Ice Needles: Ice crystals which are long and thin with a hexagonally-shaped cross section, thinner than ice columns. Ice needle formation is favoured at air temperatures from -4° C to -6° C (25° F to 21° F) ...
ice needles—A form of ice crystals.
ice pellets—Small, transparent or translucent, round or irregularly shaped pellets of ice.
The ice needles are typically a few centimetres long. While growing, they may lift or push away small soil particles. On sloped surfaces, needle ice may be a factor contributing to soil creep. ...
ICE CRYSTALS Precipitation in the form of slowly falling, singular or unbranched ice needles, columns, or plates. They make up cirriform clouds, frost, and ice fog. Also, they produce optical phenomena such as halos, coronas, and sun pillars.
See also: Frost, Temperature, Weather, Radiation, Precipitation