Weather Watch:  Factors Affecting the Size of Waves

-David Schultz, NOAA/National Severe Storms Laboratory

The size of waves depends primarily on the wind speed, duration, and
<fetch> (distance over water which the wind blows).  Generally, large
waves are associated with strong winds blowing over a long fetch for a
long time.  Other factors can also play a role.  Waves will tend to be
larger in wider bodies of water (i.e., the direction along the wave
crests).  A steeply sloping shoreline favors larger waves than a
gently sloping one.  Also, a sand or mud beach will tend to damp the
waves more than a rocky coastline.  Rain also will help to damp
the size of the waves.  Recognizing these factors, paddlers can act to
minimize the size of the waves they encounter.