On Friday, low-pressure will be positioned to the west of Scotland, continuing a theme of unsettled weather over parts of Scotland and Northern Ireland. Western parts of Northern Ireland will be most prone to thunderstorms, with a yellow warning in force for much of Friday.  

However, further south, temperatures will start building on Friday, and could reach 30°C in isolated spots in the east and southeast.  

Met Office Chief Meteorologist Dan Suri said: "It’ll be a hot start to the weekend for many as a plume of very warm air drifts across the UK from the south. Parts of east and southeast England may reach 29 or 30 ºC on Friday, with mid-twenties more widely across England and Wales.  

“By Saturday, this heat will have extended further north, with parts of Scotland also reaching the mid to high twenties, and into the low 30s Celsius or perhaps even a touch higher for inland parts of eastern England. In addition, temperatures overnight will remain high, especially in towns and cities, which will make for an uncomfortably warm night for some.” 

Dr Agostinho Sousa, Head of Extreme Events and Health Protection at UKHSA, said: “This weekend it’s important that everyone takes sensible precautions while enjoying the sun. 

“The forecasted high temperatures are expected to be short-lived but could primarily impact those over the age of 65 or those with pre-existing health conditions. If you have friends, family or neighbours who are more vulnerable, it is important to check in on them and ensure they are aware of the forecasts and are following the necessary advice.”

Turning thundery

The heat will be relatively short-lived, with a thundery breakdown arriving in some south-western areas early on Saturday courtesy of the low pressure out to the west and an associated front moving into the British Isles. This breakdown will spread northeast through the day bringing heavy showers or thunderstorms to many areas, with torrential downpours, frequent lightning, hail and gusty winds all possible hazards. 

A medium impact yellow warning has been issued for Saturday, covering most of England and Scotland. Whilst not all places in the warning area will experience the heaviest downpours, some places could see much as 50mm of rain falling in a relatively short period of time.

Dan Suri continued: “Despite the hot start to the weekend weather for most, Saturday’s thundery breakdown brings about a transition to cooler, showery conditions for Sunday onwards well into next week. 

“The main message at the moment is to be aware of the potential for heavy downpours with lightning, hail and gusty winds on Saturday. Please keep in touch with the latest forecasts because although many places will avoid the worst conditions some quite severe and impactful storms are expected.” 

With some potentially disruptive thunderstorms on Saturday, travel conditions could be impacted. Rod Dennis from RAC said: “Driving conditions will rapidly deteriorate wherever these thundery showers break out – one moment the road will be dry, the next drivers will be faced with heavy rain, hail and potentially gusty winds as well. It’s therefore crucial drivers reduce their speed accordingly, leaving a larger gap between themselves and the vehicle in front. It’s also important to ensure car headlights and taillights are switched on – but not fog lights as these risk dazzling other drivers.” 

Sunday continues unsettled, with some persistent and heavy rain slow to clear from the Northern Isles, with further showers developing elsewhere, the heaviest and most frequent of these in the west. A further warning has been issued for thunderstorms in Northern Ireland on Sunday, with a continued risk of some heavy downpours and the possibility of associated hail and lightning. Within the warning area, in excess of 35mm of rain could accumulate in a few hours.

Further ahead

The outlook for early next week is for unsettled, fresh conditions to continue, with widespread showers especially on Monday and Tuesday. These heavy and thundery at times, potentially slow moving and most intense across northern areas, and organised into longer spells of rain at times across the south.

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