Issued on 16th July 2020. Queensland is facing an increased forecast risk of cyclone activity, along with higher chances of rainfall and storms during the 2020/21 wet season. Generally most of Northern and Eastern Australia is in line to receive much better rainfall than the last few years. This current forecast outlook is based off confidence for a developing La Nina like weather pattern in the Pacific Ocean for the rest of this year. Above image via JAMSTEC

Now that we are through the Winter barrier, long range global data is much more reliable. This latest global data has just been updated during the past 24 hours and it’s indicating strong potential for a weak La Nina weather pattern to develop. Even if the ENSO falls just short of the offical -0.8C La Nina threshold, cooler than neutral sea surface temperatures in the Equatorial Pacific Ocean are expected. This will become the primary climate driver from September onwards where it should significantly increase the moisture feed across Northern and Eastern Australia. Below image via CPC

High pressure systems are forecast to be further East near New Zealand feeding moisture into inland surface troughs across QLD and NSW. These troughs will generate showers rain areas and thunderstorms with many storms being SEVERE containing Heavy Rainfall, Flash Flooding, Large Hail and Damaging Winds. They troughs are likely to be quasi stationary moving East to the coast on occasions then redeveloping inland shortly after.
Increased North West monsoon winds with more frequent MJO positive phases are also likely across Northern Australia bringing widespread rain and storms with higher chances of cyclone development and flooding.
Due to the weak La Nina increasing the Easterly trade winds across the Central and Western Pacific, the ITCZ (Inter Tropical Convergence Zone) in the Coral Sea is expected to be much more active. Tropical Cyclones will have a higher risk of developing in the Coral Sea then depending on exact synoptic patterns and steering ridges at that time, they could easily track West and South West to impact Queensland. Below image via JAMSTEC

Based off current global model data outputs, I believe we are in for a very active wet, storm and cyclone season during 2020/21. There will be some people who miss out but overall the rainfall prospects are a hell of a lot better than the past few years. The downside? Damage is also expected from storms, floods and cyclones. Any year can be a category 5 year so be prepared by becoming a Higgins Storm Chasing premium member. Detailed cyclone, rainfall and storm maps are always available in high detail on our website here >