A study about Typhoons n Cyclones

1. CYCLONES
DEFINATION
A cyclone is a low pressure area surrounded by high pressure
area form all sides . It is a circular or elliptical in shape .
Winds move from all sides to central low . They assume
anticlockwise direction in the northern hemisphere and
clockwise in the southern hemisphere due to cariolis effect.
ITS OF TWO TYPES
TEMPARERATE C YCLONE
TROPICAL CYCLONE

2. CHARACTERSTICS OF CYCLONES
To make the most efficient analysis of available data in the vicinity of typhoon, you must
be familiar with the normal wind, pressure, temperature, clouds and weather pattern
associated with these storms.
1.SURFACE WINDS The surface winds blow inward in a counterclockwise
direction toward the center. The winds in the left-rear quadrant have the
greatest angle of inflow (in the Northern Hemisphere). The diameter of
the area affected by hurricane or typhoon force winds may be in excess of
100 miles in large storms or as small as 25 to 35 miles. Gale-force winds
sometimes cover an area 500 to 800 miles or more. The maximum extent
of strong winds is usually in the direction of the major subtropical high-pressure
center, which is most frequently found to the right of the storm’s
path in the Northern Hemisphere. Surface wind speeds of 140 knots have
been successfully recorded, but accurate measurements of peak wind
speeds in large mature storms have not been possible with any reliable
degree of accuracy.

3. CHARACTERSTICS OF CYCLONES
• SURFACE PRESSURE.— The sea-level isobars are
an excellent tool with which to analyze these
storms. The isobars take on a nearly symmetrical
or elliptical shape, although deformations in the
isobaric pattern are not uncommon. For instance,
the tightest isobaric spacing (strongest pressure
gradient) is found to the right of a storm’s line of
movement, and a trough often extends
southward from these storms. The central
pressures of mature storms are well below
average. Central pressures of 890 to 930 millibars
are not uncommon.

4. CHARACTERSTICS OF CYCLONES
• SURFACECE TEMPERATURE.— In contrast to extratropical cyclones,
the tropical cyclone may show no cooling, or very little, toward the
storm center. This indicates that the horizontal adiabatic cooling
caused by lower pressures is largely offset by the heat added
through the condensation process. Upper-air temperatures have
been found warmer by 5 ‘C or more.
• CLOUDS.— The cloud patterns of tropical cyclones also differ from
those of extratropical cyclones. In mature tropical cyclones, almost
all the cloud forms are present, but by and large the most
significant clouds are the heavy cumulus and cumulonimbus which
spiral inward toward the outer edge of the eye. These spiral bands,
especially the leading ones, are also referred to as BARS. Cirrus and
Cirrostratus occupy the largest portion of the sky over these storms.
In fact, cirrus, becoming more dense, then changing to cirrostratus
and lowering somewhat is more often than not a mariner’s first
indication of an approaching distant storm or the development of
one in the near vicinity. The appearance of the sky is very similar to
that of an approaching warm front. A typical cloud distribution
chart for a tropical cyclone is found in figure 9-3-7.

5. CHARACTERSTICS OF CYCLONES
THE EYE.— The eye of a storm is one of the oddest
phenomena known in meteorology. Precipitation
ceases abruptly at the boundary of a well-developed
eye; the sky partly clears; the sun or stars become
visible; the wind subsides to less than 15 knots, and at
times there is a dead calm. In mature storms, the eye’s
diameter averages about 15 miles, but it may attain 40
miles in large typhoons. The eye is not always circular;
sometimes it becomes elongated and even diffuse
with a double structure appearance. The eye is
constantly undergoing transformation and does not
stay in a steady state.

6. INTENSITY CLASSIFICATION
• A tropical depression is the lowest category that the Japan Meteorological Agency
uses and is the term used for a tropical system that has wind speeds not exceeding
33 knots (38 mph; 61 km/h).[7] A tropical depression is upgraded to a tropical
storm should its sustained wind speeds exceed 34 knots (39 mph; 63 km/h).
Tropical storms also receive official names from RSMC Tokyo.[7] Should the storm
intensify further and reach sustained wind speeds of 48 knots (55 mph; 89 km/h)
then it will be classified as a severe tropical storm.[7] Once the system's maximum
sustained winds reach wind speeds of 64 knots (74 mph; 119 km/h), the JMA will
designate the tropical cyclone as a typhoon—the highest category on its scale.[7]
• From 2009 the Hong Kong Observatory started to further divide typhoons into
three different classifications: typhoon, severe typhoon and super typhoon.[8] A
typhoon has wind speed of 64-79 knots (73-91 mph; 118-149 km/h), a severe
typhoon has winds of at least 80 knots (92 mph; 150 km/h), and a super typhoon
has winds of at least 100 knots (120 mph; 190 km/h).[8] The United States' Joint
Typhoon Warning Center (JTWC) unofficially classifies typhoons with wind speeds
of at least 130 knots (67 m/s; 150 mph; 241 km/h)—the equivalent of a strong
Category 4 storm in the Saffir-Simpson scale—as super typhoons.[9] However, the
maximum sustained wind speed measurements that the JTWC uses are based on a
1-minute averaging period, akin to the U.S.' National Hurricane Center and Central
Pacific Hurricane Center. As a result, the JTWC's wind reports are higher than
JMA's measurements, as the latter are based on a 10-minute averaging
interval.[10]

7. INTENSITY CLASSIFICATION
CATEGORY SUBSTAINED WINDS
TYPHOON 64 – 84 KNOTS
118 - 156 KM/H
SEVERE TROPICAL
STORM
48 - 63 KNOTS
89 - 117 KM/H
TROPICAL STORM 34 -47 KNOTS
62 - 88 KM/H
TROPICAL
DISPERSION
< 33 KNOTS
< 61 KM/H

8. FORMATION OF CYCLONES
• In tropical oceans, the water in the oceans' surface layer heated by the direct solar
radiation. As a result, the air above the tropical oceans is characterized by high
temperature and humidity, resulting in air inflation that easily leads to low density per
unit volume of air. Weak wind near the equator causes the lighter air to soar and incur
convection that further attracts inflow of surrounding cooler air. The intake air then
warms up and soars again, creating a positive feedback cycle that eventually forms an air
column with high temperature, light weight and low density. This is how the tropical
depression forms.
• The air flows from high pressure towards low pressure as if the water flows from high to
low elevation. The surrounding air with higher pressure will flow towards where the
pressure is lower, creating the "wind." As the area for direct solar radiation moves
northward away from the equator in summer, the southeasterly trade wind in the
Southern Hemisphere crosses the equator and penetrates into the Northern Hemisphere
in the form of southwest monsoon, which has heads-on encounter with the
northeasterly trade wind in the Northern Hemisphere and forces the air in this area to
soar, creating more convection. Furthermore, the wind convergence resulting from the
southwesterly and the northeasterly trade winds often cause air turbulence and
whirlpool. These convergence effects, when continually enhanced by the convection
activity, further deepens the existing low-pressure vortex, resulting in more and faster
ambient air flow been drawing into the vortex center. Faster inflow corresponds to higher
wind speed which, when the near-ground maximum speed reaches or exceeds 62 km per
hour or 17.2 meter per second, is characteristic of a typhoon.

9. FORMATION OF CYCLONES

10. NAMING OF CYCLONES
• Tropical cyclones have officially been named since 1945 and are named for
a variety of reasons, which include to facilitate communications between
forecasters and the public when forecasts, watches, and warnings are
issued. Names also reduce confusion about what storm is being described,
as more than one can occur in the same region at the same time.[1] The
official practice of naming tropical cyclones started in 1945 within the
Western Pacific and was gradually extended out until 2004, when the
Indian Meteorological Department started to name cyclonic storms within
the North Indian ocean. Names were first given to storms by Australian
meteorologist Clement Wragge from 1887, Before the official practice of
naming of tropical cyclones began, significant tropical cyclones were
named after annoying politicians, mythological creatures, saints and place
names. Names are drawn in order from predetermined lists (see Lists of
tropical cyclone names) and are usually assigned to tropical cyclones with
one-, three-, or ten-minute sustained wind speeds of more than 65 km/h
(40 mph) depending on which area it originates. However, standards vary
from basin to basin with some tropical depressions named in the Western
Pacific, while within the Southern Hemisphere tropical cyclones have to
have a significant amount of gale-force winds occurring around the center
before they are named.

11. EFFECTS OF CYCLONES
• The main effects of tropical cyclones include heavy rain, strong
wind, large storm surges at landfall, and tornadoes. The destruction
from a tropical cyclone depends mainly on its intensity, its size, and
its location. Tropical cyclones act to remove forest canopy as well as
change the landscape near coastal areas, by moving and reshaping
sand dunes and causing extensive erosion along the coast. Even
well inland, heavy rainfall can lead to mudslides and landslides in
mountainous areas. Their effects can be sensed over time by
studying the concentration of the Oxygen-18 isotope within caves
within the vicinity of cyclones' paths.
• After the cyclone has passed, devastation often continues. Standing
water can cause the spread of disease, and transportation or
communications infrastructure may have been destroyed,
hampering clean-up and rescue efforts. Nearly two million people
have died globally due to tropical cyclones. Despite their
devastating effects, tropical cyclones are also beneficial, by
potentially bringing rain to dry areas and moving heat from the
tropics poleward. Out at sea, ships take advantage of their known
characteristics by navigating through their weaker, western half.

12. EFFECTS OF CYCLONES
AT SEA
• A mature tropical cyclone can release heat at a rate upwards of
6x1014 watts.[1] Tropical cyclones on the open sea cause large
waves, heavy rain, and high winds, disrupting international shipping
and, at times, causing shipwrecks.[2] Generally, after its passage, a
tropical cyclone stirs up ocean water, lowering sea surface
temperatures behind it.[3] This cool wake can cause the region to
be less favorable for a subsequent tropical cyclone. On rare
occasions, tropical cyclones may actually do the opposite. 2005's
Hurricane Dennis blew warm water behind it, contributing to the
unprecedented intensity of Hurricane Emily, which followed it
closely.[4] Hurricanes help to maintain the global heat balance by
moving warm, moist tropical air to the mid-latitudes and polar
regions.[5] Were it not for the movement of heat poleward
(through other means as well as hurricanes), the tropical regions
would be unbearably hot.

13. EFFECTS OF CYCLONES
STORM SURGE
• The aftermath of Hurricane Katrina in Gulfport, Mississippi.
Katrina was the costliest tropical cyclone in United States
history.
• See also: Storm surge
• The storm surge, or the increase in sea level due to the
cyclone, is typically the worst effect from landfalling
tropical cyclones, historically resulting in 90% of tropical
cyclone deaths.[13] The relatively quick surge in sea level
can move miles/kilometers inland, flooding homes and
cutting off escape routes. The storm surges and winds of
hurricanes may be destructive to human-made structures,
but they also stir up the waters of coastal estuaries, which
are typically important fish breeding locales.

14. EFFECTS OF CYCLONES
HEAVY RAINFALL
• The thunderstorm activity in a tropical cyclone produces intense rainfall,
potentially resulting in flooding, mudslides, and landslides. Inland areas are
particularly vulnerable to freshwater flooding, due to residents not preparing
adequately.[14] Heavy inland rainfall eventually flows into coastal estuaries,
damaging marine life in coastal estuaries.[15] The wet environment in the
aftermath of a tropical cyclone, combined with the destruction of sanitation
facilities and a warm tropical climate, can induce epidemics of disease which claim
lives long after the storm passes.[13] Infections of cuts and bruises can be greatly
amplified by wading in sewage-polluted water. Large areas of standing water
caused by flooding also contribute to mosquito-borne illnesses. Furthermore,
crowded evacuees in shelters increase the risk of disease propagation.[13]
• Flooding in Seminole County, Florida from Tropical Storm Fay (2008)
• Although cyclones take an enormous toll in lives and personal property, they may
be important factors in the precipitation regimes of places they affect and bring
much-needed precipitation to otherwise dry regions. Hurricanes in the eastern
north Pacific often supply moisture to the Southwestern United States and parts of
Mexico.[16] Japan receives over half of its rainfall from typhoons.[17] Hurricane
Camille averted drought conditions and ended water deficits along much of its
path,[18] though it also killed 259 people and caused $9.14 billion (2005 USD) in
damage.

15. EFFECTS OF CYCLONES
DEATHS
• During the last two centuries, tropical
cyclones have been responsible for the deaths
of about 1.9 million people worldwide. It is
estimated that 10,000 people per year perish
due to tropical cyclones.[21] The deadliest
tropical cyclone was the 1970 Bhola cyclone,
which had a death toll of anywhere from
300,000 to 500,000 lives.

16. EFFECTS OF CYCLONES
RECONSTURCTION AND REPOUPLATION
• Aerial image of destroyed homes in Punta Gorda, Florida, following
Hurricane Charley
• While tropical cyclones may well seriously damage settlement, total
destruction encourages rebuilding. For example, the destruction
wrought by Hurricane Camille on the Gulf coast spurred
redevelopment, greatly increasing local property values.[18]
Research indicates that the typical hurricane strike raises real house
prices for a number of years, with a maximum effect of between 3
percent to 4 percent three years after occurrence.[25] However,
disaster response officials point out that redevelopment
encourages more people to live in clearly dangerous areas subject
to future deadly storms. Hurricane Katrina is the most obvious
example, as it devastated the region that had been revitalized after
Hurricane Camille. Many former residents and businesses do
relocate to inland areas away from the threat of future hurricanes
as well.

17. EFFECTS OF CYCLONES

18. EFFECTS OF CYCLONES

19. TRACKS AND AREAS OF CYCLONES
• Tropical cyclones are more active in summer . Their
areas of activity is the tropical zone.
• The following are some of the characteristics of the
tracks of a cyclones :
• 1. Between the equator and 15°latitude, these storms
turn towards the west with the trades.
• 2. Between 15° and 30° latitude the path is very
uncertain. But these travel towards the north in the
northern hemisphere and the south in the southern
hemisphere.
• 3. As these cross 30° latitude they turn towards the
east and take much of the character of the temperate
cyclone . Their terrific energy also declines.

20. DIFFERENT NAMES OF CYCLONES IN
DIFFERENT COUNTRIES
• The chief areas of activity for the cyclone are the following :
• 1. West Indies and the Coast of Florida. In that region these
are known as HURRICANES.
• 2. Philippine Islands, the coasts of China and Japan. These
are known as TYPHOONS.
• 3. Bay of Bengal and the Arabian Sea, where these are
known as CYCLONES.
• 4. Madagascar and the coastal regions of East Africa.
• 5. Northeast and Northwestern coasts of Australia, where
they are called WELLY-WELLIES.
• They are known as TORNADOES in the U.S.A. and Mexico.

21. HISTORIC LIST
• Tropical cyclones are named for historical reasons and so to avoid confusion when
communicating with the public as more than one tropical cyclone can exist at a
time. Names are drawn in order from predetermined lists and are usually assigned
to tropical cyclones with one, three or ten minute wind speeds of more than 65
km/h (40 mph). However standards vary from basin to basin with some tropical
depressions named in the Western Pacific whilst tropical cyclones have to have
gale force winds occurring more than halfway around the center within the
Australian and Southern Pacific regions.
• The official practice of naming tropical cyclones started in 1945 within the Western
Pacific. Naming continued through the next few years before in 1950, names also
started to be assigned to tropical storms forming in the North Atlantic ocean. In
the Atlantic, names were originally taken from the world war two version of the
Phonetic Alphabet but this was changed in 1953 to use lists of women names
which were drawn up yearly. Around this time naming of tropical cyclones also
began within the Southern and Central parts of the Pacific. However naming didn't
begin the Eastern Pacific until 1960 with the original naming lists designed to be
used year after year in sequence. In 1960, naming also began in the Southwest
Indian Ocean before in 1963 the Philippine Meteorological Service, started
assigning names to tropical cyclones that moved into or formed in their area of
responsibility. Later in 1963 warning centers within the Australian region also
commenced naming tropical cyclones.

22. HISTORIC LIST
• NORTH ATLANTIC
• By 1950 tropical cyclones that were judged by the US Weather Bureau to have intensified into a
tropical storm, started to be assigned names.[1][2] Storms were originally named in alphabetical
order using the World War II version of the Phonetic Alphabet.[1] By 1952 a new phonetic alphabet
had been developed and this led to confusion as some parties wanted to use the newer phonetic
alphabet.[1] In 1953, to alleviate any confusion, forecasters decided to use a set of 23 feminine
names.[1][2] After the 1953 Atlantic hurricane season, public reception to the idea seemed
favorable, so the same list was adopted for the next year with one change; Gilda for Gail.[1]
However after storms like Carol and Hazel got a lot of publicity during the 1953 season, forecasters
agreed to develop a new set of names for 1955.[1] However before this could happen, a tropical
storm was declared significant on January 2, 1955 and was named as Alice.[1] The new set of
names were developed and used in 1955 beginning with Brenda continuing through the alphabet
to Zelda.[1] For each season before 1960, a new set of names were developed.[1] In 1960
forecasters decided to begin rotating names in a regular sequence and thus four alphabetical lists
were established to be repeated every four years.[3] The sets followed the example of the western
Pacific typhoon naming lists and excluded names beginning with the letters Q, U, X, Y and Z.[3]
These four lists were used until 1972 when the National Oceanic and Atmospheric Administration
(NOAA), replaced them with 9 lists designed to be used from 1972.[3] In 1977, NOAA made the
decision to relinquish control over the name selection by allowing a regional committee of the
World Meteorological Organization to select the new sets of names which would contain male
names and some Spanish and French names in order to reflect all the cultures and languages within
the Atlantic Ocean.[2][3] The World Meteorological Organization decided that the new lists of
hurricane name would start to be used in 1979.[2][3] Since 1979 the same lists have been used,
with names of significant tropical cyclones removed from the lists and replaced with new names.[2]
In 2002 Subtropical Cyclones started to be assigned names from the main list of names set up for
that year. In 2005 as all the names preselected for the season were exhausted, the contingency plan
of using Greek letters for names had to be used.[4] Since then there have been a few attempts to
get rid of the Greek names, as they are seen to be inconsistent with the standard naming
convention used for tropical cyclones and are considered generally unknown and confusing to the
public.[5] However the lists of preselected names for the year, are not expected to be used up
frequently enough to warrant any change in the existing naming procedure and thus the Greek
Alphabet will be used if the list of pre selected names should ever be used up again.[5][6][7]

23. HISTORIC LIST
• EASTERN PACIFIC
• Within the Eastern Pacific basin between the western coasts of the Americas and 140°W the
naming of tropical cyclones started in 1960, with four lists of female names initially designed to be
used consecutively before being repeated.[31][32] In 1965 after two lists of names had been used,
it was decided to return to the top of the second list and to start recycling the sets of names on an
annual basis.[32][33]
• In 1977, after protests by various women's rights groups, NOAA made the decision to relinquish
control over the name selection by allowing a regional committee of the World Meteorological
Organization (WMO) to select new sets of names.[3] The WMO selected six lists of names which
contained male names and rotated every six years.[3] They also decided that the new lists of
hurricane name would start to be used in 1978 which was a year earlier than the Atlantic.[34] Since
1978 the same lists of names have been used, with names of significant tropical cyclones removed
from the lists and replaced with new names.[32] As in the Atlantic basin should the names
preselected for the season be exhausted, the contingency plan of using Greek letters for names
would be used.[32][35] However unlike in the Atlantic basin the contingency plan has never had to
be used, although in 1985 to avoid using the contingency plan, the letters X, Y, and Z were added to
the lists.[35] Since the contingency plan had to be used in the North Atlantic during 2005 there
have been a few attempts to get rid of the Greek names as they are seen to be inconsistent with
the standard naming convention used for tropical cyclones and are generally unknown and
confusing to the public.[5][6] However none of the attempts have succeeded and thus the Greek
letters will be used should the lists be used up.[5][6]

24. HISTORIC LIST
WESTERN NORTH PACIFIC
• In the Western North Pacific ocean, there are two sets of names
generally used. The first are the international names assigned to a
tropical cyclone by the Japan Meteorological Agency (JMA) or the
Joint Typhoon Warning Center (JTWC). The second set of names are
local names assigned to a tropical cyclone by the Philippine
Atmospheric, Geophysical and Astronomical Services
Administration. This system often ends up with a tropical cyclone
being assigned two names, should a tropical storm threaten the
Philippines.
• On January 1, 2000 the Japan Meteorological Agency as the official
Regional Specialized Meteorological Center took over the naming of
Tropical storms. The names selected by the World Meteorological
Organization's Typhoon Committee were from a pool of names
submitted by the various countries that make up the Typhoon
Committee.

25. HISTORIC LIST
• CENTRAL NORTH PACIFIC
• In 1950 a tropical cyclone that affected Hawaii was named Able, after a tropical
cyclone had not affected Hawaii for a number of years.[40][41] The system
subsequently became widely known as Hurricane Hiki, since Hiki is Hawaiian for
Able.[40][41] Typhoons Olive and Della of 1952 and 1957 developed within the
Central Pacific, but were not named until they had crossed the International
Dateline and moved into the Western Pacific basin.[40][42] During 1957, two other
tropical cyclones developed in the Central Pacific and were named Kanoa and
Nina, by the Hawaiian military meteorological offices.[42] It was subsequently
decided that future tropical cyclones, would be named by borrowing names from
the Western Pacific naming lists.[42] During 1979, after ten names had been
borrowed from the Western Pacific naming lists, Hawaiian names were reinstated
for tropical cyclones developing into tropical storms forming in the Central
Pacific.[33] Five sets of Hawaiian names, using only the 12 letters of the Hawaiian
alphabet, were drafted with the intent being to use the sets of names on an
annual rotation basis.[33] However, after no storms had developed in this region
between 1979 and 1981, the annual lists were scrapped and replaced with four
sets of names and designed to be used consecutively.[33] Ahead of the 2007
hurricane season, the Central Pacific Hurricane Center (CPHC) introduced a revised
set of Hawaiian names for the Central Pacific, after they had worked with the
University of Hawaii Hawaiian Studies Department to ensure the correct meaning
and appropriate historical and cultural use of the names.[43]

26. HISTORIC LIST
• PHILIPPINES
• Since 1963, the Philippine Atmospheric, Geophysical and
Astronomical Services Administration (PAGASA), have assigned their
own names to typhoons that pass through its area of
responsibility.[45] Unlike the World Meteorological Organization's
standard of assigning names to tropical cyclones when they reach
wind-speeds of 65 km/h, (40 mph), PAGASA assigns a name to a
tropical depression when they either form or move into their area
of responsibility.[45][46] Four sets of tropical cyclone names are
rotated annually with typhoon names stricken from the list should
they do more than 1 billion Pesos worth of damage to the
Philippines and/or cause 300 or more deaths.[47][48] Should the
list of names for a given year prove insufficient, names are taken
from an auxiliary list.[47]

27. HISTORIC LIST
• NORTH INDIAN OCEAN
• During its annual session in 2000 the WMO/ESCAP Panel on North Indian tropical cyclones, agreed
in principle to start assigning names to Cyclonic Storms that developed within the North Indian
Ocean.[61][62] As a result the panel requested that each member country submit a list of ten
names to a rapporteur by the end of the year 2000.[62] At the 2001 session of the Panel, the
rapporteur reported that seven of the eight countries had submitted their names.[62] However,
India had refused to submit a list of names, as it had some reservations about assigning names to
tropical cyclones, due to the regional, cultural and lingustic diverstiy of the panel members.[62] The
panel subsquently studied the names and felt that some of the names would not be appealing to
the public or the media, and requested that members submit new lists of names.[62] At the
following years session the rapporteur reported that there had been a poor response by member
countries in resubmitting their lists of names.[62] In response the panel felt that it was important
that the work continued and urged the members to copperate and submit their names to the
rapporteur.[62] The names were subsquently submitted in time for the 2004 session, however,
India had still not submitted their names, despite promising to do so.[62] The rapporteur presented
the 4 lists of names that would be used with a gap left for India's names and recommended that
the India Meteorological Department's Regional Specialised Meterological Centre in New Delhi
name the systems.[62] The rapporteur also recommended that the naming lists were used on an
experimental basis during the season, starting in May or June 2004 and that the lists should only be
used until 2009 when a new list would be drawn up for the following ten years.[62] The naming lists
were then completed in May 2004, after India submitted their names, however the lists were not
used until September 2004 when the first tropical cyclone was named Onil by India Meteorological
Department.[61][63]

28. PLANS FOR DETECTION
• Because of the forces that affect tropical cyclone tracks, accurate track predictions
depend on determining the position and strength of high- and low-pressure areas,
and predicting how those areas will change during the life of a tropical system. The
deep layer mean flow, or average wind through the depth of the troposphere, is
considered the best tool in determining track direction and speed. If storms are
significantly sheared, use of wind speed measurements at a lower altitude, such as
at the 70 kPa pressure surface (3,000 metres or 9,800 feet above sea level) will
produce better predictions. Tropical forecasters also consider smoothing out short-term
wobbles of the storm as it allows them to determine a more accurate long-term
trajectory.[107] High-speed computers and sophisticated simulation software
allow forecasters to produce computer models that predict tropical cyclone tracks
based on the future position and strength of high- and low-pressure systems.
Combining forecast models with increased understanding of the forces that act on
tropical cyclones, as well as with a wealth of data from Earth-orbiting satellites and
other sensors, scientists have increased the accuracy of track forecasts over recent
decades.[108] However, scientists are not as skillful at predicting the intensity of
tropical cyclones.[109] The lack of improvement in intensity forecasting is
attributed to the complexity of tropical systems and an incomplete understanding
of factors that affect their development.

29. MANAGEMENT OF CYCLONES
• Cyclone, tropical cyclone, hurricane, and typhoon
are different names for the same phenomenon a
cyclonic storm system that forms over the
oceans. The deadliest hurricane ever was the
1970 Bhola cyclone; the deadliest Atlantic
hurricane was the Great Hurricane of 1780 which
devastated Martinique, St. Eustatius and
Barbados. Another notable hurricane is Hurricane
Katrina which devastated the Gulf Coast of the
United States in 2005.

30. MANAGEMENT OF CYCLONES
• An effective disaster management system consists of four main
components — disaster prediction, disaster warning, disaster
management and disaster relief. Disaster warning is a basic prerequisite
for ensuring disaster preparedness and in some cases to help in the
prevention of disaster itself. Clearly the most important application of
satellites is in detecting, predicting and delivering early warning of
impending disasters such as flood, drought, cyclone and even forest fires
(Rao et al. 1987; Heath 1994). Continuous monitoring by both
geostationary and low earth orbiting weather satellites like GOES, INSAT,
METEOSAT and NOAA is capable of providing early warning on cyclones
and floods. Forest fires, environmental hazards, volcanic eruptions and
even propagation of desert locust phenomena can be detected well in
time by remote sensing satellites like, LANDSAT, SPOT and IRS. Sustainable
development strategy must address this important issue in order to
provide stability and reasonable security to the vulnerable rural
population in these countries. Remote sensing information are now
operationally used to regularly monitor flood conditions, volume of water
flow and damage assessment. From such a database collected over years,
it is possible to identify different risk zones in the flood prone area based
on the severity index for flood proneness of each zone. Optimal treatment
of each zone on a long term basis, depending on the severity, can then be
attempted to achieve reduction in flood damage without impairing
environmental integrity (Rao 1993)