"How's the weather up there?"
Obviously, weather plays a huge role in astronomy. If the weather is not good, or downright unsafe, it is best to know before operating the observatory.
In addition to visual reference with the cameras, I employ two different weather monitors -- The Davis Vantage Pro 2 weather station, as well as the Boltwood Cloud Sensor.
Clear Sky & Local Radar
Other very useful tools are the Clear Sky Chart (cloud cover, and transparency forecast) and local radar feeds.