Hello all, we have the last long term outlook of the season here today, so let’s take a brief look at the state of the climate.
We have a prospect for about 10–20cm of snowfall for the Australian Alps at this point on EC for this period starting late Thursday and pushing through Friday and Saturday this coming week.
A decent sized low-pressure system that looks relatively cold, but needs a bit more moisture on the backend. Still some time for a better alignment of moisture for the Alps, rather than the precipitation that slips largely to the south.
To the contrary, GEFS needs a little more convincing with this one, quite weak:
This one is per the next pass of the long wave trough, but it is looking very much like a Southwest WA peaking type of system, delivering not a lot for the Alps in the SE of Australia.
Ensembles, EPS and GEFS, concur, the latter ridging it out. EPS shows it just clipping the SE.
The next LWT as indicated by GFS looks like it is going to pass our region during the above period.
Here we refer to the node that is south of Africa at this particular forecast period.
There’s some interest that could be noted from EC Monthly about troughing in the First week of October through the Great Australian Bight through to the SE. It’s obviously very much a long shot, but worth a brief mention. And vaguely aligned to the above LWT plot as well.
We are seeing an active MJO in the Indian Ocean weaken by the time it gets to Australia in the next week or so, which means that there is likely to be a limited impact from the MJO for us going forward. EPS concurs:
We are certainly settling back into a Niña-esque versus strong Indian Ocean pattern that we have seen most of the winter, and certainly hasn’t been delivering a great deal of results, with primarily negative tropical momentum.
We are currently in the midst of a general -AAO phase that helped to deliver our last big storm for the Australian Alps.
You will be able to notice some degree of weakening of the Stratosphere Polar Vortex in the upper echelons of that chart, that will help to keep us in a negative AAO for the next 10 days, but it isn’t going to be a long-term change in the stratosphere (not like the SSW that occurred in the Southern Hemisphere last year).
EC confirms the upward trend in the AAO, which isn’t going to help us in terms of snowfall for the Alps, overall in my opinion we are heading towards a pretty mundane month with a lacking in tropical/extratropical support, unless the AAO tanks negative again or we see something more long-term in the stratosphere.
Conclusions for the season
So I called for a “moderately better than average” season in autumn, this quite obviously was not so. We are currently at 167cm at Spencer’s Creek, which at the point where we are days from the average day where we see the highest point in the snowpack. This is considered pretty average, but let’s not kid ourselves. Until the storm a week back, Victoria had barely any natural snowpack in the resorts, same for lower parts in NSW. It has been a pretty poor season on the whole.
A number of reasons for this is:
- The negative IOD forecasted for winter didn’t really happen (yet).
- Lots of negative momentum in the tropics (lack of tropical waves and lack of MJO, not helpful).
- And conversely not a lot of negative momentum down in the SH mid-latitudes (so it leads to a rather lacking polar setup, not a lot of troughs, more ridging).
- This is set-up by a non-dynamic (until the last few weeks) set-up between an atmospheric Niña and an active Indian Ocean.
Either way, my seasonal forecast has not done well and this is unfortunately not an anomaly. A review will be made into it in the SH summer to hopefully improve forecasting outcomes.
For now, it is farewell. Given the current situation in the world, it is unlikely that many Australians will be able to go and ski overseas, but for those who just want to follow for the enjoyment of weather analysis or for whatever reason, one can follow my Northern Hemisphere seasonal and long term outlooks coming very soon.
Thanks again for reading this Australian snowfall outlook, follow me on Twitter @longrangesnow and subscribe to my email list by clicking on the tab on the main header above.