Welcome to the Climate and Water Outlook for February to April 2016.
A strong El Niño persists, but Pacific ocean temperatures are gradually cooling.
Historically, the breakdown of El Niño often sees good rains fall in some, but not all,
areas.
But summer is not over yet.
Heatwave and bushfire risks will remain high until at least the start of autumn.
First, let's look at recent conditions.
Coastal New South Wales had over one month's rain in a couple of days, with local flooding.
Heavy falls were also received during January in parts of inland Queensland and in southwest
Western Australia.
Northern Australia, meanwhile, has had a dry start to the year; fairly typical of an El
Niño wet season.
Despite some rain in January, short and long-term drought continues in many parts of the country.
Long-term deficiencies over three years persist, particularly in Queensland, northern New South
Wales and Victoria.
Turning now to temperatures: We've seen some short, sharp heat events in southern Australia—some
followed by dramatic drops in temperature.
For example, Melbourne temperatures fell 24 degrees from the 13th to the 14th of January.
This variability is typical of an El Niño summer.
Significant bushfires have hit several areas in southern Australia.
Despite wet in some areas, the heightened risk of bushfire continues.
El Niño increases the risk of dry thunderstorms: ones that bring lightning but no rain,which
can start fires.
The Yarloop fires in Western Australia during January were started by lightning and were
so large that they generated their own weather, known as pyrocumulus clouds.
Water storages have dropped even more than normal this summer.
Many are now at lower levels than they were at this time last year.
Lower-layer soil moisture remains below average across much of eastern Australia, particularly
in those areas affected by long-term drought.
Check out our new Landscape Water Balance website for more detailed information about
soil moisture at your location.
So what's driving Australia’s climate right now?
El Niño is still strong, but has begun to break down.
Sea surface temperatures in the tropical Pacific are slowly cooling.
Climate models predict a long, slow decline of El Niño during the first half of 2016.
Recently, a pair of tropical cyclones formed on either side of the equator in the central
Pacific.
This means they rotated in opposite directions, like an eggbeater, generating strong westerly
winds in the middle.
This change in winds near the ocean surface may further slow the decline of El Niño.
Models currently suggest neutral and La Niña states are equally likely in 2016, with only
a very small chance of a repeat El Niño.
While each El Niño is unique, during the breakdown phase we usually expect some wetter-than-normal
conditions in parts of southern Australia.
So what’s the rainfall outlook for February to April 2016?
Consistent with the breakdown of El Niño, odds favour above-average rainfall for much
of southern and central Australia.
In the north, rainfall is likely to remain below average.
Our rainfall outlook has low to moderate accuracy at this time of year.
Turning to the streamflow forecast for January to March:
Low flows are more likely at 78 locations.
Sixteen sites have near-median flows forecast, and only seven are likely to have high flows.
Accuracy for our streamflow forecasts is high at this time of year.
Temperature outlooks show cooler-than-average days and nights are likely for much of central
and southern Australia.
Accuracy for these outlooks is moderate at this time of year.
No tropical cyclones have crossed Australia's coast, and we're now halfway through the season.
Fewer tropical cyclones than normal are typical during El Niño, but we’ve never had a season
with none crossing our coast.
Keep an eye on our website for the latest cyclone forecasts and warnings.
So in summary: El Niño is still strong, but is easing.
Odds favour above-average rainfall in central and southern Australia, but low streamflows
are likely in most places.
Raised bushfire and heatwave risks continue.
For more details, head to our website at bom.gov.au/climate/ahead.
You can also follow us on Facebook and Twitter.
Our next video will be released on Thursday 25 February.
For the Bureau of Meteorology, I’m Paul Feikema.