My mention of the Sound Breeze the other day has had some of you asking for more information about it. So I'm going to try my best...
If you've ever started out, paddling on a calm, warm summer day, only to find yourself in the midst of windwaves and whitecaps, it was likely the Sound Breeze. Though late fall, winter, and spring weather patterns typically bring us wind and storms from the south and west, summer delivers winds from a different direction entirely.
During the summer, the weather is
dominated by moderate temperatures and relatively benign patterns. One distinction
that surprises many is the occurrence of the Sound Breeze, which are relatively
strong northerly winds that arise on warm summer days. The basics of the Sound Breeze are
that the sun heats both the water of the Sound and the land of the Northwest.
The water is able to absorb more of the sun’s heat energy and warms relatively
slowly. The land, however, warms much more quickly and radiates that heat,
warming the air above it. This causes the air to expand, creating a low
pressure system as it rises. The higher pressure air over the water then moves
in the direction of the low pressure area. We experience this as wind. The
greater the pressure gradient, the stronger the wind velocity. Rapid warming
can create stronger pressure differences. Often, Sound Breezes occur in mid- to
late-afternoons and are calmed by late evening. Wind direction is often
dependent on localized areas and the terrain nearby. In Budd Inlet in the Sound Sound, wind typically blows in from the NNW.
The graphic below depicts the typical afternoon rise in temperature, drop in barometric pressure, and rise in wind speed...
Swantown Marina Weather Station |
As the weather gets warmer (and eventually it will) we'll see more and more of the Sound Breeze. Perfect for upwind training, great for downwind fun, they often settle down just in time for beautiful sunset paddles.