Welcome to the Climate and Water Outlook for Spring 2017.
The outlook suggests drier than average conditions for parts of Western Australia, and warmer
than average for the north and southeast of the continent.
But first, let's look at recent conditions.
This winter has been one of the country’s driest on record.
Strong high pressure systems in early winter blocked cold fronts reaching Australia, particularly
in southern areas.
In June, Australia only had a third of its usual rainfall overall, with even less in
some key agricultural areas.
July brought recovery to some of these areas; and in August, more average winter rainfall
patterns returned in the south as high-pressure systems moved back to their normal positions,
allowing fronts to cross southern Australia.
However, rainfall deficiencies since April remain at serious to severe levels in parts
of Western Australia, central New South Wales and southeast Queensland.
Daytime temperatures have been at record-high levels across much of the country this winter.
Mandora in the Pilbara recorded 39.6°C on 24 August—the 4th-warmest temperature ever
recorded in Australia during winter.
Warm and dry conditions have meant fire potential in parts of eastern Australia has been unusually
high this winter.
Bushfires have already occurred in northern New South Wales and southern Queensland.
In contrast, nights have been notably cooler than average in areas such as the Murray–Darling Basin.
The third week of August brought some damaging frosts, with many parts of the Basin having
at least one night below –3°C.
Lower-layer soils are still drier than average
in New South Wales and southern Queensland.
But August rains have meant some southern areas, such as southwest Western Australia,
are now closer to average.
This means southern water storages have finally started to rise.
In southwest WA, storage levels have risen by over 6 per cent since July.
So what's driving Australia’s climate right now?
With our main climate drivers—ENSO and the Indian Ocean Dipole—both neutral, other
drivers are having an influence.
For example, warm waters in the central Indian Ocean may see more frequent easterly winds
blow across Australia, keeping the west drier than average.
The rainfall outlook for spring indicates below-average rainfall is likely for western
parts of Western Australia, with above-average rainfall possible in some parts of eastern Australia.
Turning to streamflow: Following an unusually dry winter, near-median to low streamflows
are expected for August–October, particularly in the southeast of the mainland.
Low flows are also forecast for the southwest and at some locations along the eastern seaboard.
In terms of temperatures: Days and nights are likely to be warmer than average for northern
Australia and the southeast.
However, clear nights mean the risk of frost continues—particularly in areas with drier soils.
Frost potential maps are available via the 'Agriculture' link on the Bureau's website.
In summary: Spring is likely to be warmer than average in the north and southeast; but
the risk of frost remains in the south; rainfall is likely to be below average for parts of
Western Australia; and near-median to low streamflows are expected at most locations.
For more details, visit our website at bom.gov.au/climate/ahead.
You can also get updates via Facebook and Twitter.
For your first look at October–December, our new mid-month outlook will be available
on Thursday 14 September.
For the Bureau of Meteorology, I’m Robyn Duell.