Our wet and wintry weather is expected to continue into July and August. While the La Nina conditions have now moved to “neutral” the Bureau of Meteorology advises that other factors are influencing the continuation of wetter than normal conditions.
The likely development of a negative Indian Ocean Dipole and warmer than normal waters off northern Australia facilitate the wetter conditions continuing. You may be asking: what is the Indian Ocean Dipole (IOD)? “Sustained changes in the difference between sea surface temperatures of the tropical western and eastern Indian Ocean are known as the Indian Ocean Dipole” according to the Bureau.
The IOD is one of the key drivers of our climate and can have a significant impact on agriculture as it generally coincides with the winter crop growing season. A negative IOD tends to bring wetter conditions to southern Australia while a positive IOD tends to bring drier conditions. A neutral IOD tends to bring fairly normal temperatures and rainfall. For more visit the Bureau’s web site: http://www.bom.gov.au/climate/iod/
Many agricultural areas in southern parts of Australia have had very good rain and crops over the past two years and hopefully will again this year, particularly in view of world grain shortages. Northern Australia is normally experiencing its “dry season” during winter, however some heavy rainfalls are being forecast in coming days for the north and down the east coast into NSW. After the major floods only a few months ago, they will be hoping that these rains are not as bad.
For June, the Bureau weather station measured 125 mm of rain for Daylesford compared to the long-term mean of 105.6mm. For the first six months of 2022 we have had 439 mm of rain which is 11 per cent higher than the long term average of 394 mm.
Victor Szwed is a local resident who contributes a monthly weather column to The Wombat Post.