It's been years since we've seen this type of cold in the U.S. which begs the question, WHY? In fact, Boston hasn't seen cold like this in almost 100 years! Why is it so cold and when will it end? Blame Canada Typically, the Polar Jet separates the arctic air to the north and the somewhat moderate air to the south. This is what keeps us from getting all of that bitter cold from the arctic. Sometimes this jet makes drastic moves. We call these ridges and troughs. When the jet itself dives far south, that is a trough. That dive south also allows the arctic air from the north to spill into the U.S. much like what we've seen this winter. Polar Vortex The polar vortex is a real thing. It wasn't made up by the media. And it actually exists year-round. It is the tight area of spinning air around the pole. The stronger the polar vortex, the tighter it is, and the less we hear about it. Contrary to what it might seem, the years when the vortex is weaker also happen to be the years it brings arctic air into the lower 48. When the vortex (spinning) is weaker, the polar vortex itself will start to wobble or move from the pole. When it slides toward us, the jet dives south and we feel the impacts of that bitter-cold arctic air. This is why a majority of the residents in the U.S. have been seeing so much cold air recently. Global Warming If global warming is a thing, why is it so cold? There is a big difference between weather and climate, and this recent cold is definitely weather. https://media.weathernationtv.com/news/climate-vs-weather-2/ But global warming might also be causing all of this cold. You see, shrinking ice caps mean that the polar part of the polar vortex isn't as strong. We just don't have the bitter cold to the north that would typically keep the polar vortex strong and near the pole. This lack of cold means the vortex will move more, even plunging south into the U.S. bringing us all of that cold! Just because we are colder than normal doesn't mean the rest of the world is. In fact, parts of the world and even the U.S. are experiencing temperatures above normal for this time of the year. When Will it End? Never! Kidding! Some of the weather models show that massive trough over the easter states breaking down by early next week. Better yet, it doesn't look (right now) like we will see another bitter blast like this after next week's warmup! So hang in there and stay warm! For WeatherNation — Meteorologist Jeremy LaGoo