How to Decode the Observations
Though the weather observations on our maps may look confusing at first, they provide a convenient and efficient way of displaying a wealth of weather information. These observations (also called "station models") show wind direction, wind speed, wind-driven sea height and period, swell direction, height and period, sky cover, and significant weather (i.e. rain, snow, fog, haze). Below is a sample station model, along with instructions on how to decode it. Please note that normal station models are not typically in color, the colors shown here are used for simplicity and to color-code each observation type.
9 - Wind-driven sea period in seconds. In this observation, the wind-driven sea height is 9 seconds.
5.6 - Wind-driven sea height in feet. In this observation, the wind-driven sea height is 5.6 feet.
270 - Swell direction in degrees. In this observation, the swell direction is 270 degrees, which means the swell is coming from the west.
9 - Swell period in seconds. In this observation, the swell period is 9 seconds.
14.5 - Swell height in feet. In this observation, the swell height is 14.5 feet.
- Wind direction and
speed. Each full line extending from the wind barb represents 10 knots of
wind, each half line represents 5 knots. The wind is blowing from the direction the
wind barb extends toward from the middle of the station model. In this case, there are three full lines and one half line, so the
wind is blowing from the Northwest at 35 knots.
- Observed Weather. The percentage of the circle
filled in by black is roughly equal to the percentage of the sky covered by clouds.
If significant weather (i.e. rain, snow, fog, etc.) is reported, it is indicated by a
symbol to the left of the circle. Click here for a
list of these symbols, and what each symbol represents. This observation
indicates about 50% cloud cover, with a light, steady rain falling.