The SKY NEWS Weather Severe Weather Outlook 2016/2017 has just been released and Chief Meteorologist Tom Saunders is forecasting another hotter than average severe weather season with an increased risk of severe thunderstorms, rain and cyclones.
Severe weather season, which runs from October to April, is the period in which Australia faces its most extreme weather conditions. The key climate drivers behind this season’s forecast are warmer than normal ocean temperatures off our northern and eastern coastline, a negative Indian Ocean Dipole (IOD) and the background influence of global warming.
The upcoming thunderstorm season is likely to be extremely active over eastern and northern Australia and fortunately for farmers who have suffered through four years of dry conditions, there is an increased chance of further drought breaking rainfall. The warmer than average seas off the north and east coasts should increase moisture levels and increase the number of days with suitable conditions for thunderstorm development. Brisbane, Sydney, Canberra and Melbourne should all see more days than normal with severe thunderstorms, characterised by hail larger than a $2 coin, wind gusts exceeding 90 km/h, flash flooding or tornadoes.
After the least active cyclone season on record last year, the nation could also face its busiest cyclone season in six years and wettest northern wet season in years. Tropical cyclone numbers are expected to see a significant boost this season thanks to warmer than normal ocean temperatures and the possibility of a weak La Nina developing.
Australia has sweltered through record warm temperatures over the past four and a half years, including our warmest year on record in 2013, third warmest in 2014 and fifth warmest in 2015. One of the distinguishing features of the upcoming season will again be heat with temperatures likely to remain above average across most of the country, leading to an increased risk of bushfires and heatwaves. This season will once again be hot, with maximum temperatures from October to April likely to be above average across most parts of the country.
Every Australian capital has recorded at least four consecutive years with above average maximum temperatures during the severe weather season. Sydney has now recorded 16 consecutive severe weather seasons with temperatures above average, Melbourne and Hobart fourteen consecutive years and Perth ten. There is a high probability that once again all capitals will be warmer than normal apart from Perth which is currently being cooled by cool sea temperatures off the west coast.
Considering grassland growth will be considerable following a wet winter, the Bushfire and Natural Hazards Cooperative Research Centre are predicting above average fire potential through inland southeast Australia and along much of the WA coastline. The warm temperatures will also increase the risk of heatwaves, although heatwaves are extremely rare along Australia’s east coast with Brisbane, Sydney and Hobart averaging less than one every ten years.