National Climate and Water Briefing - Bureau of Meteorology...• October maximum temperatures •...

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National Climate and Water Briefing

28 November 2013


Climate and water conditions and outlook

Dr Blair Trewin Senior Climatologist, Climate Monitoring


• Recent conditions • A review of 2013 internationally • Current and forecast state of key climate drivers • Outlook for rainfall and temperature

Climate conditions and outlook


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


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


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


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


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


Recent rainfall Rainfall totals – previous week Rainfall percentages – November to date Rainfall deficiencies – last 13 months

1 October 2012 – 31 October 2013


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


Global temperatures – high levels of last 15 years continue

• Global temperatures typical of neutral ENSO years in 21st century


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


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


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


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


Sea surface temperatures: Indian and Pacific Oceans

Sea surface temperature difference from average

Southern Oscillation Index


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


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


December to February temperature outlooks Maximum temperature outlook Minimum temperature outlook

Historical accuracy Historical accuracy


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


Hydrologic conditions and outlook

Dr Paul Feikema Manager, Seasonal Streamflow Forecasting



• Recent conditions • Water storages • Streamflow forecasts


Rainfall and evapotranspiration – October 2013 Rainfall Evapotranspiration

• Rainfall 47% below average • Evapotranspiration 25% lower • Water available for streamflow

8% lower

Reference period: 1981–2010


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


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


Change in lower layer soil moisture since 2010 June 2010–February 2011 February 2011–October 2013


October catchment conditions Observed rainfall Observed streamflow Soil moisture – lower layer


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


Water storage levels and change since last year

At 20 November 2013


• 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


• High flows most likely • Generally low forecast skill

Seasonal streamflow forecasts (Queensland and Northern Territory) Forecast streamflow November–January Skill scores


Key points

• Below average rainfall and evapotranspiration in October

• Trend for lower streamflows since July

• Streamflow outlook for near median flows at most locations


Thank you

• Next briefing Thursday 19 December

National Climate and Water Briefing - Bureau of Meteorology...• October maximum temperatures •...

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