Thunderbird is an open dataset of logs collected from a Thunderbird supercomputer system at Sandia National Labs (SNL) in Albuquerque, with 9,024 processors and 27,072GB memory. The log contains alert and non-alert messages identified by alert category tags. In the first column of the log, "-" indicates non-alert messages while others are alert messages. The label information is amenable to alert detection and prediction research.