Bob McDavitt's ideas for sailing weather around the South pacific

05 June 2016

Bob Gram 5 June 2016. Lau Aid and a Big Fat High.

Issued 05 June
Bob McDavitt's ideas for sailing around the South Pacific.
Disclaimer: Weather is a mix of pattern and chaos; these ideas are from the
patterned world.

Here's a detailed report from the 4M's, crew of AMELIE IV, a Sea Mercy Aid
vessel that arrived a week ago in Fiji:
Well it's been a bit over a week in the Lau Group and looking back it seems like
longer! We've assisted or completed 'Needs Assessments' for 5 villages on 3
different islands, and visited 3 additional villages that other Sea Mercy boats
had previously completed assessments on. The level of impact was surprisingly
varied across a relatively small distance (40 nm) and with that the
corresponding needs were quite diverse. We've now met up with the other 8 boats
in the Sea Mercy DR2A fleet to spend some time comparing notes between teams to
prioritize our efforts and our requests for supply materials. As re-establishing
reliable water sources is either urgent or will be urgent in a lot of the
villages, as the dry season progresses, that's where a lot of our efforts will
be first focused, but there's clearly a lot more needed here. It was humbling to
realize that the estimated $ Sea Mercy has already raised for this area really
only starts to cover what we've identified for re building catchment and lost
storage capabilities, let alone the myriad of other health, food, education and
sanitation needs identified. The good news is that the reports we've made are
also being used by other aid organizations that have focuses on these areas so
part of our role is to be eyes and ears for them as we've got 'boots on the
ground' here and they don't currently.

In the meantime though, there will be lots to keep us busy. A mega-yacht was
here earlier this week on the other side of the island to off load water to a
few villages that were critically short so a few of the yachts helped coordinate
and make the most of the time the mega-yacht was available. A few of us then
spent some time over the last few days helping a couple of the villages clear
away deadfall with chainsaws we brought from NZ, while others from the yachts
assisted with their community gardens and setting up composting facilities.

Next week there are strong winds forecast, so we'll stay based out of here and
focus on the Vanua Balavu villages. I'm going to the village of Mavana with some
fiberglass repair kits donated by Burnsco in NZ, to try to get two of the
village longboats back in the water, while another group will come to help
repair the community hall roof that they've already got materials for. Some
other groups will continue working with the villages on their gardens for both
food and cash crops as a new income stream to help offset what they've lost from

The week after, once the winds abate a bit, we'll likely be trying to get back
out to some of the other islands again for some small projects and possibly
water projects with a portable RO unit. It is apparent though that the all plans
are 'written in sand at low tide', and will need to be re-evaluated as needs
change, resources become available and more information becomes apparent. So,
we'll see what develops...........
And a reminder that ordinary yachts now visiting Fiji can help Sea Mercy or
Oxfam with aid missions. Some cruisers may not interested in carrying materials,
but may want to employ their own skills. Many do not realise that Sea Mercy
offers those types of opportunities. Some want to know how or where agencies are
prioritising their aid, so here is some info about Oxfam as well. If you are in
Fiji and have a few days at a loose-end, I recommend you email one of the links
below to add extra memories to your adventure:
In Fiji, Oxfam is supporting TC Winston affected people in Fiji with Water
sanitation and hygiene promotion work in most affected provinces:
Northern - Bua and Cakadrove
Western - Ra
Central - Naitisiri and Tailevu
In Vanuatu, Oxfam is supporting drought affected people, and continuing
reconstruction from TC Pam, mostly in Shefa province.
I am sure sailors with electrical/solar, plumbing, mechanical and construction
skills would be most welcome in these regions.
Sea Mercy is dealing with the distribution of educational, health and
construction materials in Fiji. They have warehouses where cruisers can pick up
materials to take to outer islands. Please contact:
People are welcome to email me if they have questions about engaging in
humanitarian relief efforts. Thank you! -- Dina Aloi, SV Good as Gold,
The Tropics
Tropical System Bonnie, the first of the year to threaten the United States, has
been lingering offshore all week and is still a remnant depression in the
A tropical depression is expected to form in the eastern North pacific this week
near 11S 120W, but should fade as it travels west.
The Indian Monsoon stalled last week and is now about a week behind normal. The
Consequential heatwave is purported to be the warmest in India for centuries.
but so far is not as deadly as last year (in 2015, over 2500 deaths were
attributed to the pre-monsoon heat wave).
The Heat wave (for eastern areas) may be seen at
The Advance of the monsoon may be seen at
Rain maps from
for the past fortnight show a weakening in the intensity and spread of the South
Pacific Convergence zone, and the extreme rainfall along Australia's east coast.

SPCZ=South Pacific Convergence zone.
SPCZ is expected to remain draped from PNG across to the Tuvalu/Tokelau area,
with a touch over northern Cooks. A passing trough is tonight over New Caledonia
and is expected to cross the Vanuatu area on Monday local, Fiji on Thursday
local and then weaken between Fiji and Tonga by Saturday. If this trough is in
the way of your plans think about avoiding it, as it is likely to contain
squalls. One yacht got hit at 18S 154W last night with 40 gusting 50 knot winds.

STR= Sub-tropical Ridge
The HIGH over NZ this weekend is a BIG FAT HIGH with central pressure near
1040hPa as seen in today's analysis.
An analysis comes from the real word (100% trustworthy), and all prognosis maps
are ideas from isobar land and as such not be 100% trusted.
When an HIGH becomes as intense as this, extra isobars have to be added to the
weather map. Isobars remain well-spaced near the centre of the HIGH , and so
these extra isobars cause all the isobars between 1012 and 1024 to squeeze
together forming what I call a SQUASH ZONE, As you can see form the above map
this intensifies the weather systems around the periphery of the HIGH. The
trough along the eastern seaboard of Australia tonight gets extra help in
deepening from the warm seas of the east Australian current, and you can see how
the gales are building huge waves and pushing them onto Tasmania.

Voyage Outlooks:
Panama to Galapagos:
Light to moderate southerly winds around Panama this week, so not a good week to
depart. Also the ITCZ seems to be active and squally at times between 8N and 5N,
so another week when it's better to stay put. There may be a change to northerly
winds near Panama after 19 June.

Travelling to Marquesas:
Winds near Isla Isabela are expected to be light southerly this week, possibly
reaching 10 knots on local Fri/Sat.
May as well get best from the current by going to 4S 100W then west to 5S 130W
and then direct.
And around Marquesas Islands expect moderate east to NE winds.

Tahiti to the west
A passing trough (with showers) is likely to bring Tahiti area NW winds until
local Monday, so wait until Tuesday.
BFH to the south travelling east along 33S from local wed to Friday may produce
a squash zone of enhanced SE winds along the route at 18S, but this can be
avoided by going to 17S.

Between NZ and the tropics
After the BFH there is an intense, but weakening, trough now expected to arrive
around Wednesday, but it may take until Friday before the seas settle over
Northland after that trough.

Between Australia and New Caledonia
The intense trough has already cleared the Queensland are, but seas may still be
rough on Monday.
Tuesday looks to be the best day this week, for after that there are more SE
winds to negotiate.
See my yotpak at for terms used.
See my website for information on tailor-made voyage forecasts
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