jysI6qfeeKTQ04o_4skIAOqPtZVPVboW_CTM_0224_GLAROS_640x360Another bout of painfully cold Arctic air is on its way to the northern United States, reviving talk of what has become popularly known as the “polar vortex.” By Thursday, temperatures will have dropped to as low as 30 degrees Fahrenheit (17 degrees Celsius) below the average temperature for this time of the year, meteorologists say, with highs dipping down into the teens in New York City and into the single digits in Chicago. Average temperatures for this time of year in those regions are generally closer to 45 and 40 F (7.2 and 4.4 C), respectively, said Bernie Rayno, a meteorologist with Accuweather. While it’s not necessarily inaccurate to refer to the event as the “polar vortex,” Rayno said, the increased hype around this phrase since January’s deep chill has warped people’s perceptions of what is actually a fairly common weather phenomenon. [Weirdo Weather: 7 Rare Weather Events] “We have seen this happen every winter in the past 24 years I have been a meteorologist, but this winter, it has happened more frequently in the upper Midwest and Northeast,” Rayno told Live Science. More