national climate and water briefing - bureau of meteorology...• october maximum temperatures •...
TRANSCRIPT
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National Climate and Water Briefing
28 November 2013
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Climate and water conditions and outlook
Dr Blair Trewin Senior Climatologist, Climate Monitoring
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• Recent conditions • A review of 2013 internationally • Current and forecast state of key climate drivers • Outlook for rainfall and temperature
Climate conditions and outlook
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Temperatures: October 2013 Maximum temperature anomaly Minimum temperature anomaly • October maximum temperatures
• Australia: 2.1 ºC above normal, 3rd highest on record
• Queensland and Western Australia: 2nd highest on record
• October minimum temperature • Australia: 0.8 ºC above normal,
14th highest on record • Severe frosts in southern New South
Wales and northern Victoria
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Temperatures: August–October 2013 Maximum temperature anomaly Minimum temperature anomaly • August–October maximum temperature
• Australia: 2.7 °C above normal, highest on record by 0.9 °C
• South Australia, New South Wales, Queensland and Northern Territory: highest on record
• August–October minimum temperature • Australia: 1.2 °C above normal,
2nd highest on record • South Australia and Victoria: highest
on record
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2013 – a record year?
Scenarios (Nov–Dec 2013) Rank
Long-term average (0.0 °C) New record
Follows ten year average (+0.5 °C) New record
Current anomaly continues New record
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Cooler on the continent's southern fringe
• Mean sea level pattern at least partly explains cooler conditions for Tasmania and southern Victoria
• On some days fronts and associated flows minimally penetrated across continent
Daily mean sea level pressure October mean sea level pressure anomaly
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Rainfall October 2013 rainfall deciles August–October 2013 rainfall deciles
• October rainfall • Australia: 51% below normal • New South Wales: 8th lowest on record,
72% below normal • Tasmania: 54% above normal
• August–October rainfall • Australia: 37% below normal • Queensland: 5th lowest on record • Tasmania: 2nd highest on record
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Recent rainfall Rainfall totals – previous week Rainfall percentages – November to date Rainfall deficiencies – last 13 months
1 October 2012 – 31 October 2013
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• Recent conditions • A review of 2013 internationally • Current and forecast state of key climate drivers • Outlook for rainfall and temperature
Climate conditions and outlook
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2013 – another year with global temperatures in top ten
• Global temperatures currently tracking 0.5°C above 1961–90 average, 7th highest
• Very warm in Australia, Africa, much of Asia
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Global temperatures – high levels of last 15 years continue
• Global temperatures typical of neutral ENSO years in 21st century
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Global precipitation in 2013
• Wet year in much of Asia, including Indian subcontinent
• Also wet in Sahel, but dry in southern Africa • United States wet in east, but very dry in west • Locally dry in northeast Brazil
%
Reference period: 1951–2000 Source: GPCC
Precipitation anomaly (gauge-based) 2013
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Recent tropical cyclones Haiyan / Yolanda, Philippines, 8 November
• 11 million people affected, over 4000 killed
• 10 minute winds 235 km/h, gusts 325 km/h
• Likely strongest tropical cyclone to make landfall
• One of seven supertyphoons since 1 October
Source: JMA MTSAT
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Arctic and Antarctic sea ice in 2013 • Arctic summer minimum,
6th lowest, lower than any pre-2007 value
• Antarctic spring maximum, highest on record
• Antarctic increase much smaller than Arctic decrease
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A very hot summer in east Asia
• Record high temperatures in Japan, South Korea, eastern China
• Hangzhou broke previous record high (40.3 °C) on 12 separate occasions between 24 July and 12 August
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• Recent conditions • A review of 2013 internationally • Current and forecast state of key climate drivers • Outlook for rainfall and temperature
Climate conditions and outlook
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Sea surface temperatures: Indian and Pacific Oceans
Sea surface temperature difference from average
Southern Oscillation Index
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Outlook for Pacific – El Niño or La Niña Average of models from Australia, EU, Japan, France, US (NOAA), US (NASA) and UK
UK data unavailable
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• Recent conditions • A review of 2013 internationally • Current and forecast state of key climate drivers • Outlook for rainfall and temperature
Climate conditions and outlook
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December to February rainfall outlook
• Drier than normal season is more likely for most of northeastern Australia
• Wetter than normal for Tasmania and northwest Western Australia
• Climate influences include locally warm sea surface temperatures around most of Australia and a neutral tropical Pacific
Historical accuracy
Chance of above median rainfall
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December to February temperature outlooks Maximum temperature outlook Minimum temperature outlook
Historical accuracy Historical accuracy
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Key points
• August to October – record maximum temperatures and widespread dry conditions
• Main climate drivers (particularly ENSO) are neutral
• Dry outlook for northeastern Australia, wet for Tasmania and parts of Western Australia
• Warm outlook for most of eastern Australia and the tropics
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Hydrologic conditions and outlook
Dr Paul Feikema Manager, Seasonal Streamflow Forecasting
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Hydrologic conditions and outlook
• Recent conditions • Water storages • Streamflow forecasts
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Rainfall and evapotranspiration – October 2013 Rainfall Evapotranspiration
• Rainfall 47% below average • Evapotranspiration 25% lower • Water available for streamflow
8% lower
Reference period: 1981–2010
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Change in upper layer soil moisture over one year Change from 2012 to 2013 October 2013
• Little change in upper layer soil moisture
• Upper layer very much below average
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Change in lower layer soil moisture over one year Change from 2012 to 2013 October 2013
• Marked decrease in lower layer soil moisture
• Generally average to below average; except in parts of Tasmania, South Australia and Western Australia
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Change in lower layer soil moisture since 2010 June 2010–February 2011 February 2011–October 2013
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October catchment conditions Observed rainfall Observed streamflow Soil moisture – lower layer
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Observed streamflow – trend towards low flows October September August July
• Trend for lower flows since July • More locations with low flows, fewer
with high flows • Similar number of locations with
median flows
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Hydrologic conditions and outlook
• Recent conditions • Water storages • Streamflow forecasts
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Water storage levels and change since last year
At 20 November 2013
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Hydrologic conditions and outlook
• Recent conditions • Water storages • Streamflow forecasts
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• Near median flows most likely • High flows more likely at
two locations • Low flows more likely at
13 locations • Moderate to high forecast skill
Seasonal streamflow forecasts (Victoria and New South Wales) Forecast streamflow November–January Skill scores
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• High flows most likely • Generally low forecast skill
Seasonal streamflow forecasts (Queensland and Northern Territory) Forecast streamflow November–January Skill scores
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Key points
• Below average rainfall and evapotranspiration in October
• Trend for lower streamflows since July
• Streamflow outlook for near median flows at most locations
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Thank you
• Next briefing Thursday 19 December