What is an ADVISORY in aviation weather?

An advisory in aviation weather is specifically designed to provide important information about hazardous conditions that may affect flight safety. This could include warnings about turbulence, icing, or low visibility, among other potential risks. Advisories are issued to alert pilots and air traffic control about these conditions so they can take appropriate precautions.

In contrast, the other choices do not align with the definition of an advisory. A warning for severe conditions typically denotes a higher level of concern, such as those associated with severe weather phenomena. Notifications about surprisingly good conditions might be useful but do not fit the purpose of an advisory, which is focused on hazards. Meanwhile, a report on routine weather updates would primarily provide standard weather information without emphasizing any specific risks or hazards. Thus, the selection capturing the essence of what an advisory aims to convey is the one that indicates it as a heads-up about hazardous conditions.