Understanding a marine forecast is critical to safe boating.
Typical marine forecasts predict wind speed and direction, wave heights and periods, roughness of near shore waters, and significant weather. Marine forecasts cover large areas and the forecast elements are often given in ranges. The significant weather may not occur over the entire area or during the entire forecast period. The ranges represent average conditions over a period of time (usually 12 hours) and the actual conditions may be lower or higher than the forecast range. Boaters should plan for conditions above and below the predicted ranges.
Take particular note of any current advisories and warnings, including Small Craft Advisories, Gale or Storm Warnings which alert mariners to either high winds or waves occurring now or forecast to occur up to 24 hours from now. Special Marine Warnings are issued for sudden increase in winds to over 35 knots (40 mph), waterspouts (tornadoes over water), and hail of 3/4 inches or greater and indicate a more immediate threat. Marine weather statements bring attention to significant rapidly changing conditions on the water including increase in winds, thunderstorms, development of dense fog and even snow squalls or strong and gusty rain showers.
For more detailed marine weather information, visit the National Weather Service page for coastal waters off Miami.