Climate outlook for January to March
Issued 15 December 2016
Climate outlook overview
- January to March rainfall is likely to be below average in parts of eastern Australia and above average in northwest and central WA.
- The January outlook shows a drier month in the east, while a wetter January is likely in northwest WA and western Tasmania.
- Warmer days and nights are likely across eastern and northern Australia, with cooler days and nights more likely in Tasmania and southwest WA.
- The outlooks are influenced by the Southern Annular Mode (SAM), as well as warmer waters surrounding northern Australia. SAM is currently negative, and forecast to remain negative through January (a negative SAM means Australia experiences higher pressures than normal, resulting in reduced rainfall and higher temperatures during the summer months). The warmer than normal sea surface temperatures surrounding northern Australia are likely to enhance rainfall in northwest WA (see the Climate Influences section for more detail).
Dry start to 2017 for eastern Australia; wetter for the northwest
- January is likely to be drier for mainland eastern Australia, and wetter for northwest WA.
- January to March rainfall is likely to be below average across large parts of eastern Australia and above average in northwest and central WA.
- The current outlook reflects a negative Southern Annular Mode, and warmer waters to the northwest of Australia.
- Historical accuracy of outlooks for January to March rainfall is moderate over most of Australia, except southern parts of WA and parts of the interior where accuracy is low to very low.
Warmer start to 2017 likely for eastern Australia
- January to March maximum temperatures are likely to be warmer than average in eastern Australia and cooler than average in Tasmania and parts of northern and central WA.
- January to March minimum temperatures are likely to be warmer than average in eastern Australia, but cooler in the far southeast, and across parts of northern and central WA.
- The current outlook reflects a negative Southern Annular Mode and warmer waters to the northwest of Australia.
- Maximum temperature accuracy is moderate over most of Australia, except eastern SA, where accuracy is low. Minimum temperature accuracy is patchy, with moderate skill across eastern Australia, the Top End of the NT and eastern WA.
- The El Niño–Southern Oscillation (ENSO) remains neutral, but continues to show some weak La Niña-like patterns, including warmer than average waters to the northwest of Australia. This may be contributing to some wetter conditions in parts of northwest Australia.
- In the shorter term, a northerly shift in the average position of westerly winds and high pressure systems (also known as the "Southern Annular Mode", or "SAM") is forecast for January. When this northward shift (a negative SAM phase) occurs in summer, weather systems are further north than usual, meaning Australia experiences higher pressures than usual. This is typically associated with below average rainfall and higher temperatures.
- In addition to the shorter-term natural drivers, Australian climate patterns are being influenced by the long-term increasing trend in global air and ocean temperatures.
- Bureau climatologists continually monitor the climate for any significant developments, with information on El Niño/La Niña and IOD events available fortnightly via the ENSO Wrap-Up. For a summary of Pacific and Indian Ocean outlooks, please see the Climate Model Summary.