Weak high pressure in the Tasman and a trough is creating a “doldrums” type pattern of slack pressure gradients and small swells this week, with a few wind changes to negotiate. No major swells expected this week. The headline feature is a potential major tropical cyclone drifting into the Coral Sea with a poleward (southwards) track late this week, over the weekend and into next week.
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Further ahead and some weather model runs are starting to look pretty damn juicy with respect to a developing TC in the South Pacific moving into the Coral Sea later next week. Still very early days but a full blown cyclone swell is now a definite possibility, possibly as early as next weekend and into the week 9/12
In the South Pacific the previously active area near the Solomons that has already spawned two tropical cyclones looks to flare up again next week with convective activity enhanced by a cross-equatorial flow. We may see a new tropical depression or even cyclone form later next week, with uncertain surf potential at this very early stage.
A small trough of low pressure off the sub-tropical coast (SEQLD likely) will see a brief flush of E/NE swell. One bright spot in a very dull forecast.
High pressure is straddling Tasmania with the remnants of a front lingering near New Zealand with an off-axis fetch. A coastal trough and an inland trough maintain unstable conditions with a developing N-NE flow over the weekend.
It’s a weak synoptic pattern with no major swell sources- a passing front weakens as it traverses the Tasman, leaving an off-axis fetch parallel with New Zealand. There should be enough minor swell sources of no real quality to stay wet through the short term.
The troughy pattern remains installed into the medium term so we’re still keeping an eye out for short range features which could supply local swell sources, although these look small and weak.
In the mix will be some inconsistent E swell from TC Mal’s run through the swell window. It accelerated as it hit the swell window so a slight winding back in size is justified but we’ll still see some defined sets in the 3 occ. 4ft range through Sat morning, easing during the day.
TC Mal enters the swell window later today and we may see some small E/NE swell Sat. The TC moves at angles to the swell window which is not good for swell production but there are winds to 60kts as it enters the swell window o/night so we can expect some bigger 4ft sets with rogue 5ft sets a real possibility.
In addition the tropical depression or TC (Mal) which is expected to track SE through the swell window Wed/Thurs is expected to send some small E/NE swell our way. It’s a tricky, compact free-standing system but we can reasonably expect some 3 occ. 4ft sets Sat into Sun with revision to come this week.