Background: Notes here on our Google Earth tracking of Jacob Adoram
The main challenge at the moment is getting south of LiHou Reef, or deciding very soon to turn and follow the wind over the top. Jacob is fighting hard at the moment to keep the track south of west. Recall his boat Emerson is big (28ft x 5 ft), and in strong wind (he has sustained 20 kts +, often a steady 25 kts, sometimes approaching 30, from the SE) it is very difficult to control the boat. He is in huge trade wind seas as well to deal with.
The situation is discussed in the video below. This morning there are signs he could turn south a bit so that is very good. The meteogram of forecasts is below, showing there is some slight improvements on Thursday and Friday, but Wed, tomorrow, still is a big challenge. The winds pick up to solid 25, which we also see in the ASCAT, and even veer a bit more to the SE. So the key now is getting past Wed.
We have a new KML file with chart segments loaded. Also found this very nice link to Sat images over AU. http://satview.bom.gov.au/
AU tides for this region are also online. There is a station at the top of the reef. Tide range is about 6.5 feet in this area. Tides affect not just the depth, but also the currents running between the cuts or passes in the reefs.
Progress now is judged not day by day, but hour by hour. The KML file is updated hourly.
Update 1640z tuesday last 4 hours very good course to the south.
Below is the GFS ensemble model, which outputs a standard deviation (SD). we expect 67% of all winds within 1 SD, but deviation could be higher or lower than mean. we see see SD about 1 for Tuesday meaning forecasts 18±1 kt, then 1.5 on wed and thurs is more uncertain with ± 2kts, then strangely Friday is back to ± 1.5. Generally the SD just gets bigger with time. Average pressures gradually falling with back to about 1015± 1 on Thursday Friday.
I think this is all pretty normal for a normally good forecast. When the forecast is bad, the SDs can get very large. For TC Ann sometimes the SDs equaled the wind speeds!
this plot is from present position on a heading of 266 T at 1.6 kts. Possible routes do not affect this too much, but as all is better to the south, the winds are also a bit lighter to the south as well.
This is from LuckGrib, which has a nice option to display the SDs.
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