The big picture - 2021 Long-range driver update
The latest global model summary released by the BOM this week shows an improvement from a fortnight ago. Neutral/wet ENSO is favoured during the business end of the winter crop and spring pasture growing conditions - although it continues trending wetter as the year progresses (similar to 2020).
The Indian Ocean Dipole outlook is again erratic, but leaning towards wet phase. What the bar charts don’t show is the warm sea temps around Australia’s northwest coming through the models as increased chance of NW cloud bands for eastern Australia. (Go to our Farmer Forecast homepage to see the warm SSTs loop around Australia).
The ENSO Modoki is trending wet (black line, below). The JAMSTEC forecast numbers sent through by the scientist there shows Modoki wet phase peaking in Nov. The BOM prediction below shows a Sep peak for this driver.
Wet Modoki and warm ocean temps around Australia are flowing through model predictions as wetter than normal conditions, despite neutral IOD and ENSO (see bottom chart “what affects me, when?”).
The chart above shows neutral ENSO conditions likely, but trending towards a late La Nina again
The BOM’s ACCESS-S model shows this indicator moving more into wet phase than a fortnight ago. A good thing for eastern Australia.
Indian Ocean Dipole outlook (8 June)
This looked settled a fortnight ago, but the passing MJO played havoc with SSTs in the Indian Ocean! All over the place again, but we have warm water outside this measuring zone - which is a good thing.
Forecast chart courtesy:http://www.bom.gov.au/climate/enso/#tabs=Indian-Ocean
What affects me, when? A rolling 3 month moving window: See here, EMI = Modoki (navy), Nino3 = ENSO (green), IOD = Indian Ocean Dipole (red) and SAM = Southern Annular Mode (yellow). White - not significant!
From Lim et al (2012): https://www.cawcr.gov.au/technical-reports/CTR_051.pdf