The WeatherDuck blog
Inversion mornings, forecast checks and practical ideas for planning your next day outside.
Tuesday 22 September 2026 was one of those mornings. From Yr Wyddfa in the north to Pen y Fan in the south, the big Welsh summits sat above a sea of cloud from before dawn until well after breakfast, and WeatherDuck had flagged it from the Sunday evening. Here’s how the morning looked, thanks to…
Likely Flagged 31 hours ahead on Yr Wyddfa. View reportLikely 12 hours ahead Wales
Morgan’s view above Glyder Fawr and Castell y Gwynt, Neil’s photos from Bannau Brycheiniog, and a closer look at the warning times.
Photos, trips and season notes
Tuesday 22 September 2026 was one of those mornings. From Yr Wyddfa in the north to Pen y Fan in the south, the big Welsh summits sat above a sea of cloud from before dawn until well after breakfast, and WeatherDuck had flagged it from the Sunday evening. Here’s how the morning looked, thanks to…
Saved forecasts against what people saw
Selected mornings we’ve checked closely. Examples, not an accuracy rate.
Looking for the evidence trail?
Evidence ledger
Every saved forecast checked against what actually happened, with the lead time, the forecast evolution and the limits kept together in each case.
Browse the forecast checksAnnual report
More than 13,000 archived mornings scored with today’s forecast formula, to show when and where UK cloud inversions are most likely.
Read the reportStay ahead of the fog
Email alerts tell you when the forecast turns Likely or better for your area, and stand you down if it falls apart overnight.
