Here we are, deep in the middle of summer with warm waters gracing most of the Australian coastline plus regular episodes of unbearable heat.
Besides a good run of trade-swell into the end of November and early December, the Gold Coast has been devoid of any decent swell until last week.
While last week's moderate to large S/SE groundswell was a touch out of season (more so autumn and winter), we're expected to move into a more seasonal period of tropical activity later this week.
This will be related to an active phase of the Madden Julian Oscillation (MJO) drifting in from the west.
The MJO is a wave of tropical activity that propagates eastward around the globe, going through certain strengthening and weakening phases along the way.
While tropical lows can form at any time during summer and autumn, the MJO enhances this by bringing increased instability, convection, and storms - the foundations for tropical lows. The more active the MJO is, the more instability and propensity for tropical storms.
The MJO is monitored and forecast out to two weeks by various weather agencies around the world, and can be visualised on the charts shown below.
While it looks quite complicated, it's actually fairly simple. The globe is set up into eight rough sections, and if you imagine looking at the diagram from the south pole, you can see Australia falls in the middle of section 4/5 in the Maritime Continent, 7/6 covers the Pacific Ocean, 8 America, 1 Africa and then back to the Indian Ocean 2/3.
The end of the blue line is where the MJO is currently placed around the globe (as of 20th January), with it travelling anti-clockwise (eastward) around the equator.
The strength of the MJO is signified by how far away from the centre the line is, and over the past fortnight we've seen the MJO very active across the Indonesian region. This has resulted in the formation of multiple cyclones, namely Ava, Irving and Berguitta last week.
The MJO is now moving in across northern Australia and current forecasts have it pushing further east through this week while maintaining strength, onwards towards the Western Pacific.
This will likely result in the formation of a tropical cyclone off north-west Australia, but of greater interest to us is if we see any developments in the Coral Sea.
Current indications are promising with a strong high pressure system forecast to stall over New Zealand and the eastern Tasman Sea, while a couple of tropical lows form on its northern flank setting up a broad and healthy trade-fetch.
This will result in easterly trade-swell building from the weekend across the East Coast, further through next week with larger surf dependent on how the tropical lows play out. We're expected to see these lows drifting south squeezing the high further, but whether this is closer to the Australian mainland or above New Zealand is still unclear.
Additional lows within the monsoon trough labelled in the above diagram will inject further energy into the region and likely also maintain activity for some time yet.
Keep an eye on Ben and Craig's Forecaster Notes over the coming fortnight for regular updates regarding the timing, size and local winds around this summer swell event.