Forecaster Blog Updated: Welcome Twin Tropical Cyclones Winston and Tatiana

9 Feb 2016 4 Share

Ben Macartney

Chief Surf Forecaster

FORECAST | Forecaster Blog

Updated Thursday, 11 February 2016

There hasn’t been much of a let-up in wave activity across the East Coast so far this summer. Whether it be distant tropical cyclones, localised coastal troughs or slow-moving Tasman lows, it seems that just as one swell passes by, another appears on the charts with impeccable timing. And what do you know, that’s exactly what we’re witnessing again this week, with twin tropical cyclone’s likely to form over the Coral Sea within the next 24 hours. The outlook surrounding an active phase in tropical storm activity now underway over the Coral Sea has changed considerably over the last 48 hours.  As discussed on Tuesday we have two tropical depressions active over distinct areas of the Coral Sea - The first is centred over the central Coral Sea, roughly 600 nautical miles east of Cairns, while the second (TD09F) is located much further east - roughly 460 nautical miles northwest of Fiji.

SEE ALSO: Weekend Surf Forecast 12 - 14 February 2016

The evolution of two tropical cyclones over the Coral Sea hold a whole lotta E swell potential for the Eastern Seaboard next week. Satellite Image: JTWC

The evolution of two tropical cyclones over the Coral Sea hold a whole lotta E swell potential for the Eastern Seaboard next week. Satellite Image: JTWC

Potential TC Tatiana: Not epic, but better than a kick in the pants

Assuming the first system does reach tropical cyclone thresholds, it will be named tropical cyclone Tatiana (TC Tatiana) by the BOM. Potential TC Tatiana is currently moving slowly southeast and there’s now high confidence on the storm’s development and track within the next 24 to 36 hours. This is characterised by gradual intensification and a continued south-easterly movement – potentially culminating in the naming of a low-strength (ie category 1 or 2), 990 hPa tropical cyclone sometime on Friday. Although the cyclone doesn’t exactly hold spectacular swell-potential for the East Coast, it’s projected to continue on a southward trajectory below New Caledonia and into southern Queensland’s swell window over the weekend – and these developments have immediate implications for surf potential across southern Queensland.

As the low deepens and moves south it will enhance a moderate ESE fetch currently in place inside southern Queensland’s short-range swell window; contributing to an upswing in short-period ESE swell across the region on Saturday. While this isn’t anticipated to push beyond 3 to 5ft across the region’s exposed stretches of coast, the close range of the fetch and relatively short interval of the resulting swell will produce consistent, peaky surf across the region all weekend.

From there, model divergence points to one of two possibilities. Going on latest GFS runs, potential TC Tatiana will stall below New Caledonia and steadily weaken under increasingly unfavourable conditions. In contrast, latest EC runs move the system SSW on Sunday and then W, towards Frazer Island on Monday – speculatively providing a second, stronger surge in short-period E swell for the region on Tuesday/ Wednesday.

FOLLOW THE EVOLUTION OF THE SWELL ON THE COASTALWATCH WAVE TRACKER

The latest MSLP Chart from the BOM depicts the deepening tropical depression off the QLD coast and the fringes of TC Winston in the upper right of the frame. Source: BOM.

The latest MSLP Chart from the BOM depicts the deepening tropical depression off the QLD coast and the fringes of TC Winston in the upper right of the frame. Source: BOM.

The still yet to form TC Tatiana is projected to track in a south-easterly direction, taking further into southern Queensland's swell window this weekend. There are also some indications the system will curve back towards the Queensland coast early next week. Source: JTWC.

The still yet to form TC Tatiana is projected to track in a south-easterly direction, taking further into southern Queensland's swell window this weekend. There are also some indications the system will curve back towards the Queensland coast early next week. Source: JTWC.

TC Winston: Hello South Pacific Swell Factory

While all this is going on within relatively close proximity of the Queensland coast, the second, more remote tropical depression near Fiji is also projected to get busy inside our long-range easterly swell window. Although the big computer models (ie GFS and the EC) continue to indicate the system will be the focus of convective activity, it’s projected behaviour and track have shifted dramatically.

TD09F is gradually intensified to low tropical cyclone strength (ie category 1 or 2) to become Tropical Cyclone Winston on Thursday. Although TC Winston is still expected to track slowly south on Friday and Saturday, it’s now forecast to be shunted eastward as it runs into a strong subtropical westerly flow – and these winds are likely weaken the system as it moves below Fiji and deeper into the South Pacific on Sunday and Monday. On one hand, the retreat of TC Winston away from the East Coast will invariably dilute E swell potential, by drawing the swell-producing winds increasingly further offshore. However, on the other hand, rather than tracking swiftly into NZ’s swell shadow as earlier model runs suggested, TC Winston is now far more likely to remain active in some form over our long-range swell window early to mid next week. Going on latest GFS and EC model runs, this will see a strong, 20 to 35kt easterly fetch setting up northeast of New Zealand on Monday and Tuesday before weakening again on Wednesday.

SEE ALSO: Anticipating The Violence In The Whitewash

Latest Wave Tracker model runs show the deepwater swell generated by both cyclones by Saturday, with TC Winston (right) clearly the strongest swell-source.

Latest Wave Tracker model runs show the deepwater swell generated by both cyclones by Saturday, with TC Winston (right) clearly the strongest swell-source.

TC Tatiana is forecast to move slowly south before being shunted westward. In conjunction with TC Tatiana, the system holds potential for a sustained run of mid-sized E groundswell effecting the East Coast over the course of next week. Source: JTWC.

TC Tatiana is forecast to move slowly south before being shunted westward. In conjunction with TC Tatiana, the system holds potential for a sustained run of mid-sized E groundswell effecting the East Coast over the course of next week. Source: JTWC.

So, while this doesn’t exhibit the hallmarks of an epic easterly swell event, it does point to another long-standing run of mid-range E swell, characterised by a series of overlapping pulses; the first filling in during Monday afternoon and showing peak size on Tuesday/ Wednesday, ahead of a second pulse starting to show on Thursday before peaking on Friday 18 and Saturday 19 February – generally producing surf ranging from 3 to 5ft for the entire East Coast. Given the lead time on these developments there’s still plenty of scope for further changes to the outlook surrounding both cyclones – and this would see further revisions to associated swell potential.

Ironically, regardless of how these twin-tropical cyclones evolve, long-range computer models now point to a much larger East Coast Low forming over the southern Tasman Sea over the course of next week – potentially big and intense enough to generate a large to heavy SSE swell for the entire East Coast mid to late next week.


Recent ECMWF model runs move TC Tatiana closer to Frazer Island early next week, while maintaining TC Winston as a slow moving system over the Southwest Pacific

Recent ECMWF model runs move TC Tatiana closer to Frazer Island early next week, while maintaining TC Winston as a slow moving system over the Southwest Pacific

Whatever E swell does materialise off the twin cyclones may be subsumed by a much larger SSE swell developing mid to late next week.

Whatever E swell does materialise off the twin cyclones may be subsumed by a much larger SSE swell developing mid to late next week.

Tags: forecast , cyclone , blog , ben , macartney (create Alert from these tags)

blog comments powered by Disqus
More From Forecaster Blog
Forecaster Blog: La Niña conditions are here, what does it mean for Surf?

Forecaster Blog: La Niña conditions are here, what does it mean for Surf?

La Nina conditions continue to develop. Will the surf pump?

3 24 Sep 2020
Forecaster Blog: Tasman Low Hammers the East Coast All Week

Forecaster Blog: Tasman Low Hammers the East Coast All Week

A deep low is dropping anchor over the central Tasman Sea..

14 Jul 2020
Forecaster Blog: Deep East Coast Low Wreaks Havoc Next Week

Forecaster Blog: Deep East Coast Low Wreaks Havoc Next Week

An impending East Coast Low looms large for the NSW coast next week.

9 Jul 2020
Recent

Watch: Episode 7 of Rivals – Bede Durbidge at Home in 4-5ft Straddie Barrels

The best surf tv show format keeps on rolling!

25 Sep 2020
Smashed In Vicco: A Couple Of The Lockdown State’s Finest Get Caught In The Mangler

Smashed In Vicco: A Couple Of The Lockdown State’s Finest Get Caught In The Mangler

1 22 Sep 2020
Master and Apprentice: Bethany Hamilton and Erin Brooks

Master and Apprentice: Bethany Hamilton and Erin Brooks

21 Sep 2020
Mick Fanning: Save This Shark

Mick Fanning: Save This Shark

23 16 Sep 2020
Watch: Episode 6 of Rivals – Shaun Cansdell at Home on the Coffs Coast

Watch: Episode 6 of Rivals – Shaun Cansdell at Home on the Coffs Coast

13 Sep 2020
Latest News

Smashed In Vicco: A Couple Of The Lockdown State’s Finest Get Caught In The Mangler

For a good chunk of this winter, it seemed like the Vicco crew had become the poor cousins of the surfing world...

Master and Apprentice: Bethany Hamilton and Erin Brooks

When Erin Brooks was nine and at the very beginning of her surfing journey, she met Bethany Hamilton.

Mick Fanning: Save This Shark

This is Mick Fanning’s take on that crazy incident at J-Bay in 2015 - the most watched moment in surfing history.

Popular This Week

Smashed In Vicco: A Couple Of The Lockdown State’s Finest Get Caught In The Mangler

For a good chunk of this winter, it seemed like the Vicco crew had become the poor cousins of the surfing world...

The Social Visa: Wondering How All These Surf Stars Are Cruising Around Indo? Here Ya Go

Remember when all this carnage started in March? And how briefly it looked like a whole Indo surf season would be going untravelled?

Padang Comes to Life as Late Season Swell hits Bali

Golden hour at perfect Padang Padang - it's been a good week to be in Bali... Photo: Childs

Go to Top