Welcome back to the first Long Range Snow Center update for the Australian Snow Season. Limited snowfall has been the story of June, but several major cold fronts should come over the coming week. So everyone is getting excited. Interesting story here, the system this week was picked up on the 15th of June on EC Monthly. Details were vague at that stage, but EC Monthly looks to have some skill. So on that note, I will have a look at the snow systems of the second part of the month. After that, I am going to have a look at our key climate drivers.
This system on EC Monthly Control shows a relatively strong cold front, pushing through on the 18th night, into the 19th. This system shows fairly cold temperatures and light-moderate precipitation. CFS suggests that Australia will be under the influence of a fairly strong high.
After a large trough, that only delivers snow to high levels, there is a small fairly weak band of precipitation, that falls as snow to 1300m on Sunday night(23rd of July) on EC Monthly Control. CFS shows a weak node, that delivers snow levels of 1400m and light-moderate snowfall.
On the 25th of July, a nice strong low just SW of Tasmania produces moderate precipitation over the Australian Alps. Snow levels on this EC Monthly system, are around 1200m. CFS shows an upper level trough, that delivers light-moderate snowfall to about 1100m.
This system, according to EC Monthly, looks pretty cold with snow levels of 1300m in the Australian Alps with moderate-heavy snowfall possible. CFS shows a high dominating this period.
This cold node on EC Monthly, is very cold, yet lacks much moisture and only contains light snowfall for the Australian Alps. It has a snow level of about 1000m. CFS shows light-moderate snowfall in the backend of a major trough for the 30th, with snow levels of about 1200m. The trough itself crosses the Alps on the 29th and delivers moderate-heavy snowfall over 1800m.
31 July-1st August
By this stage, the season should be nearing it’s peak in snowfall bearing systems. EC Monthly shows a small cold front from the south, that bears snow levels of 1300m and light-moderate snowfall, with best falls to the south. CFS shows a high coming in, after the trough on the 29th, with temperatures in this period suitable for snowmaking.
First the MJO…
This EC Monthly chart shows that the MJO is moving over the Australian region (Phases 4-6), however it is too weak to provide meaningful moisture support for Australian coldfronts. Most models agree with EC, but GFS and several other models are outliers, sending the MJO over to the other side of the world. So at the moment, the MJO is unfavourable and the forecast is for that to continue.
Next the SAM…
This GEFS forecast shows the SAM in a mostly positive phase, that is bad for our snow. But GEFS shows a gradual decline in the Positive SAM, with all other models supporting this. So in the long term, we should see a Negative SAM or at the very least, a Neutral SAM, which is good news.
And lastly, we will have a look at the polar vortex…
This is the current polar vortex. As you can see, there are under -85 temperatures at 10hPa in the stratosphere. There is also a big part of the vortex extending over Australia. This could be the reason behind the current high pressure situation, as warmer stratosphere temperatures over Australia encourages stronger low activity to break off the chain of lows surrounding Antarctica.
This is the polar vortex forecast for the next 15 days. You can see the polar vortex warms a little bit, and the polar vortex no longer extends over Australia. This could encourage stronger low encouragement and could be the reason behind the weakening positive SAM forecast. So this forecast shows potential for better conditions for lows and coldfronts to bring more snowfall.
Thank you so much for reading this forecast. The snow system forecasts look nice and the general climate outlook for the next few weeks looks good, with a better positioned polar vortex and a weakening of the current Positive SAM phase.
Disclaimer: There is low skill asssociated with using long range model forecasts to find snow systems. All systems you see here will change, as the date gets closer and may not eventuate all together. I don’t give much accuracy to these forecasts, but you can give these a bit of your time and your dreams might come true 😉 I find the chase of these long range snow systems awesome, so come and join me! The climate driver forecasts tend to have a bit more skill than the precipitation and temperature forecasts, but certainly don’t put all your money on them. However, climate drivers are an awesome tool to explain the weather around us.
Thanks again, follow me on Twitter @longrangesnow and join my email list on the top bar of this website. See you on the slopes!