Scotland soaked as Wales bathes in sunshine

A ridge of high pressure brought all parts of the UK a brief spell of more settled weather at the weekend. Whilst the sunshine was universally enjoyed on Saturday, it became restricted to England and Wales on Sunday as rain and gales piled into Scotland and Northern Ireland.

The British weather is well know for being fickle and full of contrasts, and this was certainly evident on Sunday, with one end of the UK experiencing very different weather from the other.

On Sunday much of Scotland was soaked by heavy and persistent rain, blown horizontally by gale-force winds. However, one statistic that stands out above the rest is the sheer amount of rain that fell in Kinlochewe, Highland with 96.6mm (almost four inches) in the space of 24 hours.

So why so much rain here? It’s all down to the weather set-up and the topography of Highland. There was a conveyor belt of warm, moisture laden air from the Atlantic Ocean which was pushed up over the mountainous landscape of north west Scotland – known in the world of meteorology as orographic uplift.

Clouds form when air rises and condenses, subsequently giving rain. The key factor in this situation has been the rate and length of time that warm, moist air has been forced up over the mountains by a strong wind. The result was hour after hour of heavy rain that persisted over the same area.

If the wind hadn’t been as strong, just a light breeze for example, the rate at which air was forced up over the mountains would have been a lot lower. This would have given light rain and drizzle instead, with nowhere near as much rain falling in the space of a day.

At the other end of the UK in Wales, St Athan in the Vale of Glamorgan basked in 13.8 hours of sunshine. This was courtesy of a ridge of high pressure bringing largely cloudless skies and light winds.

The warmest place was Northolt in London, where the temperature reached 17.8C – close to average for this time of year.

I’ve had another look at the prospects for the rest of May and into the first part of June. At the moment, there’s still no sign of any notable warmth or settled weather on the horizon.

Temperatures at best will reach average at 13-17C, and whilst there will be some drier and brighter days, it still looks generally unsettled with showers or rain at times.

Don’t forget, if you have any weather questions, feel free to contact me on Twitter – @liamdutton