text: A mysterious ‘warm blob’ of water off the West coast of the US could explain why states like California are experiencing their worst ever drought, while the East is battered by freezing weather. The blob in the ocean was discovered last year, with temperatures one to four degrees Celsius (two to seven degrees Fahrenheit) above surrounding ‘normal’ water. And the blob has now extended about 1,000 miles (1,600km) offshore, from Mexico up to Alaska, and could herald a warmer summer for some regions. Scroll down for video . A 'blob' of warm water 2,000 miles across is sitting in the Pacific Ocean (shown in diagram). Since last June it has extended from Alaska to Mexico. It has been present since 2013 and causing fish to seek shelter elsewhere. And a new University of Washington study says it could be responsible for droughts . A new study by the University of Washington found that a high-pressure ridge could be causing the blob, by trapping heat in the water. In June of last year, the huge patch of water stretched 1,000 miles (1,600km) in each direction, and was 300ft (90 metres) deep. Dr Nick Bond, a climate scientist at the University of Washington, coined the term ‘the blob’ in June. Since the year 2000, seven western states in the US has seen their driest periods in centuries: Arizona, California, Colorado, Nevada, New Mexico, Utah and Wyoming. And scientists in California have warned that the region may be experiencing a century-long 'mega-drought'. The warnings came after sediment studies showed California is currently experiencing the driest spell since 1580, and that the regular rainfall seen during the last century is likely to have been a temporary deviation in a cycle of droughts and very occasional rainfall over the last 3,000 years. In 2013, California received less rain than in any year since its formation as a state in 1850. However droughts lasting more than 100 years are far from unheard of in the state. Looking back over several thousand years, droughts have been known to last over a decade, and in some cases they can last a century. And the patterns tend to repeat, meaning another drought of this length will probably happen again in the future. Ten months later, the blob is now squashed up against the coast, and Dr Bond says all models point to it continuing through the end of this year. ‘In the fall of 2013 and early 2014 we started to notice a big, almost circular mass of water that just didn't cool off as much as it usually did, so by spring of 2014 it was warmer than we had ever seen it for that time of year,’ said Dr Bond. Researchers said it may have contributed to the state of Washington's mild 2014 winter and might signal a warmer summer. But exactly how this area of warmer water has formed, or how long it will stay, remains a mystery. One thing that can be studied, though, is its effects. As air passes over warmer water and reaches the coast it brings more heat and less snow, which the scientists say helped cause current drought conditions in California, Oregon and Washington. The researchers said that it might not only be causing warmer temperatures on the West coast, but also cooler temperatures on the East coast. It could also be playing a part in circulating cold and wet air to the central and eastern states of the US. California's drought (stock image shown left) is one of the worst on record, while the East coast of the US (Central Park in New York shown right) has seen unusually cold temperatures . It is also having an effect on marine life. Fish have been spotted in unusual places, supporting recent reports that West coast marine ecosystems are suffering and the food web is being disrupted by warm, less nutrient-rich Pacific Ocean water. Dr Bond noted that, while this phenomenon likely wasn’t caused by global warming, it could be a sign of similar weather to come. ‘This is a taste of what the ocean will be like in future decades,’ Dr Bond said. ‘It wasn't caused by global warming, but it's producing conditions that we think are going to be more common with global warming.’ The 'blob' is also having an effect on marine life. Fish, like the Thresher Shark (shown), have been spotted in unusual places, supporting recent reports that West Coast marine ecosystems are suffering and the food web is being disrupted by warm, less nutrient-rich Pacific Ocean water .
target: A 'blob' of warm water 2,000 miles across is sitting in the Pacific Ocean .
  It has been present since 2013 and causing fish to seek shelter elsewhere .
  University of Washington study says it could be responsible for droughts .
  But it is not clear where the blob has come from - or how long it will stay .