Wet summer warning system developed

Forecaster highlights the jetstream over the UK [image credit: BBC]

It’s more predictable than we thought, they say – at least in some ways. The test of time awaits.

Researchers in the UK have developed a method of improving the long range accuracy of summer weather in the UK and Europe, says the BBC.

The scientists found a connection between sea surface temperatures in the North Atlantic in March and April and the subsequent summer’s rain or shine.

The researchers say the new method may benefit agriculture, tourism and construction.

The study has been published in the journal PNAS.

Scientific effort to improve longer term forecasts have been focussed on winter weather patterns, which can pose a sizeable threat to humans and the environment. Developing better seasonal forecasts for the summer has lagged significantly behind.

Now researchers at the National Centre for Atmospheric Science (NCAS) at the University of Reading have found that springtime temperature anomalies in the north Atlantic are connected to the circulation of the atmospheric and the position of the jet stream over Europe in the following July and August.

“We found a strong link between sea surface temperatures east of Newfoundland during the spring and the position of the jet stream and the weather in the UK,” said lead author Dr Albert Osso from the University of Reading.

“We found that there is a predictability.”

The researchers believe the temperature anomalies in the sea change what is termed the meridional gradient and the position of the jet stream is strongly influenced by this factor.

“The jet stream gives the direction of the storms that cross the Atlantic and affect Europe and the UK,” said Dr Osso.

“What we have seen is that when temperatures are warmer than normal in this area of the ocean, the storms basically move far north and they miss the UK, not all of them, but on average most of the storms are going to miss.”

The scientists say that their findings mean that there is considerable potential to improve the seasonal forecast – with important implications for many sectors.

Continued here.