Cold temps and snow can cause acceleration of wheel defects. When a tread or flange has a fissure, water can enter the fissure, freeze and expand,thereby increasing the fissure's size. This can be aggravated by braking. In an extended brake application, the wheel heats up, causing the metal to expand and fissures to widen. Water and snow can pack in. When the wheel cools and water freezes, etc. This action is a cause of wheel shelling and spalling.