South Sea China Pressure Charts
TO PREDICT A SWELL FROM WEATHER CHARTS
a storm and verify it will be in your swell window.
Regularly review atmospheric models that depict both surface
pressure and winds (like the AVN or MRF). Look for periods
when winds are forecast to blow in excess of 25 kts towards
your beach for longer than 24 hours. Then verify that the
are forecast to be positioned within your swell window .
The best situation is to have high winds, covering a large
area, blowing at you for a long time. But only experience
determine what the requirements are for your beach.
window' is the part of your ocean that provides a swell
unobstructed, straight-line access to your beach (even 1000
or more away). Get a globe. Locate your beach. Identify islands,
shoals, land, or anything that could obstruct a swell from
straight into your beach. Using a string and a pin, tie the
string to the
pin, and stick the pin into the globe on your beach. Using
as a guide, pull it tight and out into the ocean away from
Move the string in different directions along the surface
of the globe.
Wherever the string first touches the edge of land (or anything
would obstruct a swell), trace the line of the string onto
using a pen. If you have access to "Great Circle"
charts, use them
instead. All beaches will have at least 2 boundaries to their
window, and if islands are present, perhaps many more.