What is an air mass? How do air masses generate our local weather?
An air mass is an expansive area of air with uniform temperature and moisture content. Air masses can be hundreds or thousands of miles across. They typically form over a landmass or ocean with uniform properties. For example a landmass with lakes, mountains and plains would NOT be a good place to form an air mass. The Gulf of Mexico is an example of a great place to form an airmass because it is a large area of “just” warmth and moisture. An airmass that forms over the Gulf of Mexico is called Maritime Tropical and is responsible for the summer heat and humidity in the Southeast US. Because the Tri-State area is in the Mid-latitudes air masses tend not to form here. They either form where it is really cold (i.e. northern Canada) or really warm (i.e. Gulf of Mexico). So the air masses that generate our weather come from somewhere else and bring the attributes of that region. Locally we can sometimes get a maritime air mass from the Atlantic Ocean if conditions are right. Jeff Berardell