Water, water, water everywhere. High-humidity air masses arise over the seas. This categorization of "maritime" corresponds to the same latitudes as the continental masses. It is also classified as a subsidiary category and is denoted by the letter "m." As a result, a humid, chilly mass that forms over polar waters is classified as "mP."
Cold, dry air masses are common in the middle latitudes during the winter months. These masses are classified as "d" because they are characterized by low relative humidity and high temperatures. Temperatures below freezing are not uncommon for this type of air mass. The polar regions experience these types of conditions all year round.
A maritime cold front is similar to a continental cold front except that it does not have as strong of a temperature decrease as a continental frontal system. Maritime fronts often produce heavy rain or snow across large areas of the continent.
A maritime hot front is similar to a continental warm front except that it does not have as strong of a temperature increase as a continental frontal system. Maritime fronts often cause severe weather across large areas of the continent.
A maritime tropical cyclone is a hurricane or typhoon that develops in the ocean between Canada and South America. These systems are very rare but when they do form they can bring devastating damage to their target region.
Maritime tropical cyclones are classified into three categories based on intensity: weak, moderate, and strong.
Continental air masses are dry air masses that develop over land. The maritime air masses that originate over water and are humid are their equivalents. February 25th, 2016. Drifting across the continent on a cold front, a continental air mass will cause temperatures to drop throughout its progression.
The word "mass" here refers not to weight but rather to how much air is with regard to temperature and moisture content. A mass of warm air is stable and will not move unless disturbed by something (such as wind). A mass of cool air is unstable and may fall as rain or snow. Warm moist air rises and becomes less dense than the surrounding air which causes it to rise; this is why high-pressure systems tend to bring rain with them. As for dry air, that too is becoming more common as our planet warms up. This type of air is less dense than other things around it such as trees and rocks and so it tends to flow away from these objects into low-pressure areas.
Thus, a continental air mass is a type of stable air mass that will not change state until it reaches higher altitudes where there is less pressure available to hold it together. These are also called anti-cyclonic conditions because they often come in waves corresponding to the movement of weather systems across the country from west to east.
Air masses that form over land are called continental air masses and are dry. Their counterparts are the maritime air masses that form over water and are humid. Continental air masses can be further divided into four sub-classes based on their source region: Arctic, Antarctic, Westerly, and Sub-Westerly.
Arctic continental air masses originate in the Arctic Ocean and are characterized by low relative humidity and high temperatures. They can cause cold weather when they move southward toward more temperate regions.
Antarctic continental air masses are similar to Arctic continental air masses but instead of coming from the Arctic Ocean, they originate in the Antarctic Plateau. Like their Arctic counterparts, they can cause cold weather when they move southward.
Westerly continental air masses are found west of the World's Continentals and are characterized by high pressure systems located far away from the origin continent. As the name suggests, these air masses travel across the Atlantic or Pacific Ocean before reaching their destination.
Sub-Westerly continental air masses are found east of the World's Continentals and are characterized by low pressure systems close to the origin continent. They too cross an ocean before reaching their destination.