what do you call the rain with ice
Freezing rain Freezing rain develops when falling snow encounters a layer of warm air aloft, typically around the 800 mbar (800 hPa) level, causing the snow to melt and become rain. As the rain continues to fall, it passes through a layer of subfreezing air just above the surface and cools to a temperature below freezing (0 °C or 32 °F). If this layer of subfreezing air is sufficiently deep, the raindrops may have time to freeze into ice pellets (sleet) before reaching the ground. However, if the subfreezing layer of air at the surface is very shallow, the rain drops falling through it will not have time to freeze and they will hit the ground as supercooled rain. When these supercooled drops make contact with the ground, power lines, tree branches, aircraft, or anything else below 0 °C (32 °F), a portion of the drops instantly freezes, forming a thin film of ice, hence freezing rain.[4][5] The specific physical process by which this occurs is called nucleation.
Cumulonimbus cloud Cumulonimbus, from the Latin cumulus ("heap") and nimbus ("rainstorm", "storm cloud"), is a dense towering vertical cloud[1] associated with thunderstorms and atmospheric instability, forming from water vapor carried by powerful upward air currents. If observed during a storm, these clouds may be referred to as thunderheads. Cumulonimbus can form alone, in clusters, or along cold front squall lines. These clouds are capable of producing lightning and other dangerous severe weather, such as tornadoes. Cumulonimbus progress from overdeveloped cumulus congestus clouds and may further develop as part of a supercell. Cumulonimbus is abbreviated Cb.