The radar summary chart indicates which of the following features?

The radar summary chart is designed specifically to depict weather-related information, particularly focusing on the movement of precipitation areas. This chart allows pilots and meteorologists to visualize how precipitation is evolving over time, including its intensity and direction. By analyzing the movement of these precipitation areas, users can make informed decisions regarding flight planning and safety, ensuring that any potential weather-related disruptions are accounted for.

The other options do not pertain to the primary function of the radar summary chart. For instance, heat index readings are more related to temperature and humidity conditions rather than precipitation dynamics. Flight maneuvers required for aircraft are influenced by a variety of factors, including aerodynamic considerations and airspace regulations, but are not directly indicated on radar summary charts. Similarly, paths of commercial shipping lanes involve marine navigation rather than the meteorological data provided by weather radar, which is focused on atmospheric conditions rather than maritime routes. Thus, the choice of movement of precipitation areas directly aligns with the radar summary chart's purpose of providing critical weather information for aviation and meteorology.