Slide 1 Hurricanes

1. Hurricanes are extremely potent tropical storms which typically occur in the Southern Atlantic Ocean, the Caribbean Sea, the Gulf of Mexico or the eastern Pacific Ocean.

2. The same extreme weather phenomena occur in other parts of the world, but they have a couple of different names there. For example, hurricanes which form in the western Pacific Ocean are called typhoons.

3. The hurricanes you will encounter in the Indian Ocean, the Bay of Bengal and Australia, or the South Pacific are referred to as cyclones.

Slide 2 Process of formation

1. Hurricanes need very warm ocean water to form. The water must be at least 80 degrees Fahrenheit, which is 26.7 degrees Celsius.

2. As warm water evaporates and rises higher and higher, it begins to cool, condense and form stormy clouds. The wind starts blowing in a circular pattern as a result of the earth rotating, and this wind quickly picks up speed. Once it reaches the speed of 74 mph, which is 119.09 kph, the storm officially becomes a hurricane.

Slide 3 Characteristic features

1. In the northern hemisphere the hurricane season is between June and November. On average, these massive storm systems occur 12 times a year in the Atlantic Basin. It’s also interesting to notice that in this part of the globe hurricanes rotate anticlockwise. In the southern hemisphere they rotate clockwise.

2. Hurricanes are huge and can be as much as 300 miles wide. The centre of the rotating mass of storm clouds, the so‑called eye of the hurricane, is calm and peaceful. The eye is approximately 20‑40 miles wide. When a hurricane sweeps across a given region, the passing of the eye gives the inhabitants some time to gear up for the second hit, which always comes as the storm moves forward.

Slide 4 Research

1. To learn more about hurricanes, NOAA, the National Oceanic and Atmospheric Administration, carries out research and observations of hurricanes.

2. It takes a lot of courage to work for this agency, as the pilots and scientists employed by it fly two very robust and specially equipped planes, called Miss Piggy and Kermit. Hurricane hunters, as the crew members are dubbed, fly in and out of the hurricanes to make measurements and collect data which can later be studied to better understand these phenomena.

Slide 5 Names

1. The names are not random. A list of names has been compiled and they are used on a six‑year rotation. The World Meteorological Organisation is responsible for that. Male and female names are used alternately in an alphabetical order. If a particular hurricane is especially destructive and causes numerous casualties, that name is never used again. Katrina is an example of such a name. After it was retired, it was replaced with a new one.

Slide 6 The Suffir- Simpson Hurricane Category Scale

1. Hurricane categories inform people about the wind speeds a hurricane can produce. There is a 5‑degree scale invented back in the 1970s by the engineer Herbert Saffir and the meteorologist Robert Simpson. The scale is named after its inventors. It has evolved over the years and nowadays it does not include information about flooding or tornadoes which might accompany hurricanes but it gives people an idea how bad a damage they can expect.

2. In the last one hundred years, only three hurricanes have been put in category 5, and these were: the Labor Day hurricane in 1935, hurricane Camille in 1969, and most recently hurricane Andrew in 1992. The last one affected South Florida and Louisiana.

Slide 7 Additional threats

1. It must be remembered that the Saffir‑Simpson Hurricane Wind Scale, as the name itself suggests, provides information only about a storm’s wind speed. However, apart from wind, hurricanes carry other dangers such as heavy rains and storm surge. Even category 1 hurricanes can cause very serious damage and pose a threat to people’s and livestock’s lives. Hurricanes are not only high winds but also tremendous amounts of water which cause massive flooding. No hurricane should ever be underestimated due to its category and adequate safety measures must always be implemented.

Slide 8 Tornadoes

1. As hurricanes make landfalls, they typically start to lose their energy. It does not mean, however, that they are any less dangerous. Tornado is a narrow, violently rotating funnel made of condensed water droplets, which extends from a thunderstorm to the ground. As it travels across the land, it picks up dust, debris and often heavy objects such as cars or parts of buildings. Their winds can be as high as 250 mph and they basically clear a pathway removing everything from their way. That shows how powerful tornadoes are.

Slide 9 Areas typically affected by tornadoes

1. Tornadoes occur across all continents, but their biggest concentration is observed in the USA, Argentina and Bangladesh. Tornado Alley, which is an area stretching across such states as South Dakota, Nebraska, Kansas, Oklahoma and northern Texas, is a region of the United States affected by the most destructive tornadoes.

Slide 10 Process

1. Tornadoes tend to form when warm and humid air comes into contact with cold and dry air. Although they are observed at different times of the day and year, they are most common in late afternoon as by this time thunderstorms usually form. A funnel cloud is created and at some point it descends and the moment it touches the ground, a tornado is born. Most tornadoes travel no more than 6 miles and they die out. They move at a speed of about 30 mph, but the record breaking ones went as much as 10 times faster