Despite one of the most devastating bushfire events on record just three years ago,much of the country remains unburnt. But after three years of heavy rain driven by La Nina events,strong grass growth has occurred across much of the country,which will increase fire risks.
The Bureau of Meteorology’s three-month forecast suggests maximum temperatures during December and February will be unusually high for much of the country,whilerainfall is predicted to be below average.
Climate experts study several factors to determine how strong an El Nino will be,including the sea surface temperatures in the central Pacific Ocean. This is known as the 3.4 Nino index.
This index is now about 1.5 degrees warmer than average and is likely to continue warming in the coming weeks. Values of 0.8 degrees warmer than average are typical during El Nino years.
Historically,the 3.4 Nino index has peaked at 2.6 and 2.4 degrees warmer than average in 2015 and 1997,respectively. A strong El Nino event can occur when the 3.4 index peaks above 2 degrees - which this year’s event is expected to do in December and January.
However,meteorology agencies monitor a variety of criteria to determine if an El Nino is “strong”,including rainfall and temperature. Just because the 3.4 index swings above 2 degrees,it may not be enough to classify it as a “strong” El Nino.