CLIMATE DRIVERS UPDATE - MAY FORECAST OUTLOOKS

Indian Ocean - 9 Month Outlook

The Indian Ocean is forecast to turn more negative (more warmer waters to appear throughout the basin) throughout June into July. The strength of the negative phase is forecast to increase from July into August, and you think it is wet across the eastern inland at the moment? Well, it is about to get wetter if the outlook verifies, and the rainfall will spread to much of SA and through VIC with higher frequency and intensity. So, while the weather is a little dry through some pockets of SA, this is expected to flip as it normally does through late May into June. The negative phase of the IOD is forecast to peak around September through November and the drawn-out phase of the IOD is of concern, with flooding risks increasing through late Winter and into Spring. There is some chance we will not lose the warnings over the inland parts of QLD and NSW throughout the year given the moisture content and rainfall forecasts/observed falls in recent times. The northern tropics will likely see above average temperatures through the dry season, higher humidity and above average rainfall chances and early onset wet season activity from August. This will play out through parts of QLD as well with higher falls for cattle country against seasonal averages through the north and west. In WA, widespread rainfall is forecast to emerge through the Central and Northern Interior along the jet stream which will be dragging in larger and above average rainfall chances. This could at times feed higher moisture content into the SWLD with increased rainfall chances through the southwest wet season. Crops in the east have been drowning in recent weeks and sadly the growing and harvest season is going to be challenging for many locations on this current guide.

ENSO - 9 Month Outlook

The La Nina refuses to leave but looking at the latest data sets, I think that we will see the ENSO resolve during June and into July as expected. This will see a wet influence for another 3-4 weeks, but the ENSO influence by default has lesser impact through the cooler season anyhow, so it will have less of an influence, other than pushing warmer than normal waters around the north and east of the nation. The cooler the ENSO remains through Winter, the more of a chance it will have of turning back into a La Nina phase during the end of the year. I think we are looking at another La Nina through Summer 2022/23 but how strong remains to be seen, certainly leaning in that direction. That would also enhance the early season rainfall chances over northern Australia and shorten the dry season. It would lead to enhanced storm and severe weather season for eastern Australia, with an earlier start to the season. The main impacts of the ENSO are not typically felt elsewhere across the east and southeast of the nation until Summer and into the new year, but if we do see another La Nina develop, expect the flood risks to be elevated once again for QLD, NSW and parts of VIC and a wetter wet season for the NT and QLD. The west not too impacted by the ENSO.

Next update on the drivers comes up in 2 weeks time.


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