17 Jun 2013

30C heat possible midweek

So far this summer, the highest temperatures have been focussed across the eastern half of Europe, with western parts of the continent experiencing below average temperatures.

However, in the coming days, this is about to change, as a plume of hot air surges northwards out of Africa and bathes central and western parts of Europe in heat and humidity.

Whilst some parts of the continent will hold on to the summer heat for longer than others, it will make a marked change from the cool and wet weather that has dominated so far.

With the UK being an island, it is often on the periphery of any intense heat or cold because it is surrounded by water that has a moderating affect on temperatures.

In winter, it keeps us warmer than other places at similar latitudes. In summer, it has the opposite affect, keeping us cooler than our continental neighbours.

Nevertheless, the edge of the plume of heat and humidity will briefly move across England and Wales towards the middle part of the week, before being swept away by Friday.

How hot will it get here?

At the moment, this is uncertain because the weather computer models are giving varying signals on how much cloud there will be.

Cloud amounts will dictate how much sunshine we see and thus to what extent the air is heated. As a result, there are two possible scenarios for midweek for England and Wales.

Scenario one is that is stays largely cloudy with showery rain and little in the way of sunshine. If this happens, temperatures are unlikely to get any higher than 26C.

Scenario two is that the cloud breaks to allow some decent spells of sunshine through. If this happens, then on Wednesday, parts of south east England could reach 30C (86F).

Scotland and Northern Ireland miss out on the heat, with temperatures around 17-20C.

Thunderstorm risk

The temperature is not the only element of the weather that may prove interesting. Given the combination of heat and moisture present in the atmosphere, there’s the potential for thunderstorms to develop.

With light winds expected, if thunderstorms do form, they could give some locations a lot of rain in a short space of time – bringing the risk of flash flooding.

How long will it last?

During Thursday and Friday, cooler air is likely to move in off the Atlantic, meaning that our encounter with the heat and humidity will only be brief.

Thereafter, it’s back to the more typical June mix of some rain, interspersed with some sunshine and temperatures closer to average.

Don’t forget, you can get the latest forecast on the website and I’ll be posting regular updates on Twitter – @liamdutton

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