Australia To Indonesia, Thailand, Sri Lanka, and Madagascar Route

[Alan Mighty]

One week later. wx20041030.

ITCZ artefacts at Eq near Singapore and at 15S. A scary vortex in the S China Sea.

Useable 10 knot winds in E winds in the Maritime Continent.

Likely conditions for line squalls in the S Strait of Malacca (that ITCZ artefact) and no reliable sailing wind there.

NE winds pouring over the Kra peninsula. So sailing in the Andaman Sea or approaching Phuket from the S would be neat. Little fetch, windward shore for safe anchorage at night (although you have to be aware of sea breeze at night)

[Alan Mighty]

One week later. wx20041106.

ITCZ is back right over the Eq for some reason that has to do with heat energy in the ocean-atmosphere coupling. That's a marker of how chaotic the planet is.

Expect squalls and rain (you can see the inverted triangles marking big mobs of rain, likely from squalls).

[Alan Mighty]

One week later. wx20041113.

NE winds starting to dominate the intermonsoon season.

A strong SE flow in the S Hemisphere is pushing E winds across the S part of the Maritime Continent. Calms (an ITCZ artefact type of thing at the N peninsula of Sulawesi (some great diving around there, would be good in that weather maybe).

[Alan Mighty]

One week later. wx20041120.

Chaos resumes. Obviously a year with a lot of heat energy in the ocean-atmosphere couple of the N Hemisphere.

This year, 2018, the wave of hot weather in N Asia (41.1C days in Japan leading to death by heat stress of a number of people), suggests that even more heat will be in the N Pac ocean-atmosphere couple.

A typhoon has formed over the S Philippines. A scary vortex in the S China Sea.

The "real" ITCZ is at 15S.

[Alan Mighty]

One week later. wx20041127. I've worn out my welcome. If you've not understood that July is the perfect month to enter Indonesia, nothing will convince you. Remember that each year is different. For that matter, each transit of the Maritime Continent is different. And each transit of the Strait of Malacca that I've made is different.

Back to the chart. Heat in the N Hemisphere ocean-atmosphere couple has created ITCZ-type artefacts running diagonally from 3S to 5N. Probably associated with cyclogenesis just E of the chart.

NE winds pushing across the Kra peninsula. This is the intermonsoon. A great time to be in an anchorage or marina in Thailand or Malaysia. Excellent First World credited hospitals. Boat yards that are okay. Great time to explore anywhere in Asia by low cost air carriers such as Air Asia.

But a chaotic time. That cyclogenesis that is off the chart to the E won't last. The streamline picture could change tomorrow.

The NE monsoon will establish itself, delivering reliable and dependable winds in the weeks to come. First a rainy phase. Then a dry phase.

[theway]

Originally Posted by Alan Mighty

One week later. wx20041120.



Chaos resumes. Obviously a year with a lot of heat energy in the ocean-atmosphere couple of the N Hemisphere.



This year, 2018, the wave of hot weather in N Asia (41.1C days in Japan leading to death by heat stress of a number of people), suggests that even more heat will be in the N Pac ocean-atmosphere couple.



A typhoon has formed over the S Philippines. A scary vortex in the S China Sea.



The "real" ITCZ is at 15S.

Alan again I appreciate all your info, but I’m kind of having a hard time understand your main concerns and suggestions. You’re pointing out a storm in the South China Sea in 2004, I’m guessing it went a bit west and north, Away from Indonesia.

And your prior posts about 6th and 7th moons and different calendars doesn’t give me any practical information.

If you could simply list your top three concerns, in a few lines or less, for October and November in Indonesia. I might be able to tap into the main points you’re trying to express. Then I can research more on each.


Thanks again.

[Alan Mighty]

Originally Posted by theway

If you could simply list your top three concerns, in a few lines or less, for October and November in Indonesia. I might be able to tap into the main points you’re trying to express. Then I can research more on each.

I know you're originally - like myself - a temperate waters sailor.

A temperate waters cruiser has a few rules, particularly based on looking at a weather chart showing isobars. Those rules include (at least for Australia):

* don't sail into a Low pressure area, even more don't get near an intense Low;

* don't sail into the subtropical ridge (STR aka horse latitudes) unless you want to eat the horse flesh;

* don't get in the squash zone between a High and a Low;

* stay in port, well secured, or in a good anchorage protected from wind and wave, when a front is about to pass;

* be wary when there's a big High (say 1029 or higher) on the polar side of the continent and any sort of Low almost anywhere else.

The rules for tropical cruising are different, even if only because atmospheric pressure matters little. And so isobars and a surface pressure chart are meaningless.

Ten of more degrees of Latitude away from the Eq, everyone has concerns (and rightly so) about tropical revolving storms (regardless of what bizarre local names people have invented to make their Local's Secret Business private to themselves.

In between 10S and 10N is the question. And the answers are (1) cruise there when the winds are reliable and dependable in strength and direction; and (2) atmospheric instability is low.

#1 means you don't worry about the wind direction in an anchorage. It's going to stay much the same all day (sure, near a big landmass, you'll get sea breeze effects sometimes) and all night. And during the daytime, you're likely to get the same reliable and dependable wind. To the point that in the monsoons (the SW monsoon and NE monsoon) the surface water (i.e. the current) will move in the same direction as the wind (of course, in the Maritime Continent you'll find the phenomenon called the Pacific Throughflow, where N Pac water flows through to the Indian O as part of the global ocean conveyor belt. Big whales used to (and some still do) use that as their roadway, so in the 19th C US whalers were found in the Maritime Continent. And some Indonesian still do small scale whaling using that same pathway).

#2 is about two things.

(a) When a monsoon is strong, it overrides local effects. Those local effects include what happens when a big moist landmass (e.g. Kalimantan) gets hot during the day. Kalimantan can generate some nasty t-storms and other events.

(b) the ITCZ. Let me restate first principles: at the Equinox (e.g. 21 or 22 September) the ITCZ by theory should be around the Equator. Oddly enough the ITCZ doesn't know the theory and does what it does because of heat in the ocean-atmosphere couple. A hot summer in the N Hemisphere means the ITCZ may sit to the N. But then it moves - unpredictably and not in a linear fashion. One day the ITCZ can be here. Another day there. And it does not need to move across the space between "here" and "there". Or so it seems.

So as a cruiser in temperate waters you stay in port when a front is coming. And you don't deliberately put yourself in a squash zone.

So in the tropics you stay in a good haven or harbour (a safe place) when the ITCZ is around. The locals in SE Asia know that the ITCZ (or the artefacts shown on surface streamline charts) can be as early as in the 7th moon of the year. Which happens to be Hungry Ghosts moon. And so when the ITCZ causes squalls and t-storms, the locals shrug their shoulders and say 'of course, only natural, the Gates of Hell are open.'

[Aside: The wise men who devised the Christian Gregorian calendar, choosing the weirdness that they did of starting the calendar year on the date of the Circumcision of their messiah, did an excellent job of keeping the calendar in sync with the solar year. But by doing so, they made months out of sync with moons. The Chinese lunar-solar calendar, the various Indian calendars, and the Muslim calendar all have moons, not months. The Chinese moons start on the New Moon. The Muslim and most of the Indian moons start on the day after the New Moon, the day following the first sighting of the crescent moon. Today, 30 of July by the Christian Gregorian calendar, is the 18th day of the 6th Moon by the Chinese calendar and the 17th day of Zul Kaedah by the Muslim calendar. One look at the Chinese calendar or the Islamic calendar and you know how many days since the Full Moon and how many days to the next New Moon. And you know the tide tides too, right? In my home port, the High Tide will be around 1000 and 2200 on the New Moon. And so it goes.]

In the surface streamline charts I've posted, I've tried to point out the ITCZ artefacts to you. They are the big artefacts. You don't want to be under one of them in the same way that you don't want to in a squash zone, facing a nasty front about to run you over, or sitting becalmed on the SubTropical Ridge eating the flesh of the horse you can no longer afford to water and feed.To repeat myself: those artefacts are not stationary things. They don't move linearly or in a predictable way like a front. They do their own thing, appearing and disappearing. And there are more small one that don't get charted.

Bottom line for the tl;dr crowd:

cross the Eq, transit the Maritime Continent, during the SW monsoon from S to N Hemisphere or the NE monsoon from the N to S Hemisphere.

If you are doing a fast delivery run, you can do it whenever you've good sailing wind in any season.

But if you want to enjoy the sailing and enjoy the anchorages (and the food, culture, people, experiences they bring) avoid the intermonsoons. The intermonsoons are the times to find a good haven such as an anchorage or well-protected marina in Malaysia for instance (I've mentioned Langkawi, Pangkor, Port Dickson; as Simi60 will tell you, Penang unfortunately has only one respectable anchorage and two marina berths that have to be booked in advanced for what is one of the most interesting places on the planet).

That's also when you use low cost air carriers such as Air Asia to go visit Nepal or Laos or go eat your breakfast with the red apes in the Singapore Zoo if you didn't go up river in S Kalimantan. Or do boat maintenance in one of the acceptable boat yards. Or do body maintenance in one of the First World accredited hospitals.

[Alan Mighty]

And in case the message is still unclear, here're are the perfect days on which to enter the Maritime Continent from Australia. Examples from 2004 and 2005. Our old mate, El Ping, will of course tell you that Alan just does what he does by Google (like to see his Google machine! It's better than mine).

[Alan Mighty]

Originally Posted by Alan Mighty

Winds over the Maritime Continent largely N.

Uploading and commenting on those wx graphics, I uttered a few errors.

In the line above, of course that should read "largely S".

When looking at the surface streamline charts of SE Asia, don't focus on the cyclogenesis outside the area - that's peripheral. Focus on what is happening to the wind between 10S and 10N, and look for signs of rain and the so-called ITCZ artefacts.

I've uttered other mistakes, of course.

I did not mention the Chola people or the Chola navy, which dominated the area around the year 1000. The Chola (and many but not all of the Indian ethnics in SE Asia) were/are not Indo-European peoples. In a few urban settlements in SE Asia, you find "Chulia Street" and similar markers of descendants of the Chola people and Chola kingdom. Most of the medicinal plants and so on found in SE Asia are relicts of that Chola presence, according to da experts (of which I am not one).

And of course I scarcely mentioned the Portuguese, Dutch, and Englanders, who so changed the people (massacres and disease, largely), culture, technology etc. So it was the Dutch who slaughtered the people on the Banda islands, but the Englanders who swapped one of the Banda islands for the island of Manhattan, which the Dutch possessed.

[Alan Mighty]

Any smart cruiser knows to use all possible resources for navigation.

So it goes with weather planning. You've no doubt kept up with Bob McDavitt's continuing masterwork: his blog "metbob". See yesterday's installment at:

https://metbob.wordpress.com/2018/07...-29-july-2018/

Have a gander, take a Captain Cook, at the two TRMM graphics that Bob gets from trmm.gsfc.nasa.gov. Everytime I've tried to follow the link, I discover that I need to have preregistered with someone to get access. But that's a secondary issue.

Let's look at the two most recent trmm graphics, one from 20180722, the more recent from 20180729. In what direction is the band of rain moving? Calculate the velocity of its movement (in degrees of Latitude/week).When will it cover your intended cruising area?

Focus on those areas of heavy rain. And ask yourself:
* do you want to be in that band of unstable atmosphere? (only part of which is moving over Sumatera as shown on trmm10180729)

* do you want to even near it in the tropics, when you sometimes find yourself in a tropical whiteout, a haze of humidity, condensation nuclei, and whatever that can reduce visibility to not very much?

* what will the trmm graphic look like in the 7th moon (in 12 days from today) or during the 8th moon?

* would you rather have entered Indonesia in mid-July and spent weeks enjoying reliable and dependable winds?

[Alan Mighty]

Originally Posted by StuM

Nasty! 6.4 actually on the island and only a few km deep. Could be a lot of destruction.

Apparently several hundred tourists who were trekking up the mountain are still stuck on the mountain side. 16 bodies found so far.

https://www.channelnewsasia.com/news...quake-10573474

[MikeFergie]

Austin I live in Mozambique and sail quite a lot in this region (9000 Nm in 2 1/2 years). Seychelles, Mayotte, Madagascar, Tanzania including Zanzibar, Mozambique and then South Africa you could probably spend at least a year sailing NOT only 3 months. There are truly amazing islands and waters and the joy for me is in a lot of the places you will be the only ones around with no other boats.
There is a cyclone season that covers Mauritius,Reunion,Comoros,Madagascar, and a section of Mozambique from early Jan til April but it’s safe above the zone or below it.

[Alan Mighty]

Originally Posted by Alan Mighty

Apparently several hundred tourists who were trekking up the mountain are still stuck on the mountain side. 16 bodies found so far.

Thailand media reporting 500 trekkers stranded on the mountain-side of Rinjai. 200 of them are Thai. Helicopters reported bringing in food and tents, and taking out some tourists.

See for example: https://www.bangkokpost.com/news/gen...ed-after-quake

Back to the implications for cruisers of the activity in the Ring of Fire ... I think the collegiality of cruisers lacks agreement, partly because the issue has been little discussed or debated.

Let me start by saying:

* we were cruising SE Asia in 2004, during which year we experienced the 26 December 2004 tsunami. We were ashore (Penang island, Malaysia) at the time of the quake and felt the shock. We were taking a visiting relative around the island as one does. We arrived back at our marina berth as the waves refracted around Penang island (about 68 residents of Penang state died, most on the mainland part of Penang but a few on the island). Our marina had no sea wall, so no problem for us. Being on the lee side of Penang was obviously an advantage, because the waves had to refract multiple times (around Aceh, around Penang island) to reach that marina. But when you don't know where a quake forming a tsunami will be focused, you can do nothing much.

* we of course knew and were in contact with other cruisers in the area. One good friend, on a sister ship, was in a fully enclosed marina on Langkawi. His boat took significant hull damage when the basin of that marina turned into an imitation of an agitated washing machine bowl, destroying the pontoons and bashing his boat repeatedly against a piling. Of the three marinas on Langkawi, only the marina that was not well enclosed - only a wave reduction wall - saw no damage to boats.

* the tsunami wave, as well as propagating by multiple refraction around capes and islands, also penetrated successfully up lazy rivers. One cruiser couple on a small cat were anchored in a mangrove-lined river and were surprised when suddenly the boat swung 180 degrees and 180 degrees again.

* of cruiser friend sitting at anchor, my informal survey result was that those anchored in 8 metres or more of water had no problem but some anchored in shoal water had serious problems. I used to quite like anchoring in 4 - 5 m of water. I have since adopted the practice of favouring 8 m.

* sat phones were useful. That's how one cruiser couple we knew first learned about the tsunami: a phone call from the UK that arrived before the wave front reached that cruiser. For that matter, in at least one SE Asian economy the tv news crew needed the written approval of the Minister for Information, so the news of the tsunami was reported almost 24 hours later. Of course that's before the penetration of the internet and smartphones.

* email, VHF, and HF were valuable for cruisers to keep in contact with each other. That was before the explosion of smartphones and smartphone apps.

* cruisers organised support efforts for some specific areas damaged by the tsunami, including Aceh province and the W coast of Phuket. That included transporting food and equipment (clothes, tarpaulins, etc) internationally to locals affected by the tsunami. Not all the national governments in SE Asia have the capacity to deliver such aid (see for example the mess in Laos after a dam wall broke - according to the media, the dam engineers knew the day before the incident that something was wrong!).

Bottom line for the tl;dr crowd:

* the best enclosed marinas are not always the best option in all conditions;

* anchoring out in deeper water - 8 m or more - can have advantages;

* keeping in contact with other cruisers can be valuable - you may be more likely to get help from a cruiser than a govt struggling to look after its own people.

[Wotname]

OK Alan, I understood some (most?) of your last dozen posts but can you please translate "tl;dr crowd" for me.

It eludes me ATM. If you can phrase in a way that a 6 year old can understand, I might get it

[Alan Mighty]

Originally Posted by Wotname

OK Alan, I understood some (most?) of your last dozen posts but can you please translate "tl;dr crowd" for me.

tl;dr = too long; didn't read.

Sort of thing that the grandkiddies taught me. Young fella stuff. Not the sort thing us old blokes write.

Late edit: it dates from 2003 according to wikipedia:

https://en.wikipedia.org/wiki/TL;DR