Which term in METAR indicates freezing fog?

The term that indicates freezing fog in METAR is represented as "FZFG." This abbreviation is composed of two parts: "FZ," which stands for "freezing," and "FG," which stands for "fog." When these are combined, they specify a weather condition where fog is present and the temperature is at or below the freezing point, meaning that liquid water droplets in the fog can freeze upon contact with cold surfaces, potentially creating hazardous icy conditions.

The other terms listed do not indicate freezing fog. "FG" simply denotes fog, without specifying whether it is freezing. "PL" refers to ice pellets, a different type of precipitation. "TS" indicates thunderstorms, which are unrelated to fog conditions. Understanding these specific terms is important for accurate weather reporting and safety, especially in aviation contexts where low visibility due to freezing fog can present significant risks.