Temperatures will fall significantly this week over much of the Lower 48, as a mass of cold air descends southward over the United States. (Weatherbell.com) October 28 at 6:54 PM A powerful Arctic air mass is surging southeast, leaving the Plains and Intermountain West squarely in the throes of the icy tongue of air. Temperatures dipped to nearly minus-35 in Utah, with a number of other locales set to plunge below zero toward the mid- and late week. Meanwhile, a strong storm will develop along the chilly air’s leading edge, bringing a soggy Halloween to the East. The setup The uncooperative weather — which is all tricks and no treats — is thanks to a serpentine jet stream, a river of strong winds in the upper atmosphere. Nudged north by a bubble of warmth over Alaska, the jet then collapses south, allowing a pool of cold air to spill […]