The exposed skin on my face aches and stings and my fingers are numb. The trees look brittle and the branches I pass as I ski snap and break. Another storm moving up the coast bruises the southern sky a deep purple, dark beneath the sun’s low ball of hazy light. The woods are a different world than yesterday, when it was 20 degrees warmer, the snow was soft and wet, the sky blue between passing clouds, trees tossing off clumps of slush from the storm on Saturday. But Flat Meadow Brook is still open and I stop to listen to the tumble of water running, the music of motion through a landscape descending back into winter.