A hot and dry summer is on the cards for the Illawarra, with the latest forecast models revealing a very-high likelihood of below-average rainfall and warmer-than-usual temperatures.
The odds, contained in the Bureau of Meteorology’s most-recent climate outlook, point to about a 70 to 80 per cent chance of below-average rainfall across eastern Australia between December and February.
“We are seeing a turn in the weather,” Robyn Duell, a senior climatologist at the bureau told Fairfax Media, noting that much of the country had an exceptionally wet winter.
“If we see a hot December, it will raise the risk [of bushfires] because there's a lot of vegetation around.”
The outlook for heightened fire threats matches forecasts made in August that Australia's second-wettest winters on record would lead to a delayed start to the bushfire season before conditions ramped up.
The December-to-February outlook suggests the Illawarra is likely to experience warmer than average weather overall, with a “particularly high chance of summer having a warm start” thanks to warmer-than-usual daytime temperatures in December.
Lower than usual cloud cover will be the feature for much of the summer, and with that rainfall is also likely to be less than typical for both December and summer as a whole.
The bureau said the summer outlook was strongly influenced by a climate driver called the Southern Annular Mode (SAM), which is expected to be in a negative phase during December.
“When this happens in summertime, weather systems are further north than usual, meaning Australia experiences higher pressures than normal,” the bureau said. “This is typically associated with reduced rainfall and higher temperatures.”
Ms Duell said the high-pressure systems sitting further north over the country would act as a barrier to tropical moisture reaching further south and could also “raise the risk of heatwaves”.
- with Peter Hannam
AT A GLANCE
- Below-average rainfall, particularly in December
- Warmer-than-average minimum and maximum temperatures
- Increased heatwave risk
- Bushfire potential raised
If we see a hot December, it will raise the risk [of bushfires] because there's a lot of vegetation around.Bureau of Meteorology climatologist, Robyn Duell