Snow Monsters, Juhyou, Frost-covered Trees

Surface hoar is a cause of avalanches when it forms on top of snow. Conditions that are ideal are cold clear nights, with a very light wind that is able to circulate more humidified air around the snow surface. Wind that is too abrupt will destroy the crystals. When buried by subsequent snows they may remain standing for easy identification, or become laid down, but still dangerous because of the weakness of the crystals. In low temperatures surface hoar can also be broken apart and blown across the surface forming yukimarimo.
Hoar frost also occurs around man-made environments such as freezers or industrial cold storage facilities. It occurs in adjacent rooms that are not well insulated against the cold or around entry locations where humidity and moisture will enter and freeze instantly depending on the freezer temperature.
• Advection frost
Advection frost (also called wind frost) refers to tiny ice spikes forming when there is a very cold wind blowing over branches of trees, poles and other surfaces. It looks like rimming the edge of flowers and leaves and usually it forms against the direction of the wind. It can occur at any hour of day and night.