[christensent]

Is there any way to determine through a forecast what elevation you're going to break out of the clouds? Having cancelled plans today due to the weather, I was somewhat disappointed to wake up and check the Camp Muir webcam and see that it appears you'd break out of the clouds at about 8000ft despite forecasts for moderate precipitation all weekend. Is there a way to know this beforehand? It looks like the relevance of clouds for aviation is knowing where the bottom is rather than the top so that doesn't help. Edit: That was just a very lucky time, Camp Muir is again in clouds and looks to be snowing. But regardless, the question still stands in general.

[thunderhead]

Ya, this weekend muir should be in and out of clouds as convective snow showers pass through at times. Can't really forecast each shower. For the general question, a complete answer would be quite detailed, but an easy starting point is model derived cloud tops: http://flightweather.db.erau.edu/get_loop.php?&cnt=27&dir=model_erau/NAM/FTOP/US/ Time is usually in UTC(subtract 7 hours for PDT). A few tips: the cascades like to hold onto their moisture a bit more than the models sometimes suggest... and models sometimes confuse oceans with low clouds(does not apply to muir obviously).

[thunderhead]

Also I should point out that cloud tops of a high altitude cloud layer may be no factor with their bases well above mountain height. You can also look at cloud content(RH plotted below is a good proxy for clouds) at each level(700mb is camp muir-10,000 feet). http://www.pivotalweather.com/model.php?m=gfs&p=700rh&rh=2018060912&fh=6&r=conus&dpdt= In that link you can also click any point to generate a sounding(for some models). Where the red and green lines are near eachother, expect a chance of clouds... becoming nearly certain as the lines touch. I guess I am making this more complicated pretty rapidly...

[Stefan]

go to this website: https://atmos.washington.edu/wrfrt/data/timeindep/extendedgfsinit.d2.6hr.html look down on the left column for "12KM Cloud". Then you have options of >20K or 10K-20K, and other options. Then select "Latest only"