Cyclone Geralda (1994)
Encyclopedia
Cyclone Geralda was a powerful tropical cyclone which caused catastrophic damage in Madagascar
in late January 1994. Geralda is one of the strongest tropical storms to hit Madagascar, falling only behind in intensity to Cyclone Gafilo
. It is also the third strongest tropical storm in the South-west Indian Ocean basin. Originating from an area of low pressure over the Indian Ocean
on January 25, the system began on January 26 as a weak depression . Over the following few days, the depression underwent gradual intensification, reaching its peak intensity with winds of 200 km/h (10-minute sustained) on January 31 . Cyclone Geralda made landfall near Toamasina
, Madagascar after weakening into a Category 3 storm on February 2-3 . Within hours of moving onshore, the system had substantially weakened. By February 5, Geralda had degenerated into a land depression.
(JTWC) started to monitor an area of low pressure
, that was located within the South-West Indian Ocean
about 4385 km (3000 mi) to the south of New Delhi
, India. During the next day, the low pressure area interacted with the Intertropical Convergence Zone
and an anticyclone
, convection became sufficiently organized for the Regional Specialized Meteorological Center
on the French island of La Réunion
to declare it a tropical depression
at 1800 UTC and initiate warnings on the system. During January 27 as it continued to rapidly organize further, RSMC La Reunion and the JTWC reported that the depression had developed into Tropical Storm 13S before the Mauritius Meteorological Service named it Geralda at 1200 UTC. Over the next couple of days Geralda moved towards the west around the subtropical ridge of high pressure while gradually intensifying further before late on October 28, both RSMC la Reunion and the JTWC, reported that it intensified into a tropical cyclone. At that time the system had windspeeds of 70 mph (112.7 km/h) equivalent to a category 1 tropical cyclone on the Saffir-Simpson Hurricane scale
.
was also damaged severely. 40 000 houses were destroyed or damaged. Lines of communications, railways, roads and bridges were brought down by the extreme force of the storm .
Madagascar
The Republic of Madagascar is an island country located in the Indian Ocean off the southeastern coast of Africa...
in late January 1994. Geralda is one of the strongest tropical storms to hit Madagascar, falling only behind in intensity to Cyclone Gafilo
Cyclone Gafilo
Cyclone Gafilo was a powerful tropical cyclone which struck Madagascar in March 2004, causing devastating damage. It is the most intense cyclone ever to form in the south-western Indian Ocean.-Meteorological history:...
. It is also the third strongest tropical storm in the South-west Indian Ocean basin. Originating from an area of low pressure over the Indian Ocean
Indian Ocean
The Indian Ocean is the third largest of the world's oceanic divisions, covering approximately 20% of the water on the Earth's surface. It is bounded on the north by the Indian Subcontinent and Arabian Peninsula ; on the west by eastern Africa; on the east by Indochina, the Sunda Islands, and...
on January 25, the system began on January 26 as a weak depression . Over the following few days, the depression underwent gradual intensification, reaching its peak intensity with winds of 200 km/h (10-minute sustained) on January 31 . Cyclone Geralda made landfall near Toamasina
Toamasina
Toamasina , meaning "like salt" or "salty", unofficially and in French also Tamatave, is a city on the east coast of Madagascar on the Indian Ocean. The city is the chief seaport of the country, situated northeast of its capital and biggest city Antananarivo, near the centre of the eastern coast...
, Madagascar after weakening into a Category 3 storm on February 2-3 . Within hours of moving onshore, the system had substantially weakened. By February 5, Geralda had degenerated into a land depression.
Meteorological history
Late on January 25 the Joint Typhoon Warning CenterJoint Typhoon Warning Center
The Joint Typhoon Warning Center is a joint United States Navy – United States Air Force task force located at the Naval Maritime Forecast Center in Pearl Harbor, Hawaii...
(JTWC) started to monitor an area of low pressure
Low pressure area
A low-pressure area, or "low", is a region where the atmospheric pressure at sea level is below that of surrounding locations. Low-pressure systems form under areas of wind divergence which occur in upper levels of the troposphere. The formation process of a low-pressure area is known as...
, that was located within the South-West Indian Ocean
Tropical cyclone basins
Traditionally, areas of tropical cyclone formation are divided into seven basins. These include the north Atlantic Ocean, the eastern and western parts of the northern Pacific Ocean, the southwestern Pacific, the southwestern and southeastern Indian Oceans, and the northern Indian Ocean. The...
about 4385 km (3000 mi) to the south of New Delhi
New Delhi
New Delhi is the capital city of India. It serves as the centre of the Government of India and the Government of the National Capital Territory of Delhi. New Delhi is situated within the metropolis of Delhi. It is one of the nine districts of Delhi Union Territory. The total area of the city is...
, India. During the next day, the low pressure area interacted with the Intertropical Convergence Zone
Intertropical Convergence Zone
The Intertropical Convergence Zone , known by sailors as The Doldrums, is the area encircling the earth near the equator where winds originating in the northern and southern hemispheres come together....
and an anticyclone
Anticyclone
An anticyclone is a weather phenomenon defined by the United States' National Weather Service's glossary as "[a] large-scale circulation of winds around a central region of high atmospheric pressure, clockwise in the Northern Hemisphere, counterclockwise in the Southern Hemisphere"...
, convection became sufficiently organized for the Regional Specialized Meteorological Center
Regional Specialized Meteorological Center
A Regional Specialized Meteorological Centre is responsible for the distribution of information, advisories, and warnings regarding the specific program they have a part of, agreed by consensus at the World Meteorological Organization as part of the World Weather Watch.-Tropical...
on the French island of La Réunion
La Reunion
La Reunion may refer to:* La Reunion , a communal settlement near present-day Dallas, Texas*La Réunion, Lot-et-Garonne, a town in the Lot-et-Garonne department of France*Réunion, an island in the Indian Ocean east of Madagascar...
to declare it a tropical depression
Tropical cyclone
A tropical cyclone is a storm system characterized by a large low-pressure center and numerous thunderstorms that produce strong winds and heavy rain. Tropical cyclones strengthen when water evaporated from the ocean is released as the saturated air rises, resulting in condensation of water vapor...
at 1800 UTC and initiate warnings on the system. During January 27 as it continued to rapidly organize further, RSMC La Reunion and the JTWC reported that the depression had developed into Tropical Storm 13S before the Mauritius Meteorological Service named it Geralda at 1200 UTC. Over the next couple of days Geralda moved towards the west around the subtropical ridge of high pressure while gradually intensifying further before late on October 28, both RSMC la Reunion and the JTWC, reported that it intensified into a tropical cyclone. At that time the system had windspeeds of 70 mph (112.7 km/h) equivalent to a category 1 tropical cyclone on the Saffir-Simpson Hurricane scale
Saffir-Simpson Hurricane Scale
The Saffir–Simpson Hurricane Scale , or the Saffir–Simpson Hurricane Wind Scale , classifies hurricanes — Western Hemisphere tropical cyclones that exceed the intensities of tropical depressions and tropical storms — into five categories distinguished by the intensities of their sustained winds...
.
Infrastructure
When Geralda made a landfall just south of Toamasina, it destroyed 80% of the city's seaport. Toamasina, at that time the only refinery in MadagascarMadagascar
The Republic of Madagascar is an island country located in the Indian Ocean off the southeastern coast of Africa...
was also damaged severely. 40 000 houses were destroyed or damaged. Lines of communications, railways, roads and bridges were brought down by the extreme force of the storm .