The Australian cyclone season is set to begin on 1 November and run through the end of April. There have already been two moderate tropical storms in the southwestern Indian Ocean to the west of the Australian region, but there have been no cyclones in the Australian basin.

The 2021-2022 season got off to an early start with Tropical Cyclone Paddy forming on 22 November 2021, but the season ended up being a slightly less-active than usual season with only 10 named tropical cyclone. Before looking at the details for the upcoming season, here are some factors that are expected to influence the 2022-2023 season.

Courtesy Australia BOM, APEC Climate Center and WMO

A rare triple-dip La Niña will carry through at least the first part of the season. Water temperatures in the equatorial Pacific can return to neutral levels in February, but the atmosphere can continue to be La Niña like into austral autumn. La Niña years usually favor an active tropical cyclone season.

The current negative Indian Ocean Dipole is expected to carry into the start of the season but can return to neutral by January 2023. However, high sea-surface temperatures will likely persist off northwestern Australia through austral summer. Water temperatures off northwestern and northern Australia can ease toward normal late in the season.

Courtesy Australia BOM, APEC Climate Center and WMO

The Southern Oscillation Index (SOI) remained strongly positive heading into the tropical season which is indicative of a La Niña pattern and is another good indicator of an active tropical season. A strongly +SOI also increases the likelihood of cyclones early in the season.

Warm water in the Coral Sea and Solomon Sea coupled with a weak La Nina should favor a westward shift in the development area of the southwestern Pacific toward these seas.

Most teleconnections support a normal to a more-active-than-usual tropical season in the Australian basin which is supported by the ECMWF seasonal outlooks.

Take a look at our analog years, which had a variety of seasons from well above normal to less active than normal but worked out to an average of 10.6 cyclones, or near normal.

Factoring in teleconnections, modeling and analog years, our 2022-2023 Australian Basin Tropical Season forecast is below.

Overall, we are leaning toward a close-to-normal season and a season that is a bit more active than the 2021-2022 season. There is the possibility that the season can be a little more active than normal and forecast.

There should be a fair amount of similarities between the 2022-2023 season and the 2021-2022 season with another early start to the season. Much like last season, we are expecting the first cyclone to develop before Christmas, and most likely will be off western Australia.

The first impact last season occurred in early January, and there is a good chance that the first impact from a tropical cyclone will occur in December or January with the northern or northwestern coasts being the favored area for such impact.

The number of cyclones that impacted Australia last season was only three, and there were only two severe tropical cyclones (sustained winds of 118 km/h or greater) which is a little below normal for both. In addition to expecting slightly more cyclones than the 2021-2022 season, we are favoring a bit more severe tropical cyclones and impacts with four to five severe cyclones and four impacts.

An active monsoon trough displaced a bit southwest due to the La Niña should again result in more tropical lows than usual during the period from November through April and should be on par with the past two tropical seasons with 27 and 32 tropical lows respectively. As a result, much of northern Australia should be wetter than normal during the season increasing the risk for flooding.

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