DIABLO LAKE, North Cascades National Park — The clouds lifted by noon and wind screamed down the mountainsides. Temperatures sunk to zero as Jon Riedel, a retired geologist with the National Park Service, stood on a ridge above the blue-green reservoir, which holds water that will later be released to spin the turbines at the dam here and help power Seattle. Riedel scanned the peaks across the horizon and explained the ongoing decline of Washington’s glaciers and snowpack. Both are suffering as the region warms. Cities, tribes, farms and fish in Western Washington rely on water from a consiste…