Wind speed is given here in the units of "knots" (kts). A Knot is a nautical mile per hour.
Using the table below, each short barb represents 5 knots, while each long barb represents 10 knots. A single long barb and a short barb is 15 knots, simply by adding the value of each barb together (10 knots + 5 knots = 15 knots).
Pennants are 50 knots. Therefore, the last wind barb in the chart below has a wind speed of 65 knots. (50 knots + 10 knots + 5 knots). If only a station circle is plotted, the winds are calm.
