Folks in the eastern part of the country may have "severe and punishing" weather to look forward to in less than two weeks, with cold to chill the bones and "heightened storminess." That's per weather model forecasts cited by the Washington Post, which warns of the consequences of a recent three-way split of the polar vortex—a low-pressure area of cold air that hovers over the planet's poles, and which on occasion expands southward from the Arctic, bringing bitingly extreme weather with it. In this year's case, the weakening of the polar vortex in early January was caused by a sudden stratospheric warming (SSW) that then spurred the vortex "to split into three distinct circulation areas," per the Weather Channel. What that split means is more cold air headed south toward Russia, Europe, Canada, and, eventually, the US.
However, exactly when and how the vortex may affect us is unclear, as it typically takes weeks for the effects of this weather event to manifest itself in conditions on the ground. What forecasters are predicting so far, though, is that it will be as much as 25 degrees colder than normal by the end of the weekend in the center of the US and in the east. And that may only be an "appetizer," per the Post. One weather watcher observes that the weather pattern we may see by the end of January or early February "will be a lot more impressive." "This is about the coldest planetary-scale pattern you can ask for," he notes of current weather-pattern maps. A "wild, wintry ride" is what one meteorologist predicts for the eastern US and Europe at the end of the month, noting both the US and European modeling systems are in sync on what could be heading our way. (Can the snow in Siberia give us a clue?)