It’s an epic case of weather whiplash, and while these rains are helping firefighters gain control of some of the fires and even extinguish many of them, they’re not going to end the drought or remove the bush-fire danger entirely during the rest of the summer there.
Over the weekend, dust storms and hail blew into parts of southeastern Australia, from Victoria northeastward to Queensland. According to an ABC Australia news report, golf-ball-size hail and winds of more than 70 mph hit Canberra, the country’s capital, and invaded Sydney as well. Trees were damaged in Sydney and surrounding suburbs.
In Canberra, the hail was large enough to damage cars and smash windows, and the storms led to more calls for emergency assistance in the capital than had occurred in the previous two years, ABC reported.
Extreme rainfall rates were recorded in some areas. According to the Bureau of Meteorology, 1.7 inches of rain fell in one hour at the top of Mount Moornapa, about 120 miles east-northeast of Melbourne. That has a return interval of about once every 50 years, or a 2 percent chance of occurring in any given year, the BOM reports.
A shift in the prevailing weather pattern has featured a more humid, onshore air flow that has converged on an area of low pressure set up across inland portions of eastern and southeastern Australia. This has yielded daily rounds of showers and thunderstorms, including severe storms, that has brought welcome rains for farmers and firefighters.
However, the forecast calls for a return to “severe” and “extreme” bush-fire danger in parts of South Australia, Victoria, New South Wales and Queensland. The BOM is also warning of the likelihood of dust storms as a strong cold front pushes across southern Australia on Wednesday into Thursday. Trees weakened by fire and then by heavy rains may fall more easily, the BOM warns.
Cold fronts, and their associated wind shifts, have brought some of the most devastating bush-fire days of the ongoing crisis, propelling flames at more than 40 mph in new directions that force firefighters to retreat.
While the recent rains could damper fire activity, the long-term drought conditions and high temperatures will still make for dangerous fire weather. On Thursday, in particular, heat is forecast to intensify in New South Wales and Queensland, with a high temperature of 104 degrees (40 Celsius) forecast for Sydney, along with strong winds.
The large-scale weather and climate factors that had tipped the scales in favor of an extremely hot and dry spring and summer are no longer present, the BOM reports, with an air and ocean circulation pattern in the Indian Ocean and El Niño both in position to exert far less influence over the continent’s weather for the time being.
However, long-term, human-caused climate change does raise the likelihood of more heat and dry weather in Australia over time, including the rest of this summer.