Victorian Surf Forecast by Craig Brokensha (issued Friday 17th September)

Best Days: Protected spots tomorrow, Sunday, protected spots Monday, Wednesday protected spots, Thursday, Friday morning

Features of the Forecast (tl;dr)

• Inconsistent W/SW groundswell tomorrow with strong W/NW tending W winds
• Mod-large mid-period W/SW swell Sun with strong N/NW tending NW winds
• Larger, building mid-period W/SW swell Mon with strong W/NW tending W/SW and then SW winds late
• Large, W/SW groundswell easing Tue with strong SW winds
• Easing surf Wed with fresh W/NW tending SW winds
• Building mid-period SW swell Wed PM
• Mod-large SW groundswell building late Thu with mod-fresh N/NW-NW tending winds, easing Fri with strong N/NW winds ahead of a SW change

Recap

A continuation of fun waves across the beaches yesterday with an inconsistent mix of swells to 3ft+ across the Mornington Peninsula and to 2ft on the Surf Coast. Winds were favourable most of the day with weak sea breezes.

Today we've got a touch less size and windier conditions, favouring the beaches for the keen.

This weekend and next week (Sep 18 - 24)

Looking at the start of the weekend, an inconsistent W/SW groundswell should lift wave heights into tomorrow, generated last Sunday and Monday by a broad, strong polar frontal progression in the Heard Island region.

This swell will be inconsistent but sets to 3ft are due across the Surf Coast, 4-5ft to the east but with strong W/NW tending W winds. This will favour protected spots west of Melbourne.

Sunday's swell, which revolves around a mid-latitude firing up under the Western Australian coast has been a tricky one to resolve by the models. Initially the low was forecast to be too far north, sitting high in the Bight, out of our swell window, then, stronger and more favourably positioned to the south in Wednesday's forecasts.

Well today, it's due to be favourably positioned but much weaker, with a fetch of strong W/SW winds firing up under the Western Australian south coast, reaching gale-force as the low forms, projecting through our western and then south-western swell windows today and tomorrow morning.

With the reduction in wind strengths, the swell looks to be mostly mid-period energy, coming in around the 4ft range on the Surf Coast Sunday (smaller protected spots and likely the odd bigger one at magnets at times), 6ft+ to the east. Winds will be favourable but strong and N/NW through the morning, shifting NW into the afternoon.

Looking at the secondary low that's due to fire up on the back of the initial system, and we'll see this form south-southwest of Western Australia this evening, projecting a fetch of gale to severe-gale W/SW winds through our western swell window tomorrow. The low will weaken and break down on approach to us Sunday, and turn into a trough.

This isn't great for local winds, with the trough due to bring a more southerly flow to the coast as the larger W/SW groundswell from the low fills in Monday/Tuesday. The trough will also feed the formation of a strong low in the Tasman Sea, which may influence our winds through Wednesday as well, but we'll review this on Monday as the models diverge regarding the movement of this low.

Coming back to Monday, we should see building mid-period W/SW energy from the 4ft range on the Surf Coast, to 5-6ft into the afternoon, with 6-8ft sets developing on the Mornington Peninsula. Winds will be favourable and strong from the W/NW through the morning, shifting W/SW into the afternoon and then SW later as the weakening low/trough moves across us.

Tuesday will be poor with strong SW winds and an easing W/SW groundswell from 5-6ft on the Surf Coast, 8ft to the east.

We'll hopefully see W/NW winds kick back in Wednesday morning with a drop in energy ahead of some new mid-period SW swell into the afternoon and stronger groundswell Thursday.

Both these swells will be generated by the same system, that being a strong polar low forming under the country early next week, though angled a little east-southeast rather than west to east.

An initial pre-frontal fetch of strong to gale-force NW winds are due to strengthen and swing more W/NW along the polar shelf Tuesday, producing what looks to be a moderate to large SW groundswell.

The peak in size is currently due late Thursday afternoon, with the Surf Coast building to 4-5ft, 6-8ft to the east. As touched on in Wednesday's outlook, winds are looking favourable and out of the N/NW-NW most of Thursday, with Friday seeing strong N/NW winds ahead of a trough and afternoon SW change. We'll take a closer look at the timing of this on Monday though.

Following the polar low generating the swell mid-late next week, further activity is likely into the end of the week, providing plenty of surf for next weekend, though winds look dicey. Have a great weekend!