Science of Weather: Different Air Masses 02:23. If you hear a meteorologist, say stormy weather is expected, we didn't just pull it out of thin air. Instead, we looked at weather models predicting ...

The polar vortex changes periodically, allowing very cold air to move south. (Courtesy of NOAA) When there are extreme events like wind chills 50 below zero and actual temperatures not far off ...

Polar air masses are not as cold as arctic air, originating over higher latitudes. Tropical air masses have warm and hot temperatures, originating over the lower latitudes.

Continental tropical: hot and dry airmasses that form over the deserts of the western U.S. Maritime polar: most commonly helps form storm systems that move over the pacific northwest.

For the most part, tropical air masses originate between the equator and ~25N while polar air masses originate north of 60N. The area between represents most of the continental US and is also ...

Editor's Note for Sat. Jan. 18: A polar vortex is set to impact much of the US. Click here for the latest update. A polar vortex is forecasted to blanket most of the continental United States in ...

A polar vortex is bringing cold temperatures to the U.S., impacting Utah as well. Utah will experience its coldest temperatures this winter, though less severe than areas east of the state.