MaxR Above 0C
Recall that the MaxR is created by searching for the maximum reflectivity above a certain
height, usually 2 km, in the volume scan data. Instead of using the somewhat arbitrary height of 2 km, the MaxR above 0°C uses model output to estimate the height of the freezing level. The maximum reflectivity is then computed above this level. The idea is that below the freezing level you will no further increase in hail size. If intense maximum reflectivities occur above the freezing level, this might be a signature for large hail aloft.
MaxR Above 0°C for the Pipestone supercell. Note the structural details evident in the image.