This site is all about air masses. I will state how air masses form and what they are.

    If a large body of air stays in one place for a number of days or weeks, it will change it's thermal and moisture properties depending on what the body of air is over. It will switch and switch it's temperature until it is the same as the water, land or what ever the body of air is over (that includes moisture and such). In conclusion, a body of air that that is over the same area for a period of time, changes it's moisture and temperature to the land/ water its over and is called an air mass.

Air Masses, like I said before, are a body of air that stays over the same area for a period of days or weeks. The body of air will eventually, have the same moisture and temperature of the land or water it's over.

    Something interesting: An air mass can cover an entire continent, or something as small as a park!

    The thing that separates an air mass of another is a front. That's pretty much it on fronts. If you want more information on fronts, click here.

    I don't know if air masses can get to be dangerous, but I don't think so.
Well, that's pretty much it for now ... this is all I have.