The Bureau of Meteorology (BoM) has warned that severe thunderstorms could bring heavy rainfall and flash flooding to eastern and south-eastern Australia over the coming days. A low-pressure system over South Australia, combined with moisture from the tropics moving down the eastern seaboard, is expected to generate widespread rainfalls.
Severe Weather Warnings Issued
On Tuesday afternoon, the BoM issued severe weather warnings for parts of eastern Tasmania for Wednesday and Thursday. Severe thunderstorms are also predicted to hit the central west of New South Wales before extending south towards Victoria on Thursday evening.
Meteorologist Ilana Cherny stated: "In addition to heavy falls tomorrow, we could also see areas or storms with damaging winds and large hail through parts of southern Queensland. On Thursday, that area contracts to the east, focusing on south-east Queensland and parts of central and north-eastern New South Wales."
Rainfall Totals and Risks
In the 24 hours to Tuesday afternoon, thunderstorms brought rainfalls of up to 60mm in New South Wales, 70mm in Tasmania, 20mm in Victoria and 40mm in south-east South Australia. The eastern seaboard could expect accumulated totals of about 25-100mm through southern Queensland, with heavier falls of up to 150mm around parts of the NSW coast.
Cherny explained that the low-pressure system and moisture from the tropics are being enhanced by a trough through the upper levels of the atmosphere, which is driving the increased rain activity. Heavy falls in southern Queensland and northern NSW are predicted on Wednesday and Thursday.
El Niño Development
The forecast coincides with a separate BoM update indicating signs of El Niño development in the tropical Pacific. This phenomenon can increase the likelihood of hotter and drier conditions, particularly during the Australian spring.
There has been substantial warming in the central tropical Pacific region in recent weeks, and all climate models reviewed by the bureau forecast sea surface temperatures reaching El Niño thresholds by winter. The bureau noted: "There remains some uncertainty in the likely strength of this El Niño event. Models indicate it will be at least moderate in strength, with the possibility of a strong event."
However, the strength of the El Niño does not necessarily mean strong impacts on Australia's climate, as other factors also influence weather patterns.
Outlook for the Weekend
The low-pressure system is expected to move offshore on Friday, but plenty of moisture will still wrap around the system, bringing ongoing risks of heavy falls to coastal parts of New South Wales. Residents in affected areas are advised to stay updated on warnings and take precautions against potential flooding and storm damage.
