Already in the last 6-week Mkweather forecast from ECMWF, we focused on late and widespread Indian summer forecasted for the first half of November 2021 across the Northern Hemisphere /https://mkweather.com/silence-before-a-storm-and-the-last-summer-like-weather-before-an-extremely-cold-winter-the-first-half-of-november-should-bring-indian-summer-in-europe-canada-and-siberia-forecast-until-15-novemb//.
Although this anomaly should be partially a product of an Early Canadian stratospheric warming pattern, which should be alternated by legendary cold December and early January 2021/2022 /https://mkweather.com/winter-2021-2022-forecast-a-peak-near-nao-already-in-december-ne-pacific-warm-blob-nao-and-early-spring-in-february-north-america-oppositely-warm-start-cold-end-of-winter/; https://mkweather.com/russian-meteorologists-expect-extreme-winter-around-december-january-2021-22// (this anomaly was in the past often changed into legendary cold December conditions), not 2, but in many regions the first 3 November weeks should bring unseasonably warm and very late Indian summer conditions across continents of Northern Hemisphere.
In northern parts of mid-latitudes, around 50 – 55 °N, maximum temperatures above +20°C near sunny weather should appear in many regions (only Siberia will be colder).
Southern mid-latitudes, around 45 °N will be even warmer, with regional summer days above +25°C (e.g. parts of Iberia, southern France, Italy, Balkan, southern Black sea region in Europe and maybe will surprise Great Lakes region in the USA and Canada, too).
Before these “late season heatwaves”, extremely cold conditions should hit Europe and the western USA, such as parts of Asia in October 2021 /https://mkweather.com/extreme-frosts-close-to-30c-in-scandinavia-are-forecasted/; https://mkweather.com/the-first-snow-in-europe-several-runs-of-gfs-are-extremely-cold/; https://mkweather.com/winter-is-coming-an-extreme-arctic-blast-for-europe-temperatures-in-central-parts-and-balkan-should-reach-15c/; https://mkweather.com/mould-bay-canada-237c-extreme-arctic-blasts-hit-all-western-half-of-the-usa-soon/; https://mkweather.com/labaznaya-siberia-249c-at-the-level-of-seasonal-temperature-records//.
After this warm period, short and extremely strong winter conditions are possible approximately from late November to early January 2021-2022 according to Mkweather estimates /links to Winter 2021/2022 forecasts above – will be updated in the next days/.
The 6-week ECMWF forecast for other continents you will find on maps below (11. October – 22. November 2021).
All 6-week forecast: