Thursday 21st August 2024

Becoming hot again by Sunday/Monday.

Photograph is from me this week, of a business estate in Croydon when I bought some paint. The only local photographs I have are of cloud and rain (unusually)…keeping them for next week.

The general picture sees a ridge of high pressure over the south of the UK, with low pressure closer than it has been, just to the north of Scotland, driven by a strengthening jetstream. Tropical storm Debby is off the coast of USA, and about to have an impact on our weather.

Today starts sunny, but during the morning cloud spreads across from the west, with some occasional mostly light/moderate rain and limited brightness. Breezy and around 20’C, perhaps a tad under. Patchy light rain and drizzle continues overnight, a fairly warm night at 17’C.

Friday sees any early cloud, patchy light rain clear fairly quickly, leaving good spells of sunshine and a bit of fair-weather cloud. Very warm, around 24’C or a tad more. Reasonably clear skies overnight, though tending to be a bit more cloud later, no lower than around 15’C.

Saturday starts fairly cloudy with another weak weather front passing through, bringing cloud and perhaps a little patchy rain. Some uncertainty as to how quickly it clears through, midday is probably the earliest it could clear into sunshine, late afternoon the latest, and as such there is a range of possible maximum temperatures, anywhere from 23’C to 27’C – depending on how quick the cloud breaks up. Clear skies overnight, down to around 13’C – though a small chance of mist/fog by dawn.

By Sunday, the remnants of Debby will still be over the US, but will have caused a kink in the jetstream which allows hotter air to spread up from Spain.

Long spells of sunshine likely all day, any earlier mist/fog will clear quickly, perhaps a little fair-weather cloud at times but otherwise a very pleasant summer day, and hot, around 30’C – give or take, becoming more humid too. A warm night likely overnight, somewhere between 18’C and 20’C – as low pressure approaches.

Details a bit more uncertain for Monday, as low pressure will be close to our north west, but we should hang onto the heat, and it should be hotter than Sunday, say 31’C, maybe 32’C – likely humid too, and breezy. Generally fairly sunny, some cloud, an outside chance of a shower but most likely dry. Fresher air gradually spreading across overnight, mostly clear skies and eventually down to around 14’C.

Tuesday looks reasonably sunny, some cloud around and the heat gone – around 23’C, give or take. The remnants of Debby bringing a bit of rain in the evening and overnight.

Wednesday a bit more uncertain on details, but probably cloudier earlier, sunnier later – the odd shower and warm.

From there day to day details are too uncertain, though broad-scale the jetstream looks to be further south once more, so some rain at times looks probable, but not a washout – with sunny, warm days just as much in the mix, if not more so.

The more likely outcome for the latter part of August keeps the same kind of pattern, a westerly flow, probably slightly drier than average, but some cloudier days with some rain, some pleasantly sunny days. Hot weather less likely than normal for late August, but still possible.

Enjoy the weekend, and the hot weather if you can cope!