Freezing drizzle
Encyclopedia
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 freezing drizzle accumulates on land it creates an icy layer of glaze
. Freezing drizzle alone does not generally result in significant ice
accumulations due to its light, low-intensity nature.
type cloud
s 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 °C (12 °F). At such a temperature, the water droplets stay supercool
as there are few ice nuclei
to change them to ice crystals (see freezing rain
). In winter arctic conditions it can happen at even lower surface temperatures as the air is even cleaner.
Drizzle
Drizzle is a light rain precipitation consisting of liquid water drops smaller than those of rain, and generally smaller than 0.5 mm in diameter. Drizzle is normally produced by low stratiform clouds and stratocumulus clouds. Precipitation rates due to drizzle are on the order of a millimetre...
that freezes on contact with the ground or an object at or near the surface. Its METAR
METAR
METAR is a format for reporting weather information. A METAR weather report is predominantly used by pilots in fulfillment of a part of a pre-flight weather briefing, and by meteorologists, who use aggregated METAR information to assist in weather forecasting....
code is FZDZ. When freezing drizzle accumulates on land it creates an icy layer of glaze
Glaze ice
Glaze ice or simply glaze is a smooth, transparent and homogenous ice coating occurring when freezing rain or drizzle hits a surface. It is similar in appearance to clear ice, which forms from supercooled water droplets...
. Freezing drizzle alone does not generally result in significant ice
Ice
Ice is water frozen into the solid state. Usually ice is the phase known as ice Ih, which is the most abundant of the varying solid phases on the Earth's surface. It can appear transparent or opaque bluish-white color, depending on the presence of impurities or air inclusions...
accumulations due to its light, low-intensity nature.
Formation
Drizzle is formed in low level stratusStratus cloud
A stratus cloud is a cloud belonging to a class characterized by horizontal layering with a uniform base, as opposed to convective clouds that are as tall or taller than wide . More specifically, the term stratus is used to describe flat, hazy, featureless clouds of low altitude varying in color...
type cloud
Cloud
A cloud is a visible mass of liquid droplets or frozen crystals made of water and/or various chemicals suspended in the atmosphere above the surface of a planetary body. They are also known as aerosols. Clouds in Earth's atmosphere are studied in the cloud physics branch of meteorology...
s 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 °C (12 °F). At such a temperature, the water droplets stay supercool
Supercooling
Supercooling, also known as undercooling, is the process of lowering the temperature of a liquid or a gas below its freezing point without it becoming a solid....
as there are few ice nuclei
Ice nucleus
An ice nucleus is a particle which acts as the nucleus for the formation of an ice crystal in the atmosphere.The presence of ice nuclei increase the temperature that ice will form in the atmosphere from around −42°C to about −10°C...
to change them to ice crystals (see freezing rain
Freezing rain
Freezing rain is the name given to rain that falls when surface temperatures are below freezing. The raindrops become supercooled while passing through a sub-freezing layer of air, many hundred feet , just above the surface, and then freeze upon impact with any object they encounter. The resulting...
). In winter arctic conditions it can happen at even lower surface temperatures as the air is even cleaner.