Rain and snow mixed to refer to ice pellets. This precipitation occurs when the temperature in the lowest part of the atmosphere is slightly above the freezing point of water The depth of low-level warm air (below the freezing level) needed to melt snow falling from above to rain varies from about and depends on the mass of the flakes and the lapse rate of the melting layer. Rain and snow typically mix when the melting layer depth falls between these values. Wintry showers is a somewhat informal meteorological term, used primarily in the United Kingdom, to refer to various mixtures of rain, graupel
NEXRAD tornado detection and subsequent warnings. WSR-88D sites across the nation have been upgraded to polarimetric radar, which adds a vertical polarization to the traditional horizontally polarized radar waves, in order to more accurately discern what is reflecting the signal. This so-called dual polarization allows the radar to distinguish between rain, hail, and snow, something the horizontally polarized radars cannot accurately do. Early trials showed that rain, ice pellets, snow, hail, birds, insects, and ground clutter all have different signatures with dual polarization, which could mark a significant improvement in forecasting winter storms and severe thunderstorms. The deployment of the dual