General Hurrricane Information

What is a hurricane?

By definition it is a warm-core, tropical cyclone with counter-clockwise rotating winds of 74 miles per hour or greater. A hurricane has much lower air pressure at its center (the eye) than at its periphery. It is this difference in air pressure that allows the wind to spiral inward towards the center.

Hurricanes need warm ocean water (at least 80 degrees F) in order to thrive. They also need a moist environment and non-shearing winds in the upper atmosphere so that the hurricane can grow vertically.

Hurricanes typically move in a course around the Bermuda High, a large high-pressure system typical for the mid-atlantic region. Some hurricanes move on erratic paths and can be difficult to forecast. We'll look at several different types of paths that hurricanes take and examine the ones most likely to bring worst-case conditions to our area.

We name hurricanes to keep track of which one is which. Common sense, really. We began officially naming tropical storms and hurricanes in 1953. In 1979 we added male names to the list of names; which is comprised of six annual lists that are rotated every six years. If a tropical storm or hurricane causes notable death and destruction, the name is "retired" off of the list and replaced with another name. So Mitch will replaced by another "M" male name in 2004.

What exactly is hurricane storm surge and why is it so dangerous?

Simply put, storm surge is an abnormal rise in sea level accompanying a hurricane or other intense storm, and whose height is the difference between the observed level of the sea surface and the level that would have occurred in the absence of the cyclone. Storm surge is usually estimated by subtracting the normal or astronomic high tide from the observed storm tide. Because of improvements in forecasting, the spread of information and timely evacuations, the number of fatalities from hurricane storm surge has been drastically reduced over the past 30 years. However, the element of risk is always there. With the enormous increase in coastal populations, it is more critical than ever to understand the risks from hurricane storm surge; and more importantly, heed the warnings and evacuation orders given by local emergency management officials. The rise in water, coupled with the battering waves on top of the elevated water level is the reason that sometimes millions of people are urged to evacuate their coastal homes.

Let's take a look at the processes that ultimately create hurricane storm surge:

1. Storm surge beginnings.
2. Storm surge in the open ocean.
3. The Right-Front Quadrant.
4. Category 2 and 4 hurricanes at the beachfront.
5. Angle of Attack- a critical aspect to consider.