The last several nights, usually middle of the night, I have been awoken by a loud bang coming from above (sounds like it is on the roof or in the attic). It literally sounds like someone fired a round from a gun above us. Its a quick, and very loud, bang and then it is over. It is not a creak or moan like you hear in any house. I live in South Dakota, and it is cold and the temperature is moving up and down below and above freezing. It has varied the last several days as far as snow or ice on the roof, right now there really is nothing on the roof snow or ice wise, but it is cold. I looked in the attic and from my untrained eye I see absolutely no wet boards, leaking, trauma, or anything amiss.
The noise has happened a few times during the day as well I think, but its mostly sometime in the middle of the night. It is quite startling.
Could this be a sign of a problem that can or should be addresed or is this some annoyance caused by something natural? My thought is that maybe its some thermal expansion/contraction cycle causing a few parts to move or slip creating the bang, for example two boards shifting. This is a theory from a non-expert of course. Our house has a pretty typical, medium slope roof, with I think 2x10 boards or so for the roof, then the paper and all that fun stuff, and Timberline shingles I think. We have a vaulted living room ceiling if that matters. Our house was built in 1999.