SWELL ALERT: Western, Southern Australian Coasts, New Zealand All Set To Pump!

28 Mar 2017 0

Ben Macartney

Chief Surf Forecaster

COASTALWATCH PLUS EXCLUSIVE | SWELL ALERT

Issued Tuesday, 28 March 2017 By Ben Macartney

The Southern Ocean is in chaos. As you read this, a vast low pressure complex situated below the Australian mainland is supporting a WSW fetch of 30 to 50 knots. This area of wind spans about 2,500 nautical miles of open ocean; encompassing an area that extends well beyond the length of the country itself. The incredible length and strength of this fetch has major surf implications for most of Australia’s surfable coastline.

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Western and southern Australian coastlines are about to be rocked by consecutive days of heavy Southern Ocean groundswell. PHOTO by www.surfingmargaretriver.com

States receiving maximum exposure to the resulting groundswell include Western Australia, South Australia, Victoria and Tasmania - and all of these regions will feel the full brunt of a XXL swell-event over the course of this week.

This recent MSLP Chart of the Southern Ocean depicts the continent-like size of the storm-system currently churning its way below the Australian mainland. Source: BOM

Winds within the storm depicted above drive deepwater seas and swell to peaks of 40ft plus below the continent later today

The West Coast lights up on Wednesday and Thursday

Wednesday 29 March marks the arrival of a first, heavy pulse of swell impacting all of the states listed above. For Western Australia, it manifests as a powerful, 20ft deepwater SSW groundswell inbound from an acute angle of 200 degrees. While this will produce huge surf in the 10 to 12ft plus range at Margaret River and the offshore Bombies, its arrival just happens to coincide with the opening day of the Drug Aware Margaret River Pro. Both the size and period of the groundswell along with local winds are well suited to North Point, so this is likely to be an historic day of competition well worth tuning in for. Otherwise, if you have the flexibility and mobility to chase the swell, the Northwest reefs will be lighting up on Thursday, closely followed by Indonesia this weekend.

A powerful spike in SSW groundswell peaks across the Southwest Coast on Wednesday, generating huge, clean surf across the Margaret River region all day.”

This Wave Tracker image depicts peak wave period; showing the leading edge of the SSW groundswell bearing down on the Southwest Coast during the early hours of Wednesday morning

Southern States receive large to heavy surf all week

In contrast to the West Coast, South Australia, Victoria and Tasmania all receive a similarly large swell-event on Wednesday; albeit from a very different, WSW direction. This originates from the expansive, gale force WSW fetch currently in effect below the mainland; predominantly bounded by 40S and 50S. For the vast majority of exposed beaches facing into the swell, it’s arrival will mean heavy, unruly storm-surf offering little more than a spectacle to observe from the safety of a lookout.

This Wave Tracker image depicts peak wave period, showing Wednesday’s first pulse overlapping with the leading edge of Thursday’s second, heavier SW groundswell

Victoria’s Surf Coast pumps on Wednesday and Thursday

For semi-sheltered stretches like Victoria’s Surf Coast, the combination of heavy WSW swell and westerly winds means excellent surf on Wednesday and Thursday. For Victoria, this episode is comprised of two distinct, overlapping pulses; the first arriving from a more WSW direction on Wednesday, preceding the onset of a stronger SW groundswell on Thursday.

This first pulse holds potential for large surf peaking in the 8 to 10ft range across the exposed beaches, but the stronger westerly bias in swell direction will wash off a fair bit of energy prior to reaching the Surf Coast; probably limiting peak size to 4 to 6ft plus.

Latest virtual buoy readings for Torquay show Wednesday and Thursday’s overlapping groundswells, followed by yet another large round of SW groundswell this weekend

Thursday’s second pulse is stronger; both with respect to wave-height and period. This episode is generated by a stronger area of SW gale to storm-force winds currently in effect over the far south-eastern Indian Ocean (The same source responsible for Wednesday’s swell along the West Coast). Recent satellite passes confirmed wind-speeds of 40 to 50 knots over the region – and the will continue to support these speeds as it pulls the fetch further into Victoria’s swell window over the next 24 hours. The upshot is potential for heavier 10 to 12ft storm-swell across exposed Victorian coasts on Thursday, with scope for clean 6 to 8ft plus sets across the Surf Coast.

Local conditions are looking good as the first WSW pulse arrives across the Surf Coast on Wednesday, with light to moderate WNW winds making for a full day of great waves across the Surf Coast. Thursday’s heavier push in SW groundswell coincides with early offshore W winds, making for clean conditions before a SW change sees quality deteriorating during the day.

If all this isn’t doesn’t leave you surfed out, then just wait until the weekend. Yet another massive, long-period SW groundswell is showing on latest model runs for all southern Australian coasts; speculatively peaking across Victoria on Saturday. For now this also holds potential for heavy 8 to 12ft surf across exposed breaks and scope for clean 6 to 8ft plus conditions across the Torquay reefs. Stay tuned for updates on this as the week progresses.