2014 Melbourne to Vanuatu Race - Weather Outlook Wednesday 2 July 2014

ORCV resident weather gurus Andrew Roberts and Robin Hewitt provide their observations on current weather outlook: 

 02Jul14 1-Bathymetry

The nice and fast off the wind sailing conditions are set to continue through the week with prevailing west-southwesterlies through Bass Strait and into the Tasman. Confused seas have been noted in the latest skeds and not unsurprising considering the windy conditions of the last week. Bathymetry and current effects are also likely contributors, with the nearby Bass Canyon a significant underwater sea feature. The Bass Canyon sees a steep drop off to the Tasman Abyssal Plain, with sea depths plunging from around 100m to 2500m with associated horizontal and vertical water movements often affecting surface currents and sea state. Jets and eddies of the East Australian Current (EAC) also often reach into Eastern Bass Strait further mixing things up. 

 

02Jul14 2-Directional Spectra for Eden

The Low that passed south of us on Sunday tilted and intensified between Tasmania and New Zealand and sent a southerly ground swell running up the Tasman, sweeping the east coast of Tasmania and NSW. The fleet should expect to see more of this swell the further east they go, interacting with the local southwesterly sea waves. It is currently showing up on the Manly Hydraulics Lab wave buoy off Eden – the spectral analysis below for Tuesday morning showed a SSE direction, Sig Wx 2.2m, Max Wx 4.1m.

 

02Jul14 3-4 Day Forecast 1Jul14

The weather pattern providing the prevailing west-southwesterlies can be seen in the 4 day maps. The development of the Low off WA, as mentioned in previous posts, has become clearer and looks the main feature to watch as it migrates east to Bass Strait and the Tasman Sea this weekend.

 02Jul14 5-MSLP 1000-500hPa Thickness

 

There seems to have been some fairly unpleasant weather and sea conditions for the fleet, undoubtebly mixing it up with the East Australian Current eddies and following winds. The outlook should present some fairly pleasant conditions in contrast and pleasant over the weekend. This is in comparison with our Victorian conditions which will again deteriorate over the weekend. The drivers off WA are still active with jets assisting to spin up lows which then march along to us here. Although a complex low develops off Gabo and NSW, it is expected to fill and any associated front to be fairly mild. Wind predictions are of the order 10-20kts and should allow the yachts to settle down and tidy up for the next few days. We can expect good progress along the route and some demeanour reports of a happier nature.

 

 

By Andrew Roberts and Robin Hewitt