20 Aug 2024

Unseasonably wet and windy this week – is summer over?

Low pressure rules the roost

It’s the middle of August and, after a more summer-like start to the month for most than June or July, the weather seems to have slipped back into unsettled mode.

As I looked through this week’s weather charts a little earlier, it’s a case of low pressure as far as the eye can see. In fact, I counted five areas of low pressure that will affect the UK this week – one of which will contain the remnants of Hurricane Ernesto.

So, as you might expect, with such an unsettled week ahead, wind and rain will dominate our weather story – for some, more than others.

Why is it so unsettled?

The reason for the unsettled weather this week is the jet stream, which is a fast-moving ribbon of wind that sits around 30,000 feet in the atmosphere.

Not only will it sit over or south of the UK this week, but it’ll also move swiftly at around 160mph – a speed which wouldn’t look out of place in autumn.

Images: Tropical Tidbits – showing jet stream (yellow, orange, red)

The net effect of this is for numerous areas of low pressure to be created and then catapulted towards us in succession.

Weather warning and flood risk

The focus of the wind and rain this week will be across northern and western parts of the UK – particularly western Scotland, where a yellow warning for rain has been issued for Wednesday into Thursday.

In the warning area, there could be some localised flooding and travel disruption, with as much as 100-150mm of rain falling over some hills and mountains.

An additional concern will be gale-force winds for coastal areas, which when combined with spring high tides, could cause overtopping of waves.

Whilst southern and eastern parts of the UK will see some rain, amounts will pale in comparison to elsewhere.

How unusual is this for August?

August is a funny month weather-wise. Yes, it’s still summer, but it can be remarkably unsettled sometimes, with brisk winds and heavy rain. For example, take last year, when there were two named storms in August.

Storm Antoni hit on 5 August. It blew trees onto railway lines in southwest England, caused homes in North Yorkshire to be evacuated due to flooding, and several events were cancelled.

Storm Betty followed on 18-19 August. This storm was less impactful for the UK, but it left 70,000 homes without power across Ireland.

Is summer over?

So, with a barrage of wet and windy weather on the cards this week, is summer over for the UK?

Well, as the saying goes, ‘hold your horses’. September is more than capable of delivering summer-like weather – despite it being the first month of meteorological autumn.

Last year, September delivered a heatwave and the UK’s highest temperature of 2023, when it reached 33.5C in Faversham Kent. It was also the first time on record that somewhere in the UK reached 30C or above for seven consecutive days in September.

Images: Met Office – showing mean temperature and sunshine for September 2023

There are some hints that there may be a window of more settled weather during next week – especially towards the south and east. However, it’s a tricky time of year to look too far ahead, as Atlantic hurricanes can throw a spanner in the works. So, keep an eye on the forecast for updates.

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