Tricky week with an upgrade in swell
Victoria Forecast by Craig Brokensha (issued Monday 16th November)
Best Days: Keen surfers protected spots tomorrow, exposed beaches Wednesday, Thursday, selected spots Saturday morning, beaches Sunday morning
Recap
A small, clean 2ft wave for the keen on the Surf Coast Saturday morning, while the action shifted to the more exposed beaches on Sunday with a building, long-period and inconsistent W/SW groundswell with offshore winds. The morning saw 2-3ft sets with more size and energy into the afternoon as winds strengthened from the N'th.
Today winds are around to the W/NW and strong with small 2ft waves on the Surf Coast, best in protected spots and choppy elsewhere.
This week and weekend (Nov 17 - 22)
Today we've got a strong mid-latitude frontal system pushing east across us, and this is sitting just a touch too high to generate any meaningful increase in swell until this afternoon when it dips south-east and more into our swell window.
A burst of strong W'ly winds will kick up a mix of windswell and lower-end mid-period W'ly swell that should peak tomorrow morning and ease back from the 2ft range on the Surf Coast (possibly a touch bigger on the more exposed stretches) and the 4ft range to the east.
Winds will be W/NW through the morning favouring protected spots which will be smallest, swinging S'ly late morning.
Wednesday is still looking fun on the beaches as winds shift offshore out of the N/NE, holding until about mid-afternoon before shifting E/SE though still surfable.
Size wise it looks like we'll see a mix of small energy to 2ft on the sets across the Surf Coast and 3-4ft to the east, holding most of the day.
We then look at the new W/SW groundswell due later in the week, generated by a strengthening mid-latitude front south-west of Western Australia today.
I mentioned to keep an eye on this system and those who have, would notice that it's now forecast to be significantly stronger with it 'bombing' and dropping in more than 24hPa of central pressure in 24 hours. It'll actually bottom out at 941hPa.
The low was a surface trough but today it's deepening significantly and with this we'll see a great fetch of pre-frontal severe-gale W/NW winds followed by severe-gale to storm-force W/SW winds through our western swell window, south of WA through this evening and tomorrow morning.
The low will weaken tomorrow while tracking slowly east-southeast, but we'll still see a fetch of W'ly gales generated through our swell window, prolonging the swell event through the end of the week.
What we should see is a moderate to large, long-period and initially W'ly groundswell, arriving Thursday, kicking strongly into the afternoon as it shifts W/SW and likely peaking later in the day/overnight and easing very slowly (if not holding most of the day from the W/SW on Friday).
Size wise the Surf Coast will initially be slow but improve with the shift in swell direction but we should see late sets on Thursday to 3-5ft (3ft protected spots and 4-5ft on the magnets), 8ft on the sets to the east with Friday seeing the surf easing a touch from around 4ft and 6ft+ respectively before easing slowly Saturday.
Winds on Thursday look to strengthen from the N/NE and hold ahead of a late SW change as a trough approaches from the west, while Friday will be poor with strong SW tending S/SW winds in the wake of the trough.
A slow improvement in conditions are due through the weekend as a high moves in, likely swinging winds lighter to the E-E/NE through the morning Saturday as the swell eases more noticeably from the 3ft range on the Surf Coast and 4-5ft+ to the east. Sunday looks cleanest on the beaches with a northerly offshore but small, fading 2-3ft sets.
Longer term there's nothing too significant on the cards with a small reinforcing W/SW swell early next week. More on this and any changes to the expected winds on Thursday in Wednesday's update.
Comments
12 week wait minimum if I want to order a well known brand surfboard.. custom for size I want due to demand/covid/Xmas break/supplies delay on foam and resin.
All I want is a summer swallow tail. If I order summer will be over before I get it.
#Nothappyjan
Got a wetty off a mate who is tied up some big name brands - all gone :0. The covid surf population boom has cleaned them out with retailers on waiting list for new stock. Pretty nuts
A little bird told me many big name brands that ship boards on consingment stopped sending stock during the first lockdown as they were very concerned about some retailers viability and didn't want to end up being a creditor when they went under
pretty good range of name brand boards at the ripcurl mornington store when I went in a week ago, they were closed for the whole lockdown period. Looked like a full range of wetties too
Asking a stupid question most likely but say that bombing low was in our swell window ages away (Heard Island?), hypothetically, if it stalled for a couple of days, would that produce consistent long period swell? Or does the low have to travel with the direction of the swell to keep on top of that active sea state?
The experts will give a better answer, but AFAIK if the low stalls you'll get consistent swell, but if it travels in the direction of the swell you'll get bigger swell (captured fetch).
Cheers Mate! I feel like I always think of a better way to phrase my question after I push the button. How about - What is the the required scenario for a consistent, long period, large swell?
That would be a consistently strong (fetch wise) close sitting low or frontal system projecting towards the state. The period comes from the peak wind strength and the stronger the storm the greater the period. If you have a 50-60kt low sitting just south-west of Bass Strait you'll get a large, consistent, long-period swell.
Nice. Craig can you explain why that is the case Re why the stronger wind strength / strength of the storm = the longer period. I’m trying to figure out in my head Thanks serious question
Almost there pops.
Consistency is mostly related to the distance between the source of the swell and the final coastline destination. With all things being equal though direction comes into it as well, with coasts not angled straight to the incoming swell seeing less consistent surf. Just with less sets wrapping into those protected spots on average compared to every wave hitting the straight on location.
The bigger the storm though, even at a distance and the longer-lived the more consistent the swell will appear as there'll be other different swell energies/periods in the mix providing lots of waves in between those bigger sets.
If the storm stays in one position and then weakens, the swell will remain inconsistent but have a longer life cycle than compared to a similar strength storm projecting east and creating a larger, more consistent but shorter-lived swell.
Hope that makes sense.
Boom! Cheers for the reply good sir!!
Thanks Craig, much better answer than mine. For some reason I took the word consistency to mean longevity... maybe just the way the Bone phrased the question.
Follow up question for you: "direction comes into it as well, with coasts not angled straight to the incoming swell seeing less consistent surf"
Is that due to only the longer-period waves generated by the storm diffracting far enough to reach the coast, whereas if the storm was aimed square on to the coast waves of all periods would do so?
Yeah, exactly!
Then there's also the track of the storm through the great circle path. The less along this route or the less favourably aligned the fetch, then the less consistency again.
ive seen you post images of these paths before is there an interactive map you can play around with.
Easiest way is to just load up Google Earth or Maps and draw a line between two different points. You'll see the curve and great circles easily.
I'm no hero I'm just a kook with a poobum stance. But I Have surfed the last 2 bombing lows,the first was about 8 years ago Maby. It was the first low in southern Australia to be named a hurricane. I surfed torquay it was 6-8 and 20knt onshore sw. The second was Maby 5 years ago, surfed sw vicco it was absolutely huge definitely 3 Garry's wind was North and swell was groomed and like a ruler. From memory it was a tropical low off upper western Australia and it reformed and bombed south of herd island.
Good memory, I remember both of those systems, this doesn't look to generate the size of those system's but should be decent.
A couple of great ASCAT passes of the 'bombing low'
The wild tide swings this week will make things interesting
:)