Freezing drizzle

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Freezing drizzle is drizzle that freezes on contact with the ground or an object at or near the surface. Its METAR code is FZDZ. When such drops land, it create an icy layer of glaze. Freezing drizzle alone does not generally result in significant ice accumulations due to its light, low-intensity nature.

[edit] Formation

Drizzle is formed in low level clouds, of the stratus type, when vertical motion is weak. It consists of relatively small drops, light in nature. Freezing drizzle generally occurs when drizzle forms in an airmass at below freezing temperatures but warmer than -10 ^oC (12 ^oF). At such a temperature, the water dropplets stay supercool as there is few ice nucleus to change them to ice crystals. In winter arctic conditions, it could happen at even lower surface temperatures as the air is even cleaner.