Snapshots of synoptic prognosis charts
can look insane, but these are guesses,
based on computer modelling, and just
like a butterfly flapping its wings can
cause a storm over the Amazon, the
sheer chaos and complexity of weather
systems means a lot can happen between
the prognosis chart and our reality. So,
you need to pay attention over a period
of time, preferably every day, or even
twice a day, to make sense of the trend.PROGNOSIS CHARTS – They come
from a variety of algorithms, but there
are two basic ones that power most
of the swell models you’ll see on the
forecasting sites. The first, and by far the
most widely used, is called the Global
Forecasting System (GFS). This US model
powers just about every swell model on
the planet... the little wave graphs you
read on Magic Seaweed, Coastalwatch,
Seabreeze, Swellnet, etc., all come
from GFS. You can check out the GFS
prognosis charts free, and it should be
a first port of call for anyone looking to
forecast surf.It’s not the only model, though,
and sometimes – like all models – it
completely loses the plot. Which is
where cross-checking against other
models is invaluable. The other primary
weather model in use today is the
European Centre for Medium RangeWeather Forecasts (ECMF). This is harder
to access – you usually need to pay for it- but the good news is that our very own
Bureau of Meteorology uses a model very
similar, called AccessG.
Here’s an example of how all this could
work. It’s February: cyclone season.
You hop onto weatherzone and cycle
through the weather models. GFS has a
monster cyclone storming down from
Vanuatu towards the east coast, and
the swell models are all red-lining. But
AccessG isn’t coming to the party and
has the system lolly-gagging behind
Vanuatu before dribbling back out
into the South Pacific and dissipating.
Before you go charging up to Double
Island Point or booking your favourite
Noosa accommodation chasing tropical
point perfection, spend a day or two
tracking these two weather models.
Does one start to get interested, or
do they both lose interest and dissipate
out to sea? If they both start to show
the same system move into our swell
window, load up the wagon and go! If
they are still in disagreement as the
prognosis gets closer to reality, it’s a
red light and you’re gonna get skunked;
even if the internet hype machine from
the surf sites is in full swing. Stay at
home and save your sanity.
These synoptic snapshots are just
that; it’s the pattern which matters.
Patterns matter in more than just
the day-to-day movement of weather
systems. Ocean-wide and broad-scale
atmospheric patterns create the
conditions that see certain systems and
storm tracks occur again and again
along the same corridors, with seasonal
implications for swell chasing.FIRST PRINCIPLE
THE TREND IS YOUR FRIEND.PHOTO:RESPONDEKwith – even if that did thin out crowds.
We’ll focus on old-school knowledge,
but access it with modern internet tools,
which it publishes – mostly, and bestly – for
free. No need to get sucker punched into
paying for expensive premium content on
a forecasting website if you can develop or
hone the skills on your own. Getting off the
internet spoon-fed forecasting cycle also
puts you in the driver’s seat when it comes
to ducking and weaving around crowds who
are all accessing the same information.
Bradley Norris got towed into this
wave behind Dane Gudauskas.
Understanding the shorter-scale
curving called refraction and the
larger global curved movement
along the Great Circle Paths is
the biggest breakthrough in surf
forecasting. It allows us to track
a storm thousands of miles away
off the southern island of New
Zealand and anticipate its arrival
on Tahiti’s doorstep a week later.
PHOTO: NORRIS