During the tropical storm season, mariners should monitor NOAA radio, the National Hurricane Center’s website and other public weather forecasts while being on the lookout for warning signs of approaching storms.
Abnormally large swells that are far apart, with a period of 10 to 15 seconds, may foretell the approach of a tropical storm or hurricane.
As a hurricane approaches, thin, wispy cirrus clouds appear and the barometer starts a long, slow fall. The cirrus clouds thicken into a veil of cirrostratus clouds, altostratus clouds form beneath them, and light rain begins.
Then, the barometer falls more rapidly, wind gusts increase, dark cumulonimbus clouds appear, and rainsqualls become more frequent.
When a storm approaches offshore, boaters need to do some quick analysis to determine whether they can make it to safe harbor.
If forced to remain offshore in a storm, the captain should try to get to the storm’s navigable semicircle, which in the northern latitudes is on the left side of the storm’s path facing the direction the storm is moving toward. The winds aren’t as strong because the storm’s forward motion is subtracted from the wind speed; however, the seas remain extremely dangerous.
To learn more about reading the weather, take the USPS Weather course or the Hurricanes and Boats seminar. Find a course near you at www.usps.org or by calling 888-367-8777.