Home' Afloat : AFLOAT July 2018 Contents Take monthly with water July 2018 29
July, being the middle month of winter, is also the
coldest. However, across much of eastern NSW,
the weather is typically drier and sunnier than in
June – meaning one could easily be lulled into a
false sense of “winter’s nearly over”... it isn’t,
and not by a long shot. The sunnier weather
primarily results from a seasonal shift towards
westerly winds across SE Australia, which often
leave the coastal areas in a sunny ‘rain shadow’.
However, the westerlies can be very strong and
create some serious boating hazards.
‘Surf’s up’ –
on our local lake!
The westerlies of July and August are often
strong enough to generate surprisingly large
wind chop on normally sheltered waterways
places like Lake Macquarie, Port Stephens
and Lake Illawarra along the coast, and Lake
Jindabyne, Lake Eucumbene and Glenbawn
Lake further inland are just some of the many
waterways than can literally get surf breaking
on their shores if the westerlies blow hard – and
for small boats, these conditions are arguably
BOATING SAFELY RIGHT
worse than your normal ocean swell – being
short, steep and really nasty. These waves can
come up in minutes with the freshening wind
and will easily overwhelm a small craft caught
out in the open. To stay safe when boating
or kayaking on these waterways, you should
always wear your lifejacket and check the
weather both before you go and while you
are out – paying particular attention to any
warnings, changing weather and the wind
conditions. If the wind starts to pick up, move
straight to a safe spot - or get off the water.
If you wait until it has become ‘uncomfortable’
it may be too late. While increasing cloud can
accompany a freshening westerly, this is not
always the case, especially along the coast. So-
called ‘lenticular clouds’ are sometimes present
and often indicate strong winds aloft. These are
smooth but layered clouds that often just ‘hang’
in one position, either above or a bit downwind
of high ground. They don’t bring rain, but can
warn of strong winds before they ‘mix down’ to
Flat as ever along the
coast, but a deadly trap
It’s always tempting to venture further out in
pursuit of that prized catch... maybe a bluefin
tuna out wide or huge cod on the deep reefs.
However, if the westerlies are blowing it’s
much better to stay close and stay safe. Strong
westerlies often bring very flat seas along the
coast, particularly beneath the cliffs – and this
means very tempting conditions for small boats.
However, in such situations, the wind and waves
quickly increase with distance offshore – and it
can be very difficult for a small boat to turn back
if it ventures out too far. What makes this worse
is that strong westerlies along the coast typically
build gradually through the morning, peaking in
the middle of the day or early afternoon. Early in
the morning, when people often set out on their
fishing trip, the conditions might be quite benign
for a run offshore, but as the wind freshens a
couple of hours later, it can quickly turn deadly.
Even if your boat can bash its way back, it’s
going to be slow, very wet and uncomfortable
and use a lot of fuel. If anything goes wrong,
you’ll be in serious trouble. The best safeguard
against this situation is to check the weather
very carefully before going offshore – if there
is any hint of a strong westerly in the forecast,
or any ‘strong wind warning’ stay close to the
coast. Check your safety equipment – which
will be vital if you break down and start drifting
towards New Zealand: your radio, your EPIRB,
your anchor and your lifejackets? Don’t forget a
sea anchor too... it can help keep your bow into
the waves should you break down and it is too
deep or too windy to hold anchor.
The alpine lakes become extremely cold in winter, both above and below the water.
The big westerlies that hit SE Australia often
come through initially as a NW or W wind before
swinging colder SW in association with a cold
front. Ahead of the front, the seas along the
coast are often very flat. In the hours following
the front’s passing, the coastal ocean is often
still quite flat, but with a distinct bumpiness
visible on the horizon – indicating increasing
swells offshore, running almost parallel to the
This is a warning, but not the whole story...
most of these ‘westerly changes’ are associated
with a large low pressure system that passes
across the Great Australian Bight and Tasmania
enroute to the southern Tasman Sea. Once
one of these low pressure systems moves out
into the Tasman Sea, a powerful ‘kick back’
in the form of southerly ground swell is often
experienced along the NSW coast, even when
the local winds have started to ease. Typically,
this swell reaches the coast within about 24
hours of the cold front and makes coastal
bars and shallow reefs potentially dangerous.
Whenever a big westerly has gone through,
always be on the watch for big swells to follow,
especially if the wind has shifted to the SW.
Check the Bureau’s forecasts for ‘dangerous
surf’ warnings and perhaps look at their
interactive weather and wave maps, under their
“Marine and Ocean” web page.
In addition, you can check the RMS live bar
cameras to observe wave conditions in real
time. If in any doubt, don’t go out, or at least
seek a sheltered site.
That big swell kickback
Big winter swells hitting the oil wharf in Botany Bay.
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