Hour — local time at the break, like every
time on this page.
Rating — how good the surf should be at
this hour, from 0 to 5 stars: the swell's size, its period and how well its
direction fits this break, reduced by the wind, the tide and a crossing second
swell. Half stars round down.
Verdict — the word for the star band:
poor under 2, fair 2 to 3, good 3 to 4, epic 4 and over. A break whose shoreline
has not been surveyed is unrated, never scored low.
Wave height — the significant height of
the sea at this hour, the typical larger waves in open water, not the face at
the beach.
Period — the seconds between the waves
carrying most of the energy. At the same height, a longer period carries more
power.
Swell direction — the compass
direction the swell comes from, which the rating compares with the directions
that reach this break.
Swell trains — the model splits the sea
into up to three swells; their heights, largest first. One figure means one
train, a reading and not a gap.
Tide — the predicted height of the water
about mean sea level, and whether it is rising or falling, from EOT20.
Wind — measured against this break's
own shoreline: offshore blows from the land and grooms the wave, onshore blows
in from the sea, cross sits between; glassy is almost no wind.
Gust — the strongest gust the atmospheric
model expects at this hour. A gust well above the steady wind means a surface
that keeps changing.
Sky and air — the sky at this hour and the
air two metres above the ground. The air is not the water temperature.
Rain — how hard it rains at this hour, in
millimetres per hour: a rate, not a chance of rain. Under 0.2 mm/h is not
printed.
Power — the wave power at this hour, in
kJ per metre of wave crest, from the height squared and the period: what
separates two hours of the same height.
Not forecast this far out — the sky, the
air, the rain and the gust come from the atmospheric model, which stops at ten
days. The sea, the wind, the tide and the rating carry on.