The National Climate and Water Briefing

24 January 2013

Lake Eyre - © Pete Dobre Agenda

• 2012 climate review • Climate conditions and outlook • Hydrologic conditions and outlook • Severe weather season to date

Lake Eyre - © Pete Dobre Climate conditions and outlook

Dr Karl Braganza Manager Climate Monitoring

Lake Eyre - © Pete Dobre Climate conditions and outlook

• Recent and 2012 climate conditions • Current and forecast state of key climate drivers • Outlook for rainfall and temperature

Lake Eyre - © Pete Dobre ‘A year of two halves’ – rainfall

January–March rainfall deciles April–December rainfall deciles • Annual rainfall 476 mm, 11 mm above average • A very wet first 3 months, the remainder dry • 47 per cent of 2012’s rain fell in Jan–Mar • In terms of anomalies: • Jan–Mar rain was 70 mm above average • Apr–Dec rain was 59 mm below average • State totals within 10 per cent of average except South Australia

Lake Eyre - © Pete Dobre ‘A year of two halves’ – temperature

Annual mean temperature Monthly mean temperature deciles • 2012 started cool, finished very warm • Annual mean slightly above average 0.11 °C • Jan–Jul generally cool, especially March • Warmer-than-average from August: • Nationally-averaged Sep–Dec maxima warmest on record • Annual maxima 0.51 °C above average, minima 0.28 °C below average Lake Eyre - © Pete Dobre Long-term temperature anomalies

• Globally, 2012 was the ninth-warmest year on record at 0.46 °C above average • Globally, the most recent 10 years (2003–2012) were the equal- second-warmest 10-year period on record • For Australia, it was the fifth warmest 10-year period • Australia has only experienced one cooler-than-average year in the last decade (2011) • Globally and for Australia, minima are warming faster than maxima

Lake Eyre - © Pete Dobre Long-term temperature anomalies

Lake Eyre - © Pete Dobre Shift in the frequency of record setting temperatures

Frequency of record high (red) and low (blue) max temperature Frequency of record high (red) and low (blue) min temperature Daytime temperature Night–time temperature

25 25

15 15

5 5

-5 -5

-15 -15 ) ( stations/year (stations/year) (stations/year) Number of records records of Number Number of records -25 -25 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010

Year Year Lake Eyre - © Pete Dobre Fire weather Change in the annual forest fire danger index

• Weather conducive to the spread and intensification of wild fire • Increasing at around half of the monitoring sites studied • Longer fire season extended in November and March

Satellite image of fires in New South Wales Solid purple shows increase in fire weather Lake Eyre - © Pete Dobre Australian cool season has been drier

Winter rainfall anomalies (mm/year) for Autumn rainfall anomalies (mm/year) southwestern Australia since 1900 (from for southeastern Australia since 1900 1961–1990 base) (from 1961–1990 base) )

300 200 Winter Rainfall Anomaly - Southwestern Australia Autumn Rainfall Anomaly - Southeastern Australia 250 mm 150 ( 200 100 150

100 50

50 0

0 Rainfall Anomaly (mm) Anomaly Rainfall Rainfall Anomaly (mm) Anomaly Rainfall

anomalies -50

-50

-100 -100

-150 -150 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010

Year Year Rainfall Australian cool season rainfall deciles Rainfall anomalies ( mm) anomalies Rainfall Year (November 1997–March 2012) Year

Lake Eyre - © Pete Dobre Pattern of long-term rainfall decline April–September (1997–2011) Rainfall since October 2010

October 2010–March 2011 April 2011–September 2011 October 2011–March 2012 April–September 2012 October–Dec 2012

Lake Eyre - © Pete Dobre Last four month’s minimum temperature

September–December 2012 minimum deciles September–December 2012 minimum anomalies

• Minimum temperatures were warm out west, but average to cool over much of eastern Australia

Lake Eyre - © Pete Dobre Last four month’s maximum temperature

September–December 2012 maximum deciles September–December 2012 maximum anomalies

• September to December 2013 was the warmest such period on record

Lake Eyre - © Pete Dobre Last four month’s rainfall

September–December 2012 rainfall deciles September–December 2012 rainfall totals

• Extremely dry since mid-year across eastern Australia and Tasmania • Long lead in curing (drying) time for vegetation that has been boosted by two years of exceptional summer rainfall

Lake Eyre - © Pete Dobre January rainfall to-date

January 2013 rainfall to date January 2013 rainfall to date percentage of normal

• Very little to no rain across most of the continent except the southwest

Lake Eyre - © Pete Dobre The ongoing heat – January 2013 heatwave Land-surface temperature January 1–8 • Temperatures >48 °C with highest maximum of 49.6 °C at Moomba in South Australia • Over 70 per cent of the continent recording temperatures in excess of 42 °C • 7 January 2013 Australian daily max temperature of 40.33 °C set a new record, previous highest 40.17°C set in 1972 • Sequence of Australian temperatures above 39 °C of 7 days, and above 38 °C of 11 days straight

Lake Eyre - © Pete Dobre The ongoing heat – January 2013 heatwave Maximum temperature anomaly – January so far • Temperatures >48 °C with highest maximum of 49.6 °C at Moomba in South Australia • Over 70 per cent of the continent recording temperatures in excess of 42 °C • 7 January 2013 Australian daily max temperature of 40.33 °C set a new record, previous highest 40.17°C set in 1972 • Sequence of Australian temperatures above 39 °C of 7 days, and above 38 °C of 11 days straight

Lake Eyre - © Pete Dobre The ongoing heat – January 2013 heatwave Highest maximum temperature – January so far • Temperatures >48 °C with highest maximum of 49.6 °C at Moomba in South Australia • Over 70 per cent of the continent recording temperatures in excess of 42 °C • 7 January 2013 Australian daily max temperature of 40.33 °C set a new record, previous highest 40.17°C set in 1972 • Sequence of Australian temperatures above 39 °C of 7 days, and above 38 °C of 11 days straight

Lake Eyre - © Pete Dobre Climate conditions and outlook

• Recent and 2012 climate conditions • Current and forecast state of key climate drivers • Outlook for rainfall and temperature

Lake Eyre - © Pete Dobre ENSO outlook for 2012–13: Neutral, El Niño, La Niña?

• Neutral state is when the central Pacific is within approximately 0.8 °C of normal • Simple average of seven key models, currently very close to normal

Lake Eyre - © Pete Dobre Pacific and Indian Ocean sea surface temperature anomaly

Sea surface temperature difference from average

Lake Eyre - © Pete Dobre Climate conditions and outlook

• Recent and 2012 climate conditions • Current and forecast state of key climate drivers • Outlook for rainfall and temperature

Lake Eyre - © Pete Dobre Rainfall outlook February to April 2013

• Wetter than normal for northern Queensland and a large part of southern and western Western Australia • Drier for a small region in eastern Australia and South Australia

Lake Eyre - © Pete Dobre Temperature outlooks for February to April 2013

Lake Eyre - © Pete Dobre Hydrological conditions and outlook

• Soil moisture • Water storages • Seasonal streamflow forecasts

Lake Eyre - © Pete Dobre December soil moisture and catchment streamflows

Upper layer • very much above average in Western Australia and parts of Northern Territory, average to very much below average elsewhere Lower layer • still very much above average over much of the country , average to very Upper layer Lower layer much below average for the south Observed December streamflow

Lake Eyre - © Pete Dobre Water storage levels – current status

Lake Eyre - © Pete Dobre water.bom.gov.au Low or near median flows more likely Victoria Southern New South Wales

Southern New South Wales Victoria

Lake Eyre - © Pete Dobre Low or near median flows more likely Northern New South Wales Southern Queensland

Southern Queensland Northern New South Wales

Lake Eyre - © Pete Dobre Low or near median flows more likely

Cape York Northern Queensland Cape York Peninsula Peninsula Northern Queensland

• After two-and-a-half years of above average rainfall and cooler temperatures, a dramatic reversal occurred in mid 2012 • Conditions have returned to those experience in the decade or more up to 2009 • Severe heat and fire weather so far this summer • Outlook favouring cooler but dry conditions from February through April • Low or near median January to March flows most likely for the majority of forecast sites

Alasdair Hainsworth Head of Weather Services Branch

Lake Eyre - © Pete Dobre Agenda • Summary of events • Weather trends • Fire weather • Tropical weather • Severe thunderstorms • Outlook

• Severe thunderstorms in Brisbane 16–17 November • National heatwave late December and first half of January • Extreme–catastrophic fire weather conditions most states • Four tropical cyclones: • Mitchell – stayed offshore northwest Western Australia • Narelle – stayed offshore northwest Western Australia

Bushfire damage Dunalley • Oswald – Gulf of Carpentaria and Cape York Peninsula (Source: theage.com.au) • Peta – active near Western Australian Coast

Lake Eyre - © Pete Dobre Recent weather trends April 2010 to March 2012 rainfall percentages • January 2010–March 2012 – Above average rainfall – Active monsoon with deep tropical air intrusions – Active storm seasons – Widespread flooding – Average tropical cyclone activity Flooding near Bourke (New South Wales) – Plenty of vegetative growth (Source: theaustralian.com.au)

Lake Eyre - © Pete Dobre Recent weather trends April to December 2012 rainfall percentages • April 2012–December 2012 – Below average rainfall – Increasing temperature anomalies over land – Record warm oceans off the west coast – Drying out of vegetation and soils

Recent weather trends Maximum temperatures 4 January 2013 • December 2012–January 2013 – Late monsoon onset: 17 January in Darwin (average is late-December) leading to lack of tropical moisture penetration and clear skies over continent – Lack of strong frontal activity in the south leading to no flushing of new air – Continued warm ocean temperatures to the west – Dry underlying terrain – Warming over vast parts of central Australia leading to record temperatures

• Also, persistent blocking high in the Tasman – semi-permanent feature – blocks cold fronts from west – drags hot air southwards – associated with long dry and hot spells in eastern Australia

• Heat associated with the recent heatwave developed over Western Australia in late December, migrating eastwards in early January, enhanced by solar heating and a lack of moisture over the continent • As fronts have passed to the south, the enhanced winds have generated dangerous fire weather conditions over southeastern states

Spot fire forecasts – all regions • Multiple fires this season – often generated by lightning from dry thunderstorms, leading to one death and significant property damage with hundreds of homes, structures and vehicles lost and thousands of head of stock • From 1–23 January 2013, Bureau offices have issued 762 spot fire weather forecasts

• Includes: – Detailed weather forecast for the day, – Technical details such as mixing depth of atmosphere and stability – Timing of any changes (critical) – Assumptions that underpin the forecast – Alternative scenarios, particularly with regards to timing

• Monsoon arrived in Darwin about 17 January – late compared with the average first onset time of late December • First tropical cyclone in the Australian Region was Mitchell 28–30 December off the northwest coast • Another more intense tropical cyclone (Narelle) 9–14 January affected a similar area • Two more cyclones (Peta and Oswald) have developed this week and are currently located close to the Western Australian and Queensland coasts respectively

Lake Eyre - © Pete Dobre Severe thunderstorms • A lack of moisture over land has lead to a relatively quiet severe thunderstorm season to date • Observed severe phenomena have reverted more to damaging winds and large hail – rather than the heavy rainfall of recent years • Some storms occurred in November including ones that formed over the Brisbane Metro area on Saturday 17 and Sunday 18 Nov causing

some damage Brisbane storms

Impacts on the Bureau

standby stand SARO to Staff relocation TC Narelle and Specialist forecaster relocated to assist with tropical cyclone by WARO Oswald forecasting 14 Jan+ 17 BMTC(SA) to Staff relocation NSW Fires Specialist Forecaster relocated to assist with fire weather • 11 staff relocations to another Region or returned to Jan NSWRO forecasting 9 Jan TBA BMTC(WA) to Staff relocation TC Narelle and Specialist Forecaster relocated to assist with tropical cyclone WARO Oswald forecasting duty from leave early 11 Jan TBA Contracted to Contractor NSW Fires Specialist forecaster employed on short-term contract to assist NSWRO during peak demand periods 17 Dec 15 Tindal to CbMO Staff relocation ACT Fire Wx Specialist forecaster relocated to assist with fire weather Jan forecasting • 4 United States Fire Weather Forecasters on staff 6 Jan 11 NSWRO Staff relocation NSW Fires 2 Forecasting Staff recalled to duty from annual leave Jan 13 Jan+ TBA QRO to WARO Staff relocation TC Narelle and Specialist Forecaster relocated to assist with tropical cyclone Oswald forecasting • Several instances of Darwin Tropical Cyclone Warning 13 Jan 13 WARO Staff relocation TC Narelle Forecasting Staff recalled to duty from annual leave Jan 7 Jan 8 Jan NTRO + TCWC Remote TC Narelle NT Staff assumed responsibility for monitoring and activation of Centre taking over responsibility for another TCWC to forecasting TC warnings for WA. This provided critical rest time for WA staff ahead of TC critical-activity in the region. 19 Jan 21 NTRO + TCWC Remote TC monitoring NT Staff assumed responsibility for monitoring developing QLD rest staff Jan providing forecasting and WA tropical cyclones. This provided critical rest time for QLD assistance to and WA staff ahead of potential TC critical-activity in the two WARO and regions. QRO

Lake Eyre - © Pete Dobre Severe weather outlook No obvious change in climate factors • Bushfire – Hot air has been dispersed for now and there will be moist air injected into the continent form the tropics, but the risk will not clear until the season ends or there is significant rain • Tropics – Current monsoon and spate of tropical activity may be followed by a further burst in March • Severe storms – Likely continued subdued activity with main risk from wind and hail; maybe some increase on activity to date however due to moisture injection

Lake Eyre - © Pete Dobre Forecast for the next week • Heavy rain and flooding through northern Queensland, extending southwards into Central Coastal districts • Hot conditions today in southeastern Australia with fire weather warnings, but change to move through Friday with relatively benign conditions to follow for at least a few days • Some rain/thunderstorms through New South Wales, particularly over the weekend on and north of trough • Hot spell coming up for Western Australia with strong easterly winds – potentially bad fire weather conditions • Monsoonal activity over remaining tropics – some locally heavy rain in the Pilbara and Gascoyne districts associated with Peta and subsequent low which could cause some flooding • Continuing warm/hot and dry through South Australia