During the Snowy Mountains Atmospheric Research Program SMARP in 1988 and 1989, rawinsonde release showed the mean elevation of the freezing level during cold front passages at 1300 metres; during low pressure troughs, 1400 metres; during synoptic low pressure systems, 1300 metres. These are the conditions under which snow occurs over these mountains in winter. It is well known that the number of snow-producing storms varies greatly from year to year. This is true in the Sierra Nevada and probably in the Snowy Mountains, although the number of such events in the Snowy during a 1977-81 period of analysis by SIROMATH for the Snowy Mountains Authority, was almost identical to that experienced in the 1988-89 SMARP study period. Recent studies in the Sierra Nevada have shown that it was not possible to detect any silver or silver iodide in waters from two lakes located within a seeding target area, after 42 years of winter snowpack augmentation activities.
Four decades of snowfall experience from snowpack augmentation studies in the Australian Alps and the Sierra Nevada of southwestern United States | Mountain Forum