Arctic blast: Will jet stream bring blizzards?

If you're like most people, you often awake in the middle of the night with a gasp, wondering about the jet stream what pattern it's in, how it will change in the weeks to come, and, in more serious cases, what the heck it is!

Well, wonder no more.

The jet stream is a "river" of fast-flowing air that moves from west to east. Generally, the jet stream separates cold air to the north from warmer air to the south. According to Jerry Stenger in the state's climatology office, sometimes the jet stream is in a four-wave pattern (with, amazingly enough, four crests and four troughs around the globe), and sometimes it's in a five-wave pattern.

For the first eight months of this year, the jet stream was stuck in a pattern that kept a trough positioned over the southeast, bringing cold, wet air down from the northwest and delivering it right up to our doorsteps. Whether that pattern will repeat itself this winter is anybody's guess, Stenger says.