It's raining in the Australian Alps this Friday afternoon, and despite some likely snowfalls this weekend in the cold air behind the front moving across SE Australia, peak snow depth for 2021 may already be behind us.

If that ends up being the case, then it will end up being just the third time in 67 years of data that peak season snow depth has occurred in July, as the blue dots on the graph below indicate.

And since all three of those occurrences have happened in the last 10 years, it's a strong pointer to the likelihood that the Australian snow seasons are getting shorter.

Indeed, you can clearly see via the black dotted line on the graph below how the date of peak depth has slid backwards in time from early September to late August. Earlier peaks would generally (but not always) indicate a shorter overall season.

(We're talking here about the snow depth which has been measured at Spencers Creek - roughly halfway between Perisher and Thredbo in NSW - by Snowy Hydro since 1954. This is by far the best and most accurate snow depth data set in the Aussie snowfields.)

Image: Date of peak snow depth at Spencers Creek in each year since 1954. Note that 2021 is already plotted, even though a heavy spring snowfall could change things. Source: @gergyl on Twitter, an engineering hydrologist who loves playing with data and is a friend of Weatherzone!

Just a reminder about season 2021 so far:

• There were unusual early snowfalls from the east in June (snow normally comes from the west, NW or SW) which coated NSW in about 50 cm of snow but which largely missed Victoria.
• Despite it being the fourth-warmest July on record across Australia with above-average temps in all states, July was a snowy month in NSW and VIC, so much snow that most resorts had all lifts open before Covid lockdowns kicked in during August.
• Spencers Creek reached the highest July snow depth in 21 years, with a reading of 183.6 cm on July 29.
• But that was the peak to date. The latest reading was 161.1 cm on September 2.

Image: The latest Spencers Creek update from Sept 2, compating 2021 (dark blue) to 2020 (aqua). Source: Snowy Hydro.

So it's within the realms of possibility that we could still have a major snowfall event that boosts the cover beyond July's 183.6 cm peak, and perhaps even over two metres. But we're running out of time as the weather warms.

After this weekend's snowfalls – which look like adding 15 to 30 cm to a cover severely damaged by rain and warm winds on Friday – there's not too much snow on the long-range horizon.

Our beautiful winter wonderland �� The only thing that's missing in this picture is you. pic.twitter.com/q6c8nNi434

— Perisher (@PerisherResort) August 24, 2021

But of course, conditions can change quickly and it's always worth keeping an eye on the Weatherzone snow page for forecasts, live cams and more.