Effective from: Fri 24 May '13, 02:56PM

Forecast prepared by Ben Matson.
Next update Mon 27/5 5pm.

Previous day's summary:

A small residual swell on Thursday was kept clean with offshore winds. A developing ECL off the coast yesterday afternoon has generated (and is continuing to generate) a large SE swell which is pushing slowly northwards along the coast. Wave heights were reportedly in the 8ft+ range in the lower Mid North this morning, and - as suggested on Wednesday's forecast - we are seeing a favourable window of clean strong surf in the Far North as the swell pushes ahead of the southerly wind change. In actual fact, at the time this report was prepared, the change seems to have stalled somewhere between Port Macquarie (where winds are S'ly gusting 28kts) and Coffs Harbour (where winds are SW of a similar strength), so this 'window of opportunity' ended up being longer than expected, and should hold out until the end of the day.

Forecast period ahead:

No major changes to the weekend forecast, except for a small upgrade for exposed locations on Satirday (which will be too windy to surf anyway). The ECL will generate a large S/SE swell that should reach 6-8ft+ at exposed beaches in the Far North (smaller in the lower Mid North), however gusty southerly winds will confine the best waves to protected locations and points, the more open versions of which should see very good 5-6ft surf.

Wave heights will ease steadily on Sunday, from 6ft at exposed south facing beaches down to 4-5ft. Protected locations will see smaller surf, easing from 3-5ft to 2-3ft, and more importantly, winds should veer more predominantly SW by this time. So, there should be a greater spread of locations with clean waves (some exposed beaches may still be wind affected, particularly in the Far North).

In addition to this, a small long period south swell is expected to move along the southern NSW coast on Sunday, and it should reach the lower Mid North Coast by late in the day (however probably won't push more further north than about Coffs Harbour). This swell will have originated from a series of deep lows passing below Tasmania today.

A series of strong secondary systems trailing behind are then expected to be steered up into the Tasman Sea over the weekend as a long wave trough amplifies over New Zealand longitudes. This should continue to build south tending S/SE swell across the region through Tuesday and Wednesday, and with favourably light offshore winds expected in general we should see some very good waves at exposed beaches, reaching 3-5ft at times. An easing trend will then occur from Thursday onwards.

Looking further ahead, and a blocking pattern is expected to develop across our southern swell window from mix-next week onwards, which will halt significant swell acidity from this area into the second half of next week and possibly the weekend. We will consequently see the trades develop below Fiji around the same time, resulting in a building E'ly swell from Wednesday through into the weekend (size peaking around 3-4ft at the height of the activity). More on this next Monday.