The National Climate and Water Briefing...• 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

Lake Eyre - © Pete Dobre

The National Climate and Water Briefing

24 January 2013


Agenda

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


Climate conditions and outlook

Dr Karl Braganza Manager Climate Monitoring


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



‘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


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

‘A year of two halves’ – temperature


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


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Shift in the frequency of record setting temperatures Frequency of record high (red) and low (blue) max temperature

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Frequency of record high (red) and low (blue) min temperature

Daytime temperature Night–time temperature


Fire weather

•  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

Change in the annual forest fire danger index

Solid purple shows increase in fire weather Satellite image of fires in New South Wales


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Winter Rainfall Anomaly - Southwestern Australia

Australian cool season has been drier

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Autumn Rainfall Anomaly - Southeastern Australia

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Autumn rainfall anomalies (mm/year) for southeastern Australia since 1900

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Australian cool season rainfall deciles (November 1997–March 2012)

Winter rainfall anomalies (mm/year) for southwestern Australia since 1900 (from

1961–1990 base)


April–September 2012

Rainfall since October 2010

October 2010–March 2011 October 2011–March 2012

Pattern of long-term rainfall decline April–September

(1997–2011)

April 2011–September 2011 October–Dec 2012


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


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


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


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

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


Land-surface temperature January 1–8

The ongoing heat – January 2013 heatwave

•  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


Maximum temperature anomaly – January so far

The ongoing heat – January 2013 heatwave






The ongoing heat – January 2013 heatwave Highest maximum temperature – January so far






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


Pacific and Indian Ocean sea surface temperature anomaly

Sea surface temperature difference from average


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


Temperature outlooks for February to April 2013


•  Soil moisture •  Water storages •  Seasonal streamflow forecasts

Hydrological conditions and outlook


December soil moisture and catchment streamflows

Observed December streamflow Upper layer Lower layer

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 much below average for the south


Water storage levels – current status

water.bom.gov.au


Low or near median flows more likely Victoria Southern New South Wales

Southern New South Wales

Victoria


Northern New South Wales Southern Queensland

Low or near median flows more likely

Northern New South Wales

Southern Queensland


Cape York Peninsula Northern Queensland

Low or near median flows more likely

Northern Queensland

Cape York Peninsula


Key points

•  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


Severe weather season to date

Alasdair Hainsworth Head of Weather Services Branch


Agenda •  Summary of events •  Weather trends •  Fire weather •  Tropical weather •  Severe thunderstorms •  Outlook


Summary of events

•  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 •  Oswald – Gulf of Carpentaria and Cape York Peninsula •  Peta – active near Western Australian Coast

Bushfire damage Dunalley (Source: theage.com.au)


Recent weather trends •  January 2010–March 2012

– Above average rainfall – Active monsoon with deep

tropical air intrusions – Active storm seasons – Widespread flooding – Average tropical cyclone activity – Plenty of vegetative growth Flooding near Bourke (New South Wales) (Source: theaustralian.com.au)

April 2010 to March 2012 rainfall percentages


Recent weather trends •  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

Grass fires near Narrabri, New South Wales, late November (Source: ABC.net.au)

April to December 2012 rainfall percentages


Recent weather trends •  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

Maximum temperatures 4 January 2013


Recent weather trends

•  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


Fire weather and heatwave

•  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


Serious fire weather situation – southeastern Australia


Fire weather and heatwave

•  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

Spot fire forecasts – all regions


Spot fire weather forecast

•  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


Tropical weather

•  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


Severe thunderstorms

Brisbane storms (Source: abc.net.au)

•  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


Impacts on the Bureau

standby standby

SARO to WARO

Staff relocation TC Narelle and Oswald

Specialist forecaster relocated to assist with tropical cyclone forecasting

14 Jan+ 17 Jan

BMTC(SA) to NSWRO

Staff relocation NSW Fires Specialist Forecaster relocated to assist with fire weather forecasting

9 Jan TBA BMTC(WA) to WARO

Staff relocation TC Narelle and Oswald

Specialist Forecaster relocated to assist with tropical cyclone forecasting

11 Jan TBA Contracted to NSWRO

Contractor NSW Fires Specialist forecaster employed on short-term contract to assist during peak demand periods

17 Dec 15 Jan

Tindal to CbMO Staff relocation ACT Fire Wx Specialist forecaster relocated to assist with fire weather forecasting

6 Jan 11 Jan

NSWRO Staff relocation NSW Fires 2 Forecasting Staff recalled to duty from annual leave

13 Jan+ TBA QRO to WARO Staff relocation TC Narelle and Oswald

Specialist Forecaster relocated to assist with tropical cyclone forecasting

13 Jan 13 Jan

WARO Staff relocation TC Narelle Forecasting Staff recalled to duty from annual leave

7 Jan 8 Jan NTRO + TCWC Remote forecasting

TC Narelle NT Staff assumed responsibility for monitoring and activation of TC warnings for WA. This provided critical rest time for WA staff ahead of TC critical-activity in the region.

19 Jan 21 Jan

NTRO + TCWC providing assistance to WARO and QRO

Remote forecasting

TC monitoring NT Staff assumed responsibility for monitoring developing QLD and WA tropical cyclones. This provided critical rest time for QLD and WA staff ahead of potential TC critical-activity in the two regions.

•  11 staff relocations to another Region or returned to duty from leave early

•  4 United States Fire Weather Forecasters on staff •  Several instances of Darwin Tropical Cyclone Warning

Centre taking over responsibility for another TCWC to rest staff


Severe weather outlook

•  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

No obvious change in climate factors


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

Forecast for the next week

Documents

The National Climate and Water Briefing...• 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