I was hoping to do a video on this but apologies, with Covid ruining that plan but here is the updated information for those wanting to know if we are likely to see a repeat of the past two, another La Nina in the ENSO region.
CURRENT FORECAST FOR ENSO
This is preliminary forecasting based of data that is raw and volatile so for those consuming this information, treat it with a low to moderate confidence at this time. It would be foolish to think anyone could forecast the ENSO this far out while a phase is underway.
The modelling supports a swing back to a La Nina by October and deepening through November with rainfall impacts across northern and eastern Australia likely to be felt from later November.
The strength of the negative IOD phase over the Indian Ocean will be key to rainfall anomalies for the nation through much of Spring, but as this is ongoing we may be seeing the next wet phase developing via the La Nina phase returning. But the impacts from the ENSO won't be felt really until Summer on current guide.
Confidence in this forecast package will remain low and not improve to around July but will keep monitoring
Stronger signals for another La Nina Summer right now off the models and data sets coming through but the climate models are a little more supportive of a cool neutral. Looking at all the data sets as of today, I am happy to bring the chance up to around 65% for the ENSO to be in La Nina. But, how strong it is, how long does it linger for etc will not be known for quite some time so there is no point in trying to dive into the weeds just yet. But on the current guide, La Nina would peak through January of 2023 and wane thereafter. Better guidance will be available from July.
I am continuing to work on this product in house, but you can see the outlook is swinging towards a La Nina by the time we get to November 2022. I do think on my gut read on things, that the ENSO will return to a La Nina phase during the Summer of 2022/23. That may support some higher rainfall and moisture values over northern Australia and across the eastern areas of the nation, which will be in combination with higher moisture spreading through the nation via the negative IOD. The last time we saw the two in phase with massive impact was about 10-12 years ago.
DATA AND ANALYSIS
Well the statistical support for another La Nina developing is relatively moderate to high at the moment, at this juncture. That could be of concern for the disaster zones in the east, but not a full reason to get alarmed, as we are still 6 months out from the event potentially developing and about 3 months from getting a better look at the event in general. The state of ENSO is poorly modelled at this time.
We need to resolve the current La Nina event before we can see whether another event will develop. But what happens if the La Nina does not resolve? That question does get asked a lot. The bottom line is, the ENSO can be reclassified as a cool neutral, the impact over the cooler season in Australia is quite limited.
Now as we move through Spring, we are seeing more rumblings for a developing La Nina with the dynamic and statistical models leaning more into the La Nina thresholds with a few of the members going for a deep La Nina. One one models suggests a El Nino, the bulk still cool neutral, but they are moving further towards La Nina thresholds each time this data is refreshed.
CPC - Spaghetti Plot - ENSO through to Summer 2022/23
The forecast is shifting more negative every update which supports La Nina. The overall confidence is low at this time of year, but even notice the analysis in black at the start of the spread, it is still showing a slow waning. One model supporting an El Nino but overwhelming evidence that cool neutral or La Nina is likely to return during the Summer of 2022/23.
CPC - Official Forecast - ENSO through to Summer 2022/23
Certainly looking more likely that an El Nino is something we won't be dealing with this Summer. Now I saw some forecasts from various Ag Institutions suggesting a El Niño on the basis of stats. That is not how weather works. So once again, as I repeat here, a cool neutral is the right forecast based off the data with a higher chance of La Nina forming in the late Spring or Summer.
CPC Rainfall Outlook - August to October 2022
Very wet, but this is not attached to the ENSO, it is attached to the strong negative IOD phase and I want to point out, that is the driver to watch in conjunction to the SAM phase to the south of the nation. However, as the IOD dictates the potential for severe weather, flooding and cooler than normal weather for large parts of the nation into late Winter and Early Spring, the ENSO region will then start to develop either a cool neutral or La Nina phase. So I just want to make sure you understand where the focus should be in the coming months and when to start looking at the ENSO region more closely.
CPC Temperature Outlook - August to October 2022
Classic IOD influence with the northern areas warmer and more humid than normal with a terrible dry season coming up, interrupted by rainfall and humidity. This plays out with moisture streaming south and southeast across the nation leading to flooding risks going through the roof. This means more cloud and cooler than normal weather as well, with persistent periods of gloom, rain and colder west or northwest winds. This is supporting the cloud bands dominating through late May through to around October. So those looking for warm weather, enjoy the next week or two.
I will leave it there for now, and lay down again! But I will have more details on this next week when I recover from Covid. But certainly, ENSO will become a clearer picture by July, I am leaning to a La Nina but leaning to it is not calling it. There are no prizes for being first to the post in the weather world. It is about getting decent information out to you all that does not stroke my ego, but gets you the information you need to know to help you assess the right steps forward for your situation. Rainfall and Temperature forecasts mean different things to different people so I hope that this overview assists your understanding.