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
Hail spike the multiple path at a later time than the energy that came back directly from the hail to the radar. Both are however on the same radial angle from the radar as the antenna did not have the time to turn significantly. The multipath echoes are then analyzed on the radar display as echoes extending in a radial direction behind the actual location of the hail/heavy rain core. The loss of energy by due to multiple reflections means weaker return echoes. The hail spike region has thus comparatively quite weaker echoes than the echoes directly from the hail or heavy