There are many boating weather terms that you will need to know before you go out to sea , but the most important terms to recognize deal with weather warnings and watches. Be sure you know these terms and what they mean for you before you go out on a boat. You should also check the weather before you leave, especially if you live in an area where the weather can change rapidly.
- Gale Warning: A gale warning is a National Weather Service warning. It means that sustained winds at sea have speeds from 34 to 47 knots (39 to 54 mph).
- Hurricane Watch: Issued by the National Weather Service, this means that hurricane activity is likely in an area within the next 36 hours. Pay careful attention to these reports, as conditions on the water can be very treacherous outside the immediate area of the storm.
- Hurricane Warning: An announcement from the National Weather Service that sustained winds of 64 knots (74 mph) or higher, associated with a hurricane, are expected in the area in 24 hours or less. A hurricane warning sometimes remains in effect when the water is high or waves are larger than usual, even though the winds are not hurricane strength.
- Saffir-Simpson Scale: This scale categorizes a hurricane’s intensity on a scale of 1 to 5. Storm damage rises by a factor of approximately four for each category increase. Wind measurements represent sustained peak winds lasting for one minute at a height of 10 meters, or roughly 33 feet.
- Severe Thunderstorm Watch: A warning that is issued by the National Weather Service to outline an area where strong hail that is ¾-inch in diameter or larger and damaging thunderstorm winds are expected within a three- to eight-hour period.
- Severe Thunderstorm Warning: A National Weather Service warning that defines an area where damaging winds and strong hail are expected shortly. These warnings typically have an end time that will tell you when the storm is expected to leave the area.
- Small Craft Advisory (SCA): Also known as a Wind Advisory, this warning is issued by the National Weather Service according to locally defined thresholds for wind speed and wave height. As a general rule, an SCA indicates that winds are blowing between 22 and 33 knots (25 to 38 MPH).