Given that the hurricane, as an engine, is inefficient and hard to start and sustain, once set in motion, once mature, it is an awesome natural event indeed.

The young storm stands upon the sea as a whirlpool of awful violence. Its hurricane force winds cover thousands of square miles, and tropical storm force winds--winds of 34 to 63 knots--cover areas ten times larger. Along the contours of its spiral rainbands ascend are dense clouds from which torrential rains fall. These spiral rainbands ascend in decks of cumulus and cumulonimbus clouds to the high upper atmosphere, where condensing water vapor is swept off as ice-crystal wisps of cirrus clouds by high-altitude winds. Lightning glows in the rainbands, and this cloudy terrain is whipped by turbulence.

At the lower levels, where the hurricane is most intense, winds on the rim of the storm follow a wide pattern, like the slower currents on the rim of a whirlpool; like those currents, these winds accelerate as they approach the central vortex. This inner band is the eyewall, and where moist air entering at the surface is chimneyed upward releasing heat to drive the storm. In many hurricanes, these winds exceed 90 knots--nearly twice that in extreme cases.

Hurricanes are known to have very low barometric pressures in the center. The Labor Day hurricane that struck the Florida Keys in 1935 had a central pressure of only 26.35 inches (892 millibars). And the change is swift; pressure may drop an inch (3 millibars) per mile. Hurricane Gilbert in 1988 went through a remarkable intensification period after its center crossed Jamaica. The pressure fell from 960 millibars (28.35 inches) to 888 millibars (26.22 inches) in 24 hours. The latter was observed by a NOAA aircraft on September 13, 1988--the lowest sea level pressure ever recorded in the Western Hemisphere.

At the center of the storm is a unique atmosphere entity and a persistent metaphor for order in the midst of chaos-- the eye of the hurricane. It is encountered suddenly. From the heated tower of maximum winds and thunderclouds, one bursts into the eye, where winds diminsh to something less than 15 knots. Penetrating the opposite wall, one is abruptly in the worst of winds again.

A mature hurricane orchestrates as much as a million cubic miles of atmosphere. Over the deep ocean, waves generated by hurricane winds can reach heights of 50 feet or more. Under the storm center, the ocean surface is drawn upward like water in a straw, forming a mound 1-3 feet or so higher than the surrounding ocean surface. This mound may translate into a coastal surge of 20 feet or more. Besides this surge, massive swells pulse out through the upper levels of the sea.