Weather Watch:  Factors Affecting the Sea State

-David Schultz, NOAA/National Severe Storms Laboratory

Waves are distinguished either as <sea> (waves produced locally by the
wind) or <swell> (waves generated elsewhere).  The <sea state> is a
description of the spectrum of wave heights at any given time,
comprised both of sea and swell.  The sea state can be quite confused
and dangerous as waves traveling in multiple directions interact.
This can occur when the wind shifts direction abruptly, either near a
weather front or near topography.  Also, if the wind is blowing against
the current, the waves will be short and steep, whereas if the wind is
blowing with the current, the waves will be long and flat.  Traveling
with the wind and current in the same direction is preferred in such 
situations.