Apr 30 — Good progress but challenges ahead

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

Index of Google Earth overlays.  Download the KLM file.

Jacob is trucking along making good almost 2 kts,  and doing a great job of making progress on the rhumb line with a strong wind on the beam.  This is very hard work.

He has been stopped periodically with stronger wind from squalls and we can indeed see these forecasted with the FV3 GFS simulated radar forecasts, illustrated in the video below.

With strong wind to the west and west northwest over the next few days, his challenge is to stay south and pass the Indispensable Reef to the south if at all possible.  Going north of the Reef risks getting close to the oil leaking tanker on Rennell Island. Any unlucky encounter with a patch of loose oil could ruin his water maker and the voyage.

On the horizon, meaning tomorrow or the next day, he might see a big lift from the current according to the RTOFS forecasts.  This will be interesting confirmation of the model if it pans out.  The enhanced current does not show up on OSCAR data.

Read about the oil leak in NYT. The wreck was in early Feb.

This is the RTOFS forecast for 1.5 + kt current ride starting tomorrow... if it is really there.


Here is a video demo of the above points and more...

Apr 20 — Progress slowly picking up as Tikopia hauls into view

Progress has been slow for a couple weeks, but now looking more promising.  Making steady progress to the south where needed winds should fill in by middle of next week.

Tikopia on the horizon. See related info and videos

We have updated the KML file with new currents and expanded the ASCAT coverage to reach to Cairns.  Download the latest KML to import to Google earth at this link.

JACOB-DATA.kml

Currents not favorable, but not too harmful, being about 0.5 or less to the S-SE.

We see fresh wind on the horizon at about 10º S, which is consistent with COGOW climatic data, which is also now in the KML overlays.

Check out Jacob's website for interesting news from him directly, often with a photo attached.

Here is a video look at the data along with meteograms showing that winds should pick up next week.

Apr 2 — Slow progress to the south

A reminder about the index to the overlays

Still no wind and no favorable currents, but Jacob is working his way to the south.

We updated the current models today, both are unfavorable, 0.5 to 0.7 to the East or SouthEast.  Wind still variable, under 10 kts.

We added climatic wind data to the Google Earth overlay that shows average winds every two weeks for the next 8 weeks, sample below.

To see these new data  you will need to update your KML file at this link

http://www.starpath.com/jacob/JACOB-DATA.kml

In the video below you will see that the average winds turn toward the west at the end of the month, so he might be glad he is father south by end of the month!

Note that for the past 10 days or so he has not got any closer to Cairns, but has made some valuable progress to the south.

We also discuss the value of the squall forecasting using simulated radar reflectivity available in the new FV3 GFS, which we access using LuckGrib.

Mar 26 — Couple steps forward; couple steps back

Here are the meteograms, not moving and moving at 1.5 kts on the rhumbline. Not much optimistic on the near horizon. It is a big boat that needs some help from wind and current, which are both working against him now.

Bottom image is if he can get south some by Friday he picks up a bit of northerly wind, else just stays light.

Here is a video report

I note here an average pressure drop of 1008 to 1004, which we can pull out of the oscillating daily pressure. I will check now how that compares with our reported statistical analysis of tropical pressures.  In this region and time the mean pressure is 1010—must have been a day or so ago that the drop started—and the standard deviation (SD) is 2.8 mb.  So this drop is 1.4 SD, but we have to note that this took place over 3 days and that is the difference.  Had this drop occurred in one day, that would have been a positive sign of a tropical storm.

In this case, this is the result of a weak low forming to the S-SE of Jacob, and is not a sign of anything more than that... and indeed there is no TS anywhere near him.  winds around that Low are less than 15 kts.... it is, however, a case that had there been more instability in the air it could have formed a TS. the winds are indeed going in a circle — clockwise around a Low in the Southern Hemisphere..

Mar 20 — Poor conditions but back making some progress

Last week had poor wind and current causing a big set  back, but Jacob is back going the right way.

Top shows the lost ground. Bottom shows position as of today and present winds from ASCAT.

Here is meteogram at an assumed 1.5 kts on the rhumb line.

Check out the KML file to see new currents footprint. We have expanded these to reach Cairns at this point.  He has weak west flowing current now, with hopes of a turn to the south with maybe 0.6 kts or so.

Not much on the horizon for a week or so.

Here is a video overview for today...

Mar 7 — Approaching Milestone 1,600 nmi to go.

As I write, Jacob is 35 nmi off of the 1600 mile yellow range ring.

As preferred, not much happening for the moment or next few days.

Updated both current models just now.  He is making good an excellent 60+ nmi/day = 2.5 kts, so i think the RTOFS must be right showing current with him.

Could be even the green (over 1.0 kts at the dark green line) shown above him is down on him. The OSCAR shows current against him.

Recall that severe squalls will call for reflectivity of over 30 to 40 dBZ, so  these are not on the horizon.

Waiting to hear back on last forecast that did have strong squalls slipping down from the NW.


Also as mentioned somewhere, i will come back to explain why it appears that the pressure stops its semidiurnal oscillation on tuesday. This is an artificial effect of getting pressure reports less frequently.

Mar 2 — No Stopping at Tamana

Jacob made what seems logical choice of not stopping at Tamana, but he did send this picture as he went by at about 5.3 nmi off.  Recall that all pictures taken at sea seem to diminish what you actually see. He could tell that the surf was indeed really rugged from this distance off.

He did see a fishing boat but no lights at night at all.

Here are conditions looking forward from Mar 2 with FV3 GFS model. This assumes a rhumb line (RL) route at 1.5 kts.

But for the moment he is really trucking, 60 nmi /day = 2.5 kts.  This would lead to these conditions, which go different some on Tuesday, but all light conditions.

Here is a video report. note that the two current models do not agree.