Rocket trails move sideways through the sky

Image: James Rowten

Rockets on launchpads point straight up towards their destination in space. Yet, rocket launches from Vandenburg Airforce Base in Southern California leave sideways rocket trails in the sky over San Diego. Why do rockets appear to move sideways when space is straight up?

Resources:

Smithsonian Institute: Why do rockets curve when they go into space instead of going straight up?

Additional Imagery:

Cygnus launch atop an Atlas V rocket