Hurricane Information (What is a hurricane?)

Hurricane Information

Hurricane season officially runs from June 1st to November 30th, but the most activity is usually seen in August and September. Since it gets hot enough to turn on the air conditioning in May and is miserably hot and sticky by August we sometimes get to the point of wishing for any kind of change in the weather. This is one of those times when you have to be really careful what you wish for!

What is a hurricane?	What happens in a hurricane?
Categories of hurricanes	How are hurricanes named?

Hurricane Elana seen from space

What is a Hurricane? Let's start with a definition of the different stages in the birth of a hurricane: A tropical depression is a disturbance with a clearly defined low pressure area. Its highest wind speed is 38 mph. Tropical depressions are numbered. Tropical Storm Watch: Tropical Storm conditions are possible within 36 hours. Tropical Storm Warning: Tropical Storm conditions are expected within 24 hours. A tropical storm is a distinct low pressure area well defined by rotating circulation with winds of 39-73 mph. When a tropical depression becomes a tropical storm, it gets a name. Hurricane Watch: Hurricane conditions are possible within 36 hours. Prepare your home and family and stock up on supplies. Hurricane Warning: Hurricane conditions are expected within 24 hours. Take your evacuation kit and go. Short Term Watches and Warnings: provide information on specific hurricane threats, such as tornadoes, floods and high winds. A hurricane is born when a tropical storm's constant wind speed reaches 74 miles per hour or greater. There are five categories of hurricanes. Categories of Hurricanes

Cat. Damage Winds Storm Surge 1 Minimal - Might blow over your tool shed and damage a few plants. Lowest roads flood. 74-95 mph 4-5 ft. 2 Moderate - Some building damage and a lot of plants and trees down. Mobile homes don't fare very well, either. Low-lying evacuation routes will be flooded 2-4 hours before the center of the storm arrives. This is when you start wondering if you secured your boat well enough. 96-110 mph 6-8 ft. 3 Extensive - Kiss your mobile home goodbye. Some structural damage to buildings. Flooding on the coast and anything less than 5 foot above sea level as far as 8 miles inland. 111-130 mph 9-12 ft. 4 Extreme - Your mobile home is in Tampa now, and roofs are blowing off houses. Lots of damage to lower levels of buildings on the beach, and inland terrain lower than 10 foot above sea level will flood. 131-155 mph 13-18 ft. 5 Catastrophic - You did evacuate didn't you? If not, this is when you kiss your butt goodbye. Roofs are blowing off left and right, and some buildings are just blown completely away (not even counting mobiles - they were gone long ago). Beachside buildings are going to be a huge mess on all the lower floors that they have. If you rode out the storm inland you better be on a ridge at least 15 foot above sea level, or you're going to be flooded. 156 mph... 18 ft. +

What happens in a hurricane? The winds of a hurricane cover hundreds of miles and spiral counterclockwise at a speed of 75 miles per hour and up. The lower few thousand feet of a hurricane move inwards towards the center of the storm (the "eye") and upwards - gaining speed as they approach the wall of the eye. The eye of the storm is a very cool, calm patch of weather about 20 miles wide, then the 2nd half of the storm hits with the winds striking from the opposite direction. <<< SideNote: We Floridians send the kids outside to play during the eye of the storm. You can only take so much family togetherness, then most Moms are ready to risk losing a child or two to save her sanity. The kids you think are worth keeping should stay close by - you only get about 1/2 hour to an hour before the other side of the storm hits, and it will be hitting hard. >>> Storm surge is the mound of ocean water up to 20 feet high that can come ashore with a hurricane. Evacuation zones are identified by the likelihood of being flooded by this rising water. Most hurricane-related deaths are from storm surge flooding. Storm surge flooding can occur over 100 miles of coastline and may extend inland several miles. Hurricane Bonnie Feeder bands of clouds streaking out from the extreme edges of a hurricane are not to be ignored. We call them "feeder bands" because they are pulling moisture up from the ocean "feeding" the clouds of the storm. Typically a day or two after the hurricane has passed the remainder of the feeder bands will come ashore, dropping incredible amounts of rain. Often the flooding caused by these rains causes more damage than the actual hurricane. How are hurricanes named? Lots of people think that hurricanes were always named after women - because of our volatile nature, no doubt - and that only recently did they start alternating between male and female names because of feminist outcry. Not true. Prior to 1950 storms weren't officially named at all. From 1950 to 1952 they were named simply Able, Baker, Charlie, Dog, Easy, Fox, George...not very imaginative, but it sufficed. From 1953 to 1978 someone (my guess a man going through a nasty divorce) decided to use only female names. Finally, in 1979, they started alternating between male and female names. Hurricanes are named alphabetically, years in advance and starting the alphabet over each year. (If you get a Hurricane Wilma, you know you have had a busy storm season!) The Atlantic and the Pacific have separate naming lists. These are the names assigned to Atlantic storms for the 2011 Hurricane Season:

Arlene	Harvey	Ophelia
Bret	Irene	Philippe
Cindy	Jose	Rina
Don	Katia	Sean
Emily	Lee	Tammy
Franklin	Maria	Vince
Gert	Nate	Whitney

Retired Names - There are several lists of names that are rotated year after year, but when there is a particularly bad storm that has had a severe impact on the population they retire the name. Storms that have had their names retired are:

Agnes (1972) Alicia (1983) Allen (1980) Allison (2001) Andrew (1992) Anita (1977) Audrey (1957) Betsy (1965) Beulah (1967) Bob (1991) Camille (1969) Carla (1961) Carmen (1974) Carol (1954) Celia (1970) Cesar (1996) Charley (2004)

Cleo (1964) Connie (1955) David (1979) Dennis (2005) Diana (1990) Diane (1955) Donna (1960) Dora (1964) Edna (1968) Elena (1985) Eloise (1975) Fabian (2003) Fifi (1974) Flora (1963) Floyd (1999) Fran (1996) Frances (2004)

Frederic (1979) Georges (1998) Gilbert (1988) Gloria (1985) Hattie (1961) Hazel (1954) Hilda (1964) Hortense (1996) Hugo (1989) Inez (1966) Ione (1955) Iris (2001) Isabel (2003) Isidore (2002) Ivan (2004) Janet (1955) Jeanne (2004)

Joan (1988) Juan (2003) Katrina (2005) Keith (2000) Klaus (1990) Lenny (1999) Lili (2002) Luis (1995) Marilyn (1995) Michelle (2001) Mitch (1998) Opal (1995) Rita (2005) Roxanne (1995) Stan (2005) Wilma (2005)

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