Pesky northerlies to dominate for a while
South-east Queensland and Northern NSW Surf Forecast by Ben Matson (issued Monday 20th January)
Best Days: Tues AM (Lower Mid North Coast), Tues PM (rest of MNC), and then Wed AM (a little further north into the Northern Rivers) with light winds. Otherwise, no great days due to painful northerlies.
Recap: Whilst wave heights have come in close to expectations over the last three days (3ft out of the east Saturday, building to 4ft on Sunday, persisting today), we saw much better conditions than expected across some coasts - mainly Sunshine/Gold/Tweed Coasts, and then the Mid North Coast up to about Coffs Harbour. The reasons for this are very complex (and worthy of a seperate article) but related to the extraordinary, one-in-100-year thunderstorm event seen across SE Qld overnight Friday into Saturday, which dumped an incredible amount of rain across the region in a very short space of time (up to 330mm at Loder Creek near Southport on the Gold Coast). The meteorological basis for this is above my level of expertise, but was well summarised by Queensland meteorologist Anthony Cornelius, who pointed out that thunderstorm activity around Mackay on Friday morning occurred much earlier than expected, and fizzled through the afternoon, which resulted in the southwards transport of remnant moisture. This widespread moisture then wrapped into SE Qld, and interacted with an upper low and an approaching surface trough, producing the record-breaking storms we’ve all seen over the news. From a surfing point of view, the main improvement was a broadscale easing of the synoptic wind, which was most likely the result of a major (though temporary) widespread stabilisation of the atmosphere in the wake of the thunderstorms. Whilst Friday’s notes did mentioned the chances of this occurring across the Sunshine Coast, I simply didn’t expected it to cover such a wide area, nor persist as long as it did. And thus, surfing conditions were much better than expected across these regions.
This week (Jan 21 - 24)
As discussed last week, we’ve got an extended period of northerlies ahead.
In fact aside from a few brief troughy incursions, the synoptic wind won’t return to the south for at least the next fortnight. Maybe longer. It's a little depressing, to be honest.
The reasons for this are a bit of the chicken/egg scenario, but from a synoptic point of view we’re in the midst of a blocking pattern that’s refusing to budge. A persistent cycle of troughs are occupying the coastal margin (mainly Southern NSW), and a dominant high pressure ridge across the eastern Tasman Sea is maintaining our northerly flow. The long wave pattern is not strong enough to break down this cycle, so we’re left with poor winds and unusual swell sources.
To that end, we’re looking at easing E’ly swells over the coming days, though surf size won’t drop very much. TC Toni didn’t offer a lot of swell generating potential during its brief tenure within our swell window, but it has evolved into an incredible extra-tropical low, well to the east of New Zealand (though, not quite as good as last week’s model guidance suggested).
We’ll see continuing, though smaller trade swell for most of this week, originating from the (distant) ridge between TC Toni and the high pressure system to the south, ahead of a pulse of long period E/SE swell from later Thursday and through Friday and Saturday, extending from Toni's extra-tropical developments. This will only however favour exposed northern regions (such as the Sunshine Coast) with the most size - perhaps reaching 4ft or so - and surf size will become much smaller as you track south from the Gold Coast, owing to the shadowing effects of New Zealand.
But with poor winds, there's really not a lot to look forward to anyway.
Otherwise we’re looking at small intermittent NE windswell and E’ly trade swell sources this week. Most beaches should see size in the 2-3ft range (maybe a few bigger sets on Tuesday off the tail end of the current E’ly swell cycle), but there won’t be a lot of quality around.
The best winds (i.e. light/variable) look likely to occur on Tuesday across the Mid North Coast - initially south from Port Mac, then slowly extending north up to Coffs by the afternoon, perhaps Yamba at a pinch. We'll then see this pattern push a little further north into Wednesday morning - maybe the Byron or Tweed Coast if we're lucky - before afternoon N/NE breezes redevelop by lunchtime.
I don't think SE Qld will be quite so lucky this time around. The best we'll see here will be brief, early morning N/NW winds across northern stretches.
Otherwise, the rest of the week will probably be heavily affected by northerlies.
And we can expect water temps to drop three or four degrees too.
This weekend (Jan 25 - 26)
There's not a lot of point getting overly complicated with the weekend outlook, because at this stage it appears that we'll see a continuation of the current broadscale troughy pattern, and its associated swell sources, which is primarily a local N’ly fetch running down the NSW Coast, generating small NE swells.
A small E’ly fetch developing atop a Tasman high will generate small trade swells but no major size is expected from this source (in fact this swell won’t really show until later in the weekend or early next week).
Wind wise, most regions will be under the influence of northerlies though they should peg back a little from Thurs/Fri’s strength.
Let’s take a closer look on Wednesday.
Next week (Jan 27 onwards)
Nothing major standing out on the charts at this stage - just the bog standard summer long range model guidance of teasing trade flows and migrating Southern Ocean lows. We’ll see plenty of supposedly useful E’ly swell all of next week, but if these northerlies persist I doubt there’ll be a lot of interest in surfing.