23 May 2016

Why talk of a sizzling summer is nothing but hot air

A number of recent newspaper and online weather headlines claiming that the UK is going to have a 3-month sizzling summer with blazing sunshine have got me a little hot under the collar.

There’s no doubt that we love the weather. We talk or moan about it all the time, so naturally there’s an urge to read anything that gives us hope of knowing the weather prospects further into the future than Mystic Meg.

Crystal ball under the clear sky

But sorry to shatter the dream so abruptly. It is simply not possible to predict the British weather so far ahead with any useful degree of accuracy.

I’ve been in the business for 13 years and there are days when us meteorological folk don’t even know what’s going to happen in 24 hours, let alone three months!

Misunderstood science

As well as some quotes from sources that have questionable credibility as weather professionals, it seems as though there’s been a misunderstanding (yet again) of an experimental prediction made by the Met Office.

The three month outlook aimed at contingency planners is an experimental and complex outlook based on probabilities, rather than a deterministic single outcome.

This means that is doesn’t provide a definitive prediction of what will happen, but a range of possible outcomes, with probabilities given for the likelihood of rainfall and temperature being above or below average.

What does it actually say?

When you look at the latest three-month prediction, the caveats of uncertainty don’t even support the confident headlines and stories that have been published.

Buttercup sundownAlso, it only covers the months of May (technically spring), June and July and doesn’t include August, which is a summer month.

For temperature, it states: “For May-June-July above-average temperatures are slightly more probable than below-average temperatures.”

It then goes on to add in the extra detail: “The chances of above and below-average temperatures are approximately similar.”

rain_london_g_wpFrom this, it is very clear that there is practically just as much of a chance of it being warmer than average than colder than average.

For rainfall, it states: “For May-June-July as a whole, the forecast for UK precipitation suggests that the chances of above and below-average rainfall are fairly balanced.”

So again, there is just as much of a chance of it being drier than average than there is of it being wetter than average.

So what will this summer bring?

As I’ve alluded to already, it is simply not possible to tell what the weather will do so far ahead in the UK.

Our variable weather patterns just don’t allow anything more than vague suggestions of what the weather could be compared to average.

Question mark cloud againt blue sky (Digital Composite)And even then, an average over three months doesn’t provide us with the daily forecasts that tell us the classic weather, temperature and wind direction information we see on TV or in weather apps.

Yes, it could end up being a sizzling, sunny summer, but my point is that no one has the ability to predict that so far ahead.

Now, where did I leave that newspaper? I need something to fan myself and cool down… It seems as though it’ll function better as a fan than any sign of what the weather will do this summer.

Don’t forget, you can get the latest five-day forecast on the Channel 4 Weather website. I also post regular updates on Twitter – @liamdutton

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