Effects of the 2006/7 El Ni

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Effects of the 2006/7 El Niño on Australian
climate and bushfire season

• Brad Murphy
• National Climate Centre
• Australian Bureau of Meteorology

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Outline

• ENSO impacts in Australia
• typical climate response to El Niño / La Niña
• 2006-7 El Niño in Australian region
• rainfall and temperature response
• impacts on water availability
• economic impacts
• Long-term drought in south eastern Australia
• Bushfires in south eastern Australia
• Impacts on 2006-7 Bushfire season

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Typical El Niño rainfall response
Jan Apr Jul Oct Jan Apr Jul
Oct Jan
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Previous Droughts and El Niño
2006
1994
2002
1982
1997
5
2006 Rainfall and Temp anomalies
30 of continent in decile 1 (Vic 93, Tas 74,
South Aus. 50) Alpine regions lowest on record
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Records broken in 2006

• SE Aust Tmax 1.93C (highest)
• Southern Aust 1.85C (highest)
• Record low minimum temperatures - severe,
  damaging frosts
• Major losses in the Goulburn Valley fruit crop
  (25 Sept 2.7C at Wangaratta)
• Crop losses in parts of SE Aus in Oct,
  particularly to grapes (29 Oct 12.0C at
  Charlotte Pass (NSW), new Australian record low
  for Oct)
• Examples of lowest annual rainfall on record
• Harrietville, Vic., 503 mm (opened 1884, mean
  1435 mm, previous record 707 mm in 1982)
• Burnie, Tasmania, 408 mm (opened 1944, mean 950
  mm, previous record 670 mm in 1972)

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Seasonal Outlooks from 2006
Winter
Spring
Statistical Outcome POAMA
Model Dynamic
8
Long-term drought
Last 10 years
Last 5 years
50 year trend
9
Water storages/streamflows
Lowest recorded inflows into Murray River system
(40 of previous lowest record) Severe water
restrictions in many urban and rural centres
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Agricultural Production and Drought Assistance
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Major Past Bushfires in Victoria

• 1851 - 6 February 'Black Thursday
• 5,000,000 hectares burnt, 12 lives lost, 2000
  buildings
• 1926 - February March
• 60 lives lost
• 1939 - 13 January 'Black Friday
• 2,000,000 hectares, 71 deaths, 650 buildings
• 1944
• 15-20 deaths, 1 million hectares burnt
• 1983 - 16 February 'Ash Wednesday
• 100 fires, 47 deaths, 2000 houses lost
• 2003 - Eastern Victorian (Alpine) Fires
• 87 fires on 8 Jan, burnt for 59 days, 1.3 million
  hectares, 41 homes lost
• Significant but smaller-scale fires also in
• 1898, 1932, 1942-44, 1952, 1962, 1965, 1968-9,
  1972, 1977, 1980, 1985, 1988, 1997

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Seasonal Bushfire Assessment 2006 - 2007

• Consensus assessment of bushfire potential in
  upcoming season
• Participants from NCC, Research Centre and
  Regional Fire and Water Agencies
• Modelled on U.S. National Seasonal Assessment
  Workshops
• Considers recent climate, seasonal climate
  outlooks, current fuel loads and curing
• Began in 2006, now split intoNorthern and
  Southern fire seasons

Seasonal Fire Potential Outlook for 2006-7
Seasonal Fire Potential Outlook for 2007-8
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Tasmanian Bushfires October 2006

• Record lowest rainfall Jan-Oct (232mm Hobart
  Airport - mean 402mm)
• Record October max and min temps on 12th
  (33.4C/17.0C at Hobart Airport, averages
  17.3C/7.4C)
• Gale force winds on 11th and 12th
• Extremely early start for fire season
• Worst fires since 1967
• No homes or lives lost

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Alpine Fires December 2006
MODIS Rapid Response Project at NASA/GSFC 5
December 2006

• Lightning ignited 83 fires on 1 Dec, merging
  into one major complex
• Longest fires in Victorian history (69 days)
• 1,048,000 hectares burnt (10480km²)
• 1 life lost (fire fighter - indirect)
• 51 dwellings destroyed

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Alpine Fires December 2006

• External fire-fighting resources brought in,
  highest ever international deployments NSW
  1,050, NT 108
• SA 10, Qld 14, WA 20
• Canada 52
• New Zealand 115
• USA 114
• Severe weather forecasting resources overloaded
• season began earlier (September)
• request made in September to US National Weather
  Service for fire weather forecasters to be
  deployed
• 16 forecasters arrived in January (Melbourne,
  Sydney, Hobart), invaluable in relieving
  over-worked/stressed local forecasters

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FFDI f(Ts, V, RH, Drought Factor)
2006 10,480 km² Total area burnt 2003
13,000 km ² 1939 20,000 km²
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Climate Change and Bushfires

• Fire seasons are becoming longer and severe
  seasons more frequent
• Forest Fire Danger Index (FFDI) projected to
  increase in southeast (except Tasmania)
• More extreme fire days projected
• 5-25 (low) and 15-65 (high emissions) by 2020
• 10-50 (low) and 100-300 (high) by 2050

From N. Nicholls (2007)
From Lucas, et al. 2007
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Summary

• 2006 El Niño climate impacts typical for
  Australia
• Dry/hot conditions followed long-term drought and
  warming trends
• Impacts extreme, particularly on water resources
  and agriculture
• Extreme fire conditions forecast in August
• Major fires developed in Hobart (October) and
  Victorian Alps (December-January)
• Longest fires in Victorian history, largest area
  burnt since 1939
• Resources stretched to limit, employments from
  interstate and abroad, losses minimised
• Fire seasons getting more frequent and likely to
  become more severe