1991 North Indian Ocean cyclone season
Encyclopedia
The 1991 North Indian Ocean Cyclone season was the period in which tropical cyclones formed to the north of the equator in the Indian ocean. During the season tropical cyclones were monitored by the India Meteorological Department
(IMD) and the Joint Typhoon Warning Center
. The IMD assigned all depressions that it monitored with BOB followed by a number in numerical order. The JTWC also assigned a number and either the letter A or B depending on where the depression was when the first advisory was issued.
During the year there were eight depressions that were monitored by the IMD while the JTWC monitored four during the year of which one was not monitored by the IMD. The first cyclone of the year formed on January 17 and had little effect on ships that were moving through the Arabian sea to take part in the Gulf War
. The deadliest cyclone during the year was Super Cyclonic Storm BOB 01
which killed over 138000 people.
, Sri Lanka
. Over the next couple of days the disturbance moved towards the northwest under the subtropical ridge
of pressure, before early on January 17, the JTWC noticed a steady increase in deep convection and issued a tropical cyclone formation alert
. Later that day the JTWC initiated advisories as the disturbance had intensified into a tropical storm and designated it as Cyclone 01A. As the Cyclone was suffering from being in an area of strong vertical wind shear
it was not able to intensify past minimal tropical storm strength of 65 km/h, (40 mph). During the next couple of days, strong upper level winds stripped deep convection away from the center with the JTWC downgrading the cyclone to a tropical depression early on January 19. The remaining low level circulation center slowly dissipated with the JTWC issuing their final advisory early the next day.
The cyclone posed a direct threat to allied forces, which were operating in the Arabian Sea
, Persian Gulf
and the Red Sea
, in the build up to the Gulf war
. However it was not a significant factor in the build up to the Gulf war and due to it low latitude track and weak intensity it had little effect on ships steaming to the Middle East. As a result of the cyclone remaining out to sea there was no reported impact to land.
. It also destroyed an estimated 1 million homes, leaving as many as 10 million people (a substantial portion of the country's population) homeless.
, India
. As the depression moved towards northwest, it failed to intensify any further. The depression made landfall in the Indian state of Orissa later that day and maintained its identity until it weakened into a low pressure area early on August 26. The depression's windspeeds were estimated to have peaked at 45 km/h (30 mph), whilst the lowest pressure recorded was 992 hPa.
The Cyclonic storm brought torrential rain and flash floods across southern India when it made landfall. Twenty-four hour rainfall totaled 480 millimetres (18.9 in) at Karaikal. As a direct result of the flooding at least 40 people died.
India Meteorological Department
The India Meteorological Department , also referred to as the Met Office, is an agency of the Ministry of Earth Sciences of the Government of India. It is the principal agency responsible for meteorological observations, weather forecasting and seismology...
(IMD) and the Joint Typhoon Warning Center
Joint 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...
. The IMD assigned all depressions that it monitored with BOB followed by a number in numerical order. The JTWC also assigned a number and either the letter A or B depending on where the depression was when the first advisory was issued.
During the year there were eight depressions that were monitored by the IMD while the JTWC monitored four during the year of which one was not monitored by the IMD. The first cyclone of the year formed on January 17 and had little effect on ships that were moving through the Arabian sea to take part in the Gulf War
Gulf War
The Persian Gulf War , commonly referred to as simply the Gulf War, was a war waged by a U.N.-authorized coalition force from 34 nations led by the United States, against Iraq in response to Iraq's invasion and annexation of Kuwait.The war is also known under other names, such as the First Gulf...
. The deadliest cyclone during the year was Super Cyclonic Storm BOB 01
1991 Bangladesh cyclone
-External links:** from NIRAPAD disaster response organisation.**...
which killed over 138000 people.
Tropical Storm 01A
Late on January 14, the JTWC reported that a tropical disturbance had formed about 900 km, (560 mi), to the southeast of ColomboColombo
Colombo is the largest city of Sri Lanka. It is located on the west coast of the island and adjacent to Sri Jayawardenapura Kotte, the capital of Sri Lanka. Colombo is often referred to as the capital of the country, since Sri Jayawardenapura Kotte is a satellite city of Colombo...
, Sri Lanka
Sri Lanka
Sri Lanka, officially the Democratic Socialist Republic of Sri Lanka is a country off the southern coast of the Indian subcontinent. Known until 1972 as Ceylon , Sri Lanka is an island surrounded by the Indian Ocean, the Gulf of Mannar and the Palk Strait, and lies in the vicinity of India and the...
. Over the next couple of days the disturbance moved towards the northwest under the subtropical ridge
Subtropical ridge
The subtropical ridge is a significant belt of high pressure situated around the latitudes of 30°N in the Northern Hemisphere and 30°S in the Southern Hemisphere. It is characterized by mostly calm winds, which acts to reduce air quality under its axis by causing fog overnight, and haze during...
of pressure, before early on January 17, the JTWC noticed a steady increase in deep convection and issued a tropical cyclone formation alert
Tropical Cyclone Formation Alert
A Tropical Cyclone Formation Alert is a bulletin released by the U.S. Navy-operated Joint Typhoon Warning Center in Honolulu, Hawaii or the Naval Maritime Forecast Center in Norfolk, Virginia, warning of the possibility of a tropical cyclone forming from a tropical disturbance that has been...
. Later that day the JTWC initiated advisories as the disturbance had intensified into a tropical storm and designated it as Cyclone 01A. As the Cyclone was suffering from being in an area of strong vertical wind shear
Wind shear
Wind shear, sometimes referred to as windshear or wind gradient, is a difference in wind speed and direction over a relatively short distance in the atmosphere...
it was not able to intensify past minimal tropical storm strength of 65 km/h, (40 mph). During the next couple of days, strong upper level winds stripped deep convection away from the center with the JTWC downgrading the cyclone to a tropical depression early on January 19. The remaining low level circulation center slowly dissipated with the JTWC issuing their final advisory early the next day.
The cyclone posed a direct threat to allied forces, which were operating in the Arabian Sea
Arabian Sea
The Arabian Sea is a region of the Indian Ocean bounded on the east by India, on the north by Pakistan and Iran, on the west by the Arabian Peninsula, on the south, approximately, by a line between Cape Guardafui in northeastern Somalia and Kanyakumari in India...
, Persian Gulf
Persian Gulf
The Persian Gulf, in Southwest Asia, is an extension of the Indian Ocean located between Iran and the Arabian Peninsula.The Persian Gulf was the focus of the 1980–1988 Iran-Iraq War, in which each side attacked the other's oil tankers...
and the Red Sea
Red Sea
The Red Sea is a seawater inlet of the Indian Ocean, lying between Africa and Asia. The connection to the ocean is in the south through the Bab el Mandeb strait and the Gulf of Aden. In the north, there is the Sinai Peninsula, the Gulf of Aqaba, and the Gulf of Suez...
, in the build up to the Gulf war
Gulf War
The Persian Gulf War , commonly referred to as simply the Gulf War, was a war waged by a U.N.-authorized coalition force from 34 nations led by the United States, against Iraq in response to Iraq's invasion and annexation of Kuwait.The war is also known under other names, such as the First Gulf...
. However it was not a significant factor in the build up to the Gulf war and due to it low latitude track and weak intensity it had little effect on ships steaming to the Middle East. As a result of the cyclone remaining out to sea there was no reported impact to land.
Super Cyclonic Storm BOB 01
Cyclone Two hit Bangladesh on April 29 as a strong cyclone. It brought a tremendous storm surge and massive wind damage, resulting in the deaths of over 138,000 people. Cyclone 2B was the deadliest cyclone on Earth since the 1970 Bhola Cyclone1970 Bhola cyclone
The 1970 Bhola cyclone was a devastating tropical cyclone that struck East Pakistan and India's West Bengal on November 12, 1970. It was the deadliest tropical cyclone ever recorded, and one of the deadliest natural disasters in modern times...
. It also destroyed an estimated 1 million homes, leaving as many as 10 million people (a substantial portion of the country's population) homeless.
Cyclonic Storm BOB 02
On May 30, exactly a month after the previous storm, a tropical storm formed in the Bay of Bengal. It moved north-northeastward and strengthened to a 60 mph tropical storm on June 2, shortly before it hit nearly the same place as 02B did in the Bangladesh region. It dissipated the next day, only to disrupt relief efforts. Fortunately, it caused no reported fatalities due to the well-executed warnings.Depression BOB 04
Early on August 22, reported that Depression BOB 04 had formed about 160 km (100 mi), to the southeast of BalasoreBalasore
Balasore is a strategically located city in the state of Orissa, about north of the state capital Bhubaneswar, in eastern India. It is the administrative headquarters of Balasore district. It is best known for Chandipur beach. It is also the site of the Indian Ballistic Missile Defense...
, India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
. As the depression moved towards northwest, it failed to intensify any further. The depression made landfall in the Indian state of Orissa later that day and maintained its identity until it weakened into a low pressure area early on August 26. The depression's windspeeds were estimated to have peaked at 45 km/h (30 mph), whilst the lowest pressure recorded was 992 hPa.
Cyclonic Storm BOB 08
The final storm of the season, which formed in the eastern Bay of Bengal on November 9, hit eastern India as a 45 mph tropical storm on the 15th. It dissipated the next day over the country.The Cyclonic storm brought torrential rain and flash floods across southern India when it made landfall. Twenty-four hour rainfall totaled 480 millimetres (18.9 in) at Karaikal. As a direct result of the flooding at least 40 people died.
Season effects
See also
- List of North Indian Ocean cyclone seasons
- 1991 Atlantic hurricane season1991 Atlantic hurricane seasonThe 1991 Atlantic hurricane season was the first season in over 24 years in which no hurricanes developed from tropical waves, which are the source for most North Atlantic tropical cyclones. The hurricane season officially began on June 1, and ended on November 30. It was the least...
- 1991 Pacific hurricane season1991 Pacific hurricane seasonThe 1991 Pacific hurricane season was an event in tropical cyclone meteorology. The worst storm this year was Tropical Depression Five-E, which killed one person in Mexico. Elsewhere, Tropical Storm Ignacio injured forty people in Mexico, and Hurricane Fefa caused flooding in Hawaii...
- 1991 Pacific typhoon season1991 Pacific typhoon seasonTropical Storm Enrique formed in the eastern Pacific basin, where it reached it's peak intensity as a category 1 Hurricane, becoming Hurricane Enrique. Enrique lasted for 6 days before becoming a remnant low, shortly after entering in the central Pacific....
- 1990–91 Southern Hemisphere tropical cyclone season
- 1991–92 Southern Hemisphere tropical cyclone season