has quality has quality has output has output water water-based rainfall freezing rainfall 2021-04-14T18:57:18.275Z freezing rain METAR:FZRA A surface temperature inversion is usually required. In such an inversion, the surface must have a temperature below freezing, while the temperature of the atmosphere where the precipitation forms is above freezing. Alternately, if the temperature of the ground surface and glazed objects is typically near or below freezing (0C or 32F), it is necessary that the water drops be supercooled before striking. Freezing rain can sometimes occur on surfaces exposed to the air (such as tree limbs) with air temperatures slightly above freezing in strong winds. Local evaporational cooling may result in freezing. Freezing rain frequently occurs, therefore, as a transient condition between the occurrence of rain and ice pellets (sleet). When encountered by an aircraft in flight, freezing rain can cause a dangerous accretion of clear icing. In aviation weather observations, this hydrometeor is encoded ZR by NOAA. This term exists, we're revising the definition with ESIP semantic Harmonization group, delete the old one. Consider adding axioms like PATO:"decreased temperature" to this and other cold forms of precipitation, such that we can create a grouping class to be filled by inference (with hail, sleet, snow, freezing rain). Something like precipitation below the liquid-solid phase transition point of water. envoCryo environmental_hazards envoPolar Water-based rainfall which freezes either 1) on impact with a surface to form a coating of clear ice (glaze) or 2) after percolating through surface layers. freezing rain fall frozen