Observed and forecasted (NOAA GEFSv12) wind speed (top) and temperature (bottom) in the polar vortex compared to the natural range of variability (faint shading). For the GEFSv12 forecast issued on December 1, the winds at 60 degrees North (the mean location of the polar vortex) are forecast to remain stronger than normal for at least the next 2 weeks (top, thick magenta line) before slowing down to near normal strength. Lower stratospheric temperatures over the polar cap (bottom, thick pink line) are favored to be slightly colder than normal. It’s interesting to note that these temperatures in the lower stratosphere were warmer than normal between July and October, potentially related to the increased stratospheric ozone levels. NOAA Climate.gov image, adapted from original by Laura Ciasto.