How should visibility values be entered when tower visibility is different from surface visibility?

When tower visibility differs from surface visibility, it is essential to report both values in the observation report. This practice ensures that all relevant and accurate information is conveyed to users of the data. Tower visibility reflects the visibility conditions that are observed at a higher elevation and may differ due to factors such as localized weather phenomena, geographical features, or atmospheric conditions.

Providing both surface and tower visibility enables more comprehensive situational awareness for pilots, air traffic controllers, meteorologists, and others who rely on this information for safety and operational decisions. It helps in assessing the overall visibility conditions and potential hazards, such as low visibility affecting only certain areas or altitudes. Reporting both values also aligns with best practices in meteorological reporting, allowing for more precise aviation and emergency response planning.