The Tribune

BEFORE a hurricane even happens, you can track the progress of a storm moving toward The Bahamas. Using longitude and latitude co-ordinates to pinpoint the storm's location when hurricane advisories are released by the Department of Meteorology. Longitudes are represented by the lines running up and down on the map. Latitudes are lines running across the map from side to side. Nassau, in the centre of the island chain, is located at 25 degrees North latitude and 77 degrees West longitude. The helpful Bahamas Meteorology Department website (http://www.bahamasweather.org.bs/) recommends using a map to track a storm. Once you have located it using latitude and longitude, you can use different coloured markers or small magnets to plot its movement. The concentric circles show how far, in miles, the storm is from our islands. You can keep informed of the storm's progress by taping or pinning the map up in a prominent place in your home. As the storm moves within the 500-mile range, you can again review their emergency plans to be assured that all possible preparations have been made. The source of a hurricane's energy is derived from warmer than average ocean water along the equator and a corresponding higher level of humidity, says the department. A low-pressure area is created when water-laden clouds release heavy rains as the warm air rises. Surface air spirals inward and upward in a counter-clockwise direction to fill the partial vacuum, reaching tens of thousands of feet above sea level to become the hurricane's eye. While the eye is almost calm and is often exposed to blue sky, the winds nearest the eye are strongest. More lives are claimed by storm surge and flooding than by the winds of a hurricane. The Department of Meteorology has an early warning system linked to satellites that records the formation of storms, and then tracks them. The developing storm area is visible on the satellite pictures, and its progress is monitored by the Met Office. Here are some of the definitions of terms and signals that you may be hearing during the hurricane season, from June through November: Tropical Depression is a weather front with sustained winds of less than 39 miles per hour; Tropical Storm is a cyclone where winds range from 39 to 73 miles per hour; Hurricane is a tropical cyclone with winds of 74 or more miles per hour. Torrential rains and destructive waves, known as storm surge, may create flood conditions in coastal and low-lying areas. When a Tropical Depression forms, the Met Office begins to issue a series of advisories, which include watches and warnings, based on the strength and position of an approaching storm, as follows: A Hurricane Watch is declared by the Met Office if winds are expected to reach the islands within 48 hours; A Hurricane Warning is declared by the Met Office when dangerous conditions are expected to affect the islands within 36 hours or less.