By **Lori Valigra** and **Elizabeth Miller** A skier jumps into the air in front of a large snow-making machine at Shawnee Peak in Bridgton on Wednesday, ## Feb. 16 , 2022. Modern advances in snow-making technology are helping Maine ski areas stay open despite the warming climate. Credit: Troy R. Bennett / BDN BRIDGTON, Maine — Billy Dolliver’s blue eyes twinkled at the mountain snow. Mid-20 temperatures kept the ski trail from getting slushy. The sun was warm enough so he did not freeze on the lift. This story was produced through a partnership between Bangor Daily News and Climate Central. The 72-year-old has skied the Shawnee Peak slopes since age 12, when his boatbuilder father made his first pair of skis out of barrel staves. He has noticed that winters have been getting warmer with less snow, but skiing is better than ever because of modern grooming and snowmaking.…