When augmenting an AMOS, what is the last observed element?

• A. The observer's initials.
• B. The ascribed time of the observation to the nearest minute H+55 to H+59.
• C. The station altitude above sea level.
• D. The meteorological wind direction at the station.

Answer: (B)

In an AMOS augmentation, the last element recorded is the ascribed time of the observation, rounded to the nearest minute within the 55–59 minute band (H+55 to H+59). After all the other observation data have been gathered, this time stamp is added to provide a precise temporal anchor for the augmented report. It ensures the augmentation aligns with the hourly observation cycle and can be properly correlated with the rest of the weather data. The other details—observer’s initials, station altitude, wind direction—are documented earlier in the augmentation, but the final element is the time stamp. Therefore, the correct choice is the ascribed time of the observation to the nearest minute in the 55–59 range.