The big picture: The National Weather Service warns the " polar vortex," an area of cold air around the Arctic, could expand southwards and combine with two other factors to bring "cooler than ...

The Climate Prediction Center (CPC) is forecasting a weakening of the polar vortex, which will allow cold air to seep into the United States. From Nov. 25 through Nov. 29, it's primarily …

Another Arctic blast is on the move toward the U.S., bringing the potential for cold and snow in Vermont. The Climate Prediction Center (CPC) is forecasting a weakening of the polar vortex, …

New York could see a return of Arctic air around Thanksgiving as models suggest a possible wobble in the polar vortex, bringing frigid air into the U.S.

Wisconsin is in store for a warmer weekend, but could see a return of Arctic air around Thanksgiving as models suggest weakening in the polar vortex.