How Tropical Storm Debby will bring 30C heat to UK
Another brief hot spell
If you haven’t heard already, there’s another brief hot spell on the way for some parts of the UK this week – and the emphasis really is on brief.
Long periods of continuously hot weather have been in short supply this summer. It’s been the coolest first half of summer since 2012 and the 17th coolest start to summer since 1960, according to data from the Met Office.
Why has this been the case? It’s been down to the jet stream – the arbiter of where, when and what type of weather we experience.
For much of this summer, it has been stuck over or to the south of the UK, which has caused it to often be cooler than average, and sometimes wet and unseasonably windy.
Tropical Debby’s influence
Across the other side of the Atlantic Ocean, the southeast of the US is being hit by Tropical Storm Debby, causing torrential rain, major flooding and a coastal storm surge.
Despite this storm being 3,800 miles away, it is going to play a part in bringing the brief hot spell to parts of the UK early next week – but how?
As Tropical Storm Debby moves northwards in the coming days, it will drag up some very warm tropical air, which will collide with cooler air across Canada. This contrast between the warm and cool air will not only cause the jet stream to pick up speed, but also buckle in shape.
When the jet stream buckles, it will send a ripple along it across the Atlantic Ocean, which will cause it to move north of the UK this weekend. This will pull up some very warm and humid air across southern and eastern areas.
When and where will it heat up?
As I mentioned earlier, this burst of heat will be brief, and probably only across England and Wales during Sunday and Monday. Here, temperatures are expected to reach the mid to high 20s widely, with some parts of eastern England rising to the low 30s on Monday.
Scotland and Northern Ireland may have some fine weather early on Sunday, before rain moves slowly eastwards into Monday, limiting temperatures to 15-22C.
As the heat and humidity break down later Monday, showers or longer spells of rain – even thunderstorms – are expected to drift eastwards over many areas.
What about the rest of August?
Looking further ahead, to the middle of August, the most likely outcome is for the changeable weather to continue. Whilst there will be showers or longer spells of rain at times, there’ll be some drier, brighter and warmer days in between.
Later in August, the uncertainty becomes too great to offer any sort of clear signal – especially as Atlantic hurricane activity is expected to increase.
So, if the heat is your thing, enjoy the upcoming brief hot spell. If you don’t like the heat, don’t worry; blink and you’ll miss it, as fresher air quickly returns.