One meteorologist is warning of another Sudden Stratospheric Warming (SSW) event that could plunge temperatures below average across parts of the U.S. later this month. In November, the National Weather Service (NWS) warned of a major SSW, a rare event so early in the season. SSW refers to a rapid rise in stratospheric temperatures that weakens or distorts the polar vortex, a cold-air mass typically stabilized over the Arctic. The weakening enables cold, dense Arctic air to slip southward into