Fewer cyclones than normal expected this season, BOM says

Kate Doyle
Swellnet Dispatch

Cyclone Hilda was one of a series of cyclones to make landfall on WA's coast last season. 

Cyclone Liua formed near the Solomon Islands on September 27 and was downgraded just before entering Australian waters.

This was remarkable because the South Pacific's cyclone season, like ours, is nominally from November to April — that is a whole month-and-a-half early!

So is Liua and its early arrival a sign of things to come?

The outlook doesn't suggest so. A likely El Nino this year means the weather bureau is saying the chance of more tropical cyclones than normal is small.

"Indications are for a lower-than-average number of tropical cyclones, and we are less likely to have widespread flooding," said Bruce Gunn, the state manager of BOM Queensland.

But that doesn't mean we can be complacent.

"We are heading into what should be a warmer and dryer season ahead, which means a longer bushfire season, that's already upon us, an increased chance of heatwaves, continuing drought, unfortunately, and also an increased chance of coral bleaching," Mr Gunn said.

Australia has never had a season without at least one cyclone crossing the coast.

Mr Gunn reminded us that any cyclone that formed in the Coral Sea had a one-in-four chance of crossing the coast.

"It only takes one tropical cyclone to make a season, just like we saw with Tropical Cyclone Debbie."

What is a normal year?

According to the Bureau of Meteorology's website, the long-term average number of cyclones per season in the Australian region since 1969-70 is 11, with an average of four making landfall. But since 2000 there has only been an average of nine cyclones each season.

It is projected that in the future there will be fewer but more high-severity cyclones around the world due to human-induced climate change.

The cyclone season outlook is dependent upon the Southern Oscillation Index and Pacific Ocean sea surface temperatures, both of which are also measures of the El Nino Southern Oscillation.

This is because cyclone occurrences and El Nino are linked.

Typically in El Nino years, like this one is tipped to be, there are less cyclones than average because of cooler-than-average western Pacific Ocean temperature and descending stable air over Australia.

La Nina years tend to bring more cyclones.

Who is in the firing zone?

Cyclones typically impact the coastal regions of northern Australia, but as Cyclone Debbie demonstrated in 2017, when flooding impacted from northern Queensland into New South Wales, their effects can be felt much further south.

It is expected that cyclones will travel further away from the equator as the climate warms.

© Australian Broadcasting Corporation. All rights reserved.

Comments

Lanky Dean's picture
Lanky Dean's picture
Lanky Dean commented Monday, 8 Oct 2018 at 4:08pm

Great article, with some real home truths in it.
"Australia has never had a season without at least one cyclone crossing the coast."

So how does it look from previous data for the WSL Snapper pro this year in April. D bah pro?

thermalben's picture
thermalben's picture
thermalben commented Monday, 8 Oct 2018 at 4:17pm

There's no way to tell (this far out) how that ten day waiting period will play out, to be honest. 

Mort's picture
Mort's picture
Mort commented Tuesday, 9 Oct 2018 at 1:06am

You always remind me of a cooking device. It may be the bald head, I don't know.

belly's picture
belly's picture
belly commented Tuesday, 9 Oct 2018 at 12:33pm

Are you hinting 10 days is not enough?

Mort's picture
Mort's picture
Mort commented Tuesday, 9 Oct 2018 at 1:04am

We are all dieing a small death! I am not a robot, I think?

Mort's picture
Mort's picture
Mort commented Tuesday, 9 Oct 2018 at 1:08am

I am like a Crusader, flashing my sword. I could beat Andrew, I bet you.

mr mick's picture
mr mick's picture
mr mick commented Tuesday, 9 Oct 2018 at 6:53pm

What The.....??? Late night on the piss Mort?

Mr mick

Mort's picture
Mort's picture
Mort commented Thursday, 11 Oct 2018 at 9:50pm

Yes and Swellnet has to suffer the consequences. A bit like Global Warming, you heat the dude up, he/she will express.

Mort's picture
Mort's picture
Mort commented Thursday, 11 Oct 2018 at 9:53pm

Actually Swellnet, doesn't have to suffer the consequences. I am bit like the Tasmanian Tiger cartoon , a little tornado that passes and does little damage.

Mort's picture
Mort's picture
Mort commented Thursday, 11 Oct 2018 at 10:01pm

If you go over to Andrew Bolt blog, it is like porn, you have to clear you history. I am tired of fightin, but he is such an ignorant bastard (and his followers). So Bolt posts a graph, I don't care about the graph. I care about the African animals where their lives a border line sometimes, I care about the woman whos dog died in Pureitoco, because it was so nervous (my dog hates storms).

I pick up bits and pieces.

stevehamilton_'s picture
stevehamilton_'s picture
stevehamilton_ commented Wednesday, 10 Oct 2018 at 4:16pm

Far out I just want a cyclone so I can get absolute pitted. Live for it. Got a sick new board keen for some pits. Cmon please

Mort's picture
Mort's picture
Mort commented Thursday, 11 Oct 2018 at 10:07pm

Hope for the best.