What conditions make for hurricanes in the Atlantic?
Above-average sea surface temperatures in the northern, eastern, and tropical regions of the Atlantic are one factor. If these regions are warmer than usual during the summer and fall, hurricanes will be more likely to form the following year. Because of the El Nino phenomenon, water temperatures in the summer and fall of 1997 were warmer than normal, resulting in a greater chance of hurricanes in 1998. A condition known as the Azores High, or high surface pressure near the Azores in the North Atlantic, also contributes to hurricane formation. The condition causes weaker than normal East Atlantic trade winds, which can stimulate hurricanes.