The Southern Australia Seasonal Bushfire Outlook 2016 shows a mixed picture for fire potential, with the exceptionally warm and wet conditions experienced through winter likely to continue into spring.
Every month of 2016 has seen Australia's national mean temperature above the long term average, although with the breakdown of El Niño, rainfall has been above average across most of the country - winter has seen the second wettest on record. The pattern of heavy rainfall following a strong El Niño is not uncommon and is tied to the warming of ocean waters around Australia. Spring is likely to see above average across most of the country, with the exception of parts of New South Wales and Queensland. There is a higher chance of above average rainfall across northern and eastern Australia.
The Seasonal Bushfire Outlook for southern Australia is used by fire authorities to make strategic decisions on resource planning and prescribed fire management for the upcoming fire season. The outlook is developed at an annual workshop convened by the Bushfire and Natural Hazards CRC and AFAC.
At the 2016 workshop in Brisbane in August, the Outlook was assessed and a range of broad climate and resource factors were considered.
The workshop discussed the weather, landscape conditions and cross-border implications leading into summer and determined areas that had the potential for a fire season that was above normal or below normal.
The Outlook map shows the bushfire outlook for southern Australia through to the end of 2016. This map has been combined with the outlook for the northern Australia bushfire season, which was released at the beginning of July, to show the areas of fire potential for all of Australia. (See Hazard Note 18, July 2016).
This Outlook will be reviewed towards the end of spring to take into account the impacts of actual temperatures and rainfall in the lead up to summer.
View the entire outlook at bnhcrc.com.au. The Victorian description is as follows:
Victoria
East Gippsland has a mostly below normal fire potential this year. It has received very much above average rain in the short and long term, and the temperature outlook is not likely to support strong late spring drying in the forests. The fire season in East Gippsland is expected to begin later than normal on these current signals. The marginal chances of above average rain along the Murray River and in Far East Gippsland raise the possibility of a delayed start to the fire season in those areas. This also means the Murray Valley is likely to have normal fire potential despite underlying dryness in some areas.
In west and south Gippsland, parts of Victoria’s Central Highlands, including Melbourne’s water catchments, and across most of south west Victoria, the slight chance of above average rain coupled with a high probably (80 percent) of above average temperatures, plus existing severe rainfall deficits, indicates strong late spring drying is likely in forested areas. This could see rapidly escalating fire behaviour later in summer.
Most soils in the extensive western grass plains and their forests have saturated upper layers this year, in many areas evidenced by accumulations of surface water; but a dryness remains at deeper levels, and the current weak signal for spring rain is likely to mean good overall grass growth in these areas, with insufficient available water to soak deeper into the soil to reduce the fire risk in the forests. Melbourne’s water catchments have not yet been saturated and now have a long history of underlying dryness. Forest fuels have increased since the 2009 fires, so there is once again potential for fire. Similarly, the eastern Otway Range, Brisbane Ranges, Wombat Forest, and drier forest types bordering Victoria’s box ironbark belt also have a long history of dryness. These areas have above normal fire potential.
Author: Bushfire and Natural Hazards CRC