Key Takeaways
- A series of five low‑pressure systems is delivering unusually heavy rain across eastern Australia in May, breaking multiple monthly rainfall records.
- The current weather pattern combines summer‑like humidity, instability and wind shear, raising the risk of severe thunderstorms, large hail, damaging winds and flash flooding in Queensland and New South Wales.
- Western Australia is experiencing a separate rain band ahead of a stronger weekend system that could produce destructive wind gusts up to 125 km/h near Perth.
- Despite the wet May, long‑range forecasts still favour the development of El Niño and a drier‑than‑normal winter and spring later in 2024.
- Agricultural regions from South Australia through Victoria and southern inland New South Wales are expected to receive additional rainfall, helping to alleviate early‑year drought concerns but also posing flood‑risk challenges.
Overview of the Multi‑System Rain Event
This week Australia is being drenched by a rapid succession of low‑pressure systems that have turned May into one of the wettest on record for large parts of the east coast. The first low already soaked south‑east states, delivering record‑breaking two‑day totals such as 86 mm at Dubbo (NSW) and 62 mm at Balook (Victoria). As that system moved off Tasmania’s south coast, a second low intensified near the Queensland‑New South Wales border, setting the stage for further heavy rain and thunderstorms. The pattern continues with a third, fourth and potentially fifth low expected to sweep across the continent over the next eight days, keeping rainfall persistent and widespread.
Severe Thunderstorm Threat in Queensland and New South Wales
The second low is already tapping into abundant moisture, atmospheric instability and strong wind shear—ingredients typical of major summer storm outbreaks. As a result, thunderstorms are likely to organise into bands capable of producing damaging wind gusts, large hail and intense downpours, especially from Newcastle to Bundaberg. Modelling predicts localized rainfall exceeding 50 mm in just a few hours, prompting a Flood Watch for nine New South Wales catchments from Newcastle to the Orara River. In Brisbane, the period of greatest risk is mid‑morning to mid‑afternoon, while Sydney’s outlook remains uncertain, ranging from heavy rain to a mostly dry day.
Rainfall Impacts and Record Totals So Far
The cumulative effect of these systems has already shattered May rainfall records at several locations. Renmark (South Australia) recorded 123 mm—the wettest May since observations began in 1889. Walpeup (Victoria) logged 68 mm, its wettest May since 1992, while Dubbo (New South Wales) reached 134 mm, the highest since 1983. In Queensland, Urandangi measured 67 mm, the wettest May since 1968. These totals underscore how the current wet spell is outpacing historical norms and providing crucial moisture for agriculture after an earlier dry spell.
Western Australia’s Intermittent Rain and Approaching Gale
While the east battles torrential rain, Western Australia has been waiting for a break. A cloudband off the Indian Ocean delivered modest falls south of Perth on Wednesday, with overnight totals exceeding 20 mm in parts of the Central West. However, a more significant low‑pressure system is forecast to develop this weekend, rapidly deepening off the south‑west capes. Some models suggest its central pressure could fall to near 980 hPa—comparable to a category 2 tropical cyclone—potentially generating wind gusts of up to 125 km/h along the lower west coast, including Perth. Such winds could uproot trees, cause power outages and inflict minor structural damage, even if the exact intensity varies among models.
Continued Soaking for Southern and Eastern States
A third low‑pressure system is expected to bring showers and fresh winds to south‑east Australia this weekend, but the real impact will arrive when the powerful Western Australian low moves eastward. Anticipated to sweep into the Great Australian Bight on Monday, it should generate another round of showers and strong winds across South Australia, most of Victoria and southern inland New South Wales on Tuesday. Modelling agrees that these regions will receive at least an additional 15 mm of rain, keeping soil moisture levels high and supporting pasture and crop growth, though it also maintains a flood risk in already saturated catchments.
Potential Fifth Low and Extended Outlook
Looking further ahead, a fifth low could develop in Western Australia on Tuesday and push showers eastward from mid‑week onward. If this system materialises, it would extend the wet spell well into the following week, reinforcing the pattern of frequent low‑pressure passages that have defined this May. The continued influx of moisture stands in stark contrast to the earlier drought conditions that affected parts of the east earlier in the year.
Contrast with Long‑Range Climate Forecasts
Despite the extraordinary May rainfall, seasonal outlooks remain firm in predicting an El Niño‑like state later in 2024, which typically brings drier‑than‑average conditions to eastern Australia during winter and spring. Meteorologists caution that while the current deluge provides short‑term relief for agriculture and water storages, the longer‑term trend may still pivot toward reduced rainfall and heightened fire risk as the year progresses. Consequently, water managers and farmers are advised to capitalize on the present moisture surplus while preparing for a possible shift to drier conditions in the months ahead.
Summary of Impacts and Recommendations
The ongoing barrage of low‑pressure systems has delivered record‑breaking May rains, triggered flood watches, heightened severe storm threats, and brought beneficial moisture to drought‑affected farmlands. Western Australia faces a separate but potentially hazardous wind event this weekend. Stakeholders should monitor flood warnings closely, secure loose objects against strong winds, and consider temporary water storage options to capture excess runoff. At the same time, they should keep an eye on climate forecasts signalling a likely transition to El Niño‑driven dryness, ensuring that any short‑term gains are balanced with long‑term resilience planning.