Wild WeatherWild Weather

hurricaneshurricanes

hurricane Franhurricane Fran

introductionintroduction

BASICSBASICS A hurricane is a type of tropical cyclone. In A hurricane is a type of tropical cyclone. In

the Northern Hemisphere, there is a the Northern Hemisphere, there is a counter clockwise circulation of winds. counter clockwise circulation of winds. Hurricane winds blow in a large spiral Hurricane winds blow in a large spiral around a relative calm centre known as around a relative calm centre known as the "eye." The "eye" is generally 20 to 30 the "eye." The "eye" is generally 20 to 30 miles wide, and the storm may extend miles wide, and the storm may extend outward 400 miles. They are low-pressure outward 400 miles. They are low-pressure systems. The eye of a hurricane is always systems. The eye of a hurricane is always a low-pressure area. The lowest a low-pressure area. The lowest barometric pressures ever recorded have barometric pressures ever recorded have occurred inside hurricanes.occurred inside hurricanes.

classificationclassification

Tropical cyclones are classified as Tropical cyclones are classified as follows: follows:

Tropical Depression:Tropical Depression: winds of 38 winds of 38 mph.mph.

Tropical Storm: Tropical Storm: winds of 39-73 winds of 39-73 mph.mph.

Hurricane: Hurricane: winds of 74 mph or winds of 74 mph or higher (120km/h).higher (120km/h).

Hurricane-like storms are called by different names in the different regions of the world. Hurricane-like storms are called by different names in the different regions of the world. For example, the name For example, the name hurricanehurricane is given to systems that develop over the Atlantic or is given to systems that develop over the Atlantic or

the eastern Pacific Oceans. In the western North Pacific and Philippines, these systems the eastern Pacific Oceans. In the western North Pacific and Philippines, these systems are called are called typhoonstyphoons while in the Indian and South Pacific Ocean, they are called while in the Indian and South Pacific Ocean, they are called

cyclones.cyclones.

The ingredients for a hurricaneThe ingredients for a hurricane

FORMATIONFORMATION The ingredientsThe ingredients for a hurricane include warm tropical for a hurricane include warm tropical

oceans, moisture, wind. They can combine to produce oceans, moisture, wind. They can combine to produce violent wind, incredible waves, torrential rain, and floods. violent wind, incredible waves, torrential rain, and floods. Most Atlantic hurricanes begin off the west coast of Africa, Most Atlantic hurricanes begin off the west coast of Africa, starting as thunderstorms that move out over the warm, starting as thunderstorms that move out over the warm, tropical ocean waters. The ocean water itself must be tropical ocean waters. The ocean water itself must be warmer than 26.5 degrees Celsius (81°F). The heat and warmer than 26.5 degrees Celsius (81°F). The heat and moisture from this warm water is the source of energy for moisture from this warm water is the source of energy for hurricanes. They hurricanes. They willwill weaken rapidly when they travel over weaken rapidly when they travel over land or colder ocean waters. Nevertheless a hurricane can land or colder ocean waters. Nevertheless a hurricane can extend inland for hundreds of miles.extend inland for hundreds of miles.

August and September are peak months during the August and September are peak months during the hurricane season that lasts from June 1 to November 30.hurricane season that lasts from June 1 to November 30.

Hurricane DangerHurricane Danger

Hurricanes can spawn Hurricanes can spawn tornadoestornadoes FloodsFloods are generated by are generated by torrential rainstorrential rains. They . They

also cause damage and loss of life.also cause damage and loss of life. Inland streams and rivers can flood and trigger Inland streams and rivers can flood and trigger

landslideslandslides Even more dangerous than the high winds of a Even more dangerous than the high winds of a

hurricane is the hurricane is the storm surgestorm surge -a dome of ocean -a dome of ocean water that can be 20 feet at its peak and 50 to water that can be 20 feet at its peak and 50 to 100 miles wide. The surge can devastate coastal 100 miles wide. The surge can devastate coastal communities as it sweeps ashore. Nine out of 10 communities as it sweeps ashore. Nine out of 10 hurricane fatalities are attributable to the storm hurricane fatalities are attributable to the storm surge.surge.

Each year, an average of ten tropical storms develop over Each year, an average of ten tropical storms develop over the Atlantic Ocean. Many of these remain over the ocean the Atlantic Ocean. Many of these remain over the ocean and never impact the U.S. coastline. Six of these storms and never impact the U.S. coastline. Six of these storms become hurricanes each year. In an average 3-year period, become hurricanes each year. In an average 3-year period, roughly five hurricanes strike the US coastline, killing roughly five hurricanes strike the US coastline, killing approximately 50 to 100 people anywhere from Texas to approximately 50 to 100 people anywhere from Texas to Maine. Of these, two are typically "major" or "intense" Maine. Of these, two are typically "major" or "intense" hurricanes (a category 3 or higher storm on the hurricanes (a category 3 or higher storm on the SSaffir-affir-Simpson Hurricane Scale.Simpson Hurricane Scale.

If one percent of the energy in one hurricane could be If one percent of the energy in one hurricane could be captured, all the power, fuel, and heating requirements of captured, all the power, fuel, and heating requirements of the United States could be met for an entire year.the United States could be met for an entire year.

CLASSIFICATION AND CLASSIFICATION AND DAMAGEDAMAGE

Saffir-Simpson Hurricane Scale

Saffir-Simpson Hurricane ScaleSaffir-Simpson Hurricane Scale

CatCategoryegory

Wind SpeedWind Speed EffectsEffects

11 74 to 95 mph74 to 95 mph Storm surge 4 to 5 ft (1.2 to 1.5 m) above normal Storm surge 4 to 5 ft (1.2 to 1.5 m) above normal Some flooding Some flooding No real damage to buildings.No real damage to buildings.

22 96 to 110 mph96 to 110 mph Storm surge 6 to 8 ft (1.8 to 2.4 m) above normal Storm surge 6 to 8 ft (1.8 to 2.4 m) above normal Trees down Trees down Roof damage Roof damage Small boats groundedSmall boats grounded

33 111 to 130 mph111 to 130 mph Storm surge 9 to 12 ft (2.7 to 3.7 m) above normal Storm surge 9 to 12 ft (2.7 to 3.7 m) above normal Structural damage in houses (damaged by floating debris).Structural damage in houses (damaged by floating debris).Mobile homes destroyed Mobile homes destroyed Severe floodingSevere flooding

44 131 to 154 mph131 to 154 mph Storm surge 13 to 18 ft (4 to 5.5 m) above normal Storm surge 13 to 18 ft (4 to 5.5 m) above normal Severe flooding inland Severe flooding inland Some roofs ripped off Some roofs ripped off Major structural damageMajor structural damageMajor erosion of beach areas.Major erosion of beach areas.

55 >155 mph>155 mph Storm surge at least 18 ft (5.5 m) above normal Storm surge at least 18 ft (5.5 m) above normal Severe flooding further inlandSevere flooding further inland Serious damage to most wooden structures.Serious damage to most wooden structures. Flooding causes major damage to lower floors in Flooding causes major damage to lower floors in houses houses Massive evacuation of residential areas may be requiredMassive evacuation of residential areas may be required

In a hurricane, the most violent winds occur in the In a hurricane, the most violent winds occur in the area immediately around area immediately around the eyethe eye. Hurricanes . Hurricanes produce significant damage and loss of life, produce significant damage and loss of life, mainly due to flooding. When hurricanes move mainly due to flooding. When hurricanes move onto land, they can damage buildings, trees and onto land, they can damage buildings, trees and cars. The heavy waves are called a storm surge. cars. The heavy waves are called a storm surge. Storm surge is very Storm surge is very dangerousdangerous and a major and a major reason why you reason why you MUSTMUST stay away from the ocean stay away from the ocean during a hurricane warning. during a hurricane warning. The storm surgeThe storm surge acts like a acts like a bulldozerbulldozer sweeping away everything in sweeping away everything in its path. The stronger the hurricane the higher its path. The stronger the hurricane the higher the storm surge will be. the storm surge will be.

HURRICANE HURRICANE PREPAREDENESSPREPAREDENESS

Be sure to ask family members, friends and neighbours if Be sure to ask family members, friends and neighbours if they are they are hurricane awarehurricane aware..

Being Being hurricane smarthurricane smart means knowing means knowing what to do and having a safe place to go.what to do and having a safe place to go.

The key to hurricane protection is The key to hurricane protection is preparation. Preparation through preparation. Preparation through education is less costly than learning education is less costly than learning through tragedy.through tragedy.

You may want to talk with your You may want to talk with your neighbours to coordinate preparation neighbours to coordinate preparation plans and help each other out.plans and help each other out.

Before hurricane seasonBefore hurricane season

Plan an Plan an evacuation routeevacuation route or , if you’re staying, determine the safest or , if you’re staying, determine the safest place in your home — an interior room, a hallway. Never decide to stay in a place in your home — an interior room, a hallway. Never decide to stay in a mobile home.mobile home.

Don't be in a room with Don't be in a room with windowswindows that can be broken. that can be broken. If your house doesn't have a windowless room, you should at least stay If your house doesn't have a windowless room, you should at least stay

under a table or behind a sofa.under a table or behind a sofa. Once a window is broken, the wind blows inside to not only wreck the Once a window is broken, the wind blows inside to not only wreck the

interior, but also to apply upward pressure on the roof, which might be interior, but also to apply upward pressure on the roof, which might be enough to send it flying. If this happens, the walls collapse and your house enough to send it flying. If this happens, the walls collapse and your house is flattened. Permanent shutters are the best protection.is flattened. Permanent shutters are the best protection.

Have an evacuation or Have an evacuation or survival kitsurvival kit ready with nonperishable food, water, ready with nonperishable food, water, a first aid kit and other things you'll need: cash and credit cards, and do a first aid kit and other things you'll need: cash and credit cards, and do not forget your insurance policy!! You may need it!!not forget your insurance policy!! You may need it!!

Make arrangements for pets. Pets may not be allowed into emergency Make arrangements for pets. Pets may not be allowed into emergency shelters for health and space reasons.shelters for health and space reasons.

Take “before” pictures of your home for insurance claims.Take “before” pictures of your home for insurance claims. Teach family members how and when to turn off gas, electricity, and water.Teach family members how and when to turn off gas, electricity, and water.

During a hurricane watch/ During a hurricane watch/ warningwarning

Have a battery-powered radio (to get the latest Have a battery-powered radio (to get the latest news).news).

Evacuate early if you live in a mobile home (to Evacuate early if you live in a mobile home (to avoid traffic).avoid traffic).

Fuel car.Fuel car. Bring in outdoor objects such as lawn furniture, Bring in outdoor objects such as lawn furniture,

toys, garden tools, mailbox and your garbage can toys, garden tools, mailbox and your garbage can (rubbish bin). The greatest threat to your home in (rubbish bin). The greatest threat to your home in most hurricanes is not the wind itself but wind-most hurricanes is not the wind itself but wind-blown debris that can break windows and doors.blown debris that can break windows and doors.

Remove outside antennas or satellite dishes.Remove outside antennas or satellite dishes. Turn refrigerator and freezer to coldest settings. Turn refrigerator and freezer to coldest settings.

Open only when absolutely necessary.Open only when absolutely necessary. secure boat.secure boat. Reinforce the garage doors.Reinforce the garage doors. Park your car where it will be most protected if it Park your car where it will be most protected if it

must be outdoorsmust be outdoors

During the hurricaneDuring the hurricane

At this stage your main priority is to At this stage your main priority is to remain calm and out of danger. remain calm and out of danger. Outside your shelter, raging winds are Outside your shelter, raging winds are blowing torrential rain and battering blowing torrential rain and battering your town. There is no reason, unless your town. There is no reason, unless in an absolute emergency, that one in an absolute emergency, that one would need to venture outdoors. Local would need to venture outdoors. Local officials have the authority to close officials have the authority to close roads and bridges.roads and bridges.

Tips/PrecautionsTips/Precautions

Stay indoors and away from windows.Stay indoors and away from windows. Stay tuned to radio (or TV if Stay tuned to radio (or TV if

available) for weather bulletins.available) for weather bulletins. Use flashlights as a source of light. Use flashlights as a source of light. Candles can easily become a fire Candles can easily become a fire

hazard hazard Listen to local authorities.Listen to local authorities. Avoid elevators (lifts)Avoid elevators (lifts)

After the hurricaneAfter the hurricane

Take pictures of the damage for Take pictures of the damage for insurance claims.insurance claims.

Drive only if absolutely necessary Drive only if absolutely necessary and avoid flooded roads.and avoid flooded roads.

Check for gas leaks.Check for gas leaks. Look for electrical system damage.Look for electrical system damage. Check for sewage and water lines Check for sewage and water lines

damagedamage

NAMING AND FORECASTINGNAMING AND FORECASTING

To better track hurricanes, weather officials decided to To better track hurricanes, weather officials decided to name them.name them.

Until World War II, hurricanes were given only Until World War II, hurricanes were given only masculine names. In the early 1950s, weather masculine names. In the early 1950s, weather services began naming storms alphabetically and with services began naming storms alphabetically and with only feminine names. By the late 1970s, this practice only feminine names. By the late 1970s, this practice was replaced with alternating masculine and feminine was replaced with alternating masculine and feminine names. The first hurricane of the season is given a names. The first hurricane of the season is given a name starting with the letter A, the second with the name starting with the letter A, the second with the letter B and so on. According to NOAA, "the name letter B and so on. According to NOAA, "the name lists... have an international flavour because lists... have an international flavour because hurricanes affect other nations and are tracked by the hurricanes affect other nations and are tracked by the public and weather services of many countries." public and weather services of many countries."

Hurricanes in the Pacific Ocean are assigned a Hurricanes in the Pacific Ocean are assigned a different set of names than Atlantic storms.different set of names than Atlantic storms.

forecastingforecasting

In the early part of this century, coastal In the early part of this century, coastal residents residents used to haveused to have less than a day to less than a day to prepare or evacuate their homes from an prepare or evacuate their homes from an oncoming hurricane. Today, these same oncoming hurricane. Today, these same locations receive warnings to evacuate locations receive warnings to evacuate from one to two days in advance, let alone from one to two days in advance, let alone the extra days they are also aware of its the extra days they are also aware of its existence. Before satellites and radars, existence. Before satellites and radars, people had very little knowledge of the people had very little knowledge of the weather just 100 kilometres offshore. weather just 100 kilometres offshore.