Secret of UK weather – in sea 2,000 miles away

IF YOU are trying to work out whether next summer will be a washout, it’s tempting to look up a long-term forecast.

But for the clearest prediction, you might be better off studying a patch of ocean more than 2,000 miles away, experts have suggested.

Researchers believe the weather in an area of the North Atlantic can give us an accurate forecast for how wet or dry the British summer will be, two months in advance.

If the expanse of sea east of Newfoundland is warm from April to May we can expect a drier summer in July and August, experts said. When the temperature in the region is cold in the spring, the opposite will occur and Britons can expect a much more damp summer.

The test is nearly 60 per cent accurate, according to the University of Reading team. The reason warm seas near Canada, 2,100 miles away, affect our weather is because of the jet stream – a fastmoving wind which blows summer rainstorms to the UK.

With warmer temperatures the jet stream blows further north, missing the British Isles.

The effect is known as the Summer East Atlantic (SEA) pattern.

While the researchers are not able to predict whether a particular day or weekend will be picnicfriendly, the breakthrough should make forecasting more accurate than before, it was claimed.

Lead researcher Dr Albert Osso said the difference between a wet and a dry summer is about 3.5in (90mm) of rain.

He said that until now there had been no accurate method of forecasting the British summer two months in advance. ‘Historically, the forecast community has been more interested in predicting winter time, and the big storms, and heavy rainfall,’ Dr Osso said. ‘Summer time has had less attention.’ Reiterating his findings, Dr Osso said: ‘The SEA pattern has a particularly strong influence on rainfall in the British Isles.

‘When its waters in spring are warmer than normal, [this] leads to reduced summer rainfall over the UK, while when its waters are colder than average it leads to increased rainfall.’

The temperature readings he based his model on were taken by satellites, ships and buoys in an area of roughly 386,000 square miles (1million square km). The research was published in the journal PNAS. A spokesman for the Met Office called the research ‘an exciting development’.

‘If the research from Reading does predict future rainfall that will be very helpful to other climate scientists and forecasters,’ he said. It is one of the areas of climate science that has a pioneer element to it.

‘More and more of these discoveries are being made which will help lock these findings into weather and climate models.’

‘Exciting development’