Answer:
Convection
Step-by-step explanation:
Convection is the transport of heat by a fluid like air or water.
Hot air is less dense than cold air, so hot air rises and cold air sinks.
In weather, convection refers to the vertical transfer of heat and moisture from the surface to a cooler area aloft.
Conduction is wrong. It involves the movement of heat by collision of molecules.
Radiation is wrong. It does not need a medium to transfer the heat.