UK weather defies prediction, say forecasters

Jet streams and ocean currents ensure that British weather is some of the most changeable on Earth It has been a year that has seen weather patterns turned upside down. In 2011, Britain had one of the finest springs on record. This was followed by one of our worst-ever summers. And the Met Office says there is more to come. At least, that is the message from forecasters and meteorologists who are studying the twists and turns of the British weather. The strange patterns of rain, wind and sunshine that have swept the nation reveal a fundamental truth, they have found. The UK is one of the most erratic, changeable places on Earth when it comes to weather. Inverted patterns of rain, sun and wind are simple facts of life and we had better get used to them. In 2009, somewhat shamefacedly, the Met Office decided to withdraw its seasonal forecasting service, amid recriminations over baking summers that had mysteriously failed to materialise . But there are good reasons why British weather forecasters often get it wrong. “We are a small island, in a temperate climate, at a high latitude with one of the world’s biggest oceans on one side of us, and a huge continent on the other,” said Helen Chivers, a forecaster at the Met Office. “The combination makes it very difficult to predict weather here. We can do it in the short term but not over long periods, unlike other parts of the world. For example, in the United States the weather is far easier to forecast because the country forms part of a very large landmass.” This point was backed by Alan Thorpe, director of the European Centre for Medium-Range Weather Forecasts. “In some parts of the tropics, you can forecast weather up to four weeks away, but not in the UK. The best you can hope for is about five days to a week.” A key problem facing forecasters in Britain is the jet streams: these are narrow ribbons of fast-flowing air that are found at altitudes of around 35,000ft. They play a key role in bringing weather systems to Britain from America across the Atlantic. “The problem is that jet streams do not flow in straight lines. They can often coil like snakes – and that is what happened at the beginning of this year,” said Chivers. “They coiled above Britain in March, April and the first half of May and trapped a region of high pressure over the country. That brought fine weather to the country for those months.” Then the jet streams straightened out and pushed rainy weather across the Atlantic – dumping it on Britain. “The result was a bad summer,” said Chivers. “However, from what we can see at

Posted by on September 3, 2011. Filed under News, Politics, World News. You can follow any responses to this entry through the RSS 2.0. You can skip to the end and leave a response. Pinging is currently not allowed.