- November 30th, 2008
- in Yachting
Winter is closing in and the still calm of summer is broken up rapidly by freshening weather. Whilst in the summer we worry about hurricanes in between sweltering heat, winter climes change every few days. Worried you should not be.
I recall a sailing trip to Sandy Spit one summer. Three yachts turned up and we had a barbeque on the beach, good island fun. Attracted to the fire, millions of seemingly dormant, hungry and in-bad-mood sand fleas popped up for a feast. They chased us back to the yachts, climbed aboard and munched relentlessly- sand fleas from a zombie movie! Two of the yachts had air conditioning. The third was gone by morning, the skipper later recalling to us his reason for early departure. Midnight revelling sand fleas had ravaged him all night and he motored back to Road Town with a swarm in tow, constantly waving his hands- Deliverance, Tortola-style. We could only laugh because his welts had gone.
Although temperatures do not change drastically, the difference between seasons is humidity, in the winter – going, going, gone! In general the BVI offers 84 degree water temperature with 84 degree daytime air temperature; 2 inch monthly rainfall (Jan-Apr), 3.3 inch monthly rainfall (May-July)and a 4.9 inch monthly rainfall (Aug-Dec). Lying just over 1000 miles from the equator, the British Virgin Islands has a sub-tropical climate, plied and cooled by variable trade winds. Temperatures rarely drop below 77 degrees in the winter or rise above 90 degrees in the summer, with the average temperature normalizing at around 84 degrees, with slight variations between seasons. Tropical weather found between the Tropic of Cancer and the Tropic of Capricorn is different from other patterns on the globe; therefore, our seasons do not have the sharp changes in climatic conditions as weather found in other areas, (known well to our visitors).
One of the best feelings at sea is to run your time not from a watch, but by daylight. There is a deviation of only two hours of daylight between the June, or summer half of the year, and December, the winter half. Sunrise from the autumn equinox through the spring equinox normally occurs at approximately 6:00 am, with sunset at approximately 5:50 pm. During the spring to autumn equinox, the daylight hours lengthen a bit bringing summer sunrises at approximately 5:00 am, with sunsets at around 7:00 pm. Rainfall in the BVI averages at 40 inches per year with 60% – 70% falling during the months of April through October.
The BVI has one or two high tides and low tides each day with a tidal range of 12 to 18 inches. The height of the tide partly depends on the atmospheric pressure. The higher the pressure – the lower the water level and conversely, the lower the pressure the higher the water level. It must be remembered that the British Virgin Islands are the dividing line between the Atlantic Ocean, on the northern side, and the Caribbean Sea on the southern.
This gives our islands an exciting and stable weather pattern that is most favourable for vacationing. You can bank on it! In the BVI, charter companies have the privilege of good weather; good winds, sunshine and close-proximity inter-island sailing. The trade winds in this part of the world push North Atlantic water westward, forming the North Equatorial Current. From the equator, 0 degrees to 30 degrees N, the winds are influenced by the spin of the earth and are bent from the north to the south. This is called the Coriolis Effect.
These winds affect the currents, which run through the BVI and other West Indies islands and then turn northwards. Warm waters from the Caribbean and the Gulf of Mexico join this water and these currents to form the Gulf Stream, which moves along the western side of the Atlantic. These two conditions, the Easterly Trades and the Coriolis Effect, produce the excellent wind conditions that make the BVI the sailing capital of the Western Hemisphere.
Winter Season. December through March. While North America and most of Europe take considerable temperature drops, the BVI attracts visitors with steady trade winds and plentiful sunshine. Located at latitude 18 degrees north and longitude 65 degrees west, our islands are subject to easterly trade winds named for the direction from which they begin. These winds are called trades, because originally they brought clipper ships filled with goods from Europe and Africa to the BVI and other areas of the Caribbean. In the winter our stable weather pattern is broken when depressions move across the southern United States and exit on the Eastern Florida coast into the Northern Atlantic.
These depressions do not normally enter the Caribbean directly, but have a trailing cold front that reaches as far east as the BVI and occasionally, well beyond. When strong high pressure centres are located in the North Atlantic, they cause what sailors and water sports enthusiasts refer to as the Christmas Winds and windy gusts can reach over 30 knots. Later, winter and spring winds will then ease back into trade winds with an ESE or SE direction and blow between 15 and 20 knots with seasonal gusts.
This long fetch of cold fronts creates ground swell causing waves to rise on the northern shores. The Atlantic topography with sandbars, reefs and rock points creates some of the best waves in the Caribbean, notably more crowded every year. Hardly a backpacker’s surfing paradise, the cost of travel and accommodation keeps the numbers somewhat restricted. There is however a significant following to Tortola for its waves.