Is it Sunny at Muir? Meteorology Q's

I am curious what predictive products y'all use to tell if its sunny at Camp Muir, or more broadly what level the cloud deck is? (other than the webcam of course)

I have a couple of tools in mind, but I was curious what other folks use.

Thanks!

hope, luck, web cams and the aviation portion of the Seattle forecast discussion.

along with the hope and luck part, usually, especially in the spring, if the NOAA sky cover forecast has the clouds stopping in the vicinity of rainier and the cascade crest and there is a hint of blue in the sky on the paradise webcam:

noaa sky cover: eli3.posterous.com/126949999

Its worked the last few times i've been up there.

You can somewhat infer based on the telemetry.
Sure giveaway is the Solar W/m2 - if that's above 400 or so, for this time of year, it's sunny. That number goes down in winter, more like 250?
The problem with that measure is you need the actual SUN, so can't tell based on the early AM readings that you have to use before deciding whether it's worth the 2.5hr drive.
Next best is the RH%. Inexact but better than nothing. If that's below 60%, probably sunny. 60-85% or so, probably OK but not necessarily sunny. 85-95 is uncertain, it usually means a cloud deck level is nearby. 95% or above Muir's certainly in a thick cloud deck.

I use satellite photos in the National Weather Service website and for forecasting future conditions, the MM5 model (which can be linked from NWS "Model Forecasts"), specifically the "Integrated Cloud Column" product with several different resolutions available and forecasts for each 3 hour period for a couple of days out.