How is wind speed represented in meteorological observations?

Wind speed in meteorological observations is rounded off to the nearest 5 knots and is symbolized by various markers. The symbols used to represent different wind speeds are:

• Full feather: Represents 10 knots (11.5 mph)
• Half feathers: Indicates 5 knots
• Pennant: Signifies 50 knots
• Circle drawn around the station circle: Indicates calm conditions