I am photographing mountains 50 miles away. If I want predict cloud cover — I'm looking for low clouds for sunrise — which location should I choose?
Should I choose where I am standing, or the cloud cover forecast for the mountains 50 miles away?
If you want the clouds to be in your photograph, check cloud coverage for where you want the clouds to be. This may be between you and the mountains, directly over the mountains, or beyond the mountains. Cloud coverage over the camera is unlikely to appear in frame unless you are pointing the camera straight up.
If you have some other reason for wanting clouds to be directly above the camera, check cloud coverage for the camera's position.
You need to check the weather forcast for your shooting location and every other location that will be within the camera's field of view. Who says you can check the forecast for only a single location?