Hurricane Ophelia on Friday strengthened into a Category 2 storm in the Atlantic and is forecast to strike Ireland next week with the potential to cause damage worth hundreds of millions of dollars. Ophelia’s top winds had risen to 165 kilometres an hour by early Friday, reaching the second level of the five-step Saffir-Simpson scale. The storm, about 1,000 kilometres south-west of the Azores, is forecast to weaken before approaching Ireland on Monday, the US National Hurricane Centre said. Ophelia could become the strongest post-tropical system to rake Ireland since Hurricane Debbie in 1961, which killed 18 people, stripped almost 25 per cent of the trees in some areas and caused US$40 million (Dh147m) in damages at the time, according to Weather Underground. Sixty people died in a plane crash in the Azores caused by Debbie. Debbie’s damages would have reached $338m in today’s dollars, said Chuck Watson, a disaster modeller at Enki Research in Savannah, Georgia. Based on its current forecast track, Ophelia will probably cost Ireland $769m and the UK an additional $173 million, he said. Two well-known computer forecast models were split over whether Ophelia would strike the southwest of Ireland near counties Kerry and Cork, said Bob Henson, a meteorologist at Weather Underground in Boulder, Colorado. The US Global Forecast System keeps the hurricane offshore, while the European Centre for Medium Range Weather Forecasts model takes it into Ireland sometime Monday. By that point, Mr Henson said, Ophelia’s strongest winds will not be confined to its centre, a hallmark of a storm transitioning from a tropical system to a post-tropical one. He said the wind field would be spread out over a large area and with speeds of up to 100kph. “That is enough to cause pretty severe damage, especially in an area where you don’t get winds that strong.” The Atlantic hurricane season, usually a bigger threat to the United States, Mexico and Caribbean, has produced 15 named storms this year, including 10 consecutive hurricanes - the most since the late 19th century. The storms have killed hundreds and caused an estimated $300 billion in damage across Central America, the Caribbean and the US. The US alone has been struck by six storms, four of which were hurricanes. The magnitude of potential damages in Ireland will not be clearer until later this weekend, Met Eireann, the Irish meteorological service, said on its website. In the UK, “there may be gale-force winds, or even severe gale-force winds, on Monday, possibly Tuesday,” said Nicola Maxey, a spokeswoman for the UK Met Office. The west coasts of Ireland and England will probably be worst-hit. The storm is expected to lose intensity as it travels north-east, away from the warm water it needs to maintain strength, Ms Maxey said. “They dissipate quite quickly once they hit land.”