Typhoon? Hurricane? Cyclone? Here's the difference - CBS News
Hurricanes, Typhoons and Tropical Cyclones Reviewed Articles and Books - and B. N. Hanstrum, The relationship between tropical cyclones near. Once a tropical cyclone reaches maximum sustained winds of 74 miles per hour or higher, it is then classified as a hurricane, typhoon. What is the relationship among hurricanes, typhoons, and tropical cyclones? Tropical revolving storms are called hurricanes in the Atlantic and.
The role of synoptic systems in the interannual variability of Sahel rainfall. Investigation of mixed layer response to Bay of Bengal cyclone using a simple ocean model. Cloud and water vapour motion vectors in tropical cyclone track forecasting - A review. On the bogusing of tropical cyclones in numerical models: The influence of vertical structure. Sensitivity of hurricane intensity forecasts to physical initialization. Characteristics of the asymmetric circulation associated with tropical cyclone motion.
Recent trends in Australian region tropical cyclone activity. High resolution numerical simulation of tropical cyclone Drena undergoing extra-tropical transition. Tropical cyclone track predictability. Dissipative heating and hurricane intensity. Relative timing of tropical storm lifetime maximum intensity and track recurvature. Rainfall and the day wave-like disturbance in West Africa during summer On the role of "hot towers" in tropical cyclone formation.
The formation of tropical cyclones. A study of hurricane dynamics using a two-fluid axisymmetric model. Carr, III, and M. Progress toward a generalized description of the environment structure contribution to tropical cyclone track types.
Multi-year prediction model of North Atlantic hurricane activity. Tropical cyclones, day oscillations, and tropical-extratropical interaction over the Northwestern Pacific. A fast moving easterly wave of the West Africa troposphere. Eastern hemisphere tropical cyclones ofMon. Structure and evolution hurricane Claudette on 7 September from airborne doppler radar observations.
Statistical analysis of the characteristics of severe typhoons hitting the Japanese main islands, Mon. Atlantic hurricane season ofMon. Atlantic Tropical Systems of and Eastern North Pacific hurricane season ofMon. A look a global tropical cyclone activity during Contrasting high Atlantic activity with low activity in other basins.
The extremely active Atlantic hurricane season: Upper-Ocean temperature response to hurricane Felix as measured by the Bermuda testbed mooring, Mon. The impact of multispectral GOES-8 wind information on Atlantic tropical cyclone track forecast in Satellite-derived latent heating distribution and environmental influences in hurricane OpalMon.
Improved hurricane track forecasting from the continuous assimilation of high quality satellite wind data.
LeMeurand R. Improvement of the NCEP global model over the tropics: An evaluation of model performance during the hurricane season.
The performance of the United Kingdom Meteorological Ofice global model in predicting the tracks of Atlantic tropical cyclones in Tropical cyclone forecasts made with the FSU global spectral model. Case study of Erin using the FSU nested regional spectral model. Numerical prediction of Hurricane Opal. Spatial and temporal extent of sea surface temperature modifications by hurricanes in the Sargasso Sea during the season. Objective diagnosis of binary tropical cyclone interactions for the Western North Pacific Basin, Mon.
Tropical cyclone eye thermodynamics. A simple theoretical model for the intensification of tropical cyclones and polar lows,Q. Greek letters are used if the entire list is used within a season and if a hurricane forms outside the official hurricane season, it is named after the date on which it occurs.
But people pay the most attention to them when they come near land, and rightly so, because hurricanes can do a lot of damage.
They are also much bigger than other violent storms, like tornadoes. But at the same time, they are part of an enormous and complicated natural system that makes our planet a place we can live. How Hurricanes, Form, Move, and Die Anatomy of a Hurricane Hurricanes are more complicated than they appear on the radar image of a weather report.
Air rushes around as if on a carousel, while at the same time moving inwards at the bottom of the storm and outwards at the top. Hot, wet air is constantly rising, and cool, dry air is constantly sinking. All the while, the entire system is moving across the surface of the Earth. Scientists who study hurricanes use esoteric terminology to describe the way they move them, speaking of things like deep moist convection, inertia-gravity waves, and vorticity.
But, broadly speaking, a hurricane has only four main parts: Gabby Wharton The eye of a hurricane is the cloud-free, relatively calm area right at the center of the storm, usually between 20 and 40 miles 32 to 65 km in diameter.
The eye remains calm and clear because air slowly sinks into it, suppressing the formation of clouds and keeping wind speeds below about 15 mph. It is surrounded by the eyewall, a towering ring of clouds characterized by heavy rain and strong winds. Wind speeds are fastest in the eyewall, which is why it is dangerous to assume a hurricane has died down as its eye moves over you. Super-strong winds will return as the hurricane continues to advance. Surrounding the eyewall are bands of cumulus clouds, which are often tens of miles wide and usually release rain.
These are the rainbands of the hurricane. Unlike the central ring of the eyewall, the rainbands spiral out from the center of the storm, sometimes intersecting the eyewall at their inner end.
Outer rainbands may organize into a ring shape and move inward, replacing the original eyewall in a process that temporarily weakens the hurricane.
Rainbands also produce tornadoes. The eyewall of Hurricane Isabel in as seen from a plane. In fact, underneath the cloud cover, stormy rainbands which you can see on radar images alternate with rainless gaps where light breezes blow. Air that rises in the rainbands then spirals out of the top of the hurricane through this uppermost cloud layer. How a Hurricane Dies Hurricanes dissipate for a variety of reasons. They weaken quickly over land, which cuts them off from the moisture and heat of tropical ocean water and slows them down with greater friction than the sea surface.
Even the warmest and swampiest areas of land, like the Everglades in Florida, will considerably slow down wind speeds and raise the pressure in the low-pressure center of a hurricane. Vertical wind shear allows dry air into the core of a hurricane, which will weaken it considerably. Hurricanes also weaken when they move over colder water outside of the tropics. But none of these things are guaranteed to stop a hurricane.
For instance, a hurricane might weaken when it passes over land, but rejuvenate when it moves out over tropical water again, like Hurricane Andrew did after passing over the Bahamas in If it moves out of the tropics, a hurricane can become a different kind of storm. Hurricane Ike grew to a Category 4 hurricane temporarily but the Caribbean islands took away its steam.
Once a hurricane hits land it loses its source of power, namely, the heat and moisture of the ocean. NOAA What happens during an extratropical transition? As it moves out of the tropics, a storm may encounter increased vertical wind shear, changes in humidity over distance, and decreased or quickly changing sea surface temperatures—all conditions that disrupt hurricanes.
Instead of rotating symmetrically around a core, the storm disarranges itself and spreads out to a much larger size. The high-level canopy layer of clouds, which is characteristic of a hurricane, no longer resembles a symmetrical pinwheel in satellite images.
The structure of the storm starts to look like it does when a warm and a cold front meet each other—a comma shape instead of a spiral shape. As it enters the mid-latitudes, the storm gets caught in the prevailing westerly winds, and it picks up speed, accelerating from perhaps 11 miles per hour in the tropics to 45 miles per hour at higher latitudes.
After the extratropical transition, a storm can still generate lots of rainfall and large ocean waves, and sometimes even hurricane-force winds. A mid-latitude cyclone can be just as dangerous as a hurricane under certain circumstances, even though its winds are not as fast.
But it too will eventually lose steam. In remnants of Tropical Storm Bill dropped over 10 inches of rain in one night in southern Oklahoma, a prime example of how cyclonic storms can cause major damage even far from the coast. Certainly, humans are capable of changing the natural world in many ways, from damming mighty rivers to breaking shipping passages through Arctic ice. People have wondered if humans could stop a hurricane by seeding it with silver iodide, placing substances on the ocean surface to inhibit the ocean-air heat transfer, cooling surface waters with ice, pumping cold water to the surface from lower down in the ocean, adding moisture-absorbing substances to the hurricane, and even attacking it with nuclear weapons.
The other ideas are also impractical. We can instead opt to spend resources on predicting them and building infrastructure to resist them. Variation Across the Globe The World Meteorological Organization designates seven different hurricane formation basins in the world.
A map of the hurricane basins around the globe. Hurricane-level storms that occur in the northern Atlantic Ocean and northeast Pacific Ocean are called hurricanes, while those in the Northwest Pacific are called typhoons. In other parts of the world, these storms are called severe tropical cyclones, severe cyclonic storms, and tropical cyclones. This can get confusing, but the key similarity is that they all gain their power from tropical warmth.
Calling hurricanes different things in different places is a matter of convention. However, there are substantive differences in the hurricane activity that occurs in different hurricane basins.
For one thing, hurricane season varies from basin to basin. And, notably, the North Indian season has two peaks—one in May and one in November. The dip in hurricane activity between them is due to the way the monsoon affects wind shear. Basins also differ in the number of hurricanes they see every year.
In the Atlantic basin, the annual average is about six hurricanes. The Northwest Pacific sees by far the largest number of hurricanes each year, with an average of More hurricanes occur in the Northern Hemisphere 69 percent than the Southern 31 percent.
Furthermore, of the hurricanes occurring in the Northern Hemisphere, 57 percent occur in the Pacific Ocean and 31 percent occur in the Indian Ocean, with only 12 percent occurring in the Atlantic. While there are many different names for hurricanes across the globe, keep in mind that just because a storm swirls in a massive cyclone doesn't mean it is a hurricane from the tropics—there are other types of cyclones.
Mid-latitude cyclones occur when a mass of cold air collides with a mass of warm air. Hurricane Tracks Knowledge of major atmospheric circulation patterns in different basins allows us to make generalizations about the most common tracks of hurricanes.
For example, a hurricane that forms in the tropical Atlantic will typically be blown westward by the easterly trade winds that dominate the low latitudes. If you look at the aggregate of the paths of all Atlantic hurricanes over the past century or so, they will show you a broad-brush version of this recurvature. North Atlantic tropical storms and hurricanes NOAA General hurricane tracks can similarly be sketched for other hurricane basins, largely based on major atmospheric circulation patterns.
For example, hurricanes in the Northwest Pacific basin tend to move westward towards the East China Sea and then recurve northward and northeastward around the area of high pressure in the Northern Pacific Ocean. Those in the Southwest Indian basin tend to proceed more directly westward across the Indian Ocean towards Madagascar and the eastern coast of continental Africa. Infor example, a hurricane spotted off the coast of Florida was later reported to be moving north and northeast, seemingly following the typical Atlantic recurvature and remaining out at sea.
But the next day, the hurricane hit Long Island, New York, bringing with it a foot wall of water called a storm surge and killing hundreds of people. Studying Hurricanes The Hurricane Forecast Over the past thirty years, we have gotten dramatically better at predicting the tracks of hurricanes—what paths they will follow and where they will hit land.
In the late s, the U. Nowadays, the NHC only misses by about miles.
Typhoon? Hurricane? Cyclone? Here's the difference
Except for sending pilots to fly through a hurricane and measure wind speed, using an algorithm called the Dvorak technique to interpret satellite images of hurricane shape is currently the best way to judge its intensity.
The satellites use specialized radar and microwave technology to map the precipitation of a hurricane and help scientists study the storm. This scan is of Hurricane Patricia in For instance, when Hurricane Irma hit Florida init made a big difference to the people living there whether the landfall was predicted for the west coast of the peninsula or the east coast of the peninsula.
The answer lies in a subdiscipline of mathematics called chaos theory that was developed during the s by a meteorologist named Edward Lorenz. It tells us that a very small variation in initial conditions can produce a huge and sometimes unexpected variation in eventual outcomes. Lorenz called this the butterfly effect—imagine a butterfly in Brazil stirring up a tiny amount of air by flapping its wings, influencing a tornado in Texas several weeks later.
Which Is It? Hurricane, Typhoon Or Tropical Cyclone? : The Two-Way : NPR
On September 8, it was still unclear whether Hurricane Irma would hug the eastern coast of Florida or steer towards the western coast along the Gulf of Mexico, leading many Floridians on both coasts to question whether they would bear the brunt of the storm.
Today, meteorologists use a range of models as well as their own savvy to make the very best predictions they can. Statistical models aggregate decades of historical data to predict what a hurricane is likely to do based on how past hurricanes have behaved. Dynamical models use powerful computers to model the atmosphere using equations and data from satellites, on-the-ground measurements, and hurricane flyers.
Meteorologists use their expertise to sort through all the data from the field and results from the models, and then they make a prediction. In addition to predicting where a hurricane will go scientists must also predict to what extent it will intensify, and this too is a tough job. In general, scientists use data about how warm the ocean is, how much moisture there is in the air, and how consistent the winds are throughout the layers of the atmosphere to determine how much a hurricane will build in intensity.
But there are other, smaller processes like thunderstorm formation, rain formation, and ice formation that can affect that intensification process. Hurricane Michael ofthe third strongest storm to hit the continental United States, is a prime example of such intensification.
The storm jumped from a Category 2 to a Category 5 in only 24 hours, an intensification that proved to be tough to predict. Researchers from one such study combed through recently translated indigenous Hawaiian newspapers to find references to natural disasters, a process that revealed a reference to the notoriously devastating hurricane in By piecing together damage accounts from across the Hawaiian Islands the historians determined the trajectory and intensity of the hurricane. Many things can throw a wrench into hurricane track predictions.
First described by Japanese meteorologist Fujiwhara Sakuhei inthe Fujiwhara effect occurs when two hurricanes get within miles km of each other. Once they are within that distance, they will rotate around a point directly between their centers, like dancers circling each other.
If the storms are about the same size, the interaction might simply alter their trajectories before they break apart. On the other hand, if one storm is much smaller than the other, then the larger storm might absorb the smaller one once they get close enough.
Meteorologists classify tropical cyclones depending on their wind speed. Once the winds reach 74 mph km per hourthe storm graduates to hurricane status. Usually, that is the wind speed necessary for an eye to form in its center.
Meteorologists sort hurricanes into five categories depending on their maximum sustained wind speed. Versions of the Saffir-Simpson Scale are used officially in the U. Terrifying Category 5 storms have petered out at sea without doing any human damage at all. Hurricanes and the Natural World When we think of hurricane damage, we tend to think of the way these storms impact people and human infrastructure—and for good reason.
But even when hurricanes barely touch humans, they can wreak havoc on the natural world. A hurricane can leave its mark by rearranging geography.
Hurricanes change coastlines, uprooting trees with their powerful winds and moving earth with the force of water. When Hurricane Agnes hit the Chesapeake Bay init reconfigured the hydrology of the area, eroding away the mouths of tributaries to the Bay and transporting huge amounts of sediment upstream.
In the tropics, new islands can be formed by the accumulation of coral skeletons, and sometimes entire blocks of reef are displaced by the hurricane and deposited on top of the shallow near-shore zone of the reef. These crops were toppled by Typhoon Sarika in in Hainan, China. When Hurricane Agnes hit the Chesapeake Bay, it decimated the population of oysters and soft-shelled clams in that estuarine ecosystem.
In the Chesapeake Bay, Agnes severely stressed organisms that lived only in a specific salinity range and lacked the ability to move into a less affected area. Hurricanes may also destroy coastal wetlands Source 51reduce the population of submerged aquatic plants—which shelter and feed many aquatic species—and depress the reproduction of fish whose eggs and larvae are washed away. Coral reefs are particularly prone to hurricane damage because they are shallow-water ecosystems in the tropics.
The damage begins with brute-force destruction dealt by high-intensity waves and debris in the water. Hurricanes smash and sweep away corals, and reefs that run perpendicular to the prevailing winds and waves bear the brunt of the impact.