wxd-london.bsky.social

wxd-london.bsky.social

11 October 2026 12:51

[1/4] 🌀 Polar vortex tracking is back for winter 2026-27. We check the GEFS 31-member ensemble 4x daily for wind reversal at 10hPa, 60°N. Today the vortex is moderate at 17.6 m/s, and 0/31 members show a reversal.

wxd-london.bsky.social

wxd-london.bsky.social

11 October 2026 12:51

[2/4] Some context. The UK just had its hottest summer on record: a 16.5C mean, 40 days at 30C+ and 38.1C in August, and it was very dry for many. Meanwhile a strong El Niño is building, and September's reading was the highest since 1982.

wxd-london.bsky.social

wxd-london.bsky.social

11 October 2026 12:50

[4/4] 🧠 Also new: our forecast write-ups now run on Claude Sonnet 5.5, up from 4.6. The weather models and data are the same, and the commentary is sharper on dates and numbers.

wxd-london.bsky.social

wxd-london.bsky.social

11 October 2026 12:50

[3/4] El Niño tends to raise the odds of a stratospheric warming in late winter, which can open the door to cold, blocked patterns over the UK. No guarantees and no expectations, but who knows. We'll post when a signal appears.

Owen Griffiths

ogriff79.bsky.social

11 October 2026 12:50

@winchesterweather.bsky.social