A "Bulging Lobe" Of Polar Vortex Madness Headed For U.S. East Mother Nature across the Mid-Atlantic can only be described by the Katy Perry lyric, “You’re hot, then you’re cold,” as a meteorologist warns that a "tropospheric polar vortex" will sweep across the Lower 48 this weekend into early next week, abruptly ending the summer-like conditions in Washington, D.C. "A bulging lobe of the troposph