Air Masses: Types, Naming, and Characteristics

• Air masses are large, roaming bodies of air with uniform temperature and humidity, shaped by their formation location over land or water.
• Meteorologists analyze air masses to forecast weather conditions.

Air Mass Naming Conventions

• Names indicate formation over land (continental) or water (maritime) and temperature (tropical, polar, or arctic).
• Continental air masses are drier.
• Maritime air masses are moister.
• Tropical air masses are warmer.
• Polar air masses form over cooler locations.
• Arctic air masses form over the coldest regions.

Air Mass Abbreviations

• Continental is represented by "c".
• Maritime is represented by "m".
• Tropical is represented by "T".
• Polar is represented by "P".
• Arctic is represented by "A".

Types of Air Masses

• Maritime tropical (mT): moist and warm/hot.
• Continental arctic (cA): dry and very cold.
• Maritime arctic (mA): moist and very cold.
• Maritime polar (mP): moist and cool.
• Continental polar (cP): dry and cool.
• Continental tropical (cT): dry and warm/hot.
• Maritime Polar air masses feature higher humidity than Maritime Arctic air masses

Air Mass Formation in North America

• Maritime tropical (mT) air masses form off the coasts of California/Baja California and in the Gulf of Mexico/Florida, bringing warmer, moister conditions.
• Continental arctic (cA) air masses form in northern Canada and the Arctic Circle, resulting in dry, very cold weather.
• Maritime arctic (mA) air masses do not form in North America but influence the British Isles with cold, wet, and snowy weather.
• Maritime polar (mP) air masses form over the Pacific off Alaska/Canada and in the Atlantic off Canada, causing wet, cold, and rainy weather.
• Continental polar (cP) air masses form in Canada, bringing dry, cold conditions.
• Continental tropical (cT) air masses develop over Mexico and the American Southwest (Texas), leading to warmer, drier conditions.

Influence on Weather

• Jet streams, fast-moving upper atmosphere air bands, move air masses from west to east.
• Stagnant air masses cause prolonged weather conditions based on their characteristics.
• Frontal boundaries occur when air masses collide, leading to weather changes.
• Cold fronts form when colder air masses push under warmer ones, causing thunderstorms and snowstorms.
• Warm fronts develop when warm air masses rise over cooler ones, resulting in rain followed by warm, humid conditions.
• Cooler air masses are denser and stay near the ground, while warmer air rises.

Cloud Formation

• Rising air and moisture lead to cloud formation as water droplets attach to airborne particles.
• Cumulus clouds form when cool air pushes under warm air; these can become cumulonimbus clouds, causing storms.
• Convectional lifting occurs when warm air rises, cools, and falls, creating convection currents and cumulus clouds, often in equatorial regions.
• Orographic lifting happens when air masses are forced over mountains, cooling and forming clouds, leading to increased precipitation (including snow) on one side of the mountain, as seen in North Carolina.

Air masses are large volumes of air with uniform characteristics, named based on their formation location and temperature. Meteorologists use air mass analysis to predict weather. Common types include maritime tropical (mT) and continental arctic (cA).