What does LTG VC signify in a METAR report?

LTG VC in a METAR report indicates that there is lightning in the vicinity of the reporting station. This means that lightning activity is occurring within a specified distance from the station, typically within 5 to 10 statute miles. The term "vicinity" conveys that while lightning is not directly at the airport, it is close enough to potentially affect operations and should be of concern to those involved in flight operations and safety.

Understanding the use of "VC" is crucial for pilots and air traffic controllers, as it helps them assess the weather conditions that may impact safety. The other options present inaccurate interpretations or imply a level of significance or proximity that is not captured by the term "vicinity." Thus, recognizing the specific definition of "LTG VC" provides important situational awareness in aviation meteorology.