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.