Hurricanes



What is a hurricane?

It is a violent storm that develops over tropical waters. It is characterized by a significant low-pressure "eye" or center, surrounded by an organized system of storm clouds that form a spiral which, in the case of the Northern Hemisphere, rotates in a counter-clockwise motion. A hurricane is also distinguished by sustained winds of at least 120 km per hour or higher, as well as by large amounts of rainfall and strong tides.


How do hurricanes develop?

A key element that contributes to the formation and development of this natural phenomenon is the sea surface temperature, which must be higher than 27 degrees Celsius.


Where does the word "hurricane" come from?

It comes from the name used by the Mayans to refer to Storm God, but also to evil spirits.


What other names are used in other places to refer to hurricanes?

Cyclone in India
Baguio in the Philippines
Typhoon in the west area of the Northwestern Pacific
Willy-Willy in Australia
Taino in Haiti 


In which regions do hurricanes occur?

North Atlantic Region: the Caribbean Sea, Gulf of Mexico and Western Atlantic.
North Pacific Region: Western Mexico.
North Pacific: Western Pacific Ocean, Sea of Japan, China Sea, and the Philippines.
India: Gulf of Bengal, Sea of Arabia.
South Pacific Region: Northern Australia and Coral Sea.
Western Indian Ocean: Madagascar y and the eastern coast of South Africa
Eastern Indian Ocean: Northwestern Australia, Arafura Sea, and Southern Indonesia. 


How have hurricanes given names throughout history?

During the 18th and 19th centuries, as well as in early 20th century, hurricanes were named after saints. Subsequently, during World War II a code in alphabetical order was used to identify hurricanes. In 1953, the U.S. National Weather Service decided to use female names in alphabetical order. In 1978, it was decided to alternate the use of female and male names to make reference to hurricanes that occurred in the Northeastern Pacific. In 1979, this practice of alternating female and male names was also incorporated into the lists of hurricanes occurring in both the Atlantic Ocean and the Gulf of Mexico.

Actualmente los nombres de este fenómeno que integran la lista, son seleccionados y convenidos en las reuniones internacionales de la Organización Meteorológica Mundial (OMM) por los países que integran la organización. Las letras Q, U, X, Y y Z no están incluidas para denominar los huracanes del océano Atlántico por los pocos nombres comenzados por estas consonantes. Cuando los huracanes ocasionan un impacto muy severo en su área de influencia, causando numerosas pérdidas de vidas y muchos daños económicos, el nombre es retirado de la lista.


How is hurricane intensity classified?

The Saffir-Simpson scale is used to classify hurricane categories:

Category 1 (119-153 Km/h)
Category 2 (154-177 Km/h)
Category 3 (178-209 Km/h)
Category 4 (210-249 Km/h)
Category 5 (over 249 Km/h)

What should we do if a hurricane poses a threat to us?

Listen to local radio or TV stations for weather updates and last-minute news about the storm;
Secure all outdoor objects and bring in all garden furniture, ornaments and decorations found outside (hanging plants, garbage cans and shovels, among others);
Secure the house roof, doors and windows. Board up windows with shutters and bear in mind that adhesive tape does not prevent window glass from breaking; therefore, its use is not recommended;
Fill up the gas tank of your car;
Make sure to keep handy matches, candles, flashlights, first-aid kits, medicines, drinking water, a radio, personal documents and canned food;
Keep all important family documents in plastic bags and store them in a safe place in the house, far above the ground;
Dentro de la casa preparar el lugar más seguro y fuerte.
Prune trees next to or around the house; and,
Make sure that pets and other animals are in a safe and covered place.


What should we do after the hurricane?

If evacuation has not been advised, stay indoors and away from windows, in the middle of the house, in a closet or in a bathroom with no windows;
Do not go out after the eye of the storm. Winds will start again in a matter of minutes or up to a half hour. They will blow stronger and, this time, in the opposite direction.
Listen to all announcements released by those institutions in charge.


What to do after a hurricane?

Continue listening to local radio stations or TV channels in case other instructions are given
If you had to evacuate, do not go back to your house until authorities indicate that it is safe to do so.
Do not touch any electric wires on the ground.
Inspect the house to find out if it has been damaged.
Use flashlights if it gets dark. Avoid using candles.
Cyclonic swells may develop.


What are cyclonic swells?

These swells are formed due to high winds that blow over the ocean, lakes and rivers, causing large waves that reach a speed similar to cyclones. After striking the shore, swells could rapidly penetrate nearby areas.

 

Bibliographical references

1. Revista EIRD Informa N° 3, 2001
2. Barrios G. Javier, "Desastres Naturales: Manual para agentes comunitarios". Acción Médica Cristiana. Noviembre, 2000