There's set patterns /cycles that tend to follow for a few months . and they only slightly shift over a month . It takes a total change in patterns ( significant anomaly for them to reset or shuffle ) . Usually it will shift slightly shorter than a two week period .
Just don't ask me why and when they will shift ....
You won't like the answer . ( and i don't mean Centrelink is controlling it ) hahah

Thanks Southy, it's a pity centrelink doesn't control it, because then i know I could get on some sort of scheme and manipulate it. With these weekend patterns I may as well get a job at centerelink , I miss having my midweek surfs with just a handfull instead of fighting for a carpark on a weekend. The solution of course is a month of solid swell.

I remember when I was living back in SA and a full up Uni schedule meant I could only go on the weekends. There was a run there when every weekend for a couple of months was the same with small fun swells and offshores.

Another time later in Uni when I worked the schedule to score a free day or two, I remember going down nearly every Tuesday for a month scoring good swells and offshore winds.

It is as Southey said a pattern cycle thing, and if you live in SA during summer you'll notice there is a bout a week between cycles from full blown SE'lys to 2 days on NE winds and then back to the SE again. If it fits in your schedule it's great but if it doesn't it's hell!