Polar vortex status
The SPV is currently marginally weaker than ERA5 average and is forecasted to remain weaker than average (according to GEFS-mean) 4 of 31 members have stronger vortex than average at the last forecast step (2025-09-24 18:00:00) The SSW probability in GEFS is: 0%. The zonal mean zonal wind at 10 hPa 60N is today (GFS analysis): 5.2 m/s Weakest zonal wind at 10 hPa 60N in ERA5 record for todays date is: 3.0 m/s 1986 Strongest zonal wind at 10 hPa 60N in ERA5 record for todays date is: 8.2 m/s 2021