This photo shows rime ice after two days of freezing fog. Rime ice, formed from supercooled fog (water droplets that remain below freezing until they have a surface on which to freeze), is an accumulation of granular ice tufts on the windward side of exposed objects. These ice needles, about 2 inches (5 centimeters) long, point into the direction from which the wind was blowing during the fog.
