Ice Multiplication by Crystal Growth?Ice growing from the vapor along with tiny amounts of salt solution sheds free ice crystals, at -5C and saturation with respect to liquid water, in quiescent conditions. This is a more appealing explanation for the Hallett-Mossop effect than rime splintering, if it occurs primarily at temperatures near -5C.

Charles A Knight, National Center for Atmospheric Research, Boulder, CO, United States