Extended forecast

Effective from: Mon 21 May '12, 03:00PM

Forecast prepared by Craig Brokensha
Next update Wed 23/5 5pm.

Previous day's summary:

The weekend started out poor with a small onshore swell down South and beginner waves on the Mid Coast. A new swell started to build during the afternoon though and this peaked through Sunday with good 3ft sets at Middleton, 4ft waves at Waits and 1ft surf on the Mid Coast that increased a touch with the incoming tide. Winds were great all day as well with a high pressure ridge moving in quickly after Saturday's change resulting in a light and variable airstream.

The swell has eased back a touch into this morning with winds freshening from the N/NW favouring the South Coast as the Mid Coast saw tiny bumpy surf. A shift to the NW has been seen this morning but winds shouldn't go past W/NW, favouring the slightly protected spots down South.

Swell events within the forecast period:

1) Medium to large sized SW groundswell building Tuesday with a stronger pulse for Wednesday, peaking during the afternoon, easing Thursday
The coming few days are looking great down South with a series of strong SW groundswells expected to push in. These two swells have been generated by a broad and strong frontal progression pushing up from south-west of WA under the country, while generating winds in the gale to severe-gale-force range.

One of the systems is currently to our south, pushing towards Victoria and this will produce tomorrow afternoon's and Wednesday morning's increase in SW groundswell. Middleton should build to 3-4ft tomorrow afternoon with larger 4-5ft sets at Goolwa and Waits with the Mid Coast increasing to an inconsistent 1-2ft+. This swell should hold into Wednesday morning but a stronger pulse is due during the afternoon generated by the secondary system that will race up towards us during tomorrow.

Middleton should rise to 4-5ft during the afternoon with 6ft sets out at Waits and Goolwa, with the Mid Coast pulsing to 2ft to occasionally 3ft with the incoming tide. The swell should fade into Thursday down South but a third frontal system pushing up into the Bight during Wednesday will keep the Mid Coast topped up with 2ft+ sets.

Conditions will be best in slightly protected locations down South with a NW tending W/NW wind tomorrow while as the swell peaks on Wednesday a similar but stronger wind pattern is expected with a more W'ly wind into the afternoon. Thursday is looking poor with S/SE winds moving in as a low moves across us, but this should favour the Mid Coast, creating fun waves all day. Friday looks poor for down South again with a S/SE airstream with Saturday being a write off due to fresh and gusty S/SW'lys.

Long term forecast (6+ days):
As discussed in the last update, the upper level Long Wave Trough will intensify over the south-east of the country during the end of this week resulting in two swell events. The first will be a medium sized but strong S/SW groundswell for Sunday, generated by a vigorous polar frontal progression but also in the mix will be a low quality S/SW windswell produced by a deepening low to our east. Winds will be onshore in any case creating poor conditions but check back here on Wednesday for an update.