| Why is understanding meteorology important aboard a sailboat?
To some that probably sounds like a very stupid question. Duh! To avoid
a horrible storm.
Well, that is absolutely true. That is, unless you are one of those daredevils
that purposely seeks unfavorable sailing conditions in which to sail,
either by picking bad times or bad locations. That wouldn't be us. Nonetheless,
understanding weather is more critical to sailing than just avoiding a
storm. Do you know what is like to find yourself with too large a sail
in the middle of the night when the wind picks up? Have you ever spent
a day or two "parked" in the middle of a dead calm zone? Unless
you are familiar with sailing, you haven't had the "joy" of
either situation.
Adjusting and optimizing sails and course based on weather patterns is
what ocean sailing is all about.
Fundamentally, for any given wind direction, wind speed, and waves there
is a corresponding combination of course, sails and trimming (adjustment
to sails and yards) that is optimal and a range under which such a combination
will operate safely. Now, this is not an Americas
Cup sailboat so we don't have the complexity of a dozen sails with
us. But neither do we have a full crew of a dozen professional sailors.
Therefore, the task of staying one step ahead of the weather is just as
daunting to us.
How do we do it? Aboard O'Comillas, meteorology consists of the following:
- Live observations
- GRIB files
- Weather analysis, reports, and forecast images
1. Live observations:
Our own senses and experience, coupled with wind instruments and barometers,
are the best tools for observations on the sailboat. After all, who cares
what any given image or report says, if we are witnessing changes in wind
direction or speed, precipitation or changes in atmospheric pressure.
We
try to anticipate changes and understand the probable ranges among the
different variables. For this a barometer is a great tool. At a constant
elevation (seal level is pretty constant), there is a direct correlation
between pressure and weather. I say constant elevation because there
is also a link between pressure and altitude. Therefore, on the sailboat,
if pressure remains the same so will the weather, pressure increases weather
improves, pressure decreases weather deteriorates. The faster a change
in pressure the more dramatic the change in weather will be.
2. GRIB images:
GRIB or "GRaphics In Binary" is a standard format for
transmission of meteorological Forecast Models. We receive these files
daily over email and use them in conjunction with Raymarine RayTech Navigator
computer software.
The GRIB files contain a composite of information such as atmospheric
pressure, wind direction and speed, currents, etc. that are overlayed
directly on top of the RayTech Navigator map. The weather display is a
loop from current conditions to 3 and even 7 days forecast allowing us
to see pattern changes and what we will be encountering further down the
route.
A great function of Raytech Navigator usage of GRIB files is that it
shows the current position of the sailboat, and all information from the
instruments, while simultaneously showing us weather information. Therefore,
we can zoom into any given area and alter the existing route to avoid
any potential hazardous weather or take advantage of wind shifts.
3. Weather analysis, reports, and forecast
images:
We have prepared a comprehensive list of images that we can access with
the browser before departure and over email during our journey. There
are also fax reports available via radio. Here too much information could
be overwhelming and we could spend the entire journey looking at weather
stuff and not enjoying sailing. The balance is to only get a basic set
of reports on a regular basis and then, if we notice something developing
that could affect us, request more relevant images via email or fax.
So, we use our long list of images and reports as our in-depth library.
If we are curious about something, then we might get longer horizon projections
or additional information on the subject.
Note: for more details on the Raytech Navigator
software, instruments, email and connectivity to the internet in the middle
of the ocean or anything else related to O'Comillas please check out the
section about the "Sailboat".
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