The snow sure looked daunting. It was only about 15 feet of sidewalk, but the snow, already deep, was getting heavy as the sun worked on it. It was even deeper at the corner, where a plow had deposited a big pile at the intersection of Turner and Morning streets on Munjoy Hill in Portland. That’s where 11-year-old Jonathan McKeever was standing, bundled up in a parka and knit cap.