Hurricanes

Tropical revolving storms, or hurricanes, occur on the western side of the north Atlantic mainly during the late summer months, and are one of nature’s most destructive forces. The old sailor’s ode goes like this:-
June, too soon
July, stand by
August, come she must                                          
September, remember
October, it’s over.
Although a handy rhyme to remember it is not exactly accurate as the occurrence of hurricanes varies from year to year. Below is a chart showing the average number of hurricanes per month.

Although the hurricanes occur over the western side of the Atlantic and the Caribbean They are born on the eastern side of the Atlantic, usually between latitudes of 5˚ and 15˚. They are formed by the meeting of air circulations of the northern and southern hemisphere causing a cyclonic disturbance. If conditions are right namely, local surface heating of air of high humidity usually found in the vicinity of islands, the Earths geostrophic force, (unlikely below a lat of 5˚) can cause a cyclonic disturbance that will form into a Tropical Revolving Storm as it tracks its way westwards. As the storm heads for the western Atlantic it deepens as it is fed by warm moist air.
By the time it is reaching the Caribbean the diameter of the storm can be between 50 and 800 miles, and be moving at an average speed of between 10 and 15 knots. Wind speeds can be in excess of 130 knots, though in the eye of the storm winds are light and the sky is relatively clear, but even here seas are confused and mountainous.
Even before a TRS has reached its most dangerous intensity a storm of this magnitude would be disastrous for a yacht, in fact large commercial vessels will alter course if possible to avoid the danger area, yachts probably would not have the speed to do this. Therefore passage planning and knowledge are essential for a safe Atlantic crossing. It is always best to get local knowledge of "hurrican holes", harbours, bays etc that offer round shelter and room for when a hurricane hits.
Avoid the months mentioned aiming to complete a passage before early June and depart after mid November. For more information on Hurricanes visit Allmetsat

The following rules generally hold true

• Caribbean bound. Do not leave the Canaries or Cape Verdes before mid November.
• Remaining in Caribbean. Be south of Grenada by the beginning of June.
• Europe Bound direct. Depart Caribbean by mid-May. Earlier if course via Bermuda with stopover.
• North via Bahamas &US Intracoastal Waterway. Be North of Cape Hatteras early June.

The winds attain maximum force close to the point of lowest pressure. The diameter of the area affected by winds of destructive force may exceed 240 km (150 mi). Gale force winds prevail over a larger area, averaging 480 km (300 mi) in diameter. The strength of a hurricane is rated from 1 to 5. The mildest, Category 1, has winds of at least 120 km/hr (74 mph). The strongest (and rarest), Category 5, has winds that exceed 250 km/hr (155 mph). Within the eye of the storm, which averages 24 km (15 mi) in diameter, the winds stop and the clouds lift, but the seas remain very violent.

Weather Underground www.wunderground.com  provide a hurricane tracking service click Tropical & Hurricane under Severe Weather tab