May 29—Waiting out the forecasts.

Background: Notes here on our Google Earth tracking of Jacob Adoram

                                 Index of Google Earth overlays.  Download the KLM file.

We are updating frequently now, so best to download the KML file and update your Google Earth.

Jacob is poised and ready to finish this epic voyage, but on hold due to the longer term forecasts. His next leg is a 160 nmi run to the NW to the entrance of Flora Pass, which takes him though the Great Barrier Reef, and then on to Cairns,  about 40 nmi from there.

The problem now is that last turn into Flora Pass and the passage through the Reef. The strong SE winds are excellent for running up to the Pass, but not good at all for turning to south of west to transit the Reef area. His large boat cannot be controlled with strong winds on or near the beam.

Details of the passage through the reef can be seen in the Google Earth overlay.

He has been watching this forecast now for several days, and it has not been very encouraging. First the winds are strong at the turning time (up to 28 kts, often to 20+) and second, the models do not agree on the forecasts.   We have an article in another blog that compares these models along with other models that even provide probabilities of winds.

In any event, it looks like the strong wind forecast is not going away anytime soon. It could be well into next week.  Furthermore, Jacob knows by direct hard first hand experience that these trades can crank up to 15+ and stay that way for weeks.   So this is a time for patience.

Below are weather maps from BOM that show the source of these strong trades.

We see that the isobars where we care about are affected by the High over AU as well as fronts moving around to the SE of AU.

I am not sure if models used by BOM are independent of the ones we follow in the link above, but here is what they forecast for this period... we are using 12z on Fri as a benchmark. These are taken directly from our Google Earth overlay on Jacob's track. The data are from BOM.

 

Here are now the maps from Thursday May 30:

We see the main problem by looking at the 1016, 1020, and 1024 isobar as they approach Queensland from offshore.  They get closer together and that is what makes this strong wind near the coast. There is some indication here that this is weakening on June 3, but we have to wait and see.