When the station anemometer is not operational but the observer estimates wind speed to be 10 knots, how is it reported?

When reporting estimated wind speed in a weather observation, the conventional format is to express the speed followed by the proper unit abbreviation. In this case, if the observer estimates the wind speed to be 10 knots, it should ideally be reported as "10KT" to indicate the unit clearly.

The choice labeled with just the numeral "10" lacks the unit abbreviation and does not conform to standard meteorological reporting conventions. This omission can lead to confusion, as other individuals reading the report may not understand the value represents wind speed without the accompanying unit notation.

The preferred format of "10KT" effectively communicates that the measured wind speed is 10 knots and adheres to the required meteorological reporting standards. Therefore, while the estimation is indeed 10 knots, the chosen answer does not fulfill the necessary criteria for proper meteorological reporting. The correct format should have included the unit to enhance clarity and universally communicate the observation.