2019-2020 Australia Tropical Cyclone Season Recap and Out of Season Development Potential
By
Jason Nicholls, AccuWeather senior meteorologist
Published May 1, 2020 2:26 PM EDT
The 2019-2020 Australian basin tropical cyclone season ended on 30 April, but that does not mean that the threat of cyclones is over as there can be out-of-season development. We will first take a quick look back at the official Australian basin tropical season and see how the AccuWeather forecast for the season compared to what actually transpired. We will then look ahead at the potential for out-of-season tropical development around Australia.
The AccuWeather Australian Basin tropical outlook that was issued in October 2019 called for a below-normal season and a less active season than the 2018-2019 season which featured 11 cyclones. The AccuWeather forecast is the top image below with bottom image being the actual numbers for the season.
The Australian Bureau of Meteorology also called for a less-active-than-normal tropical season but did not give specific numbers like the AccuWeather forecast.
As we can see, AccuWeather called for nine named cyclones which was close to the actual number of seven named cyclones for the season. Regardless, the 2019-2020 tropical season had fewer than the normal of 11 storms as was predicted.
In addition to predicting a less active tropical season, AccuWeather also correctly predicted a slow start to the season. An excerpt from the AccuWeather outlook is on the top with the actual timeline of tropical cyclones on the bottom.
The regional breakdown on the number of storms also worked out as forecast with the greatest number of named cyclones occurring off the northwestern coast of Australia or in the southeastern Indian Ocean.
At the end of the seasonal outlook, there was also a mention of a better-than-usual chance for out-of-season tropical development similar to what occurred following the 2018-2019 season.
We are currently watching two areas of potential development around Australia in early May. A strong Madden-Julian Oscillation or MJO pulse is now in phase 4 which coupled with an Equatorial Rossby Wave should lead to a tropical low forming off southern Sumatra and Java this weekend or Monday.
Conditions will be favorable for any tropical low to strengthen as it drifts west-southwestward early next week, and there is a medium chance the low can reach tropical cyclone intensity by the time it passes near or just north of the Cocos/Keeling Islands late next week. Regardless of whether the low reaches tropical cyclone intensity or not the main threat from this feature will be heavier rain across the Cocos Islands later Thursday into Saturday.
The area we are monitoring is circled in orange below.
The other area of concern is around New Caledonia and Vanuatu for late next week with a weakening MJO pulse still over the western Pacific. The area and dates of concern for development are shown below.
Conditions look to be less than ideal for any low to strengthen into a tropical cyclone, but there is still a small chance it can become a named cyclone late next week. However, it is more likely the low becomes a sub-tropical storm or a mid-latitude storm with tropical characteristics southeast of Vanuatu later next week. This hybrid storm could pass close enough to bring some rain to the northern island of New Zealand between 10 and 12 May.
Beyond these two systems, we are not seeing any other out-of-season development around Australia at this point, but stay tuned to AccuWeather.com for any updates.
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Weather Blogs / Global weather
2019-2020 Australia Tropical Cyclone Season Recap and Out of Season Development Potential
By Jason Nicholls, AccuWeather senior meteorologist
Published May 1, 2020 2:26 PM EDT
The 2019-2020 Australian basin tropical cyclone season ended on 30 April, but that does not mean that the threat of cyclones is over as there can be out-of-season development. We will first take a quick look back at the official Australian basin tropical season and see how the AccuWeather forecast for the season compared to what actually transpired. We will then look ahead at the potential for out-of-season tropical development around Australia.
The AccuWeather Australian Basin tropical outlook that was issued in October 2019 called for a below-normal season and a less active season than the 2018-2019 season which featured 11 cyclones. The AccuWeather forecast is the top image below with bottom image being the actual numbers for the season.
The Australian Bureau of Meteorology also called for a less-active-than-normal tropical season but did not give specific numbers like the AccuWeather forecast.
As we can see, AccuWeather called for nine named cyclones which was close to the actual number of seven named cyclones for the season. Regardless, the 2019-2020 tropical season had fewer than the normal of 11 storms as was predicted.
In addition to predicting a less active tropical season, AccuWeather also correctly predicted a slow start to the season. An excerpt from the AccuWeather outlook is on the top with the actual timeline of tropical cyclones on the bottom.
The regional breakdown on the number of storms also worked out as forecast with the greatest number of named cyclones occurring off the northwestern coast of Australia or in the southeastern Indian Ocean.
At the end of the seasonal outlook, there was also a mention of a better-than-usual chance for out-of-season tropical development similar to what occurred following the 2018-2019 season.
We are currently watching two areas of potential development around Australia in early May. A strong Madden-Julian Oscillation or MJO pulse is now in phase 4 which coupled with an Equatorial Rossby Wave should lead to a tropical low forming off southern Sumatra and Java this weekend or Monday.
Conditions will be favorable for any tropical low to strengthen as it drifts west-southwestward early next week, and there is a medium chance the low can reach tropical cyclone intensity by the time it passes near or just north of the Cocos/Keeling Islands late next week. Regardless of whether the low reaches tropical cyclone intensity or not the main threat from this feature will be heavier rain across the Cocos Islands later Thursday into Saturday.
The area we are monitoring is circled in orange below.
The other area of concern is around New Caledonia and Vanuatu for late next week with a weakening MJO pulse still over the western Pacific. The area and dates of concern for development are shown below.
Conditions look to be less than ideal for any low to strengthen into a tropical cyclone, but there is still a small chance it can become a named cyclone late next week. However, it is more likely the low becomes a sub-tropical storm or a mid-latitude storm with tropical characteristics southeast of Vanuatu later next week. This hybrid storm could pass close enough to bring some rain to the northern island of New Zealand between 10 and 12 May.
Beyond these two systems, we are not seeing any other out-of-season development around Australia at this point, but stay tuned to AccuWeather.com for any updates.
Report a Typo