It is time to do some serious sailing again. We
need to leave New Zealand as early as possible if we are to reach Darwin in time
for the Indonesian rally that leaves there at the end of July. We intend to sail
to Fiji and Vanuatu before crossing to Cairns in Queensland.
The hard part is to find a weather window that
will allow us good weather all the way to Fiji. Here in New Zealand the weather
has become autumnal. As I write the rain is teeming down and we have had some
strong winds during the day. The air temperature is OK still but swimming is
becoming a bit painful.
The idea is to leave here just after a low
pressure system has transited North Island before another one winds its way in
from the Tasman Sea. This should give pleasant sailing conditions in south
westerly winds that become increasingly light as New Zealand is left behind.
Once far enough north one should pick up south easterly trade winds to blow
onward to the Tropics and Fiji.
However, there are a number of factors that can
stymie this benign plan. The most significant of these is that La Ninâ is still having an effect and consequently the
sea temperature off Australia in the Coral Sea remains 2.5º above the norm. The
significance of this for us is that the sea is therefore warmer than normal in
just the place where cyclones breed. Although cyclones are rare at this time of
year they are not unknown and they have even occurred in June.
Another problem is that the ITCZ or Inter-Tropical
Convergence Zone is unusually far south for the time of year and we would have
to cross it to reach Fiji. This is an area of unsettled weather where similar
air masses are colliding and causing convection and unpleasant conditions
including thunderstorms. Although not as potentially unpleasant as a cyclone it
is not recommended that we sail deliberately through an active ITCZ if at all
possible.
Finally there is the chance of a “bomb”. This is a
rapidly forming low pressure cell that has spun off from further north but
become “squashed “ against an anticyclone. This can happen to the north of New
Zealand and produce an area of enhanced winds known as a “squash zone”. These
occur when there is pleasant weather in New Zealand (the effect of the
anticyclone) and predicting them is apparently difficult as they form very
quickly. If you look up on the web “Queens Birthday storm” you will find some
interesting accounts of one such bomb that hit cruising boats leaving New
Zealand one year. The Fastnet disaster was created by an equivalent bomb in the
northern hemisphere producing exceptional conditions in a very short time frame
that was difficult to predict.
Anyway the upshot of all this is that the decision
to leave is a difficult but crucial one. There is basically nowhere on the way
to seek shelter if the worst happens so we would just have to tough it out.
Of course, we need to make sure the boat is ready
to go i.e. that we are watered, fuelled and provisioned and that we have all our
clearances completed. We notified the New Zealand Customs today that we hope to
leave shortly but we still need to complete the rest of their clearing out
paperwork before we are free to wander the high seas again.
Wish us luck!
PS We left on Tueasday and so far the weather has
been perfect and the forecast remains good for the rest of the passage.
