Which air mass provides the moisture that produces the clouds and precipitation?

The MT is the air mass that provides the moisture that produces the clouds and precipitation. An air mass is a volume of air that is defined by its temperature and water vapor or moisture content. MT is the abbreviation of marine time air mass. Air masses can control the weather for a relatively long time period from a period of days, to months, Most weather occurs along the periphery of these air masses at boundaries called fronts.