Final answer:
When 'light and variable' is used to describe winds aloft forecast and coded groups, it means the wind speed is less than 5 knots and the wind direction is constantly changing.
Step-by-step explanation:
When the term "light and variable" is used in reference to winds aloft forecast and coded groups, it means that the wind speed is denoted as less than 5 knots. This term is used when the wind direction is constantly changing and the speed is very low.
For example, if a forecast states that the wind is 'light and variable' at 230 m/s, it means that the wind speed is less than 5 knots and the direction is constantly changing.
This information is important for pilots and meteorologists to accurately predict the weather conditions and plan air travel.