Cyclonic winds, cyclones: South Asia
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In brief
See graphic
The India Meteorological Department (IMD) classifies cyclonic winds into three categories--cyclonic disturbance (maximum wind speed 59kmhr), cyclones (wind speed 60 to 90 kmhr) and severe cyclones (wind speed 90 kmhr or more). Cyclone data for the years 1891 to 2012 shows a seasonal pattern. The mildest of these turbulent wind systems -cyclonic disturbances -peak in the monsoon season with an average of six to seven such incidents a year. The probability of cyclones and severe cyclones, on the other hand, is highest in the post-monsoon months. The data also shows that on an average, the Bay of Bengal is hit by at least one severe cyclone and a minimum of two cyclones each year
The cyclone season
October 10, 2018: Hindustan Times
The country’s cyclone season runs from April to December, with severe storms often causing dozens of deaths, evacuations of tens of thousands of people from low-lying villages and wide damage to crops and property.
Categorisation of cyclones
October 10, 2018: Hindustan Times
Here’s how cyclones are categorised and what they mean:
Categories of Cyclones
Category 1: Wind and gales of 90-125 kph, negligible house damage, some damage to trees and crops.
Category 2: Destructive winds of 125-164 kph. Minor house damage, significant damage to trees, crops and vehicles, risk of power failure.
Category 3: Very destructive winds of 165-224 kph. Some roof and structural damage, some caravans destroyed, power failure likely.
Category 4: Very destructive winds of 225-279 kph. Significant roofing loss and structural damage, vehicles blown away, widespread power failures.
Category 5: Very destructive winds gusts of more than 280 kph. Extremely dangerous with widespread destruction.
Naming tropical cyclones
The Hindustan Times, December 9, 2016
October 10, 2018: Hindustan Times
How are tropical cyclones named?
• Tropical cyclones are named to provide easy communication between forecasters and the general public regarding forecasts, watches, and warnings.
• The first use of a proper name for a tropical cyclone was by an Australian forecaster early in the 20th century. He gave tropical cyclone names after political figures he disliked.
• During World War II, tropical cyclones were informally given women’s names by US Army Air Corp and Navy meteorologists (after their girlfriends or wives) who were monitoring and forecasting tropical cyclones over the Pacific.
• From 1950 to 1952, tropical cyclones of the North Atlantic Ocean were identified by the phonetic alphabet (Able-Baker-Charlie-etc.), but in 1953 the US Weather Bureau switched to women’s names. In 1979, the World Meteorological Organization and the US National Weather Service (NWS) switched to a list of names that also included men’s names.
• The Northeast Pacific basin tropical cyclones were named using women’s names starting in 1959 for storms near Hawaii and in 1960 for the remainder of the Northeast Pacific basin. In 1978, both men’s and women’s names were utilised.
• The Northwest Pacific basin tropical cyclones were given women’s names officially starting in 1945 and men’s names were also included beginning in 1979. Beginning on 1 January 2000, tropical cyclones in the Northwest Pacific basin are being named from a new and very different list of names.
• The Southwest Indian Ocean tropical cyclones were first named during the 1960/1961 season.
• The Australian and South Pacific region (east of 90E, south of the equator) started giving women’s names to the storms in 1964 and both men’s and women’s names in 1974/1975.
• The North Indian Ocean region tropical cyclones are being named since October 2004.
In 2016, Bay of Bengal witnessed Roanu, Kyant, Nada and Vardah (names of the tropical cyclones) which also affected India.
Vardah is the Arabic and Urdu word for ‘rose’, a name provided by Pakistan in the comprehensive nomenclature list for cyclones in the Arabian sea and Bay of Bengal.
In September 2004, an international panel on tropical cyclones decided that countries from the region would each put in names, which would be assigned to storms in the Bay of Bengal and Arabian Sea.
Eight countries -- India, Pakistan, Bangladesh, Maldives, Myanmar, Oman, Sri Lanka and Thailand – participated and came up with a list of 64 names.
In the event of a storm, the Regional Specialized Meteorological Centre, New Delhi, selects a name from the list.
The late origin of this naming system -- unlike storms in the Atlantic, which have been getting named since 1953 -- was ostensibly to protect sensitivities in the ethnically diverse region.
The purpose of the move was also to make it easier for “people easily to understand and remember the tropical cyclone/hurricane in a region, thus to facilitate disaster risk awareness, preparedness, management and reduction,” according to the IMD.
Citizens can submit names to the Director General of Meteorology, IMD, for consideration, but the weather agency has strict rules for the selection process.
A name, for instance, ‘should be short and readily understood when broadcast’. The names must also be neutral, ‘not culturally sensitive and not convey some unintended and potentially inflammatory meaning’.
Furthermore, on the account of the ‘death and destruction’ a storm in the Indian Ocean causes, their names are retired after use, unlike those in the Atlantic and Eastern Pacific lists, which are reused every few years.
Names reused every six years
• Atlantic and Pacific storm names are reused every six years, but are retired “if a storm is so deadly or costly that the future use of the name would be insensitive or confusing,” according to forecasters at the US National Hurricane Center in Miami.
• Hurricane Sandy was the 77th name to be retired from the Atlantic list since 1954. It will be replaced with “Sara” beginning in 2018, when the list from 2012 is repeated. Hurricane Sandy was the deadliest and most destructive hurricane of the 2012 Atlantic hurricane season that hit the US last year.
Not without controversy
Cyclone Mahasen, which hit in 2013 and was named by Sri Lanka, was changed to Viyaru after protests by nationalists and officials in Sri Lanka.
They said Mahasen was a king who had brought peace and prosperity to the island, and it was wrong to name a calamity after him.
Cyclone Vardah: December 2016
Andaman and Nicobar Islands
Please see: Andaman And Nicobar Islands: Natural calamities
Tamil Nadu
The Hindu, December 12, 2016
Cyclone Vardah heads towards Chennai shores
Cyclonic storm Vardah is likely to make landfall by December 12, 2016 along north Tamil Nadu and south Andhra Pradesh coast, close to Chennai, accompanied by strong winds with speeds of 80 to 90 kmph.
S. Balachandran, director, Area Cyclone Warning Centre in Chennai, told the media on Sunday the rains would gradually increase from the morning of December 12 and were expected to last until the next day in the northern districts of Chennai, Tiruvallur and Kancheepuram.
Moderate rain
S.B.Thampi, Deputy Director General of Meteorology said, most places along north Tamil Nadu and south Andhra Pradesh coasts would get to light to moderate rain with possibilities of heavy rainfall of up to 20 cm as the system makes landfall.
“During landfall, Chennai, Tiruvallur, Kancheepuram and Puducherry will get rainfall and once the system crosses, Vellore and Dharmapuri will begin to get rains,” he said.
Chief Minister O. Panneerselvam chaired a meeting in the Secretariat on Sunday to review the preparations by government agencies. Schools and colleges in Kancheepuram, Tiruvallur, Villupuram and Cuddalore districts have been closed on Monday.
The government also issued an advisory to private undertakings and establishments to permit their staff to avail of a holiday or to work from home.
“Due to the storm surge, the seas are expected to be rough and the tidal wave will be 1 m higher than normal. Fishermen have been warned not to venture out into the sea,” he said.
National Disaster Response Force (NDRF) and State Disaster Response Force teams have been stationed at Chennai, Tiruvallur and Kancheepuram districts as a precautionary measure.
Impact
The Hindu, December 13, 2016
Cyclone Vardah made landfall in Chennai on December 12, 2016 between 3 p.m. and 5 p.m., uprooting trees, defacing highrises, smashing cars, disrupting public transport and telecommunication, bringing the metropolitan area to a standstill.
The weather system that was first noticed nearly five days ago, grew into a ‘very severe cyclonic storm’ and by the time it crossed the city near the Chennai Port, it had weakened into a ‘severe cyclonic storm’ with maximum wind speeds touching 110 kmph-120 kmph.
Lull as eye crosses city
This was a large weather system, measuring nearly 40 km in diameter, which explains the time taken for the system to cross.
There was a lull between 2-30 p.m. and 5 p.m. as the eyewall of the cyclone was in transit and it normally is empty, bringing very little, or no rainfall.
The windspeeds decreased to 60-70 kmph, and the system now a ‘cyclonic storm’ moved westwards, bringing moderate to heavy rainfall to the interior areas as well. Rainfall over the northern coastal districts is expected to continue till Tuesday noon. Vardah, an Urdu word meaning red rose, contributed by Pakistan, will turn into a deep depression early on Tuesday, sources said.
While vast devastation was caused to trees and property, the total rainfall received has only partly bridged the city’s rain deficit. Before Vardah struck, the annual rainfall deficit was over 60 cm, and while the storm has narrowed the gap, there is a solid 40 cm of rainfall the city needs for the reservoirs to fill up and meet its water needs until the next monsoon.
Water managers expect another spell of rainfall before the next monsoon.
Official sources said three people had died from rain-related causes in the State on Monday. Chief Minister O. Panneerselvam announced a solatium of Rs. 4 lakh each to the families of the victims.
Corporation officials pegged the number of trees fallen at 568 along the 471 bus routes and over 33,000 interior roads in the 426 sq km of the Greater Chennai Corporation limits, impeding the flow of traffic.
Most of the suburbs were cut off from other parts of the metropolitan area.
As dark clouds gathered over the city all day, power supply was disrupted. Banking transactions were affected and PoS devices failed at retail outlets.
Holiday for schools
The Tamil Nadu government declared Tuesday would be a holiday for educational institutions in three districts.
“All government, government-aided, private schools, colleges and other educational institutions in Chennai, Kancheepuram and Tiruvallur districts will remain closed on December 13,” an official release said.
Steps by the central government
The Hindu, December 19, 2016
Central team to visit TN to assess Vardah impact
At least 18 people were killed when cyclone Vardah hit Tamil Nadu and Andhra Pradesh on December 12.
The team, headed by Joint Secretary Praveen Vashishtha from the Home Ministry comprised officials from the Ministries of Finance, Agriculture, Industries and Rural Development, among others.
Immediately after the cyclone, the Chief Minister had sought disbursal of Rs. 1,000 crore as an interim relief package. However, the Central Government had responded by releasing an interim aid of Rs. 500 crore, which the State felt was inadequate.
Mr. Panneerselvam, accompanied by officials, called on Tamil Nadu Governor (in-charge) Ch. Vidyasagar Rao at the Raj Bhavan. The meeting, described as a courtesy call in an official release, came as a surprise since it came just one day ahead of the Chief Minister’s Delhi visit.
Andhra Pradesh
The Andhra Pradesh government remains on high alert, monitoring the progress of cyclone Vardah with real-time updates from the Indian Space Research Organisation (ISRO), even as the system changed course towards the northern Tamil Nadu coast. Its initial track forecast landfall between East Godavari (Kakinada) and Nellore districts.
The government has been tapping into ISRO’s data following an understanding reached with the agency earlier this year for weather forecasting.
Naidu meets ISRO team
Chief Minister N. Chandrababu Naidu, who cancelled his Dubai visit to monitor the likely impact of Vardah, held a meeting with ISRO scientists on Saturday.
According to official sources, the State government is getting inputs from the ISRO through its National Remote Sensing Centre and other wings round the clock.
Contingency plan
Later in a teleconference, Mr. Naidu told officials of various departments that the cyclone could cross the coast between Sriharikota and Chennai by Monday evening and trigger heavy rains in Chittoor, Kadapa and Nellore districts. He called upon the heads of departments to be prepared to face the contingency by drawing on their experience during Cyclone Hudhud two years ago.
NDRF teams have been deployed in Sullurpet and Tada in Nellore district. Four IAS officers — Mukesh Kumar Meena, B. Sridhar, M. Ravi Chandra and Ram Gopal — have been deputed as special officers to Prakasam, Nellore, Chittoor and Kadapa to handle the situation.
Cyclone Mora: May 2017
Bangladesh and northeastern India
Cyclone Mora that lashed Bangladesh's coastlines forcing the evacuation of millions of people and shutting the country's main port and river transport, killed at least six people in Cox’s Bazar and Rangamati before moving to northeastern India.
The cyclone, which lashed the coastal belt with a wind speed of 128 kmph and made landfall at around 6 a.m. (0000 GMT), cut off Kutubdia, Moheshkhali and Teknaf from other parts of the country.
Road transportation was affected, phone lines were disrupted, more than 20,000 houses destroyed and hundreds of trees were uprooted. The Disaster Management Ministry said it moved to safety more than 2.5 million people in 10 coastal districts which were most vulnerable to the tropical storm as the Met Office upgraded the cyclone warning to Great Danger No. 10, the highest level.
About 18 million people live in 19 coastal districts, 10 of them in high-risk areas. As it moved towards India, heavy showers and gusty winds lashed Mizoram on Tuesday disrupting power and telecommunication network, damaging houses and triggering landslides.
Cyclone Ockhi: December 2017
In brief
The name Ockhi was given by Bangladesh, (In Bengali, ockhi means ‘eye’.)
Cyclones are no strangers to the Indian coast, our east coast in particular witnessing several cyclonic storms each year. Yet, Ockhi, the latest powerful cyclone, is unlike other recent ones.
What is special about Ockhi?
Mostly, the area in which it developed. Cyclones are known to originate in both the Bay of Bengal and the Arabian Sea sides of the northern Indian Ocean; there is much more frequency on the Bay of Bengal side though, especially of the stronger cyclones — in fact, the Bay of Bengal side witnesses four times more cyclones than the Arabian Sea side on average.
But Ockhi originated near the south-western coast of Sri Lanka, and travelled very near the southern-most tip of the Indian mainland, along the coasts of Tamil Nadu and Kerala, towards the Lakshadweep islands, where it was at its most powerful. It weakened considerably after that and continued further, taking a north-easterly turn towards the Maharashtra and Gujarat coastlines —cyclones in this area are not a common phenomenon.
Why does the Bay of Bengal have more cyclones than the Arabian Sea?
Meteorologists say the relatively colder waters of the Arabian Sea are not conducive to the formation and intensification of cyclones. Additionally, the eastern coast of India receives cyclones that form not just in the Bay of Bengal, mostly around the Andaman Sea near the Andaman and Nicobar Islands, but also those travelling from the Pacific Ocean, where the frequency of ‘typhoons’, as these are called there, is quite high. Most of these cyclones weaken considerably after encountering a big landmass. Therefore, these do not travel to the Arabian Sea side. The western coast of India thus witnesses only those cyclones that originate locally or the ones, like Ockhi, that travel from the Indian Ocean near Sri Lanka.
How powerful was Ockhi?
Ockhi was described as a ‘very severe cyclonic storm’, the third strongest category according to the definitions used by the India Meteorological Department (IMD). Cyclones are categorised by the maximum wind speed they generate. At its most powerful, Ockhi had wind speeds between 155 and 165 km per hour, touching the upper border for ‘very severe cyclonic storm’.
Cyclones with wind speeds between 165 and 220 km per hour are classified as ‘extremely severe cyclonic storm’. Those with even higher wind speeds are called ‘super-cyclones’. The most famous instance of a ‘super-cyclone’ was the one that hit the coast of Odisha in October 1999. It was the strongest-ever cyclone recorded in that area, with wind speeds touching 260 km per hour. It was also the most devastating cyclone to have hit India.
The 2013 Phailin cyclone very nearly got categorised as a super-cyclone. It had maximum wind speeds of around 220 km per hour.
Cyclone forecasts by the IMD in the recent past have been made five to six days in advance, thereby minimising the damage caused — was the IMD late in issuing a warning for Ockhi?
How early the forecast is depends on how far we are from the place where the cyclone is emerging. Many of the big cyclones in recent years, like Phailin in 2013, Hudhud in 2014 or Vardah in 2016, developed near the Andaman Sea. From there, it took those cyclones about five to six days to hit the Andhra Pradesh or Odisha coasts.
These forecasts can be made only after an emerging depression is detected to have the properties of a cyclonic storm. This was true in the case of Ockhi as well. But the origin of Ockhi was much closer home. The cyclone formation was detected during the morning of Wednesday, November 29. An alert was issued around noon. But many areas in Tamil Nadu and on the Kerala coast started feeling the impact from Thursday itself. A day later, the Lakshadweep islands bore the brunt of the cyclone. Because it developed nearby, the lead time for the forecast was much less than in other recent cyclone cases.
Impact, state-wise
Goa
Prakash Kamat, December 5, 2017: The Hindu
Ripple effects
High tides due to the ripple effectasof Ockhi cyclone that hit Tamil Nadu, Kerala and Lakshadweep damaged several beach shacks, temporary eateries and other tourist structures along Arambol, Morjim, Mandrem and Cavelossim.
Several shacks have reportedly been affected by the swelling of waters along the coastline, due to the twin impact of Ochki cyclone and the super moon last night. Several videos of sea water creeping dangerously close to beach shacks and shack workers scurrying to salvage their beach beds and other equipment were also uploaded to social media on Monday, triggering panic among the tourism and travel industry stakeholders, even as government sources said that efforts were on to declare the damage as a state disaster. The maximum losses was reported in the coastal sub-district of Pernem, where nearly 30 shacks were damaged.
Over 10 shacks at Morjim were damaged while eight each in Mandrem and Arambol too were damaged due to the high waves.
Shack owners claimed that mattresses, plastic tables and other property were damaged by the waves lashed the shacks. There were reports of damages to electronic items such as refrigerators. The water level was so high that the waves inundated their kitchens and destroyed food items which were kept on ground.
Mr. D’Souza said this may force the government to reconsider the location of temporary shack when permits are allotted.
“It is, nevertheless, an eye opener not only for Goa, but other coastal states too, to review tourism trade activities close to the shoreline,” he added.
Meanwhile, a government spokesperson said on Sunday that fishermen have been asked to not venture into the sea at least for the next three days.
A report from North Goa Magistrate Nila Mohanan said that there was considerable damage to almost 50 shacks in Morjim, Mandrem, Arambol and Querim beaches in Pernem taluk of North Goa. In Bardez taluk, only soil erosion in Anjuna and Baga beaches and damage to a retaining wall at Coco beach in Nerul have been been reported.
Initiatives
It has provided assistance to 187 people in distress
The Navy has so far provided assistance to 187 people in distress in sea, as on December 7, 2017, besides saving 148 lives as part of Op Sahayam, an exercise for search and rescue, and humanitarian assistance and disaster relief (HADR) launched in the wake of Cyclone Ockhi.
The force has also evacuated three bodies from deep sea. A media release said nine naval ships besides helicopters and race aircraft remained deployed for extended scouring of seas up to 300 miles west of the Lakshadweep and Minicoy islands and 450 miles off Kerala coast. A P8-I long-range maritime patrol aircraft detected a fishing vessel, St Damian, late Tuesday night some 180 miles northwest of Kavaratti and directed INS Chennai to render assistance. “The 13-member crew were taken on board Chennai early morning on December 6 and provided with food, water and medical aid. The boat was towed and handed over to Coast Guard Ship Shoor as part of Op Synergy since the boat engine had become unserviceable and could not be repaired in sea despite the best efforts by the team of INS Chennai,” the release said.
INS Kalpeni embarked six local fishermen from Kochi and INS Kabra embarked two fishermen from Kollam to join the ongoing SAR (search and rescue) efforts. “INS Jamuna positioned at Kavaratti has provided 12,000 litres of fresh water as requested by the island administration.”
INS Sharda, which returned to Kochi for refuelling, has now embarked materials requested by the Minicoy administration. The items will be delivered on Thursday morning. The naval contingent at Minicoy actively involved in clearing of roads and distribution of rations, the Navy said.
Cyclone Titli: October 2018
Impact, state-wise
Odisha
Cyclone Titli has made landfall on the coast of Odisha. It is a very severe cyclonic storm. The location of the landfall is 86km Southwest of Gopalpur in Odisha. The cyclone is forecasted to bring in its wake very heavy rain, which could lead to flooding, and strong winds. By night of October 11, 2018, Titli will weaken into a cyclonic storm before ultimately dissipating as a depression by the night of October 12.
Impact on agriculture- Kharif crop
Kharif crop over 2,13,801 ha affected, houses damaged, October 17, 2018: The Hindu
The devastation wrought by the cyclonic storm Titli and the resultant heavy rain has cast a shadow on Dussehra festivities across Odisha, especially for farmers.
Hundreds of puja pandals in the State — where Durga Puja got under way — are witnessing low turnout as people are yet to recover from the shock of the cyclone.
After toiling for six months and investing hard-earned savings, farmers were anticipating a healthy harvest in the next two months. However, cyclone and heavy rain damaged the standing crop at many places.
The kharif crop has been affected over an area of 2,13,801 hectares (paddy 1,48,681 ha and non-paddy 65,120 ha) in nine districts — Ganjam, Gajapati, Rayagada, Kandhamal, Mayurbhanj, Cuttack, Khordha, Balasore and Puri.
The damage has been severe in Ganjam, Gajapati, Rayagada and Kandhamal. Although all is not lost in districts like Kendrapara, Jagatsinghpur and Jajpur, farmers fear that there would be a drop in harvest.
“Multi-department assessment of crop damage is under progress and the final report is expected within a week,” said Bishnupada Sethi, Special Relief Commissioner.
The SRC has also directed District Collectors to provide ex-gratia to the next of the kin of those who died in the cyclone and the resultant floods within three days. The Odisha government had earlier announced an ex-gratia of ₹4 lakh each to the next of kin of the deceased.
As per a report of the Directorate of Animal Husbandry and Veterinary Services, livestock loss has been severe. Fishermen were also not spared, with 300 boats fully damaged and 265 partially damaged. Moreover, 607 fish ponds covering 428.97 ha and 69 private fish seed farms in an area of 47.250 ha have been damaged.
“Who is thinking of any Dussehra festivities? The first priority is to repair damaged houses as winter is fast approaching. This Dussehra has turned into a black one for us,” said Haribandhu Karji, former sarpanch of Gangabada panchayat of Gajapati district, which was worst-hit by the disaster.
Cyclone ‘Gaja’: November 2018
Impact, state-wise
Tamil Nadu and Puducherry- heavy rainfall
Coastal areas of north Tamil Nadu would experience moderate rainfall and heavy rainfall in isolated places from the night of November 14, the Met office said. The deep depression over the Bay of Bengal intensified into Cyclone ‘Gaja’. North Tamil Nadu and Puducherry are likely to get good rain on November 14 and 15, India Meteorological Department officials said.
Named ‘Gaja’, the cyclone lay 840 km east of Chennai and 880 km east of Nagapattinam.
May weaken gradually
It is expected to move west-northwestwards during the next 36 hours and then west-southwestwards towards the north Tamil Nadu–south Andhra Pradesh coasts in the subsequent 48 hours. While moving west-southwest, it is likely to weaken gradually and cross the north Tamil Nadu–south Andhra Pradesh coasts between Cuddalore and Sriharikota during the forenoon of November 15. Rainfall in most places, with heavy spells at isolated places, is likely to start over north coastal Tamil Nadu and south coastal Andhra Pradesh from the evening of November 14.
According to the the IMD bulletin, rainfall in most places with heavy falls at isolated places is likely to commence over north coastal Tamil Nadu and the adjoining south coastal Andhra Pradesh from evening of November 14.
On November 15, the rainfall intensity will increase gradually at most places and it will be heavy to very heavy at a few places and extremely heavy (above 20 cm) at isolated places over north Tamil Nadu.
Rainfall is likely to be heavy to very heavy over south Tamil Nadu, south Coastal Andhra Pradesh and Rayalaseema.
100 kmph gale wind
Squally wind speed reaching 45-55 kmph, gusting to 65 kmph is likely to commence along and off north Tamil Nadu–south Andhra Pradesh coasts from November 14 morning. It is likely to increase gradually, with wind speed at 80-90 kmph off north Tamil Nadu–south Andhra Pradesh coasts over west central & adjoining southwest Bay of Bengal from midnight onwards.
As the sea will be rough, fishermen have been advised to not venture in from 12 November. The fishermen, who were in deep sea, have been advised to return by November 12, the officials said.
As for Chennai, the sky will be cloudy and some areas will get mild showers for the next two days. While the maximum temperature will be 32 degree Celsius, the minimum temperature will be 24 degree Celsius.
