National Climate and Water Briefing - Bureau of Meteorology · Carbon dioxide concentrations over...

Bureau of Meteorology www.bom.gov.au National Climate and Water Briefing 27 March 2014

National Climate and Water Briefing


Welcome

Dr Rob Vertessy CEO and Director of Meteorology


Climate and water conditions and outlook

Perry Wiles Manager, Climate Liaison Section


Climate and water

Conditions and outlook

• Recent conditions • Current and forecast state of key climate drivers

• Outlook for rainfall, temperature and streamflow


Maximum temperature anomaly Minimum temperature anomaly

Temperature

February

• Maximum temperature anomaly, −0.45 °C

• Minimum temperature anomaly, +0.14 °C

• Mean temperature anomaly, −0.16 °C


Rainfall

Summer

Rainfall deciles: Summer December and January February


• February rainfall has had some impact on long-term severe rainfall deficits in central Queensland

Rainfall deficiencies, 16 months October 2012–January 2014

Rainfall deficiencies

Rainfall deficiencies, 17 months October 2012–February 2014


Rainfall

March to-date

Rainfall totals Percentage of mean rainfall


Upper layer soil moisture, February Soil moisture change, January to February

Upper layer soil moisture

• Below average soil moisture in southeastern Queensland, northeastern New South Wales and Victoria

• Increase across northeastern Australia since January


Lower layer soil moisture, February Soil moisture change, January to February

Lower layer soil moisture

• Below average soil moisture for most of eastern Australia

• Little change over the last month in soil moisture throughout most of eastern Australia


• Low streamflows continue in southeastern Queensland, New South Wales and Victoria.

• Streamflows for northern Queensland locations have increased from low to near median and high

January February

Observed streamflows


Water storage levels


Murray–Darling Basin storage levels

Beardmore Dam

Hume Dam

Dartmouth Dam

Copeton Dam


Climate and water


• Recent conditions

• Current and forecast state of key climate drivers • Outlook for rainfall, temperature and streamflow


Indian and Pacific Ocean sea surface

temperatures

February value of NINO3.4: – 0.3 Current value of NINO3.4: + 0.1


Outlook for the Pacific

Average NINO3.4 forecast from seven international climate models (Australia, EU, Japan, France, US (NASA and NOAA) and UK)

UK data unavailable


El Niño

Neutral conditions El Niño conditions


El Niño indicators

Sub surface temperature anomalies Westerly wind anomalies Southern Oscillation Index


• Greatest impact normally occurs during winter/spring

• Impacts can vary from one event to another

• 1997 El Niño:

• strong ENSO signals in Pacific Ocean

• weak rainfall impacts in Australia

Winter–spring rainfall deciles from 12 El Niño events

Typical El Niño impacts on rainfall

10

9

8

7

5-6

4

3

2

1

Mean rainfall deciles


Climate and water


• Recent conditions

• Current and forecast state of key climate drivers

• Outlook for rainfall, temperature and streamflow


• Above median rainfall likely in the southwest

• Drier outlook for areas in the north and east

Chance of above-median rainfall, April–June Chance of above-median rainfall, March–May

Rainfall outlook

April–June


• Warmer days likely in the east and north; strongest signal in Tasmania and Victoria

• Warmer nights over much of Australia; strongest signal in the southeast

Chance of above-average maximum temperature Chance of above-average minimum temperature

Temperature outlook

April–June


• Low flows more likely for southern locations

• Near median or high flows more likely for northern locations

• Low or very low skill for many forecast locations

Most likely streamflow outcome Forecast skill

Streamflow forecasts

March–May


In summary

• An El Niño event is looking more likely from late-winter

• Some reasonable rain during February and March, but long-term deficiencies persist

• Dry lower layer soils

• Dry outlook for eastern and northern Australia; wetter in southwest

• Warmer outlook over northern and eastern Australia

• Low flows more likely for southern locations for; near median to high flows for northern locations


Thank you

Questions?


Dr Karl Braganza Manager, Climate Monitoring


400

380

360

340

320

300

280

260

240

220

200

800 700 600 500 400 300 200 100

CO2 (ppm)

Thousands of years ago

Atmospheric CO2 concentrations reached 395 parts per million in 2013

Carbon dioxide concentrations over the last 800 000 years


State of the Climate


Carbon dioxide emissions


Evidence that the Earth’s climate continues to warm is unequivocal.


Changes in the global climate

system


Ocean heat content Warming of the world’s oceans accounts for more than 90% of additional energy accumulated from the enhanced greenhouse effect.


Sea level Global mean sea level has increased throughout the 20th century. By 2012 sea level was 225 mm (±30 mm) higher than in 1880.


Welcome

Dr Rob Vertessy CEO and Director of Meteorology

Australia’s climate has warmed, and the frequency of extreme weather has changed, with more extreme heat and less extreme cold.


Annual mean temperature

changes

Daytime maximum temperatures have warmed by 0.8 °C over the same period, while overnight minimum temperatures have warmed by 1.1 °C.


Sea-surface and surface air

temperature

Sea-surface temperatures in the Australian region have warmed by 0.9 °C since 1900.


Distribution of monthly

temperatures

Since 2001, the number of extreme heat records in Australia has outnumbered extreme cool records by almost 3 to 1 for daytime maximum temperatures, and almost 5 to 1 for night-time minimum temperatures.


Extreme temperatures and

heatwaves

The duration, frequency and intensity of heatwaves have increased across many parts of Australia, based on daily temperature records since 1950.

Days where extreme heat is widespread across the continent have become more common in the past twenty years.


Rainfall averaged across Australia has slightly increased since 1900, with the largest increases in the northwest since 1970.


Northern wet season (October–April) rainfall deciles since 1995–96

Increased rainfall?

Australian rainfall total since 1900


Rainfall has declined since 1970 in the southwest, dominated by reduced winter rainfall. Autumn and early winter rainfall has mostly been below average in the southeast since 1990.


Southern wet season (April–November) rainfall deciles since 1996

Drying across the south

Southwest Australian rainfall anomalies since 1900


There has been an increase in extreme fire weather, and a longer fire season, across large parts of Australia since the 1970s.


Trends in extreme fire weather days

Forest Fire Danger Index at Melbourne Airport since 1963

Annual cumulative FFDI … increased with statistical significance at 16 of 38 climate reference sites from 1973–2010.

Extreme fire-weather days have become more extreme at 24 of the 38 locations since the 1970s.


Projections for Australia


Australian climate projections for the end of the century RCP8.5

Annual temperature change April to September rainfall change

Percentage rainfall change for 2081–2100 with respect to 1986–2005 Temperature change in degrees for 2081–2100 with respect to 1986–2005

High RCP2.6 Low

RCP8.5 High

RCP2.6 Low


Thank you

Questions?


Next briefing

Wednesday 30 April 2014

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