Effective from: Wed 19 Jun '13, 12:20PM

Forecast prepared by Craig Brokensha
Next update Fri 21/6 1pm

Previous day's summary:

Small to medium levels of S/SE swell continued across the North Coast yesterday with tiny waves on the Gold Coast's beaches, but a new S/SE groundswell filled in later in the day and has held into this morning.

This was providing 2-3ft waves at open beaches with 5ft sets at south swell magnets on the North Coast, while the Goldy saw inconsistent 1-2ft waves on the beaches. This swell will ease into this afternoon but new levels of short-range S'ly swell will take its place as winds tend fresh S'ly.

Swell events within the forecast period:

The Tasman low responsible for this week's pulses of S'ly swell is now moving off slowly to the east, opening our region to a more favourably aligned fetch of strong to gale-force S/SE winds on its western flank. This fetch through today will be followed up by a secondary burst of severe-gale S'ly winds up through the Eastern Tasman Sea this evening and tomorrow, generating a large pulse of S/SE groundswell for later Friday and Saturday morning.

The North Coast should build to a solid 3-5ft across open beaches Friday afternoon with 4-5ft+ sets at south facing locations before easing from a similar size Saturday morning. The Gold Coast should see an increase late in the day to 2ft+ at open beaches and 3-4ft on the Tweed before peaking early Saturday to 2-3ft and 3-5ft respectively.

This will spell the end of the swell from the Tasman Low, with wave heights expected to drop steadily into Saturday afternoon and further Sunday.

Our attention will then turn to the developments of a low pressure system off the East Coast during the weekend as a surface trough drifting south from the Coral Sea feeds off a deep pool of cold air in the upper atmosphere.

The models are still divergent on the intensity and positioning of this system, with GFS leaning towards an East Coast Low off the Sydney Coast, while ECMWF has a weak easterly dip. We'll probably see something in between with all the action initially occurring to our south again. During the early stages of the low formation on Saturday evening and Sunday an in-feed of E'ly winds should give us a fun pulse of E'ly swell, but check back here on Friday for the latest on this.

Long term forecast (6+ days):
The longer term outlook revolves around the low pressure system forming off the East Coast, so check back here on Friday for a clearer idea on this system and it's swell potential for our region.