The MJO's effect on the Surf Coast

Craig's picture
Craig started the topic in Thursday, 19 Sep 2024 at 6:40am

As more research is conducted regarding climate drivers and the teleconnections they create across hemispheres and ocean basins, this one interests me the most.

There is a strong correlation between an active MJO signal in the Western Pacific Ocean (sectors 6/7 in the below MJO plot) and an increase in the upper zonal winds across south-east Australia, ie increased frontal activity potential = swell.

That being the large convection profile of the MJO during our winter/spring (when it is in the Northern Hemisphere) forces a planetary wave which in turn brings increased cold outbreaks and frontal activity to the south-east of Australia (blue oval across Australia in the below chart).

This first chart shows the current MJO position and phase, as you can see it's currently strong in sectors 6/7.

The second chart shows the typical atmospheric response during Aug/Oct/Sept when the MJO is in certain sectors.

When in 6/7 (Western Pacific) we see heightened potential for cold outbreaks and frontal activity for the south-east of the country. Alternatively we see suppressed activity when it is in sectors 1/2 (across Africa).

The current setup being a text book example.

We've got an active MJO signal across sectors 6/7 and the response in the Southern Ocean is clear with strengthening, back to back storms pushing up and across the south-east.

This correlation is strongest during winter/spring and less so through summer/autumn as noted in this study.. https://research.usq.edu.au/download/e8d75c49188ac65e1aec47b950fa30a4b17...

But I've found the correlation to exist through summer as well, though more research has to be undertaken.

Take home point, when the MJO has strength across sectors 6/7 expect strong frontal activity across South Australia/Victoria.

Craig's picture
Craig's picture
Craig Thursday, 19 Sep 2024 at 8:08am

Some early morning reading to get the brain ticking over.

carpetman's picture
carpetman's picture
carpetman Thursday, 19 Sep 2024 at 9:20am

Nice Craig. Not to undermine, I thought the MJO single strength and location, and the impact on possible swell production was fairly well understood. Or am I missing something here?

Craig's picture
Craig's picture
Craig Thursday, 19 Sep 2024 at 9:24am

Tropical swell production yes but mid-latitude connections less so.

carpetman's picture
carpetman's picture
carpetman Thursday, 19 Sep 2024 at 9:30am

Interesting. I'd oblivious oversimplified. Typical layman.

Bnkref's picture
Bnkref's picture
Bnkref Thursday, 19 Sep 2024 at 4:10pm

Nice one Craigos. Cheers.

AlfredWallace's picture
AlfredWallace's picture
AlfredWallace Thursday, 19 Sep 2024 at 7:02pm

Craig. Thank you for your always impressive work and information, your knowledge imparted to us is gold.

I really enjoy reading and understanding them all.

I hope your little loved one and your partner are doing fine. AW

indo-dreaming's picture
indo-dreaming's picture
indo-dreaming Friday, 20 Sep 2024 at 7:34am

Yeah agree with that AW

Pop Down's picture
Pop Down's picture
Pop Down Friday, 20 Sep 2024 at 8:58am

Hello Craig

Great work , Sherlock Holmes !

Looks like U have added a lovely Teleconnection , 2 your Forecasting Tool Box .

U are the Man , when it comes 2 finding Surf !

Any idea how the MJO , is reacting 2 the Climate Driving , CO2 ?

Perhaps , way 2 early 2 tell , as it's History , is just emerging ?

I have No idea and will read your post , 4 a 4th time :)) .