1. ENSO and Seasonal Outlook - Queensland Jim Davidson, Bruce Gunn: Queensland Regional Office Compiled with the assistance of William Wang, Elise Chandler, Andrew Watkins & Grant Beard, National Climate Centre, Melbourne

2. Climate conditions and outlook Recent climate conditions Current state and forecasts for key climate drivers Outlook for rainfall temperature, fires, storms, floods

3. La Niña – a very strong event One of the strongest La Niñas on record: 1917, 1955, 1975 July 2010 – March 2011 Rainfall highest on record: 752mm (707mm in 1973-74) July 2010 – March 2011 day temperatures 2 nd lowest July 2010 – March 2011 rainfall deciles July 2010 – March 2011 maximum temperature deciles

4. A return to drier conditions Rapid breakdown of the La Niña in autumn changed rainfall patterns over Australia January to March: 77% above normal rainfall for Australia (2nd highest on record) May to July: 24% below normal rainfall for Australia January to March rainfall deciles May to July 2011 rainfall deciles bom.gov.au/jsp/awap

5. Recent climate conditions Current state and forecasts for key climate drivers Outlook for rainfall temperature, fires, storms, floods Climate conditions and outlook

6. September La Niña indicators Southern Oscillation Index September 2010: +25 September 2011: +5 20102010 20112011 bom.gov.au/climate/enso Southern Oscillation Index (SOI) La Niña El Niño

7. Current state of ENSO 7 Subsurface temperatures indicate collapse of western Pacific warm anomaly & re-intensification of central Pacific cool anomaly. 2011 Another La Niña developing? US NOAA already calling this a La Nina But the majority of dynamical models of the ocean indicate that the cooling of the central Pacific ocean may have peaked. Not yet coupled into atmospheric circulation and SOI

8. Pacific Ocean – forecast Neutral Pacific Ocean conditions consensus forecast for spring and early summer Number of models show some further cooling El Niño(warm) highly unlikely Weak La Niña(cool) remains possible for (late?) summer Australia’s POAMA model forecast for NINO3.4 (August 2011) International climate model forecasts MODEL / GROUP Forecast Start Date1-3 MONTHS (Sep 2011 to Nov 2011) 4-6 MONTHS (Dec 2011 to Feb 2012) POAMA Australian Bureau of Meteorology 29 AugustNeutral POAMA-2 (Experimental) Australian Bureau of Meteorology 1 AugustNeutralNeutral^ GloSeaGloSea UK Met Office12 AugustNeutral/CoolNeutral/Cool# CFSCFS NCEP (US)28 AugustNeutral/CoolCool CGCMv1CGCMv1 * NASA GoddardGMAO(US)1 AugustNeutralNeutral/Cool System 3 System 3 ECMWF (EU)1 AugustNeutralNeutral/Cool JMA-CGCM02JMA-CGCM02 Japan Met. Agency11 AugustNeutral KMA-SNUKMA-SNU Korean Met. AdministrationUnavailable BCC_CMA BCC/CMA (China)Unavailable bom.gov.au/climate/enso

9. Climate conditions and outlook Recent climate conditions Current state and forecasts for key climate drivers Outlook for rainfall temperature, fires, storms, floods

10. Vegetation – abundant grass growth across much of the country

11. Rainfall Deciles for the past 3 months Rainfall in July, and early August has been well below average Upper soil moisture is drier than normal However, deeper soil moisture remains average to above average Hence, slight potential for above average run off if significant rain occurs

12. BUSHFIRE OUTLOOK 2011-12

13. Number of SEQ severe storm days per season (1956-2000) Number of severe thunderstorms in SEQ usually peaks in November Lightning activity in SEQ usually peaks in December Number of severe storms in SEQ If ENSO: Neutral ~ 35% above average El Nino ~ 5 % below average La Nina ~20% below average Yeo, C. 2005. Severe Thunderstorms in the Brisbane region and a relationship to the El Nino Southern Oscillation, Aust. Met Mag. 54 (2005) 197-202.

14. PRELIMINARY: Rainfall Outlook for October to December This time last year Spring 2011 PRELIMINARY: Not for public release

15. Global model forecast

16. Soil moisture from AWAP Top layers are average to dry, although lower layers are generally average to wet. Full storages & wet subsoil imply potential for above average runoff after onset of significant rainfall 16 Current upper layer soil moisture Current lower layer soil moisture

17. SOI and Queensland Floods ~1920 to 2009 Jun 2010-Mar 2011 SOI = 19.1 1973/74 1955/56 1975/76 1950/51

18. Tropical Cyclones Preliminary outlook: Slightly above average numbers of tropical cyclones are expected in the Eastern (Coral Sea) region during the 2011-12 season. Average of 3-4 tropical cyclones each year in Coral Sea -all or none could be severe, and possibly make landfall This outlook is based on statistical relationships between annual tropical cyclone numbers, and the El Niño – Southern Oscillation (ENSO). This outlook is based on neutral ENSO conditions that currently persist in the Pacific Ocean, however some allowance has been made for a potential return of weak La Niña conditions by the end of the year. The outlook will be reviewed and updated over the coming months as more data becomes available

19. Key points - ENSO La Niña has ended, the Pacific has returned to neutral ENSO conditions (neither La Niña or El Niño), but precursors for another La Niña are clearly there. Neutral conditions are forecast to continue through spring, but a reforming (weak) La Niña remains possible. If the ocean cools a little further + the SOI rises, and these conditions remain at these elevated levels for several weeks, only then will we consider we have a resurgence of the La Nina.

20. Key points – ENSO ctd Far cry from where we were at this stage last year La Niña indicators much weaker than at this point in 2010 (2010-11 was possibly second strongest after 1917-18, and stronger than 1973-76) A borderline neutral/La Niña summer is less favourable for widespread above median rain than the very strong event we had last year. Change in forecast is possible. BoM will be closely monitoring.

21. Key points – Season Outlook (Queensland) At this early stage….. Above average 2011-12 fire season over much of Queensland Average to above average number of spring/early summer severe storms in SE Queensland Above average rainfall likely across Queensland in Oct – Dec period, particularly in the north of the state Tropical Cyclones: preliminary indications are for slightly above average number of tropical Cyclones in the eastern (Coral Sea) region in 2011-12 However the chance of widespread flooding and above average cyclones is not as high as last yearHowever the chance of widespread flooding and above average cyclones is not as high as last year Nevertheless, there will almost certainly be major floods somewhere in Qld during 2011-12 though unlikely to be as widespread as 2010-11Nevertheless, there will almost certainly be major floods somewhere in Qld during 2011-12 though unlikely to be as widespread as 2010-11

22. Key points – Season Outlook (Queensland) BoM will be closely monitoring for any changes. ENSO Wrap-Up and Climate Models summary will be updated fortnightly The seasonal outlook will be updated on 28 th SeptemberThe seasonal outlook will be updated on 28 th September

23. Thankyou Bureau of Meteorology Queensland