A look at the ENSO once again and now that all the May data is in, I can now bring a bit of a write up on what is going on in the short term, the impacts on the nation as we move into the cooler season. Also looking at what is going on into the longer term, and as I posted last week, there is some indication from the models that La Nina could return over Summer 2022/23.

We will see the confidence in the forecast surrounding the ENSO improving as we get to about July, so expect more changes and any specific or definitive forecasting should be treated with the skepticism it deserves as the guide is not great at this time of year.

I will mention, in the longer term data sets and in my discussions and attendance at some weather conferences in recent weeks, there are hints and a broad consensus that El Nino may be on the cards next year which would not be unsurprising, however the confidence in going out that far and suggesting the ENSO is going to be in one phase or another, particularly when we are seeing the data errors and forecast errors relating to this current event, should offset any concern for now, but something to watch and I will have more to say on that in our Spring!


ENSO FORECAST - Next 9 Months - Updated May 17th 2022 - Next Update June 16th 2022

The shift to a cool neutral influence from the ENSO region is forecast to continue throughout the Winter, with the seasonal override in place. This means that because we are in Winter, while there is a La Nina, it has little impact on Australia during this time, but does keep the warmer waters closer to the east coast of the country, but the prevailing wind regime is likely to be more westerly than easterly, so we don't see the impacts as per a Spring or Summer season. That said, the cool neutral/weak La Nina phase may help to keep the Southern Annular Mode more towards neutral throughout Winter, reducing the impacts of the westerly wind belt somewhat. This in times without the IOD in a negative phase would lead to a drier Winter for much of Australia, but I do think we will see the IOD take the reins from the ENSO in terms of major weather maker through this period. Now as we move into Spring, the ENSO should resume taking a role in influencing the weather for northern and eastern Australia. This leading to early onset rainfall and buildup, early start to the storm season and higher rainfall likely through harvest, in conjunction with the negative IOD phase, the nation looks to be swimming on paper, but in reality, these things look somewhat different. So be aware, make preparations but there is not enough information to panic yet. The peak of the next La Nina on current information is next January or February, if it forms. Current guide has risen to a 61% chance of formation through Summer 2022/23. The latest data sets by chance coming through at a 50-60% chance of the La Nina returning.


IRI - Probabilistic ENSO Outcomes - MAY 2022 OUTLOOK

You can see across the members that the signal for a La Nina or even Cool Neutral will persist through Winter with the chances of La Nina marginally coming up over the Spring and Summer later this year. Now this time last year we had this model and members suggesting an El Nino developing, but this year, we are seeing the weak La Nina/cool neutral persisting, which is rather unprecedented, following the past 2 La Nina years.


You can see that the signals for COOL NEUTRAL/WEAK LA NINA stays with us through to early next year. I will mention that this same model had forecast the La Nina to well and truly done by early April and look where the members adjusted to for this period. So, there is some skill score error even with the best models in this space. So be aware, that as we move through to the middle of the year, that is when we should be paying more attention to these forecasts as the confidence improves on the forward data.


The general consensus is for the models to stay at COOL NEUTRAL through the remainder of Winter and then the shift to La Nina could be on during the Springtime, but I will say that the global modelling has softened on this idea since my earlier forecast update. But as I will mention a few times below, how it looks in July is more critical than where we are now, with the confidence in the data improving from that point on.


As I keep mentioning, we are knocking on the door of our next period of dry across the country and that may start to emerge in 12 months' time. So the time to prepare, to conserve water, to manage your situation to factor this risk into your plans is critical to offsetting the shift, which will be here before you know it!


The Euro shows the La Nina waning through the coming 4 weeks which I suspect is the right call and I am forecasting that as well. Then COOL NEUTRAL conditions through to about October, but that is where the modelling starts to turn back to La Nina, only 2 members really suggesting a surge into WARM NEUTRAL. This is very similar to last year and I suspect that these will likely follow the majority of members and fall to COOL NEUTRAL OR LA NINA by the time we get to July, but that is a gut call more than anything.


Latest data has offered a little wobble back towards COOL NEUTRAL for the remainder of the year, where this model was forecasting a deep La Nina throughout the remainder of the year and into 2023. So will be interesting to keep watch on this particular product. However, the skill score of this product is rather poor.


We are due to get the MAM figures in early June and they will be telling. Looking at the latest SSTs Anomalies, it supports that through Autumn, the La Nina phase had strengthened and maintained that strength. That does mean we are moving into a season where we could see La Nina having little impact through Australia, other than pushing warmer waters towards the east coast of QLD and NSW. We will know more on the developing ENSO for Spring and Summer by July onwards. You can see that conditions may start to turn neutral or La Nina during September onwards.


As mentioned, you can see the cooler than normal waters over much of the ENSO region with the warmer waters still persisting around northern and eastern Australia and this is unlikely to change too much through Winter. It is forecast that the ENSO will likely shift back to La Nina phase into Spring, increasing the warmer SSTs across eastern and northern Australia, setting up another damp and stormy Summer.


The two driving forces to watch through this period. The IOD will rule to roost through the cooler season while the ENSO will rule the roost coming into the warmer season. The issue for all Ag areas across Australia will be what happens IF we see the negative IOD overlap the developing La Nina. That has happened in the past (which I have spoken about at length here - review the Climate Section by clicking the tab and choosing Climate Weather to see all posts) and this could lead to a nasty period of flooding throughout pockets of the country to finish 2022.

More to come on this as we move through the coming weeks, but certainly more advice coming during July 2022 when the data becomes a little firmer in telling us where things are more likely to go.