Day 11: Converging on the convergence zone (the Doldrums)
We are fast approaching the Intertropical Convergence Zone (ITCZ) otherwise known as the famous Doldrums. Crossing this area of no wind and squalls to get to the equator and then the south east trades is actually the trickiest part of the passage I think. I want to minimize our time in dead calms waiting for squalls to rain down on us, although a mild one would be welcome to have a nice cool shower!
Anyway, I have been plotting the ITCZ coordinates daily since 15th March from the NWS forecasts to try see if I can spot any patterns to try and predict where it will be when we get close and what kind of convention we can expect.
This is an example of the info I get from the NWS forecast
INTERTROPICAL CONVERGENCE ZONE…AXIS 05N80W TO 06N90W TO
03N99W TO 05N140W. SCATTERED MODERATE ISOLATED STRONG WITHIN 30
NM OF AXIS FROM 90W TO 95W AND BETWEEN 111W AND 132W.
So, may have found a couple of patterns..
1) The convergence seems to stay in a latitude range for a period of time before moving.. i.e.
From 15th-26th March the ITCZ was bounded by latitudes 4N-6N
From 26th March – Apr 1 the ITCZ moved lower and was bounded by 1N-4N
In the last couple of days the ITCZ seems to jumping back up to 4N-5N, but need a couple of day more to determine if this is really the case. In any case, if the ITCZ is up at 5N, then the convective cells (squalls) are typically north a couple of degrees. ie, 7N. So we gybed today to stay above 7N until we get to 128/129N and then we will gybe back.
2) The convection seems to move east (80-90W) or west (123W-130W) on the ITCZ and stay there for a couple of days.
From 31st March to 2nd April it has been in our crossing area, 125W-130W. It now seems to be moving back to 94W. Hoping that when we decide to cross in a couple of days it will be back down at 80-90W
3) The occurrences of convection since Mar 15 seems to be greatest at 130W and 128W. Next is 129W, 127W and then 126-123W. We want to cross as close to 130W as we can, so we will be looking at crossing at 129W rather than 130W.
Is it that obvious that I have time on my hands? 🙂 This is like being in Las Vegas trying to figure out where the ball will land on the roulette wheel..
No fish today 🙁
All is well and enjoying the rock with the roll
[Post by HF radio email]