What Does Australia’s Climate Divide Mean for the 2025 Snow Season?

3 May

As much of southern Australia comes off a record-dry 12-month period and northern inland Australia experiences widespread flooding and inland river flows, attention now turns to what this dramatic climate divide might mean for the upcoming snow season in the Australian Alps and Tasmanian highlands.

A Dry Setup: Southern Australia's Poor Start

With very little autumn rainfall and continuing high pressure dominance, the conditions leading into winter are less than ideal for natural snow development:

Dry soils and warm ground temperatures reduce snow retention and delay base formation.
Weak frontal activity through autumn means fewer opportunities for early-season snowfalls.
Persistently strong subtropical highs may continue to block cold fronts from reaching the Alps in early winter.

El Niño: Gone, but Not Forgotten?

The El Niño event that dominated 2023–24 has officially ended. Sea surface temperatures in the central and eastern Pacific have returned to neutral levels, and subsurface cooling suggests the Pacific may even move toward La Niña later this year. However, the atmosphere can take longer to adjust than the ocean.

Key indicators such as surface pressure patterns, convection over the tropics, and the strength of the subtropical ridge may still reflect an El Niño-like influence well into early winter. This means that while the ocean no longer supports a drying pattern, the atmosphere might not fully cooperate just yet.

For the snow season, this lag increases the risk of a slow start — especially if cold fronts remain weak or infrequent through May and June. A clearer break from El Niño’s legacy may not occur until mid-winter.

What Could Turn the Season Around?

Negative SAM (Southern Annular Mode) events can help bring cold fronts further north, increasing the chance of snowfalls.
East Coast Lows or Tasman Sea troughs can occasionally produce significant snowfall, particularly for NSW resorts, even in dry frontal years.
Snowmaking infrastructure at resorts like Perisher, Hotham, and Falls Creek can offset the lack of early natural snow — assuming temperatures allow for artificial snow production.

Tasmania: More Vulnerable Than the Alps

The Tasmanian highlands are particularly exposed this year. With little recovery in soil moisture and a continued lack of cold fronts, snow coverage at sites like Ben Lomond and Mount Field is likely to be limited unless the synoptic setup changes significantly by mid-winter.

Snowpack Decline and Earlier Melts: A Longer-Term Trend

Even beyond seasonal climate drivers like El Niño and the SAM, there’s a broader story playing out across the Australian Alps: the ongoing decline in snowpack depth and duration.

Long-term records from Snowy Hydro and CSIRO show that:

Maximum annual snow depth at sites like Spencers Creek has declined by around 15–20% since the 1950s.
The snow season is getting shorter — starting later and melting earlier, with fewer deep snowpack years.

Notably, both the 2023 and 2024 snow seasons saw unusually early melts — with significant snow losses occurring in late August or early September with snowfalls beyond mid-August non-existent. These early melts shorten the effective ski season and impact runoff timing for alpine water storage.

With 2025 again starting warm and dry, and the possibility of higher temperatures persisting into winter, there’s a real risk that should another early melt occur, combined with a slow start, the 2025 season could be a short one unless cooler, snow-bearing conditions kick in mid-season.

Mid-Season Outlook

As we move into June and July, the big question becomes: Will the westerlies return?

If the subtropical ridge begins to weaken and frontal systems start reaching the Alps regularly from July onward, the snow season could still turn out to be average. However, if blocking patterns persist, this may be another below-average year — particularly for natural snowfall and lower-elevation coverage.

Snow Season Summary (as of early May 2025)

May–June: Below average. Few fronts, dry soils, and warm ground = low snow accumulation.
July–August: Watch for a shift in SAM and a breakdown in blocking. Could improve if patterns shift.
September: Possibly stronger than early winter if cold air returns and moisture increases.