Image caption
Observed and forecasted (NOAA GEFSv12) wind speed at the 10-hPa pressure level and the 60-degrees North latitude circle. The average timing of the final stratospheric warming occurs around April 12th (where thin purple line falls below 0 m/s and stays there through summer). The forecasts indicate that this year the final warming will occur later than average. NOAA Climate.gov image, adapted from original by Laura Ciasto.