The National Climate and Water Briefing March 2012 Lake Eyre - © Pete Dobre Agenda • Climate conditions and outlook • Questions • Hydrological conditions and outlook • Questions • Lunch Lake Eyre - © Pete Dobre Climate conditions and outlook Dr Andrew Watkins Manager Climate Prediction Services Lake Eyre - © Pete Dobre Climate conditions and outlook • Recent climate conditions and trends • Current and forecast state of key climate drivers • Climate outlook Lake Eyre - © Pete Dobre Calculating deciles Historical record Sorted historical record Deciles 1 to 10 1 2 3 4 5 6 7 8 9 10 Group into tenths Sort and rank for deciles Lake Eyre - © Pete Dobre Recent rainfall • February: Australia 12% below normal, New South Wales and Murray- Darling Basin double normal February rainfall • Summer: Murray-Darling Basin 6th highest, New South Wales 9th highest, Tasmania 26% below normal • Summer: Australia 2012 245mm vs 2011 367mm (2nd highest) • Summer: Victoria 2012 136mm vs February 2012 December 2011 – February 2012 2011 340mm (highest) Lake Eyre - © Pete Dobre Recent rainfall February 2012 December 2011 – February 2012 December 2010 – February 2011 Lake Eyre - © Pete Dobre Maximum temperature 3rd hottest ‘summer’ • Australia: 8th coolest summer since at least 1910 • NSW: 2nd coolest summer on record – 1st was 1955/56 1.8°C above average • A very ‘La Niña’ summer… 1.3°C above average 8 ‘heatwaves’ February 2012 December 2011 – February 2012 Lake Eyre - © Pete Dobre A hot summer in Perth • Mean maximum temperature • Highest temperature was was 31.7 °C, fourth highest in 42.1 °C on 28 January a record dating from 1897 • Mean minimum temperature (1.3 °C above average) was the equal fifth warmest • Six heatwaves equalled the on record, and the highest summer record set in 1977–78 since 1991–92 • First time ever each summer month had two heatwaves Lake Eyre - © Pete Dobre Minimum temperature • Below average minima were widespread, except in the far south and west • Queensland 3rd lowest state-average minimum temperature for February February 2012 December 2011 – February 2012 Lake Eyre - © Pete Dobre The big wet week: heaviest 7-day rainfall in southeast Australia history • Record weekly rainfall in several New South Wales and Victorian catchments (27 Feb – 5 Mar) • Double previous record in Murrumbidgee, Lachlan and Upper Murray catchments • Highest total 525 mm at Mount Buffalo (northeast Victoria) • With 294 mm, Ivanhoe (New South Wales) was only 12 mm short of annual average rainfall Lake Eyre - © Pete Dobre So how much water are we talking about? • Rain which fell over New South Wales (104k Gl) would fill Sydney Harbour 185 times • Victoria’s rain (23k Gl) would fill 0.9 Port Phillip Bays • Total water volume which fell on the Murray-Darling Basin (108k Gl) is equal to 8 times Australia’s mean February 14 March 5 FebruaryMarch 12 25 annual water consumption Lake Eyre - © Pete Dobre Forecasting the big wet week (27 February–5 March) January–March seasonal outlook Week 2–3 outlook (experimental) 7-day outlook Lake Eyre - © Pete Dobre Forecasting the big wet week (27 February–5 March) ‘One way we can adapt to climate change (whether it brings drier or wetter conditions) is to make better use of the climate predictability we get from ENSO. By using the Bureau's seasonal climate outlooks, we will be better adapted to current climate variations, so the impact of any exacerbation by global warming will be diminished. Likewise, taking better advantage of the rapidly improving short-term weather forecasts from the bureau can help us prepare for floods better than we have been able to do in the past.’ Prof. Neville Nicholls Observed rainfall week ending 5 March (SMH/The Age, 13 March 2012) 7-day outlook Lake Eyre - © Pete Dobre La Niña – vegetation index February 2009 February 2011 February 2012 Lake Eyre - © Pete Dobre La Niña – deep soil moisture February 2009 February 2011 February 2012 Lake Eyre - © Pete Dobre Global conditions • US heat wave 2012: 1801 daily records set since March 9 • International Falls, Minnesota (US ‘icebox’) 25°C on 17 March - Previous record for that day: 12.8°C (records to 1895) International Falls • Chicago >80F (26.6°C) 5 successive days • Impacts on agriculture: drier and warmer • Most humid airmass on record for March means potential now for flood Snow depth (inches) 15 March 2011 vs 2012 Land surface temperature 8 – 15 March 2012 Lake Eyre - © Pete Dobre Climate conditions and outlook • Recent climate conditions and trends • Current and forecast state of key climate drivers • Climate outlook Lake Eyre - © Pete Dobre La Niña 2011–12 La Niña +8 ▲ - 8 ▼ El Niño September 2011 October 2011 November 2011 December 2011 February 2012 January 2012 Sea surface temperature difference from average Southern Oscillation Index Lake Eyre - © Pete Dobre La Niña – the end is nigh • Significant warming of tropical Pacific – indices have returned to neutral • Latest Southern Oscillation Index around +6 • Wind and cloud patterns also show a move away from La Niña back to neutral Sea surface temperatures difference from normal Equatorial Pacific heat content – top 400 m: • BUT… persistence of warm 1 17January March 2012 2012 difference from average water off Australia: caution still required Lake Eyre - © Pete Dobre Pacific Ocean – long range forecast • Continued warming of the tropical El Niño Pacific is expected during autumn El Niño and winter +0.8 ▲ • Likely to see slightly warmer than - 0.8 ▼ average temperatures in April La Niña La Niña • Triple-header La Nina? Historically nine events 2 or more years, three POAMA forecast Current conditions (Feb 2012) events 3 years… Lake Eyre - © Pete Dobre bom.gov.au/climate/enso Climate conditions and outlook • Recent climate conditions • Current and forecast state of key climate drivers • Climate outlook Lake Eyre - © Pete Dobre Review of summer Outlook: December to February Summer was … • Generally wetter than average, except in Tasmania and parts of the southeast • Cooler than average over New South Wales, southern Queensland and much of Western Australia • Warmer than average in far north, along west coast and in far southeast Chance of exceeding median summer rainfall Chance of exceeding median summer maximum temperature Lake Eyre - © Pete Dobre www.bom.gov.au/climate/ahead Rainfall outlook for April to June 2012 Historical accuracy Chance of above median rainfall Simple multi-model outlook Lake Eyre - © Pete Dobre Temperature outlook for April to June 2012 Maximum temperature Minimum temperature Lake Eyre - © Pete Dobre State of the Climate Snapshot • Dr Karl Braganza will give a full summary of the climate snapshot next briefing • Each decade warmer than previous decade • Australian mean temperatures have risen 0.9 °C since 1910 • Australian ocean surface temperatures in 2010 highest on record • Global average sea level rise 210mm Australian temperature trends 1910–present Number monthly max. temperature records set every year since 1880; recently 3mm per year • Warming around Australia cannot be explained by natural variability alone Lake Eyre - © Pete Dobre Key points 1. La Niña is approaching its inevitable end 2. Still potential for strong wet season rains 3. Record weekly rainfall over south eastern Australia in late February/early March 4. April to June rainfall outlook: likely wetter in the east, drier in the south 5. April to June temperature outlook: warmer days in south, cooler in east Lake Eyre - © Pete Dobre Hydrologic conditions and outlook Jeff Perkins Acting Manager Flood Forecasting and Warning Lake Eyre - © Pete Dobre Hydrologic conditions and outlook • Current flood situation • Storage and catchment conditions • Streamflow forecasts for March to May 2012 Lake Eyre - © Pete Dobre Hydrologic conditions and outlook • Current flood situation • Storage and catchment conditions • Streamflow forecasts for March to May 2012 Lake Eyre - © Pete Dobre Flooding in February and March • Queensland – Mitchell, Roma, St George (record) – Charleville, Augathella, Gympie, Blackall • New South Wales – Biggest floods in 20-40 years – Moree, Burke, Wagga Wagga, Narrendarra, Griffith, Forbes, Hay • Victoria – Nathalia and Walwa • Western Australia – Tropical Cyclone Lua (Cat 4) – Moderate to major flooding in De Gray, North Kimberley and Ord March 2012 February 2012 – Affected Nullagine, Kalumburu (record) Lake Eyre - © Pete Dobre Daily rainfall extremes Lake Eyre - © Pete Dobre Floods in the Murray-Darling Basin Wagga Wagga 6/3/2012 St George (February 2012) Charleville Levee holding Photo by Andrew Meares Photo by 7_Cannon (Twitter) Murray-Darling October 2011- March 2012 Lake Eyre - © Pete Dobre Flow outlook for South Australia • Currently around 20–30,000 Ml/d 21 days • May reach 60 000 Ml/d – floods some shacks (minor flooding) 14 days Darling peak – February 2011 was 93 000 Ml/d; 1956 - D/S Tilpa Lachlan peak 25 days was 350 000 Ml/d, 1974 was - D/S Condobolin 8 days 1 day 9 days 180 000ML/d 12 days 9 days Murrumbidgee peak • Peak timing based on Murrumbidgee - D/S Hay Town 1-2 days 4 days flows – mid to late April • Long travel times mean further rainfall always a possibility Lake Eyre - © Pete Dobre Murray-Darling river conditions Approximate travel times Current flood situation Current river conditions Last 7 days rainfall Forecast for next 8 days Lake Eyre - © Pete Dobre Hydrologic conditions and outlook • Current flood situation • Storage and catchment conditions • Streamflow forecasts for March to May 2012 Lake Eyre - © Pete Dobre Water storage levels – current status