With the arrival of spring heralding a return to warmer temperatures, attentions are turning once again to prospects for the forthcoming fire season across the country.

The latest outlook released by the Australasian Fire and emergency service Authorities Council and the Bushfire Cooperative Research Centre this morning shows that large sections of southern Australia, Queensland, the north western Northern Territory and north western Western Australia face an above normal fire risk this summer.

Specific regional outlook summaries follow.

 

SOUTHERN FIRE OUTLOOK

 

The 2012/2013 northern Australian wet season (summer) saw vast areas from the Western Australian border, through to the Great dividing range along the east coast, record below average rainfall, with central Queensland, south east south Australia and western Victoria recording very much below average rainfall.

Over the same period daytime temperatures were well above average across the majority of Australia, with an extensive Australia-wide heatwave lasting from late December through to mid/late January.

Since the beginning of the 2013 southern Australian wet season (May), the Indian Ocean Dipole (IOD) has been negative (the opposite to its value in 2012), leading to above average rainfall from the Pilbara in WA, through to south east Australia.

The exception to this is south west WA and parts of inland Queensland, which have recorded below average rainfall.

August saw the IOD ease, bringing with it below average rainfall south of the tropics.

The exception to this was south-west  WA, south east south Australia, much of
Victoria and Tasmania, which all received average to above average rainfall during this time.

Warm to hot temperatures began early in August, with record warm temperatures in central Australia and very warm temperatures pushing into the south east of the country during the last week of August.

Expected climate outlook

Neutral ENSO (neither La Niña nor el Niño) conditions have persisted since April 2012 and are expected to continue through spring and into summer 2013/2014.

A negative IOD event is in progress and expected to continue until mid-spring, despite recent signs of easing.

A negative iOd during winter/spring increases the chances of above normal rainfall over southern Australia.

Warmer than normal sea surface temperatures currently persist around Australia, which can provide more moisture to the atmosphere. In combination with the right weather systems (e.g. interactions with cold fronts), these conditions may result in increased rainfall.

The Bureau’s official spring seasonal outlook shows an increased chance of above average rainfall over most of south east Australia and the top end of the Northern Territory. This outlook is influenced by the persistence of the negative

IOD into mid-spring and above average Sea Surface Temperatures around Australia.

The maximum temperature outlook shows an increased chance of warmer than normal spring days over most of northern Australia, Coastal WA, and Tasmania, while cooler days are more likely across central and north west Victoria.

 

QUEENSLAND

The fire season in Queensland is long and Traditionally commences around July in the Cape York Peninsula and Gulf Country and progresses to the central inland and coastal areas south to the NSW border during Spring and into summer.

In the West and South West of the state the fire season can begin as early as August and extend well into February.

However, timeframes can vary significantly from year to year, as they are largely dependent on long-term climate, short-term weather conditions and available fuel loads.

This season, the combination of Queensland’s climate and seasonal trends has created vast variations in vegetation growth and fuel conditions.

Northern Australia wet season

Rainfall was well above average for the southern coastal areas. In contrast, large areas of the Lower Gulf of Carpentaria, far western and southern Queensland received well below average rainfall during the same period.

Over the winter months rainfall remained near to below average for most of the state, with the majority of south western, central west and north west Queensland now under drought declaration.

The grassland areas across the state have moderate to abundant fuel loads with a less continuous fuel bed than in previous years.

This is due to a combination of large scale fires, rainfall deficiencies and stocking rates.

As a result of milder temperatures this winter, grassland curing in the eastern areas is slightly lower than this time last year. In the north, far west and south west of the state grasslands are fully cured.

Despite large scale fires in the northern and western areas of Queensland during the last fire season, there are still vast areas with moderate to abundant grassland fuels and low stock levels that could experience large scale, fast running grass fires.

An above normal fire potential has been assessed for areas between Dalby and

Warwick, south to the NSW border and West to Goondiwindi. The area to the west between Wallumbilla and Dulacca, south to St George and an area extending from the Sunshine Coast hinterland into the western areas of the Wide Bay Burnett region are also assessed as above normal fire potential.

(More details on northern Queensland outlook below)

NEW SOUTH WALES

Above average rainfall for much of the preceding three years is likely to continue the trend of heavy grass fuel loads throughout the Grassland areas of NSW. These grassland areas include those west of the Great Dividing Range,  the Tablelands and the Upper Hunter.

Above normal fire potential is expected to continue in these areas due to high grass fuel loads, combined with the predicted ENSO neutral (that is, neither El Nino or La Nina) summer outlook. Normal fire conditions are likely in far west NSW.

Over much of the forested areas of NSW, below average rainfall since July has resulted in a drying trend in forest fuels. If this trend continues, above normal fire activity conditions are expected for the forested areas of Central and Southern NSW coast and ranges. A slightly higher chance for above average rainfall is likely to result in a normal fire season for both the far north coast and north coast.

AUSTRALIAN CAPITAL TERRITORY

The outlook for the grasslands reflects the current vigorous grass growth which will continue into spring and the drying trend in the Bureau of Meteorology’s seasonal outlook. As a result, above normal fire potential has been assessed for the grasslands in the ACT.

The recovery of fuels since the 2003 fires continues to be monitored and managed.

However should the forests dry out as we head into summer, there are concerns for the potential for above normal forest fire activity.

VICTORIA

Over the past 12 months, much of Victoria has experienced below average rainfall. The exception is the east, where average rainfall occurred. Forests are expected to be more flammable than normal due to the lingering effect of last summer’s extreme dryness and heat, with dry underlying soil profiles and more abundant dead elevated, near-surface and bark fuels in these forests.

Despite some chance of above average spring rains and reasonable winter rainfall, significant underlying dryness is likely to continue to be present in many western and central forests. These areas can expect above normal fire potential. strong drying of soils and fuels has also commenced in east Gippsland, which may result in early bushfire activity if this trend continues.

The exception to this is in coastal parts of the south West, Mallee and West and south Gippsland, where above average rainfall has occurred in the past few months. As a result of this rain, a normal fire season is expected
in these areas.

Current expectations are for average to above average grass growth in western Victoria and north east of the state, based on receiving average to above average rain during spring.

The timing and severity of grass fires will depend strongly on rainfall patterns
throughout spring.

TASMANIA

Normal fire potential is expected for the lead up to summer, except for small areas in the Derwent Valley and the mid-east Coast, both of which are currently drier than usual.

The majority of Tasmania has either average or above average soil moisture and this will reduce fire activity while promoting growth, which may become available for large fires in the New Year. The fuel types which are less dependent upon soil moisture levels, such as moorland, heaths and scrub, have a normal
fire potential.  Forest fuels in the north of the state will require a considerable drying period to be available for widespread fires.

SOUTH AUSTRALIA

Above normal fire potential is predicted in the North West Pastoral and Flinders districts due to abundant and continuous grass fuels. This is as a result of the previous season’s growth remaining, and the rainfall received, linked with conducive growing conditions.

For the remainder of the state, including the agricultural areas, the most likely scenario is for near normal levels of fire activity.

Both the North West Pastoral and Flinders Districts have received above average rainfall.

When this is combined with the abundant fuel loads from the previous growing season, the result is above normal fire potential for both districts. The area adjacent to the Northern territory border (communities north of the APY Lands) is of normal fire potential, recognising that the Northern Territory has not indicated above normal level of activity.

Resource implications of an above normal fire danger season may see the need for firefighting resources committed to incidents for a longer period of time.

The North West Pastoral and Flinders Districts may pose resourcing issues this fire season, as was experienced in the North West Pastoral district last season, where firefighters and aircraft were committed for lengthy periods.

WESTERN AUSTRALIA

Across the Mid West and desert regions, above normal fire potential is expected as a consequence of high rainfall, which has resulted in very high annual grass growth and high fuel loads.

Above normal bushfire potential is also forecast in the south West, which has seen reduced rainfall, soil moisture deficit and high fuel loads.

The Wheatbelt has been assessed as having a normal fire potential, with average to below average rainfall resulting in average fuel loads. In the Nullarbor, normal fire potential is expected east of the Fraser Range.

 

Full details of the current seasonal bushfire outlook for the Northern territory, as well as northern Western Australia and northern Queensland, below.
 

 

NORTHERN FIRE OUTLOOK

 

 

 

 

 

 

 

 

 

Seasonal factors

By the end of February this year, most of the Northern territory, Queensland and northern Western Australia had experienced below average rainfall for the five months of the wet season.

The two exceptions were the south east Queensland coast, including the Capricornia Coast, where ex-tropical Cyclone Oswald caused major flooding in late January, and the Pilbara and interior regions of WA, which saw heavy rainfall from the landfall of tropical Cyclone Rusty in February.

Despite some good rain in the top end of the NT over Easter, Northern Australia ended the wet season with generally average to below average rainfall totals, especially in northern and western Queensland.

Where rain was received, the short bursts of wet weather followed by long exposure to sunshine was ideal for vegetation growth.

Looking ahead, the Bureau of Meteorology suggests ENSO-neutral conditions (ie neither El Nino or La Nina) are most likely to prevail during the coming spring/summer.

Contributing factors to the outlook for this year’s northern wet season include:

A negative Indian Ocean Dipole (IOD) event is favoured to develop during the dry season and continue until October or November 2013. A negative IOD increases the chances of above normal humidity levels and rainfall over north western and central Australia during the dry season due to an increase in cloudband events. However, five of the last six years that had both a negative IOD and a neutral ENSO saw below average early wet season rainfall; 2005 was the exception to this.

Warmer than normal sea surface temperatures currently surround northern Australia. Warmer ocean temperatures can provide more moisture to the atmosphere, which in favourable weather conditions (for example, interactions with fronts?or north west cloudbands) may result? in increased rainfall. This is reflected in ?the current rainfall outlook covering the remainder of the northern dry season, with most of Australia expecting above normal rainfall. The area surrounding the Gulf of Carpentaria has an equal chance of above and below average rainfall this season.

The temperature outlook for Australia ?favours warmer than average maximum and minimum temperatures for the remainder of the dry season along the north coast. This is most likely driven by the warmer than average sea surface temperatures that currently surround northern Australia.

Central and southern Queensland, the southern NT and WA’s southern interior can expect an increased chance of below average maximum temperatures this season.

State/territory specific forecasts:

 

NORTHERN TERRITORY

Overview

In the top end, a significant amount of late season rain, averaging 200 mm, has complicated mitigation efforts, with some of the rains falling after initial fuel hazard reduction burns commenced. This resulted in later efforts being less effective. An additional broad scale aerial incendiary run has partially addressed this, but the real effectiveness is yet to be tested. In addition, ground access into much of this area is still difficult due to wet country. The Wadeye area has once again had little early season mitigation works primarily because of access and limited resources. The Douglas Daly region is starting to see the effects of gamba grass, which cures later than native species. The Darwin peri-urban area also has gamba grass related effects, including increased fuel loading and a considerable reduction in the number of grazing cattle, as well as a later curing period due to the late rain. Accordingly, this area is assessed as above average fire potential.

The Gulf region experienced a relatively poor wet season with little rain, so the effective mitigation program by staff and landholders has led to average fire potential. The Victoria river downs region is also considered to be of average fire potential, with only isolated pockets of high fuel after mitigation efforts. The Sturt Plateau area south of Katherine is currently well grazed and fuel is being managed, resulting in average fire potential.

The extensive fires in Central Australia during 2011 and into 2012 have reduced ?the fire potential across the majority of the southern NT, especially in the Tanami and Simpson Deserts. The developing mitigation capacity on the APY lands is continuing? to increase and limit the fire potential on?this estate and neighbouring areas. The fuel loadings across the Barkly region have been adjusted down to four tonnes per hectare and the remaining southern regions, including Alice springs, adjusted down to three tonnes per hectare on average.

With the rainfall received to date, current land use regimes, and mitigation programs and activities undertaken, the prognosis is for average fire potential for the remainder of the territory. It must be recognised that significant fire activity will still occur, and in some cases this will cause significant impacts and potential losses of property, earning capacity, and environmental values.

Outlook

There is one area identified as above average for fire potential in the Nt. The north west top end, extending around the greater Darwin peri-urban area and into the Vernon and Arafura fire Control regions, has had a continued trend of increasing density and range of gamba grass. The ineffectual management of this single species of weed has been largely responsible for an increase in average fuel loadings within this area from between 4.5 and 6 tonnes per hectare to between 9 and 11 tonnes per hectare; even exceeding this in some smaller areas.

 

QUEENSLAND

Overview

Queensland’s bushfire season is primarily influenced by long-term and seasonal short-term climate conditions and the relationship the climate has on vegetation. Climate conditions have generally been moderate in recent months with a variance effect on rainfall across most of Queensland.

In late January 2013, the severe weather event associated with ex-tropical Cyclone Oswald affected most central and southern coastal and inland coastal centres. Significant rainfall over catchment areas culminated in the flooding of major rivers, which produced considerable damage to land production industries,?public infrastructure and the loss of many residences and businesses within the affected communities.

Despite this catastrophic weather event in late January, early February saw below average rainfall over most of the north Queensland coastal and inland areas with the exception of the lower Capricornia, Curtis, Wide Bay-Burnett and south east Coast weather districts.

The prolific growth in pastures over north Queensland in recent years has slowed generally during 2013 due to below average rainfall during autumn and winter.

Current grassland fuel levels throughout Queensland are assessed as average to abundant and continuous. Soil profiles are dryer than average over most northern coastal areas with exceptional dry soil conditions inland. The current grass fire risk over inland areas is assessed as above average. Forest areas with average to high fine fuel loads, are assessed to have an above average fire risk.

Early start to season

A slightly early start to the fire season? is anticipated due to high fuel loads, especially in the inland savannah landscapes that have not burnt in recent years. This prediction may well also apply for inland and far inland areas south of?the savanna to the New south Wales/south Australia border.

There may be a slight extension of the fire season based on a late arrival of the northern monsoon season.

Grass fires in coastal areas where there is prolific growth may produce high flame heights and high intensity fires with a high forward rate of spread. fast running, high intensity grass fires can be expected over most of the state, with concerns for larger fires in some rural areas due to the abundance and continuity of the grassland sward.

Woodlands may have similar fire behaviour with a grassy understorey; however, rates of spread may be slightly less.

Forest fires are expected, but with moderate intensities early in the bushfire season. The intensity may increase later ?in the season, especially if the season is prolonged. This will be due to the drying moisture profile within the forest soils and an increase of fine forest fuels available, coupled with warmer temperatures and? the influence of dry north westerly to south westerly winds.

 

WESTERN AUSTRALIA

There is an above average bushfire potential in the central region of northern Western Australia. The areas to the east and west? of the central zone are of average fire potential.

Kimberley

The Kimberley area has been subject to ?high rainfall in recent months and this will result in significant and widespread grass growth across the region. This assessment is mindful of the increased prescribed burning planned across the region, but the rainfall and consequent regrowth fuel loads are significant.

Pilbara

Rainfall across the Pilbara has been average or above average in recent months. As a result of this rainfall pattern, there is above average bushfire potential in the central region. The outlook potential is for basically an average season on the western and eastern side of the central zone.