Submitted by thermalben on Mon, 11/18/2013 - 18:06
Western Australian Surf Forecast by Ben Matson
(issued Monday 18th November)
Best Days: No great days.
Recap: Friday's late arrival of a small long range groundswell provided some good waves in the Margs region on Saturday morning as winds swung E'ly. Slowly building swell throughout Sunday was marred by early northerly winds preceding a gusty S/SW change as a trough pushed across the region. Gusty SE winds have padded out today with a reasonable but wind affected swell.
As for Perth, wave heights have been very small for the entire period but conditions were clean Saturday morning before moderate onshores developed in the afternoon. Winds then veered N'ly early Sunday ahead of a moderate W'ly tending SW change from mid-morning. Very small but clean waves have been on offer for the start of the working week.
This week (Nov 19-22)
It's a very simple surf forecast for WA this week - easing swells and windy conditions at first, becoming less windy mid-late week with a small increase in new swell some time on Friday.
The reasons for this are very simple: a large blocking high has dominated our primary swell windows over the last few days, keeping most swell generating activity confined to the western Indian Ocean. As such we've got no new swell events due until about Friday lunchtime, however this new energy will have been generated many thousands of kilometres from the mainland (actually, from a moderate storm west of Heard Island at the moment).
So, what arrives on Friday will be only small in size, and very inconsistent. Certainly not worth working around unless you're totally desperate.
Conditions wise, we've got a strong ridge of high pressure dominating the southern coast of WA at the moment, which is resulting in gusty SE winds. They'll persist through Tuesday before tending E'ly and starting to relax through Wednesday as the ridge breaks down and a weak trough develops along the coast. Current expectations are for light and variable winds through Thursday and Friday at this stage.
This weekend (Nov 23-24)
The blocking Indian Ocean high responsible for this week's small spell is expected to momentarily break down later this week, which will allow a mid-latitude low to advance near the coast throughout the weekend. This will bring about an increase in new swell for the start of the following week - however it'll also likely contribute onshore winds to the region on Sunday (mainly the Margs area; Perth may escape the bulk of the SW airstream and see more southerly winds).
In any case, Friday's small new swell is expected to peak early Saturday (again!) with early light winds possibly swinging onshore as the low approaches (confidence is not high on the timing or strength of this yet). In any case, with an easing swell due through Saturday and most of Sunday, I'd recommend an early Saturday session at your favourite swell magnet down south if you simply have to surf in the next two weeks.
Long term (Nov 25 onwards)
As per last week's forecasts, we're looking at a peak in swell activity from this low sometime around Monday. The latest model data has eased back the projected size range (3-5ft at swell magnets), and with likely onshore winds in the Margs region it probably won't be worthwhile.
Otherwise, computer model guidance is suggesting we'll see a more significant break in the blocking pattern early next week, which will allow a more significant series of weather system to generate large swells for the second half of next week and the following weekend. Check back on Wednesday for an update regarding this.