17 Sep 2013

Summer set to fight back this weekend

The first half of September has been distinctly autumnal this year, with low pressure bringing cool, wet and windy weather to our shores.

September is traditionally a time of year when the weather starts to change, as summer and autumn battle for supremacy. And, so far, autumn has definitely had the upper hand.

However, there’s a strong signal that this is likely to change this weekend, as high pressure builds over the UK, leading to a return to sunshine and warmth for many.


Ex-hurricane Humberto’s influence

What you may be surprised to hear is that the remnants of Hurricane Humberto will play a notable part in bringing a return to summery weather.

The leftovers of the storm will move northwards in the mid Atlantic (see image below from the Met Office), sending a plume of very warm sub-tropical air around the western side of an area of high pressure.


When warm air surges northwards on the western side of an area of high pressure, it helps it to build and become more established – something known as ridge amplification.

It is this area of high pressure that will drift over the UK this weekend and linger into the middle of next week.

When will the weather settle down?

England and Wales will be first to experience the change to more settled weather this weekend, with brighter skies and lighter winds.

Scotland and Northern Ireland will stay wet and breezy this weekend, with high pressure not exerting its influence here until Monday.

At the moment, it looks like the area of high pressure will linger over the UK until around Wednesday. Thereafter, the threat of rain will return.

How warm will it be?

England and Wales will experience the greatest warmth, with temperatures reaching 19-23C, which will feel pleasant in light winds.

Scotland and Northern Ireland will be closer to 17-21C, but again with little wind, it’ll feel warmer than recently.

However, despite the days being warm, the mornings and nights are going to be chilly. As the number of hours of darkness increase, there’ll be more time for cooling to take place.

Dense fog risk

fog_bench_g_wpThere are hints that widespread dense fog may become an issue early next week. The wet ground from recent heavy rain, combined with chilly nights will cause moisture in the air to condense – effectively forming a cloud on the ground.

This means that some places could start the day on a cold, grey note, with fog giving visibility of 100-200m, before slowly brightening up with afternoon sunshine.

Don’t forget, you can get the latest forecast on the Channel 4 Weather website. I’ll also be posting regular updates on Twitter – @liamdutton

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