Understanding Air Masses

You hear the meteorologist talk about it all the time - a 'cooler' air mass or a 'warmer' air mass will heat up or cool down our temperatures.  But have you ever really wondered just where those air masses originate from?

Have you ever heard the two terms Continental Air Mass or Maritime Air Mass?  Maybe you have, but just haven't given it much thought.  Well an air mass, like a body of water, is a large body of air with fairly uniform temperatures and humidity.  Depending upon where that air mass originates from, will help determine its characteristics.  And just as if you were to heat up or cool down water for a long period of time, the longer an air mass stays over a particular region, the more the air mass will acquire that lands characteristics.

There are basically two main air mass types that are determined by their moisture content.  They are Continental and Maritime.  A Continental air mass - written out on maps as a lowercase 'c'- starts over land and is a dry air mass because of it.  A Maritime air mass - written out on maps as a lowercase 'm' - starts over water and is a moist air mass.  From there, you can break down the air mass category even further to account for the different surface temperature of where the air mass is originating from.

For example, an air mass that develops over land near the Arctic will be known as a Continental Arctic Air Mass because of the very dry and cold region it originates from.  Polar air masses form over the higher latitudes of both the land and sea, but are not quite as cold as the 'cA' air mass (Continental Arctic).  Tropical air masses can originate from either land or water in the desert southwest or near the Equator.

Here's the fun part - we can now begin putting together or different types of air mass designations together.  For example, an air mass that originates at the higher latitudes over water is referred to as a 'mP' air mass, or Maritime Polar air mass.  Or an air mass that originates over land from the southwest will be a 'cT', Continental Tropical air mass because it's a hot and dry, but is close to the tropics.

Following Monday evenings cool front a different type of air mass will arrive for Tuesday.  Any guesses as to what type of air mass that will be?  If you guessed 'cP', you're right!