The polar vortex is one of Earth’s most powerful climate systems and scientists believe it may be collapsing. This could ...

When it’s in its easterly phase, it can weaken the polar vortex, making the jet stream less steady and pushing frigid Arctic air farther south. As a result, central and north-central Wisconsin could ...

A warmer-than-average winter is anticipated across the southern tier of the United States, including California ... Reliable ...