Week-long UK heatwave on way with 'monster' temperatures possible later this month

North Wales Live

a day ago

A third UK heatwave is expected this week and some models suggest it could last at least a week with a short interlude in between. One renowned meteorologist has detected signs this summer is 'reminiscent of summer 2022' when the mercury hit 37.1C in Flintshire and 40C in eastern England.
Most weather models have backed down from scenarios showing these kind of extreme temperatures in the coming days. More likely is temperatures sitting around 5C-10C lower than these peaks.
The GFS system is currently suggesting highs of 31C in the Welsh Borders over several days. In its ensemble forecasts, the Met Office is more cautious, predicting peaks 1C-2C lower.
However Netweather meteorologist Ian Simpson said 'monster' temperatures cannot be ruled out for late July. 'It now looks probable that any really exceptional heat will not set in until later in the month,' he said.
Heat is expected to start building from Wednesday, July 9, as warmer air moves up from the near continent. As this plume moves north, the West Midland is in the firing line, with the heat spreading across Wales.
The weekend is expected to be very warm, peaking on Saturday, July 13: according to the Met Office, highs of 28C-29C are expected widely across North Wales.
The forecaster said Wales will become 'increasingly warm' at the end of this week. By Friday and over the weekend, the Met Office: 'Many parts of the UK are expected to be part way through a period of high temperatures and humidity. The duration, geographical extent and intensity of the heat are all rather uncertain at present, but there is the potential for some very hot weather to be realised, especially across some inland southern and eastern areas.'
Current models suggest some respite early next week with the heat plume retreating from Wales and ebbing in England. By Wednesday, July 16, the heat may then start building again, particularly in England. At present, it's less certain whether high temperatures will return to Wales, thought the expectation is that it will be warmer than average.
Mr Simpson said the weather patterns seen so far this year have echoes of those in 2022, when continental Europe experienced its hottest ever summer. Like then, rainfall totals have been low, especially in eastern England. Parched ground has primed some regions for a 'higher than average chance of substantial heatwaves', he said.
As in 2022, the UK weather has also been marked by an 'enhanced northwest-southeast split", with cloudier and wetter weather in northwest Britain.
Despite this, Mr Simpson said: 'I see it as unlikely that we will see another 40C in Britain this year, as a lot of things would have to fall into place synoptically for that to happen.
"But the chances of it are higher this year than during the summers of 2023 and 2024, and the chances of us getting into the mid-30s Celsius at some point this summer are quite high.'
Next week, hotter weather is forecast to establish again over western Europe, with temperatures widely in the mid-30s in France. Sign up for the North Wales Live newsletter sent twice daily to your inbox
Mr Simpson said: 'This will leave Britain quite prone to the occasional burst of notable heat, especially in the east of England, during the second half of July, should we pick up a southerly flow pulling this hot air in from France at some stage.
'The forecast models have, however, currently backed down from predictions of monster heatwaves with temperatures widely into the low 40s Celsius in France and touching 40C in parts of England around 12-15 July.
"Temperatures in these regions, while still hot by most standards, are now generally forecast to be around 5-10C lower than those figures.' Higher peaks are possible later in the month, he added.