Rapid Stratospheric Temperature Spikes Over the Arctic When temperatures in the polar stratosphere suddenly climb, climate analysts instantly recognize this as one of the most critical warning signs.

Yes, it's winter. It's been a while since we've had a cold spell of this magnitude and for this long. What's causing it?

In the United States, our weather patterns usually travel from the west to the east. Sometimes, we can see variations in that a system will move in from the northwest or southwest, but Missourians ...

The jet stream is about 14 percent slower in the fall now than in the 1990s, according to a recent study by Francis. And when it slows, it moves north-south instead of east-west, bringing more unusual ...