Storm Barney: severe gales for southern UK on Tuesday

The Met Office has named the second storm of the season, with Storm Barney set to bring gales and locally severe gales to southern parts of the UK later on Tuesday.

Storm Barney follows Storm Abigail, which hit the UK and Ireland at the end of last week, bringing disruption to the far north and west of Scotland.

After a generally quiet autumn so far, the weather has picked up the pace during the last fortnight, with strong winds and heavy rain becoming commonplace.

Why so windy?

The reason for the recent change to wet and windy weather is a fast-moving jet stream across the Atlantic Ocean, which at times has been travelling at around 170mph, 30,000ft up in the atmosphere.

As the temperature contrast between the North Pole and equator increases, the jet stream is powering up significantly.

The jet stream is not only responsible for spawning low pressure systems, it also acts as an atmospheric superhighway, catapulting them towards us.

For long as the jet stream remains on a more southerly track, areas of low pressure will continue to affect our shores.

Stormy Barney: how windy?

In comparison to Storm Abigail, there is a much greater level of uncertainty with the track and intensity of winds that Stormy Barney will deliver later on Tuesday.

This is because, in order for the low pressure to develop enough to give very strong winds, it needs to interact with the jet stream high up in the atmosphere at exactly the right moment.

If it does, then gusts of wind of 60-70mph, locally 80mph around exposed coasts, will move eastwards across southern parts England and Wales tomorrow.

If the low pressure doesn’t interact with the jet stream at the right moment, then it won’t develop as much and the winds won’t be as strong.

The latest forecast takes the strongest gusts of wind across Wales 3-6pm, central southern England 6-9pm and south east England 9pm-midnight.

This strength of wind will have the potential to damage and even bring down some trees, as well as cause transport disruption – highlighted in a Met Office yellow “be aware” warning.

There’ll further rain in the next 48 hours, which could cause some localised flooding across north western parts of England and Wales, given that the ground is saturated from recent rain.

Cold and snow next weekend

Whilst much of this week looks wet and windy, there’ll be a big change to the first notable cold of the season for many.

A northerly wind will bring Arctic air southwards across the UK during Friday and Saturday, with a big drop in temperature. Daytime temperatures are likely to be just 2-7C on Saturday, with a significant wind chill.

There’ll also be plenty of wintry showers, with snow settling on the ground across northern parts of the UK – mainly over the hills and mountains.

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