Effective from: Wed 23 May '12, 03:10PM

Forecast prepared by Craig Brokensha
Next update Fri 25/5 5pm.

Previous day's summary:

The last couple of days have seen a gradual uptick in size with a series of strong W/SW groundswells filling in. The Cape du Couedic wave buoy has registered a steady building trend and is now hovering between 4-5m average wave heights with peak periods of 14-15 seconds. This is resulting in solid 3-5ft waves breaking across the Middleton stretch down South with bigger sets at Waits while the Mid Coast has built from 2ft+ to 2-3ft this afternoon. Fresh N/NW winds favoured the slightly protected spots down South while the Mid Coast is a semi-stormy mess.

Swell events within the forecast period:

1) Easing SW groundswell tomorrow with a lower period SW swell for the afternoon, easing Friday
Today's strong SW groundswell will peak this afternoon and drop into tomorrow morning but a further easing trend into the afternoon will be stopped by the arrival of a new SW swell. This swell is being produced by an unfavourably aligned and tracking cold front that is currently pushing up into the Bight while generating winds in the strong to gale-force range.

The front will move across us overnight tonight with winds tending S/SE creating cleaner conditions on the Mid but poor waves down South. The swell should hang around 2ft+ tomorrow on the Mid with 3-4ft sets at Middleton and 4-5ft waves at Goolwa and Waits. Friday should see smaller 1-2ft waves on the Mid and 3ft waves at Middleton with 4ft sets at Waits as winds go back to the S/SW and begin to freshen.

2) Mix of medium sized S/SW windswell and groundswell building Saturday with a peak in groundswell Sunday and reinforcing pulse for Monday
A deepening low will form over Victoria during the end of the week with a weak cold front moving in from our west during Friday combining with this low to produce a strengthening fetch of S/SW winds aimed into the South Coast on Saturday.

This should kick up fresh levels of weak windswell to 1-1.5ft on the Mid Coast and 3ft+ down South during the afternoon. Of greater importance is the arrival of a S/SW groundswell generated by a vigorous polar front producing winds in the severe-gale to sub-storm-force range over the next couple of days. This swell should build to a similar size later Saturday ahead of a peak on Sunday around 3-4ft at Middleton and 3-5ft at Goolwa and Waits. The Mid Coast will unfortunately only pick up 1ft+ waves due to the southerly swell direction.

This swell should hold into Monday morning as a secondary reinforcing S/SW groundswell fills in generated by a secondary polar front as winds improve from a fresh S'ly on Sunday to a lighter E/NE'ly. Check back here on Friday though for confirmation of these winds and the size of the S/SW groundswell

Long term forecast (6+ days):
Next week will be made up mostly of small to medium sized S/SW groundswells as the storm track remains focussed just east of Tasmania. Winds should improve further for the South Coast as well but we'll go over this again on Friday.