Sleet and
freezing rain only occur in temperature inversions. However snow and
ordinary rain can also occur in an inversion. Some hypothetical
inverted temperature profiles and the associated form of precipitation are
shown below.
(a) If the temperature at the top of the inversion is below freezing the precipitation is snow.
(b,c) If the temperature at the top of the inversion is above freezing and the surface temperature is below
freezing then the precipitation can be either sleet or freezing rain depending upon the thickness of the
subfreezing layer and the temperature at the surface.(d) If the surface temperature is above freezing, then the precipitation is rain.