Abundant snow seasons

The prime conditions for heavy snowfall in the Australian Alps are persistent strong westerlies through the winter, which produce abundant precipitation and are generally accompanied by relatively low temperatures. There is no particular relationship with El Niño or La Niña, though the tendency for less precipitation in El Niño years usually leads to a poor season. The favored conditions are generally different to those which produce snow at low levels, for which a strong cold outbreak (with generally south to southwesterly winds) is required.

On the Snowy Mountains the greatest snow depth in the 46 years from1954 to1999 was just over 3.5 metres, achieved in both 1961 and 1981. The winter of 1981 was also exceptionally wet in South Australia, Victoria and southern New South Wales: a severe storm struck Adelaide on 1 June, and thisheralded three months of almost uninterrupted influence by depressions in the westerlies, which brought copious rain and snow. At Perisher Valley the snow depth rose steadily to 3.6 metres in early September before beginning to decline. Snow didn't disappear completely until mid-November. More recently, 1992 was a very long season with deep snow.

At Spencer Creek and Perisher Valley in NSW the snow depth reached the high level of three metres at regular four-year intervals: 1956, 1960, 1964 and 1968. These were also years of heavy snow cover on the Victorian Alps. In each case weather patterns were characterised by strong, persistent westerlies and abundant rain at lower levels. In each case the snow cover persisted until late November, and in 1956, into December. In 1964 a particularly stormy third week of July dumped prodigious quantities of snow, stranding people at Falls Creek and Mt. Hotham.

"Winter snow depth (cm) at Spencer Creek in the Snowy Mountains, 1964 through 1995 (data courtesy of Snowy Mountains Hydro-electric Authority)."

In Australia, the annual spring melting of the mountain snow is not in itself sufficient to cause flooding. However, in years when the snow depth is great, a combination of heavy rain and mild to warm conditions can augment spring floods.

Go to top

cyclone | storm | drought | flip side | flood | temperature | fire