Hurricanes: A Beginner’s Guide

Image Credit/NASA
Hurricanes of Categories 3 and higher are considered major hurricanes, with the winds to potentially cause billions in damage. Hurricane Fran, a major Category 3 hurricane, caused $3.2 billion in damages in 1996.

Jaclyn Wiley/Editor-in-Chief

Florida is a great place to live, but it has some hazards. These hazards range from alligators (which will ignore you as long as you leave them alone) to extreme heat (airflow is key to keeping cool), to the elderly while driving (always be aware). The most dangerous of the Florida hazards is the hurricane.

The Avion Newspaper is dedicated to spreading information to the students of Embry-Riddle, especially information that can influence their safety. For this reason, the Avion Newspaper has partnered up with the Embry-Riddle Meteorology Department and the Department of Campus Safety and Security to provide a guide to understand what hurricanes are, how they can be dangerous, how Embry-Riddle is keeping its students and its property safe and how you can keep safe during the storm.

 

What is a Hurricane?

For the six-month period from June 1 to Nov. 30 every year, massive, westward-bound storm systems form from groups of thunderstorms over the North Atlantic Ocean.  Some of these systems grow so large, with winds so fast, they become classified as hurricanes.

A hurricane is defined by the National Oceanic and Atmospheric Administration as “an intense tropical weather system with a well-defined circulation and maximum sustained winds of 74 mph or higher.”

Storm systems form in the North Atlantic Ocean due to the temperature differential between the water and the air, which is greatest during late summer. The difference in temperature causes water from the ocean to evaporate and form clouds, which eventually build into storms. Storms come together and form into systems.

When the winds of a storm system reach 20 mph at the system’s center, the storm is classified as a tropical depression. These storms are not named, though they are tracked by multiple weather agencies around the world.

A storm earns a name when it becomes a tropical storm; a storm system is considered a tropical storm when its winds reach 50 mph.

The name is from a predetermined list of names published each year by the United Nations World Meteorological Organization (WMO). There are 21 names on the list, alternating male and female in alphabetical order. The letters Q, U, X, Y, and Z are skipped due to the lack of names starting with those letters.

A storm is officially a hurricane when its winds reach 75 mph. Hurricanes are separated into one of five categories by wind speed according to the Saffir-Simpson Scale.

The wind speed and potential damage are directly related, as are many of the dangerous phenomena that are associated with hurricanes, like storm surge and tornadoes.

A hurricane is considered a major hurricane when its winds reach over 111mph, which corresponds to a Category 3 or higher hurricane.  These hurricanes are the most dangerous and damaging to life and property.

 

Hurricane-Related Hazards

Besides the high winds and levels of rainfall, hurricanes can also bring on other hazards, like storm surge, storm tide, tornados, rip currents and flash floods.

Storm surge occurs when the high winds of the hurricane push ocean water onto the coast, causing flooding.  The larger and more intense the storm, the worse the storm surge, usually.  Storm surge is the most damaging product of hurricanes since it is so dangerous to life and property.

Storm tide is the rise in water level during a tropical storm or hurricane that is caused by a combination of the natural cycle of the tides and the unnaturally high storm surge.  This high tide can result in flooding, and when combined with the high winds, can result in large, highly damaging waves.  These waves then batter the coastline and cause significant amounts of damage.

Image Credit: National Hurricane Center. An artist's depiction of storm tide and storm surge. The normal tide is 2 ft, but with the added 15ft of storm surge, the storm tide is 17ft.

Image Credit: National Hurricane Center. An artist’s depiction of storm tide and storm surge. The normal tide is 2 ft, but with the added 15ft of storm surge, the storm tide is 17ft.

Tornados can also result from hurricanes, though they are usually smaller than those seen in the mid-western United States.  Despite their small size, these phenomena are a significant threat to health and property.

Rip currents are the result of the large waves caused by the storm. When these waves hit the coast, they cause large, dangerous currents that lead away from shore.  These currents can pull even the strongest swimmers out to sea.

Flash floods occur when the high levels of rainfall lead to rapid and massive increases in water level. These floods are often very destructive and deadly.

Many of the deaths associated directly with hurricanes are due to drowning in flash floods, rip currents and storm surge.

For more information visit the WMO website.

The Uncertainty of Predicting the Paths of Hurricanes

Image Credit: The National Hurricane Center. The National Hurricane Center (NHC) provides graphics to those in the danger zone for tropical storms and hurricanes, in order to convey forecast information. In order to portray the uncertainty that comes with trying to predict nature, the path of a storm is modeled by a cone. This cone does not indicate the potential size of the storm, but rather the potential error in the prediction.

Image Credit: The National Hurricane Center. The National Hurricane Center (NHC) provides graphics to those in the danger zone for tropical storms and hurricanes, in order to convey forecast information. In order to portray the uncertainty that comes with trying to predict nature, the path of a storm is modeled by a cone. This cone does not indicate the potential size of the storm, but rather the potential error in the prediction.

Jaclyn Wiley/The Avion Newspaper. This chart, based of data from the National Weather Service and the National Hurricane Center gives information about each category of tropical cyclone, including a tropical depression.

Jaclyn Wiley/The Avion Newspaper. This chart, based of data from the National Weather Service and the National Hurricane Center gives information about each category of tropical cyclone, including a tropical depression.