As the tilt of the Earth’s axis changes throughout the year and the northern hemisphere begins to point toward the Sun, the oceans above the equator start to get warmer together with the atmosphere. By spring this warming of the ocean-atmosphere environment generates cells of disturbed weather over the Indian ocean that are pushed over equatorial Africa by easterly winds.
The interaction of these cells with the moisture-laden and very warm environment over equatorial Africa in turn generates rain, thunderstorms and even larger cells as the atmosphere and the ground interact with each other. As this process is repeated tropical waves are generated every few days, which continue to move toward the west along a corridor that becomes a tropical wave assembly line.
Like pulses these tropical waves some of which grow to be quite large, perhaps 500 – 700 miles in diameter, march toward Africas’s west coast and the warming waters of the eastern Atlantic to the south of the Cape Verde Islands. Once these waves emerge over the Atlantic prevailing winds steer them westward along hurricane alley, where numerous factors including what is happening in the eastern Pacific waters off the coast of Peru, and other Pacific atmospheric cycles, as well as the coriolis effect from the earth’s rotation, influence the route these tropical waves take and their potential conversion to tropical cyclones.
Over the last couple of weeks both the tropical wave assembly line and hurricane alley appear to have become more active and dynamic as the tropical waves being generated are larger, better organized and stronger.
On 19 August 2010 Hurricane Alley was loaded with tropical waves that had congealed into a huge area of disturbed weather, generating rain and thunderstorms, which was more than 2000 miles long, while the assembly line over equatorial Africa appeared to generate more intense and closely spaced tropical waves.
As it is, on 20 August 2010 the whole Earth was ringed by a ‘belt’ of tropical waves, generating rain and thunderstorms, mainly north of the equator, as shown in the composite full-disk view of Earth western hemisphere below:
Historically the most active phase of the Atlantic annual hurricane season takes place from mid-August to mid-October reaching its peak in September. Satellite data and other observations appear to indicate the coupled ocean-atmosphere environment is already sending signals of becoming more active.
Of interest to nations in the Caribbean, Central America, Mexico and USA interests along the Gulf, in Florida and the Atlantic seaboard, is the fact that the La Nina event, signified by the cooling waters of the eastern Pacific off the coast of Peru, is continuing and appears to be getting stronger. Historically La Nina has contributed to a favorable environment for the generation of hurricanes in hurricane alley.