Looks to me like they are just repackaging the National Weather Service data. But on the National Weather Service site, you get more information (e.g., elevation). I do use the National Weather Service site, now, for all my backpacking trips, and have found it helpful in terms of deciding how warm a sleeping bag I should bring and how robust my rain gear should be.
Here is what I use for Whitney (elevation I choose is close to Trail Camp, but a little higher, so predictions are a little colder). If you click to go close in, you can actually pick out Consultation Lake, Trail Camp, etc.
Link to 7 day forecast near Trail Camp 
