A Prosperous Period for Snow in the Australian Alps

We’ve been beating the drum on this period for a couple of weeks now, and the second half of July is shaping up to be particularly dynamic for south-eastern Australia. While models are grappling with some large anomalies in the long-range, there’s growing stability across ensemble guidance, suggesting that the winter pattern will persist, even as run-to-run models continue to tussle over the finer details.

Click to enlarge: ECMWF’s Ensembles models blend the mean climatological outlook with the probability (confidence level). Confidence is reduced in the last week of July due to the longer lead time; however, there is some good alignment with other ensemble models. Source: ECMWF

This signal is driven by large planetary waves in the circumpolar flow (see this explained in the last SnowStack release).

The figure below is the 14–20 July outlook in the upper troposphere. The Australian Alps sit roughly at the 8 o’clock position on the following plot. A quasi-stationary 3-wave pattern remains anchored in our region during this period, allowing a prominent polar node to rotate through and drive frontal systems across the southern states of the continent.