Wind forms because of pressure or temperature (which affects pressure) differences in the atmosphere. In the big picture, air moves from areas of high pressure to areas of low pressure. There are a couple different ways to visualize this. First, you can think of an area of high pressure as an inflated balloon that hasn't been tied off. As the elastic sides of the balloon try to contract back to its normal shape, the air inside is put under pressure and sqeezed out into the lower pressure of the room, creating a wind of sorts that, because of the basic laws of physics (you know, Newton's three laws, specifically the one that states "For every action there is an opposite and equal reaction"), blows the balloon all across the room. You can also look at it from a pressure gradient viewpoint on a map, with contour lines of equal pressure arranged like a topographic map. The closer the lines, the greater the slope (rate of change) in pressure/depth. A ball will fall faster down a steeper slope, and the wind will blow harder across a bigger, quicker change in pressure. It's not a perfect parallel because acceleration due to gravity affects the ball example and not necessarily the wind example, but it's close enough for our purposes.

Temperature also affects the wind by changing the local pressure of a given area. Hot air rises and cool air sinks, which we all know, but this phenomenon has a profound effect on local pressures. When really warm air, like in the desert, rises, it creates an area of low pressure, which in this case is called a "thermal low." The interaction of this low with other high and low pressure areas changes wind speed and velocity, as explained in the previous paragraph. Temperature changes also are responsible for the "sea breeze/land breeze" effect. Because of the different thermodynamic properties of water and solid earth, the water tends to stay at a more or less constant temperature, while the land heats up and cools relatively quickly. In the morning, when the land is still cold and the ocean relatively warmer, the temperature difference of the air over the two areas sets up a pressure gradient, and the wind blows in a convection pattern from the cooler, sinking air towards the ocean, to replace the relatively warmer air that is rising. Once the sun has been up for long enough, the land warms up to a temperature higher than the ocean, so the convection current reverses, and now the wind blows from cooler water over the ocean to replace the rising warmer air over the land. This can produce locally gusty areas, but in general isn't as important to the sea state as winds from afar associated with storm systems.

Now, how does the wind affect the ocean? We all know that wind creates waves, because of the friction of the particles moving past each other. Three factors are important for determining the heights of waves created by the wind: wind speed, wind duration, and fetch, or the horizontal distance over which the wind blows. We may not see a drop of rain from a storm in the Northern Pacific, but if the wind is blowing in the right direction, for a long enough time, over a long enough distance, we'll still see a fairly large swell generated from the storm. Or, there could be a hurricane well to the south, generating lots of wind and really stirring things up off Baja. We might not get any rain or wind from the storm, but we all saw the long period swell from the south and big surf we had last summer. This long period, "deep water" swell is what is picked up by the Southern California Swell Model map, which is formed using data about swell height, period, speed, and direction at the Harvest Buoy off Pt. Conception. Since the map is created using data from Pt. Conception, the map is sometimes ahead of the actual conditions by a few hours in a swell from the northwest, and behind by a few hours during a south swell.

Local winds also create significant waves, and are responsible for the "chop" or "slop" we see on the water. Usually the swell model map does not pick up these short period waves. The Beaufort Scale describes the sea conditions for a given velocity of wind, travelling over a significant fetch for a significant amout of time. Some of the important marks for us on the scale are:

Wind under 1 kt: seas glassy, not even appearance of "scales"
Wind 4-6 kts: small wavelets, crests of glassy appearance
Wind 7-10 kts: crests begin to break, scattered whitecaps
Wind 11-16 kts: whitecaps more common, waves become longer (10 to 12 kts. is typically when we see our first whitecaps for local winds, remember, the Beaufort Scale describes winds over a fairly long distance)
Wind 17-21 kts: many whitecaps, some spray, waves taking longer form.
Wind 22-27 kts: larger waves forming, whitecaps everywhere, more spray
Wind 28-33 kts: white foam from breaking waves begins to become blow in streaks along direction of wind
Wind 34-40 kts: foam is blown in well-defined streaks, edges of crests begin to break into spindrift, lots of spray

Some general rules of thumb for the text forecasts:
Local winds start with 10 knots equals 1-2 ft. wind chop, 15 knots equals 3 ft. wind chop, 20 knots equals 4 ft. wind chop, etc. Don't forget to add the wind waves to the swell to get the combined seas! They sometimes do this for you.
The wave heights described are an average of the highest 1/3 of the waves measured. That means you will get some bigger and some smaller waves when you're actually out there, and statistically speaking, the biggest wave you might encounter could be almost double the forecast wave height!

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