thermalben

Good surf ahead for Victor and the Mid

South Australian Surf Forecast by Ben Matson (issued Wednesday 21st January)

Best Days: Fri: possible late pulse of new swell for both the Mid and Victor. Sat: light winds with good waves on both coasts. Sun: OK waves across the Mid but bumpy under a cross/onshore breeze. Wed: small but decent groundswell for Victor with good winds.

Recap: Flat across the Mid Coast Tuesday but great surf down south with offshore winds and a small to moderate groundswell. Onshore winds today with a building short range swell, including some small dribbly waves along the Mid Coast.

This week (Jan 22 - 23)

Note: forecast notes will be brief this week as Craig’s away

A couple of strong fronts will pass south of the state over the coming days, not really influencing our local weather to a great degree but they will however maintain generally light to moderate southerly winds across the coastal margin (periods of variable winds are possible here and there).

A small new SW swell is building across the coast right now, and this should hold into Thursday morning, of which there’s a reasonable chance that we’ll see surfable conditions for a period in the morning under the variable pattern.

Size will be small though, best suited to either the Waitpinga or Goolwa ends of the coast (3ft+), with only small surf at Middleton (2ft+). 

Very little surf is expected on the Mid on Thursday, just tiny teaser lines well under a foot.

Smaller surf is then expected through Friday morning down south, with similarly tricky winds: possibly light W/NW in Victor at dawn but likely to swing fresh SW by mid morning. 

Late afternoon, the leading edge of a bigger groundswell - generated by the mid-week progression of a strong front/low combo in the Southern Ocean - is expected to make landfall. This should provide some late sets in the 3-4ft+ range at Middleton with even a few small waves across the Chiton stretch on dusk. The day’s onshore airstream should also start to abate during this time so if you’re in the area it’ll be worth sniffing out a late session as the swell starts to build, as thetre could be a window of decent surf if we're lucky.

There’s also a chance for a late session on the Mid Coast too, but it’s hard to be confident on the timing - it’ll probably arrive very late in the day so you’ll have to monitor the South Port surfcam for signs of life.

In actual fact, a smaller W/SW swell generated by a front just ahead of ther primary low should provide a small increase in new energy during the morning with inconsistent 1-1.5ft waves through the middle of the day, and conditions should be OK with light to moderate southerly winds.

Keep an eye on the Cape du Couedic buoy for a noticeable J curve during the day, and then allow 3-5 hours for a transition to the coast: if the buoy isn’t showing Hsig above 3m by early afternoon, then the Mid’s chances for a decent late session will be somewhat lessened. However there’s certainly a reasonable chance for some 2ft+ sets in the hour or three before dark. In addition, the easing SW airstream may allow for a late land breeze from the S/SE.. wouldn't that be nice?

This weekend (Jan 24 - 25)

Great surf is expected across the peninsula on Saturday. The new swell due late Friday should peak overnight or early Saturday morning with 3-5ft waves at Middleton and up to 6ft+ at Goolwa and Waits (the Chiton stretch should perform well with this energy too).

The Mid Coast should also see reasonable waves all day in and around the 2ft+ mark, although it will probably be under some tidal influence at times which may cause lengthy lully periods.

An approaching front front the west will swing an early light and variable airstream to a moderate nor’wester by mid morning, cleaning up the South Coast nicely. These winds will probably remain light all day along the Mid Coast.

At this stage Sunday’s looking to be under the passing influence of the cold front, meaning SW winds for most regions. There’ll still be plenty of surf down south as the swell eases, but conditions will be ordinary. 

The Mid Coast will also see plenty of waves on Sunday - the fetch trailing the front should maintain 2ft+ surf for much of the day - but no great quality is expected, unless we see local winds fall below current forecast levels. I’ll revise all of these particulars in more detail on Friday.

Next week (Jan 26 onwards)

Nothing major on the charts for next week. A deep polar low is expected to form near Heard Island around Friday, and then scoot along the ice shelf over the weekend - setting up a small but decent S/SW groundswell around Wednesday - probably not enough size for the Mid Coast but ideal for the break breaks across the state’s exposed coasts, includig Victor Harbor. 

Prior to that we’ll be looking at easing leftovers from the weekend with variable winds.

Next Wednesday’s groundswell looks like being only small to moderate in size but of high quality, and at this stage early indications are for a light NE airstream thanks to a slowly eastward migrating high from the Bight across Bass Strait into the Tasman Sea. 

Beyond this indications are for an easing trend through into the weekend. As such next week’s attention is presently focused around Wednesday. More on this in Friday’s update.

Comments

thermalben's picture
thermalben's picture
thermalben commented Thursday, 22 Jan 2015 at 10:14am

Bugger.. the Mid came in bigger than I thought.

One of the problems of grabbing the reins of the South Oz forecast (Craig's away, so I filled in yesterday) is that the short term outlook is hard to be confident in - any incoming swell for the following day or two is likely to already be in the water (so, the weather system responsible for it would have disappeared from the charts days ago) which makes it very hard to hindcast small events.

As such, this small lil' groundswell has slipped through the net, as I wasn't watching the charts late last week or over the weekend, when it was probably generated. And the buoy data didn't look very promising yesterday, nor does it look particularly exciting today either!

And, the current CdC buoy data brings up another interesting point that I've discussed here (and elsewhere) before: the Mid Coast really benefits from lower period swells. The reason being is that the energy of lower periods swells penetrates to a much shallower depth than long period swells, and therefore suffers less frrictional effects.

Therefore, the shallow entrance of Investigator Strait often has a negative effect on long period swells as they lose a lot of size pushing through the gulf - but low swell period events (like today - Tp of 11sec and Tz of 7sec) can pass on by with greater ease.

yorkessurfer's picture
yorkessurfer's picture
yorkessurfer commented Thursday, 22 Jan 2015 at 11:46am

Yesterday was a bit of a surprise down here too Ben. I'd written off surfing for the day but after lunch the wind died right out and I could see the small swell building out the front of my shack. I went down and surfed 3 to 4ft Chi's by myself. It was all over by 3pm when a sea breeze hit.
With that short period swell and no one else out I caught 10 waves in ten minutes, something of a rarity out there.

thermalben's picture
thermalben's picture
thermalben commented Thursday, 22 Jan 2015 at 11:57am

Wow.. that's awesome. Yeah these short period swells are the real surprise packet in South Oz I reckon. Most people focus on big purple blobs and long periods, but they often under deliver at many locations - while these ones sneak under the radar and produce fun sessions. Good work YS!