30 Jul 2013

A brief burst of 30C heat later this week

After years of disappointing summers, this year has seen a change in fortunes, with much of July delivering sunshine and heat across the UK.

Not only have we experienced our highest temperature since July 2006, we’ve also had 19 consecutive days where the temperature somewhere in the UK has reached 28C or more – something that last happened in 1997.

The prolonged spell of fine weather was due to the jet stream moving to the north of us, steering cloud and rain towards Iceland, leaving us to lie beneath a big area of high pressure.

Recent showers and thunderstorms

The past week has seen the jet stream return southwards, but as I wrote in my blog last week, it’s going to wriggle around over or close to the UK, rather than get stuck.

As the jet stream wiggles north, plumes of hot air will give us occasional hot days, but when the jet stream wiggles south, cooler air will move over us, with rain or showers.

In the past few days, showers and thunderstorms have been sweeping across the country, with some places seeing more than a month’s worth of rain in the space of a day.

Whilst this is impressive, summer rainfall in the UK does tend to come in the form of thunderstorms, so large amounts of rain would be expected in short bursts, rather than evened out throughout the month.

Heat and humidity to return

At the end of this week, the jet stream will briefly push northwards again, which will drag a plume of heat and humidity across us from Iberia.

England and Wales are going to feel the effects of this the most, with hot sunshine expected on Thursday and part of Friday, before thunderstorms sweep eastwards in time to freshen things up again for the weekend.

Nevertheless, temperatures here will reach around 24-30C on Thursday and Friday, with the hottest weather across East Anglia and south east England.

Scotland and Northern Ireland are likely to miss out on the heat this time round, with cloudier skies and showers or longer spells of rain expected. Temperatures will be close to average at 18-23C.

Next week and beyond

The weather towards the middle of August looks mixed, with a prolonged spell of heat unlikely, but there’ll still be some occasional hot days.

Low pressure is unlikely to be too far away for much of the time, so when this interacts with any heat and humidity, thunderstorms are likely to form.

Don’t forget, you can get the late forecast on the Channel 4 Weather website. If you take any interesting weather picture, please send them to me on Twitter – @liamdutton

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