Polar vortex outlook for winter 2026/27: El Niño analogs vs ECMWF SEAS5 🌀 Polar cap (60-90°N) temperature anomaly, Oct-Apr, from the surface to the stratosphere. 📊 Analogs (strong East-Pacific El Niño years 1997, 2015, 1982, 1957; NOAA CORe): A cold, strong polar vortex from November through most of January. Then a sharp stratospheric warming in late January / early February that works its way down towards the lower stratosphere by March. ECMWF SEAS5 (October run, 51 members): The same overall story: a cold vortex in November and December, then a strong warming signal that arrives earlier, from late December, peaking in January and reaching below 100mb by February. The takeaway: both point to a strong vortex in early winter, followed by a vortex disruption in mid-to-late winter. The main difference is timing: SEAS5 brings the warming about a month earlier than the analogs. A weaker vortex in late winter raises the odds of a negative AO / NAO pattern and cold outbreaks into mid-latitudes, but the timing is uncertain at this range. Also, the analogs are only 4 years, with high variance. @judah47 @webberweather @RyanWeather