordinates. The image data also has a large pixel size which reduceds accuracies. I think your line needs to be shifted to the west.

The CDEC snow sensor data will give you point values of snow depth. There is a rainshadow effect that makes the eastern escarpment of the Sierra drier than the west side, particularly the Great Western Divide. I think the snow depth at Cottonwood Lakes is in the 20" or less range, yet it is over 100" in west side elevations over 10,000. Bishop Pass is stilll quite deep, but it looks like the sensor has gone dead. The big drop at Chacoopa Plateau is probably a reading error. The snow IS melting. Cool temperatures the next week so maybe not so fast yet.

http://cdec.water.ca.gov/cgi-progs/snow/DLYSNOWDP

[stjoris]

Thank you! Seems no SoSHR for me this season.

What surprises me is that the higher regions on the east seem to have less snow, mt Whitney is not even covered in snow according to this data. What to make of this?

Welcome to HST!
Picture taken from just above Trail Camp was posted on Instagram by timwoo, taken 5/9/17, looks like plenty of snow to me.

[stjoris]

I think your line is mis-located. It is hard to overlay a line from a map source onto a satallite image. There are all sorts of distortions when using two different sources. I am not sure if the NOHRSC images are corrected to agree with map coordinates. The image data also has a large pixel size which reduceds accuracies. I think your line needs to be shifted to the west.

The CDEC snow sensor data will give you point values of snow depth. There is a rainshadow effect that makes the eastern escarpment of the Sierra drier than the west side, particularly the Great Western Divide. I think the snow depth at Cottonwood Lakes is in the 20" or less range, yet it is over 100" in west side elevations over 10,000. Bishop Pass is stilll quite deep, but it looks like the sensor has gone dead. The big drop at Chacoopa Plateau is probably a reading error. The snow IS melting. Cool temperatures the next week so maybe not so fast yet.

http://cdec.water.ca.gov/cgi-progs/snow/DLYSNOWDP

Sorry, that might have been confusing, that's not the district line, although yeah it's quite close. This is the SoSHR (https://caltopo.com/m/DDDG). It's a very snowy year, but unfortunately I'm only in the US until end of June, so let's see if the snow will melt on that side.