Floods far from over
THE dams are full, streams are swollen, soil moisture is high in many areas, and there’s an even chance Australia will get its third rainy summer in a row.
In other words, prepare for more floods.
That’s the message from weather bureau chief executive Andrew Johnson as the nation heads into its traditional “danger season” – the peak time for thunderstorms, cyclones, bushfires, floods and heatwaves. Dr Johnson
said there was a 50 per cent chance another La Nina event would be declared by November.
The condition is typically associated with wetter and cooler conditions on the east coast, though “every La Nina is different”, Dr Johnson said.
He said another La Nina would make three in a row – grim news for fans of a long, hot summer – but back-toback-to-back La Ninas have been recorded before, in 1954-57, 1936-76, and 1998-01.
According to the bureau’s outlook, most of Queensland,
NSW and Victoria, and significant parts of South Australia and the Northern Territory are likely to experience above-median rainfall this spring. The only belowaverage rainfall is likely to be in western Tasmania and northern WA.
Median rainfalls are expected in central and NorthWest Tasmania, but Dr Johnson said there was a chance of above-median rainfall on the state’s East Coast. A huge concern is the level of soil moisture, as already-wet soils lead to more
run-off, then flooding.
Asked whether La Nina conditions made forecasting harder, Dr Johnson said the reverse was often the case.
“When climate drivers are strong that generally gives us higher confidence and higher skill in terms of our forecasting,” he said.
“This time last year in September we were flagging the very high risk of flooding as a consequence of the La Nina cycle we were in, and that’s exactly what played out.”
Even so, the bureau was taken aback by the extent of the rain in northern NSW.
“There were rainfall events and rainfall phenomena there that were not in modern human experience in that part of the world,” Dr Johnson said.
While flooding remains the chief concern, high temperatures are likely in far north Queensland, the Top End and all of Tasmania.
Dr Johnson said Tasmanians could expect warmer days and nights “in terms of median maximum temperatures” from August through to October.