Western Australia Surf Forecast by Craig Brokensha (issued Wednesday April 13th)

Best Days: Friday in the South West, early Saturday, Sunday protected spots, Monday morning, Tuesday morning, Wednesday morning, Thursday morning

Features of the Forecast (tl;dr)

• Easing, small inconsistent SW groundswell tomorrow with E winds and afternoon sea breezes
• Inconsistent mid-period SW swell building Fri with mod-fresh E/NE winds and weak sea breezes
• Moderate sized + SW groundswell for Sat with early SE tending strong S/SW winds
• Mix of swells building Sun, peaking into the afternoon with fresh S/SE-S winds, strengthening later
• Easing surf Mon with E tending S/SE winds (SE Perth and Mandurah in the AM)
• Mid-period, moderate sized + SW swell building Tue with E/NE tending SW winds
• Stronger mix of larger S/SW groundswell building later Wed with E/SE tending S winds, easing Thu with E tending S winds

Recap

Easing surf with clean conditions and 1-1.5ft sets in Perth, 1-1.5ft in Mandurah and around 4ft across the South West.

Today the swell is smaller and slower but clean across all locations. An inconsistent, background SW groundswell has lifted wave heights slightly this afternoon in the South West but with a developing sea breeze.

This week and next (Apr 14 - 22)

The small, inconsistent SW groundswell seen this afternoon is due to ease into tomorrow with mostly 3ft sets and possibly the odd 4ft'er on the magnets early in the South West.

Conditions will be clean with an E'ly offshore wind tomorrow morning ahead of sea breezes, clean again Friday with a moderate to fresh E/NE offshore ahead of weaker sea breezes.

On Friday the first of our three pulses of strengthening and building groundswell are due with the second arriving for Saturday and a third Sunday.

These back to back swells will be generated by back to back polar fetches moving through our swell window, and at this stage Saturday's now looks to be the best.

A first initial front will generate a mid-period swell for Friday, building to 4-5ft across the South West through the day with those favourable winds. Perth and Mandurah will remain tiny.

Saturday's swell will be generated by a better fetch of W/SW gales moving through our swell window, with surf to 6ft due in the South West, 1-2ft across Mandurah and Perth. A final weaker but broader low following the gale-force fetch will produce a reinforcing mid-period SW tending S/SW swell for Sunday which should push sets to 6ft+ into the afternoon but of lesser quality.

Mandurah and Perth should build to 2ft, with all locations easing Monday from 6ft and 2ft respectively.

Looking at the local winds and an approaching trough will bring early SE winds Saturday, shifting S/SW and strengthening through the day with fresh S/SE-S winds due on Sunday, strengthening later.

Monday looks the pick with E'ly offshore winds (SE Perth and Mandurah), swinging S/SE into the afternoon.

Longer term we've got a large S/SW groundswell on the cards for the middle of the week, generated by a strong polar low firing up south-west of us on Sunday. While significant in size and strength it's a little late to generate any extra-large size but we should still see a severe-gale SW fetch generating a long-period groundswell for later Wednesday and Thursday morning.

There'll be some mid-period energy from the SW ahead of the swell, generating by W/NW gales and building Tuesday, reaching 6ft across the South West and 1-2ft in Mandurah and Perth with the groundswell arriving later and coming in around 8ft on the sets, easing from 6-8ft Thursday. Perth and Mandurah will miss a bit of size because of the swell angle with 2ft sets.

Winds look to remain favourable with E/NE tending SW winds on Tuesday ahead of a weak trough, then back to the E/SE Wednesday morning. Thursday looks great with E offshore winds but we'll confirm the swell and winds again on Friday.