Placing markings on a trajectory chart will help you to combine the information on this chart with the information on cloud charts. For example, the circle indicating the trajectory arrival location tells you where to look for clouds using the map corresponding to the time of arrival (March 15, 0000 UTC). The other circle tells you where to look for clouds using the map corresponding to a time 24 hours earlier (March 14, 0000 UTC). In the altitude graph at the bottom of the trajectory chart, the units of altitude are “meters AGL”, which means “meters above ground level”.