High pressure, sunshine and warmth later this week
For just over a week now, I’ve been saying that there were signs of high pressure building for the middle of the month, and this is still set to be the case.
However, you may recall that I made the point that there was still a great deal of uncertainty about how warm it would be.
This was due to the different weather computer models predicting a variety of outcomes for the orientation of the high pressure, which in turn would determine which direction the wind was coming from.
Alas, as we’ve got closer to the time, the detail for later this week is now somewhat clearer, although there is still a question mark as to how long the settled, warmer weather will stick around for.
Jet stream heading north
During the past two weeks, the jet stream has been over or just to the south of the UK and moving relatively quickly, which has spawned areas of low pressure and pushed them towards us.
However, this week, the jet stream is going to slow down and push to the north of us, which will steer low pressure towards Iceland and Scandinavia, allowing high pressure to build.
Through May and June, the average trend for the position of the jet stream is for it to move further northwards, as the zone of greatest temperature contrast shifts northwards, as the northern hemisphere warms up.
What can we expect?
Monday and Tuesday will continue the sunshine and heavy, showers theme that we had at the weekend. Although with lighter winds than recent days, the showers will be slow-moving. So, it you catch one, it’ll linger for longer that it did at the weekend.
High pressure starts to build in earnest from Wednesday onwards, exerting its influence the strongest across England and Wales. Weather fronts will still brush over Scotland and Northern Ireland, resulting in the weather there staying mixed.
From midweek, England and Wales will seeing increasing amounts of dry and fine weather, with temperatures 17-23C. Coastal areas will tend to be cooler, with sea breezes developing.
For Scotland and Northern Ireland, amounts of cloud will be more variable, as weather fronts drift by at times, bringing showers. Nevertheless, even here, there’ll be some pleasant spells of sunshine at times.
Even though the days will be warmer, the nights will remain relatively cool, with temperatures widely dropping down into single figures.
How long will it last?
Unfortunately, this is where it starts to get a little tricky. The weather computer models are offering a variety of outcomes for next weekend.
Some keep the fine, warm weather going until Monday, whereas others turn it more unsettled with rain arriving on Sunday.
The warmth at the end of the week could well give us the warmest day of the year so far, which would surpass the 22C that was recorded at Aviemore on 28 April.
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