Cyclone Laila
Encyclopedia
Cyclonic Storm Laila named by Pakistan (IMD designation:BOB 01, JTWC designation:01B) is the first cyclonic storm to affect southeastern India in May since the 1990 Andhra Pradesh cyclone
. The first tropical cyclone
of the 2010 North Indian Ocean cyclone season
, Laila developed on May 17 in the Bay of Bengal
from a persistent area of convection. Strengthening as it tracked northwestward, it became a severe cyclonic storm
on May 19. The next day, Laila made landfall
in Andhra Pradesh
, and it later dissipated over land. It caused flooding and damage along its path. Laila is an Arabic name, meaning Night
. It is the worst storm to hit Andhra Pradesh over the last 14 years.
n city of Kolkata
(formerly Calcutta) in the Bay of Bengal
. It was initially disorganized, although satellite imagery indicated a mid-level circulation
. After a few days, the convection began consolidating around a developing low-level circulation, and rainbands became evident. With low amounts of wind shear
in the region, the Joint Typhoon Warning Center
(JTWC) assessed its chances of development
as fair. The official warning agency in the basin – the India Meteorological Department
(IMD) – classified the system as Depression BOB 001 at 0900 UTC
on May 17. About three hours after the depression was first classified, the IMD upgraded the system to a deep depression, indicating sustained winds of at least 34 mph (55 km/h).
Late on May 17, the JTWC classified the system as Tropical Cyclone 01B, based on further organization. By that time, it was located about 485 miles (780 km) east-southeast of Chennai
, Tamil Nadu
, and was moving westward due to its position southwest of the subtropical ridge
. The IMD upgraded the deep depression to Cyclonic Storm Laila early on May 18. With further consolidation of the convection throughout the day, the JTWC noted that the storm "[appeared] to be rapidly intensifying
", which is a term referring to a quick drop in barometric pressure
that usually coincides with a sharp increase in winds. By late on May 18, an eye feature
became evident on satellite imagery, and at 0000 UTC on May 19, the JTWC assessed Laila as producing peak winds of 75 mph (120 km/h), the equivalent of a minimal hurricane. A few hours later, the IMD upgraded Laila to a severe cyclonic storm.
After reaching peak intensity, Laila briefly decelerated as it moved around the periphery of the subtropical ridge. At the same time, wind shear began increasing, and the cyclone began weakening as it remained just off the coast. Between 1100 and 1200 UTC on May 20, Laila made landfall
near Bapatla
, Andhra Pradesh
.
Thousands of passengers were also stranded after railway tracks were flooded across the country. Several train stations had to suspend operations. The Lankan Parliament, located in a Colombo suburb, was adjourned after an adjoining lake threatened to overflow and flood the premises.``The weather conditions experienced were caused after Sri Lanka was hit by `feeder bands' (clouds on the outer spirals of a cyclone but connected to its centre) of the cyclone as it moved up the Indian east coast.
Early in the duration of the cyclone, the IMD noted the potential for heavy rainfall and gusty winds along the coast of Andhra Pradesh. The agency advised fishermen to avoid being in open seas. Additionally, the agency contacted state governments in the region to warn of the storm's threat. The weather office has stated that the cyclone will not have an effect on the monsoon
season.
Cyclone Laila battered Ongole town; it received heavy rain of 320 mm on May 20 and 142 mm on May 21, and has made rivulets like Gundlakamma, Addavagu and Pothurajukalva swollen. Addanki received the highest rainfall of 522 mm, followed by Maddipadu with 510 mm and Kothapatnam in 24 hours on May 21.
The cyclone caused heavy destruction in Prakasam, Krishna and Guntur districts and preliminary reports prepared by the State government put the loss at over Rs 500 crore. According to a BBC
report, Cyclone Laila is the worst storm to hit Andhra Pradesh in 14 years.
1990 Andhra Pradesh cyclone
The 1990 Andhra Pradesh cyclone was the worst disaster to affect Southern India since the 1977 Andhra Pradesh cyclone. The cyclone formed as a tropical disturbance early on May 4, 1990 while moving towards the northwest...
. The first tropical cyclone
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...
of the 2010 North Indian Ocean cyclone season
2010 North Indian Ocean cyclone season
The 2010 North Indian Ocean cyclone season was a very active event in the annual cycle of tropical cyclone formation with some 8 depressions and 6 named storms, nearly above the average of 4-6 storms in the region due to a moderate La Niña...
, Laila developed on May 17 in the Bay of Bengal
Bay of Bengal
The Bay of Bengal , the largest bay in the world, forms the northeastern part of the Indian Ocean. It resembles a triangle in shape, and is bordered mostly by the Eastern Coast of India, southern coast of Bangladesh and Sri Lanka to the west and Burma and the Andaman and Nicobar Islands to the...
from a persistent area of convection. Strengthening as it tracked northwestward, it became a severe cyclonic storm
Tropical cyclone scales
Tropical systems are officially ranked on one of several tropical cyclone scales according to their maximum sustained winds and in what oceanic basin they are located...
on May 19. The next day, Laila made landfall
Landfall (meteorology)
Landfall is the event of a tropical cyclone or a waterspout coming onto land after being over water. When a waterspout makes landfall it is reclassified as a tornado, which can then cause damage inland...
in Andhra Pradesh
Andhra Pradesh
Andhra Pradesh , is one of the 28 states of India, situated on the southeastern coast of India. It is India's fourth largest state by area and fifth largest by population. Its capital and largest city by population is Hyderabad.The total GDP of Andhra Pradesh is $100 billion and is ranked third...
, and it later dissipated over land. It caused flooding and damage along its path. Laila is an Arabic name, meaning Night
Night
Night or nighttime is the period of time when the sun is below the horizon. This occurs after dusk. The opposite of night is day...
. It is the worst storm to hit Andhra Pradesh over the last 14 years.
Meteorological history
In the middle of May 2010, an area of convection, or thunderstorms, persisted about 865 miles (1400 km) south of the IndiaIndia
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...
n city of Kolkata
Kolkata
Kolkata , formerly known as Calcutta, is the capital of the Indian state of West Bengal. Located on the east bank of the Hooghly River, it was the commercial capital of East India...
(formerly Calcutta) in the Bay of Bengal
Bay of Bengal
The Bay of Bengal , the largest bay in the world, forms the northeastern part of the Indian Ocean. It resembles a triangle in shape, and is bordered mostly by the Eastern Coast of India, southern coast of Bangladesh and Sri Lanka to the west and Burma and the Andaman and Nicobar Islands to the...
. It was initially disorganized, although satellite imagery indicated a mid-level circulation
Atmospheric circulation
Atmospheric circulation is the large-scale movement of air, and the means by which thermal energy is distributed on the surface of the Earth....
. After a few days, the convection began consolidating around a developing low-level circulation, and rainbands became evident. With low amounts of 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...
in the region, 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...
(JTWC) assessed its chances of development
Tropical cyclogenesis
Tropical cyclogenesis is the term that describes the development and strengthening of a tropical cyclone in the atmosphere. The mechanisms through which tropical cyclogenesis occurs are distinctly different from those through which mid-latitude cyclogenesis occurs...
as fair. The official warning agency in the basin – the India Meteorological Department
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) – classified the system as Depression BOB 001 at 0900 UTC
Coordinated Universal Time
Coordinated Universal Time is the primary time standard by which the world regulates clocks and time. It is one of several closely related successors to Greenwich Mean Time. Computer servers, online services and other entities that rely on having a universally accepted time use UTC for that purpose...
on May 17. About three hours after the depression was first classified, the IMD upgraded the system to a deep depression, indicating sustained winds of at least 34 mph (55 km/h).
Late on May 17, the JTWC classified the system as Tropical Cyclone 01B, based on further organization. By that time, it was located about 485 miles (780 km) east-southeast of Chennai
Chennai
Chennai , formerly known as Madras or Madarasapatinam , is the capital city of the Indian state of Tamil Nadu, located on the Coromandel Coast off the Bay of Bengal. Chennai is the fourth most populous metropolitan area and the sixth most populous city in India...
, Tamil Nadu
Tamil Nadu
Tamil Nadu is one of the 28 states of India. Its capital and largest city is Chennai. Tamil Nadu lies in the southernmost part of the Indian Peninsula and is bordered by the union territory of Pondicherry, and the states of Kerala, Karnataka, and Andhra Pradesh...
, and was moving westward due to its position southwest of 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...
. The IMD upgraded the deep depression to Cyclonic Storm Laila early on May 18. With further consolidation of the convection throughout the day, the JTWC noted that the storm "[appeared] to be rapidly intensifying
Rapid deepening
Rapid deepening, also known as rapid intensification, is a meteorological condition that occurs when the minimum sea-level atmospheric pressure of a tropical cyclone decreases drastically in a short period of time. The National Weather Service describes rapid deepening as a decrease of...
", which is a term referring to a quick drop in barometric pressure
Atmospheric pressure
Atmospheric pressure is the force per unit area exerted into a surface by the weight of air above that surface in the atmosphere of Earth . In most circumstances atmospheric pressure is closely approximated by the hydrostatic pressure caused by the weight of air above the measurement point...
that usually coincides with a sharp increase in winds. By late on May 18, an eye feature
Eye (cyclone)
The eye is a region of mostly calm weather found at the center of strong tropical cyclones. The eye of a storm is a roughly circular area and typically 30–65 km in diameter. It is surrounded by the eyewall, a ring of towering thunderstorms where the second most severe weather of a cyclone...
became evident on satellite imagery, and at 0000 UTC on May 19, the JTWC assessed Laila as producing peak winds of 75 mph (120 km/h), the equivalent of a minimal hurricane. A few hours later, the IMD upgraded Laila to a severe cyclonic storm.
After reaching peak intensity, Laila briefly decelerated as it moved around the periphery of the subtropical ridge. At the same time, wind shear began increasing, and the cyclone began weakening as it remained just off the coast. Between 1100 and 1200 UTC on May 20, Laila made landfall
Landfall (meteorology)
Landfall is the event of a tropical cyclone or a waterspout coming onto land after being over water. When a waterspout makes landfall it is reclassified as a tornado, which can then cause damage inland...
near Bapatla
Bapatla
Bapatla, formerly known as Bhavapuri, is a town and mandal of Guntur District, Andhra Pradesh, India. It is located south of Guntur City on the East Coast.-Assembly constituency:Bapatla is an assembly constituency in Andhra Pradesh....
, Andhra Pradesh
Andhra Pradesh
Andhra Pradesh , is one of the 28 states of India, situated on the southeastern coast of India. It is India's fourth largest state by area and fifth largest by population. Its capital and largest city by population is Hyderabad.The total GDP of Andhra Pradesh is $100 billion and is ranked third...
.
Preparations and impact
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Sri Lanka
Cyclone Laila displaced nearly 280,000 people, triggering floods, delaying flights and submerging many areas of capital Colombo. The indirect impact of the cyclone was compounded as heavy pre-monsoonal showers set in over parts of the country as the storm developed over the Bay of Bengal. The Sri Lanka air force helicopters and navy vessels were pressed into service to ferry stranded passengers from Colombo to the international airport after parts of the connecting roads were washed away. All planes international and domestic, were either delayed or cancelled because of heavy rain. Colombo experienced 350 mm of rain over the last five days ending May 20. Sri Lanka's Disaster Management Center has reported that 513,586 from 118,888 families have been affected and 20 people have died by this evening due to the devastating floods caused by incessant torrential rain. A United Nation assessment team visited the flood affected areas in Kalutara district on May 20 to evaluate the situation. The team visited the Gampaha district and met the relevant officials to coordinate relief efforts. The Met Department said. The prevailing unusual weather pattern is caused by the activation of the South-Western monsoon period on top of the feeder bands of Cyclone Leila moving over the island, it said.Thousands of passengers were also stranded after railway tracks were flooded across the country. Several train stations had to suspend operations. The Lankan Parliament, located in a Colombo suburb, was adjourned after an adjoining lake threatened to overflow and flood the premises.``The weather conditions experienced were caused after Sri Lanka was hit by `feeder bands' (clouds on the outer spirals of a cyclone but connected to its centre) of the cyclone as it moved up the Indian east coast.
Tamil Nadu
Nine people were killed in rain related incidents in Tamil Nadu, as the cyclonic storm "Laila" battered the Coastal areas in Northern parts of Tamil Nadu, Chennai city and its suburbs. Several fishermen, who put out to sea in 100 boats were reported missing since May 17, according to fisheries department sources. The fishermen of Pamban, Uchipuli and nearby areas who ventured into sea on May 17 night in boats with outboard motors were missing.Andhra Pradesh
The toll in the cyclone-related incidents rose to 36 on Friday with 12 more deaths reported from Krishna (4), Guntur (3), Vizag (3) and Prakasam (2) districts. "Several persons are reported missing from the worst-hit coastal districts. More than 170 houses were completely destroyed and 265 suffered partial damage while 367 livestock perished in the cyclone.Early in the duration of the cyclone, the IMD noted the potential for heavy rainfall and gusty winds along the coast of Andhra Pradesh. The agency advised fishermen to avoid being in open seas. Additionally, the agency contacted state governments in the region to warn of the storm's threat. The weather office has stated that the cyclone will not have an effect on the monsoon
Monsoon
Monsoon is traditionally defined as a seasonal reversing wind accompanied by corresponding changes in precipitation, but is now used to describe seasonal changes in atmospheric circulation and precipitation associated with the asymmetric heating of land and sea...
season.
Cyclone Laila battered Ongole town; it received heavy rain of 320 mm on May 20 and 142 mm on May 21, and has made rivulets like Gundlakamma, Addavagu and Pothurajukalva swollen. Addanki received the highest rainfall of 522 mm, followed by Maddipadu with 510 mm and Kothapatnam in 24 hours on May 21.
The cyclone caused heavy destruction in Prakasam, Krishna and Guntur districts and preliminary reports prepared by the State government put the loss at over Rs 500 crore. According to a BBC
BBC
The British Broadcasting Corporation is a British public service broadcaster. Its headquarters is at Broadcasting House in the City of Westminster, London. It is the largest broadcaster in the world, with about 23,000 staff...
report, Cyclone Laila is the worst storm to hit Andhra Pradesh in 14 years.