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Here is the 2009 Northern Atlantic hurricane forecast and some commonly-asked questions about hurricanes.
2009 Hurricane Forecast
The 2009 Atlantic hurricane season is expected to have slightly fewer hurricanes than usual—unlike last year's above-average activity—according to hurricane experts at Colorado State University.
Key contributing factors include:
- Cooler waters in the tropical Atlantic (warm water is needed to generate the heat that storms need as fuel)
- Increased probability of a weak El Nino (a pattern of warm weather in the Pacific Ocean that can limit storm formation)
- Stronger-than-normal trade winds (which inhibit weather systems from gathering).
Still, eleven named storms are predicted for the Atlantic Basin between June 1 and October 30, 2009.
From those storms, five hurricanes are predicted, two of which will be classified as "intense" or major hurricanes with sustained winds of 111 mph or more. Even in a less active hurricane season, an "intense" storm's power does not diminish.
Note: Forecasts cover the Atlantic Basin—the area encompassing the Atlantic Ocean, Caribbean Sea, and Gulf of Mexico.
For the Almanac forecast, see the long-range forecast in your region. Specifically, watch out for an active Florida season as well as a hurricane to hit the Gulf Coast and a late-August hurricane along the Atlantic Corridor.
See up-to-the-moment weather maps at The National Oceanic & Atmospheric Administration.
Q. What are the chances of a hurricane actually hitting the East Coast?
A. Hurricane forecasts do not tell us specific information about where a hurricane will land (called "landfall"). However, for those living on the East Coast, including the Florida Peninsula, there is a 28 percent probability of having a Category 3, 4, or 5 hurricane (on the Saffir-Simpson Hurricane Scale; more about this later) actually reach land. The average from the last century is 31 percent.
For the residents of the Gulf Coast from the Florida Panhandle westward to Brownsville, Texas, the probability of landfall is similar—28 percent, compared to 30 percent last century.
Q. What will the 2009 hurricanes be called?
A. The names chosen for the tropical storms of the 2009 Atlantic season are: Ana, Bill, Claudette, Danny, Erika, Fred, Grace, Henri, Ida, Joaquin, Kate, Larry, Mindy, Nicholas, Odette, Peter, Rose, Sam, Teresa, Victor, and Wanda.
Most names are taken from a permanent list that rotates every 6 years. More than 60 names have been retired since 1950 because they resulted in significant property damage or deaths, including Camille (1969), Agnes (1972), Carmen (1974), Hugo (1989), Andrew (1992), Mitch (1998), Floyd (1999), Lili (2002), Dennis (2005), Katrina (2005), Rita (2005), Stan (2005), Wilma (2005), Dean (2007), Felix (2007), Noel (2007), Gustav (2007), Ike (2008), and Paloma (2008). A name can be retired at the request of a country affected by the storm. It should be noted that not all hurricanes were named, including some of the most deadly or damaging storms known to man.
Q. How many hurricanes can we expect during any given hurricane season in the Atlantic Ocean?
A. Each year an average of ten tropical storms develop in the Atlantic Ocean, Caribbean Sea, and Gulf of Mexico. Six of them, on average, will actually achieve hurricane status. Many of these storms will die out over the ocean.
2009 Hurricane Forecast (Colorado State University)
| Prediction | Average |
|---|---|
| Named tropical storms – 11 | 9.6 |
| Named tropical storm days – 50 | 49.1 |
| Hurricanes – 5 | 5.9 |
| Hurricane days – 20 | 24.5 |
| Intense hurricanes – 2 | 2.3 |
| Intense hurricane days – 4 | 5.0 |
| Net tropical cyclone activity – 85 | 96.1 |
Q. Just what is a hurricane?
A. A hurricane is a tropical storm with winds that have reached a constant speed of at least 74 mph in the North Atlantic Ocean, Caribbean Sea, or Gulf of Mexico. A hurricane's winds blow in a large spiral around a relatively calm center of extremely low pressure known as the eye of the storm. Around the rim of the eye, winds may gust to more than 200 mph. The eye of a storm is usually 20 to 30 miles wide and may extend over 400 miles. The entire storm can be up to 340 miles in diameter, dominating the ocean surface and lower atmosphere for thousands of square miles.
The dangers of a storm include torrential rains, high winds, and storm surges. A hurricane can last for 2 weeks or more over open water and can follow a path across the entire length of the eastern seaboard, coastal areas, and barrier islands. All Atlantic and Gulf coastal areas are subject to hurricanes or tropical storms. Although rarely struck by hurricanes, parts of the Southwest and Pacific Coast suffer heavy rains and floods each year from the remnants of hurricanes spawned off Mexico. Islands such as Hawaii, Guam, American Samoa, and Puerto Rico also are subject to hurricanes.
Q. Is a hurricane the same as a cyclone?
A. A hurricane is actually one of three kinds of tropical storms, or cyclones, that circulate over tropical waters. The circulation is counterclockwise in the Northern Hemisphere. Tropical cyclones are classified as follows:
-
Tropical depression
An organized system of clouds and thunderstorms with a defined circulation and maximum sustained winds of 38 mph (33 knots) or less.
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Tropical storm
An organized system of strong thunderstorms with a defined circulation and maximum sustained winds of 39 to 73 mph (34 to 63 knots).
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Hurricane
An intense tropical weather system with a well-defined circulation and maximum sustained winds of 74 mph (64 knots) or higher. In the western Pacific, hurricanes are called typhoons. Similar storms in the Indian Ocean are called cyclones.
Hurricanes are further classified by rank according to how strong their winds are.
Q. How are hurricanes classified?
A. The Saffir-Simpson Hurricane Scale is a 1-5 rating based on the hurricane's present intensity. This is used to give an estimate of the potential property damage and flooding expected along the coast from a hurricane landfall. Wind speed is the determining factor in the scale, as storm surge values are highly dependent on the slope of the continental shelf in the landfall region. Wind speeds are measured using a 1-minute average.
| Saffir-Simpson Hurricane Scale | Average Wind (mph) | Representative Hurricanes |
|---|---|---|
| Category One | 74 - 95 | Danny; 1997 |
| Category Two | 96 - 110 | Bonnie & Georges; 1998 |
| Category Three | 111 - 130 | Rita; 2005 |
| Category Four | 131 - 155 | Charley; 2004 |
| Category Five | 156 + | Andrew; 1992 |
Q. What do the hurricane warnings mean?
A. A watch means that hurricane-force winds are possible within 36 hours. A warning means that hurricane-force winds are likely within 24 hours.
Q. How is a hurricane formed?
A. A tropical ocean and its atmosphere create the right conditions for a hurricane. Hurricanes draw their energy from the warm surface waters of the tropics (usually above 27°C, or about 81°F) and the latent heat of condensation. Powered by heat from the sea, they are steered by the easterly trade winds and the temperate westerlies, as well as by their own ferocious energy. Around their core, winds grow with great velocity, generating violent seas. Moving ashore, they sweep the ocean inward while spawning tornadoes and producing torrential rain and floods. When hurricanes move over cold water or over large landmasses, they can die out quickly because they lose the power of the heat and condensation.
