Note: This video is designed to help the teacher better understand the lesson and is NOT intended to be shown to students. It includes observations and conclusions that students are meant to make on ...

This upper-level temperature animation shows a deep trough plunging Arctic air south from Canada, allowing the polar vortex to funnel the coldest air of the season into the eastern United States.

Forecast 850-millibar temperature animation (1 mile above the surface) This is a good proxy indicator of how temperatures will respond at the surface. Blue shading is cooler than normal air, while ...