Victorian Surf Forecast by Ben Matson (issued Monday 12th October)

Best Days: Tues: strong though inconsistent groundswell, spoiled a little with onshore winds. Wed: good options east from Melbourne. Fri/Sat: another decent groundswell but potentially spoiled by local winds. 

Recap: Saturday punched a little higher than expected with 3ft+ sets across Surf Coast swell magnets, whilst Sunday came in a little underdone, easing rapidly to 1-2ft. Bigger surf was reported east of Melbourne (4-5ft easing to 3ft) and conditions were generally Ok with variable winds, though it did trend onshore both afternoons. Today is seeing a new swell build across the coast (2ft Surf Coast, 3ft east of Melbourne). It’s running a little late and should peak later this afternoon. Conditions are clean with light winds.  

This week (Oct 13 - 16)

*This week’s Forecaster Notes will be a little erratic as Craig’s on annual leave*

I gotta say, of all the times to pick up the reins of the Vicco forecasting bench, this morning is the least desirable of the lot (having not looked at the Southern Ocean synoptics in quite a while). 

We’re right on the cusp of two interesting long period groundswells - the first of which is running late and thus presently undersized; the second of which is trailing close behind but was generated by an impressive cut-off low.

So, do I assume Friday’s prediction for 3-5ft surf west of Melbourne today and 6-8ft east of Melbourne is correct? Hindcasting this event won’t shed much light on the situation; invariably I’ll end up with the same result as Craig did. Ordinarily it’d be best to wait for the swell to fill in before recalibrating. But, I’m time-limited today, and it’s likely we’ll have a result in the hours following publication of this forecast anyway. So let’s crack on with it, eh?

Truth be told, whilst the parent systems that generated these approaching swells do look impressive, there are a couple of limiting factors. Today’s swell source was a very long way from the mainland (midway between Heard Island and West Oz longitudes), which means the enormous travel distance will shave off a lot of size and (more importantly) consistency. So even if we do reach the predicted size, set waves will be extremely infrequent.

The issue I have with tomorrow’s swell is that whilst the cut-off low responsible for the swell was very strong, and travelling in a manner conducive to a capture fetch, the actual fetch was relatively short and narrow, compared to a typical Southern Ocean front being driven by a core Polar Low. 

This somewhat weaksn my confidence. In my experience, these kinds of swells tend to favour a small number of spots where the magic numbers (size/period/direction) are optimal, but many locations usually miss out. 

So with this in mind, I’m going to pull back tomorrow’s size estimation and place a strong emphasis on the consistency of the swell (or lack thereof).

As it is, conditions won’t be great anyway, with a weak trough crossing the coast, swinging overnight northerlies to the west then the south. It won’t be terribly strong but these onshores will certainly take the sheen off an otherwise nicely lined-up groundswell.

Let’s peg exposed reefs across the Surf Coast in the 3-5ft range (smaller elsewhere), and expect very long breaks between sets. East of Melbourne should be very strong (though equally inconsistent) with 6ft+ sets.  

Wave heights will then slowly ease from Wednesday onwards and winds will veer E/NE - not too strong - but enough to cause issues across the Surf Coast reefs (very inconsistent 3-4ft easing to 2-3ft during the day). East of Melbourne will be a much better choice, with easing 4-6ft surf down to 3-5ft.

Wednesday may also see a minor SE swell across the Suf Coast (mainly west from Torquay) from developing easterly winds through Bass Strait Tuesday - though current expectations are that the fetch will be more E/NE in alignment, so we probably won’t see a lot of size. 

Thursday looks to be a bit of lay-day with early freshening N’ly winds ahead of a shallow W’ly change mid-morning in Torquay, and then around lunchtime across the Peninsula. We’ll be down to 1-2ft surf west of Melbourne by this time. If you’re lucky, east of Melbourne should have a brief window of small open beaches.

Friday has good swell potential but poor local winds. Over the coming days, a moderate though strengthening polar low near Heard Island will traverse the waters well below the continent, and from later Tuesday into Wednesday will start to project E/NE up into our swell window (see below). This is a great angle for the storm track, and so despite not being an amazing system, should generate a really nice groundswell for our region.  

The problem is that  a weak front will concurrently clip the coast overnight Thursday, delivering moderate to fresh S’ly winds. There’s a chance that a building high pressure may swing the wind to the east, but this will only favour open beaches east of Melbourne - and they may be overpowered with solid 6ft+ sets. West of Melbourne should come in around the 4ft+ mark by the afternoon.

I’ll firm things up on Wednesday.

This weekend (Oct 17 - 18)

There’s quite a bit of divergence regarding the weekend outlook.

A weak coastal trough expected to be near South Australia on Friday is unclear as to how it’ll evolve. We’ll either see a near-stationary ridge of high pressure extending west from Tasmania dominating the weekend outlook, maintaining moderate to fresh easterly winds - or, the trough will move slowly west, swinging the winds to the north ahead of a fresh W’ly change overnight that’ll maintain onshores throughout Sunday. 

However, either solution won’t provide any significant new swell for the state.

Saturday morning will see easing SW groundswell from Friday’s increase (3-4ft west of Melbourne, 4-6ft east of Melbourne, much smaller by the a'noon), so at this stage it’s looking like a poor start across the Torquay stretch.

We may also pick up some small SE windswell west from Torquay, thanks to Friday's developing easterly fetch through Bass Strait.

With some luck, the aforementioned coastal trough will influence local winds and allow open beach breaks to clean up through Saturday. 

I’ll take a closer look on Wednesday. 

Next week (Oct 19 onwards)

With the weekend outlook already divergent, there’s not a great deal of point in looking beyond into next week, as it’ll all change quite a bit over the coming days. 

See you Wednesday!