Low pressure returns as normal service is resumed

Today may be the summer solstice in the northern hemisphere, when the sun reaches its highest point in the sky, but the weather will far from reflect summer during the coming days.

After a brief respite from unsettled conditions, the jet stream is poised to spring back to life which will mean low pressure is set to return to our shores bringing wind and rain.

This month so far has been remarkably wet with some places seeing their average June rainfall in just a few days. There’s certainly a distinct possibility that once this month has drawn to a close and the data checked, some places may have had their wettest June on record.

As I mentioned in a previous blog, it’s not unheard of to experience wet and windy weather in June but what has been unusual is the persistence of it.

The next area of low pressure that arrives during Wednesday night into Thursday will be a little different to the previous storms that have affected us in recent weeks.

Rather than racing across the Atlantic Ocean as a fully fledged system, it’s going to develop just to the south of the UK and engage some warm, moist air from the near by continent.

It’s this warm, moist air that will provide a lot of potential energy in the atmosphere which, if released, will turn the rain thundery. This would give some places a lot of rainfall in a short space of time and heighten the risk of surface water flooding.

The difficulty for weather computer models and forecasters is establishing exactly where and when this potential instability in the atmosphere is likely to be released.

Having looked at the latest information, Wales and south west England are most at risk from the heaviest downpours with 40-60mm possible in the next 48 hours with a Met Office warning in force.

Other parts of the UK will see wet weather too, but rainfall amounts aren’t likely to be as great – generally around 15-30mm.

However, with the ground still wet from recent rain, the Environment Agency three day flood forecast highlights a low risk of surface and river flooding across a large swathe of England and Wales.

As well as turning wet, it will also turn windy with gusts as high as 40-50mph around the coasts and over the hills.

After the initial spell of heavy rain the low pressure system will sit across the UK through the weekend bringing further heavy showers and gusty winds.

The longer term trend for the next few weeks is pretty mixed with no signs of prolonged sunshine and warmth. However there’ll still be nicer days in between any rain or showers.

Don’t forget a local forecast is available on the Channel 4 Weather website or you can always contact me on Twitter – @liamdutton