Britain, still struggling to cope with ice and snow during its coldest winter in 30 years, faces the added risk of floods as milder air and rain moves in, forecasters warned on Thursday. The Environment Agency said it was monitoring water levels in Yorkshire and the northeast in particular, after snow and ice began to melt. “There is a possible flood risk if rain falls as the snow melts, as this adds to the volume of water as well as speeding up the rate of thaw,” said Phil Younge, its regional flood and coastal risk manager. Meanwhile, the Met Office warned of slippery conditions across England and Wales as rain mixed with sleet and snow. “It has led to very icy conditions in many areas, particularly untreated surfaces,” it said in a statement. “Be aware that these conditions may persist, despite a gradual thaw of lying snow over the next couple of days.” Rain will affect northwestern parts Friday, perhaps falling as snow over higher ground in Scotland. The rest of the country will be mainly dry and cloudy with winds strengthening from the south. Airports remained open Thursday but there were warnings about possible delays after a fresh blanket of snow Wednesday. Several train services remained disrupted, particularly in London's commuter belt and in northern England, just as services had begun to improve after last week's heavy snow. A number of roads in the Highlands in Scotland were closed. The government asked local authorities Tuesday to halve the amount of grit put on icy roads to conserve salt supplies. Foreign imports of salt are expected to arrive in the next few days. East Sussex Coastguard Rescue Teams said they had been called in to help two hospitals transfer nursing staff and doctors, including a surgeon, to and from work in their 4x4 vehicles. A woman in labour was also taken to hospital in Eastbourne, while three stranded ambulances had needed a tow.