polar-vortex_winds-temperature_graph_stack_20240108.png

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 January 7, only a few model runs predict a reversal of the vortex winds (top, thin magenta lines), and the average of all the runs (thick magenta line) predicts wind speed and direction will be near normal. Individual forecasts for temperature (bottom graph, light red lines) average out to just below normal temperatures (thick pink line). NOAA Climate.gov image, adapted form original by Laura Ciasto.