The National Weather Service, an office of NOAA, issues weather advisories, watches and warning throughout the U.S. to warn citizens of impending foul weather so they can take appropriate measures. As mariners, several of these marine weather advisories, watches and warnings apply to boating activities. Before boating, obtain a marine weather forecast to know if one of these conditions is forecasted so you can make the best safe boating decision possible.
Small Craft Advisory
Small craft advisories are issued to alert mariners to sustained (more than two hours) weather or sea conditions, either present or forecast, that might be hazardous to small boats. The threshold conditions for the Small Craft Advisory are usually 18 knots of wind (less than 18 knots in some dangerous waters) or hazardous wave conditions, usually waves 4 feet or higher.Wind Advisory
A wind advisory is issued when sustained winds of 31 to 39 mph or gusts of 46 - 57 mph are expected for 3 hours or longer.Gale Warning
Gale warnings are issued when winds within 39 - 54 mph (34 - 47 knots) are expected within 24 hours, or frequent gusts between 35 knots and 49 knots are expected. Gale warnings may precede or accompany a hurricane watch.Storm Warnings (wind over water)
Storm warnings are issued when winds within the range of 55 - 73 mph (48 - 68 knots) are expected within 24 hours.Severe Thunderstorm Watch/Warning
A severe thunderstorm warning is issued when winds of 58 mph or higher and/or hail at least 3/4 of an inch in diameter are occurring or imminent in the warning area. At severe thunderstorm watch is issued if the conditions are possible in and near the watch area, but the watch doesn't necessarily mean they will occur.Tropical Storm Watch/Warning
A tropical storm warning is issued when the following conditions are imminent within 24 hours or are occurring: storm surge, coastal flooding, river flooding and winds of 39 mph to 73 mph. A tropical storm watch is issued when these conditions are possible within 36 hours, but it doesn't mean they will occur.Hurricane Watch/Warning
A hurricane warning indicates that hurricane winds of 74 mph (64 knots) and higher, or a combination of dangerously high water and rough seas, are expected to impact a specified coastal area. When a hurricane warning is announced, hurricane conditions are considered imminent and may begin immediately, or at least within the next 12 to 24 hours. When a warning is announced, it is of utmost importance that precautionary measures are taken for protection of life and property.the following conditions are occurring or imminent. A hurricane watch is announced when hurricane conditions are posssible within 36 hours.Inland Hurricane Watch/Warning
This watch is issued when hurricane force winds (74 mph or higher) are expected to move inland from the coast beyond areas that are covered by the hurricane warning. The watch does not mean that the hurricane force winds will occur.Dense Fog Advisory
A dense fog advisory is issued when widespread fog is expected to reduce visibility to 1/4 mile or less over a large area for an extended period of time (more than 3 hours).
