Western Australian Forecast by Ben Matson (issued Monday November 25th)

Features of the Forecast (tl;dr)

• Easing surf, tricky winds Tues/Wed
• Powerful groundswell Thursday with generally offshore winds
• Size easing Friday with early light winds
• Average/poor weekend
• Very large windy swell early next week

Recap

Metro beaches have been very small for the last few days, they were clean over the weekend but wind affected under fresh southerlies today (with some building windswell). Margs was small and clean over the weekend but have also become wind affected today as southerlies have become strong to gale force. A new swell is also building across the SW region. 

This week (Nov 26 - 29)

A strengthening ridge will maintain fresh winds across the state on Tuesday, though they’ll be SE across metro regions early on, and more S/SE across the lower SW.

Either way, with today’s swell easing back in size there won’t be many options on hand. The Margs region will be too wind affected (sheltered bays and points won’t have enough size) and there’s not enough groundswell component in today’s swell increase north of the capes - it’s mainly local windswell - and this will ease back overnight. So keep Tuesday's expectations low.

Smaller surf is expected into Wednesday morning with light morning offshore winds ahead of fresh sea breezes after lunch. 

Later Wednesday, the leading edge of a new long period groundswell is expected to arrive though we won’t see the main size increase until Thursday. 

The models are really undercooking this swell, which was generated by a powerful polar low below Heard Island over the weekend. Wave heights should push up into the 8-10ft+ range across the Margaret River region, and early morning winds are expected to be light offshore so conditions should be nice and clean. 

This swell should also produce nice waves across metro beaches in the 2-3ft range. 

Conditions should be good for most of the day under moderate easterlies, late sea breezes are possible though.

Wave heights will then ease back rapidly through Friday with early morning offering clean conditions under early NE winds. Expect small clean 2ft waves across metro beaches and 4-6ft surf in the lower SW.

This weekend (Nov 30 - Dec 1)

A classic winter pattern is on the boil for the second half of the weekend, with strong pre-frontal NW winds on Sunday tending gale force W’ly on Monday behind the change.

A minor bump in mid-range swell is expected Saturday from a decent front pushing through the swell window this week however local winds look a little problematic - probably onshore though likely variable early morning. 

Sunday looks like a write-off with easing surf and freshening NW winds. 

More on this in Wednesday’s update.

Next week (Dec 2 onwards)

The first week of winter will kick off with victory-at-sea conditions on Monday under strong to gale force W’ly winds - there may be some workable options at the protected bays and points. Metro beaches will have bumpy waves for keen surfers. The source of the groundswel lis a very large mid-latitude low flaring up well to the SW of the continent over the weekend (see below). It's a great looking system that should generate a couple of days of waves, albeit with difficult winds (south from Perth).  

Easing size and improving conditions are then expected through the rest of the week, with modest swell activity and more classic summertime winds from the southern quadrant.  

See you Wednesday!