Rain an occluded front, with thunderstorms possible, but usually their passage is associated with a drying of the air mass. Occluded fronts usually form around mature low-pressure areas. What separates rainfall from other precipitation types, such as ice pellets and snow, is the presence of a thick layer of air aloft which is above the melting point of water, which melts the frozen precipitation well before it reaches the ground. If there is a shallow near surface layer that is below freezing, freezing rain (rain which freezes on contact with surfaces in subfreezing environments) will result. Hail becomes an increasingly infrequent
Cumulonimbus and aviation the shear between rising and sinking air. If the airspeed is too high at this point, the airplane will break apart. The crash of Flight AF 447 is indirectly related to this situation: the pilot, being short on fuel, opted for the shortest path while crossing the thunderstorm line associated with the intertropical convergence zone, and the pitot tubes iced over. What followed is known. On-board radars can be deceiving. Hail shafts generate weak radar echoes and are significantly more dangerous than cloudbursts. Close to the ground, heavy rain (or snow at altitude) tends to dampen turbulence (it is said