Tok Tok place: October 2012

Western Australia snow

Western Australia / September 10, 2019

Bluff Knoll at dusk, viewed from the northwestBluff Knoll at dusk, viewed from the northwest

Mountain snowfalls are typically confined to the higher peaks of the Stirling Range in the state’s south. Situated about 90km inland from Albany, this is a range of rugged peaks rising abruptly from low-lying and mostly flat farmland. Five of the peaks rise to over 1000m, with the highest being Bluff Knoll at 1095m. Although not a great height as far as mountains go, in this region it is high enough to receive occasional light snowfalls in most years.

The southwest corner of Western Australia

Sometimes, but far less often, snow may also fall on the Porongorup Range. This is a smaller, lower range (highest point 670m) between the Stirling Range and the coast. However, if snow falls on the Porongorups it will have also fallen in greater quantity on the Stirlings, and so Bluff Knoll is the focus for snow-seekers in WA.

The southwest corner of Western AustraliaOutside of the Stirling and Porongorup Ranges, the only other significant mountains in WA are too far north and of insufficient height to attract snow. Some areas in the southwest which have received rare snowfalls are hilly (eg Perth Hills and around Greenbushes), but these are generally considered as low level falls.

When It Falls

The earliest that snow has been recorded in WA is April 20th (1970), and the latest is November 19th (1992), however it is very improbable towards the ends of this range. Since WA was settled by Europeans (Albany in 1826, Perth in 1829) only three falls have ever been reported in November, and only four falls prior to June.

As the monthly distribution chart shows, the best likelihood of finding snow is in the July to September period. July and August are the coldest months of winter, and although September marks the start of spring, good wintry outbreaks can still occur and the mountain has cooled further. One of the heaviest falls in recent decades occurred in early October, so early spring should not be discounted.

Near Bluff Knoll's summit facing southWhen snow does fall, the best accumulation occurs overnight or in the morning when temperatures are lower. Snow showers may occur at any time of day, but even on the coldest days on the highest peaks maximum temperatures are above freezing, even if only just, and melting occurs.

How Often It Falls

Since 1965, reports of snowfalls known to the Bureau of Meteorology (as listed in the historical data page) suggest an average of just over one snow event per year, as shown on the chart below. Prior to this, reports become progressively less complete the further back in time one looks. Low level falls are much less frequent than those on the Stirling / Porongorup peaks, and appear to be decreasing with time. Whether this reflects climate change or not is hard to say, because of the probable incompleteness of the snow records.

Total number of known snow events in WA each year, from 1965 to 2003.
Each horizontal line indicates one day on which snow was reported in WA;
white asterisks (*) indicate snow at low levels as well as on the peaks.

It is not known with certainty how often it snows on the Stirling Ranges. Anecdotal evidence suggests snow may settle on Bluff Knoll two or three times per year on average, with the possibility of a couple more very light falls going unwitnessed or unreported. Instances of snowflakes briefly falling but not settling on the ground - such as in precipitation downdrafts over ground that isn’t cold enough - may occur more often.

Near Bluff Knoll's summit facing south

The uncertainty is due to the lack of people in a position to clearly see the snow on the mountains. The Stirling Range sits in a large national park surrounded by thinly populated farmland; apart from the nearby ranger’s residence and caravan park (altitude only 218m, below the snowflakes), there simply aren’t many observers around. Light snow on the summits can be hard to spot from below and at a distance, even if not obscured by cloud, and when clear, a light dusting melts quickly. Falling snowflakes might only be seen by people climbing the summits, but few people do this in the inclement weather required for snow, especially outside of weekends and school holidays.

Source: www.feargod.net