The 1996 North Indian Ocean cyclone season was an above average and extremely deadly season. it had several deadly tropical cyclones, with over 2,000 people killed during the year. The India Meteorological Department (IMD) – the Regional Specialized Meteorological Center for the northern Indian Ocean as recognized by the World Meteorological Organization – issued warnings for nine tropical cyclones in the region. Storms were also tracked on an unofficial basis by the American-based Joint Typhoon Warning Center, which observed one additional storm. The basin is split between the Bay of Bengal off the east coast of India and the Arabian Sea off the west coast. During the year, the activity was affected by the monsoon season, with most storms forming in June or after October.
The first system originated on May 7 in the Bay of Bengal, which is the body of water east of India; the storm developed in tandem with a storm in the southern hemisphere, and ultimately struck Bangladesh. Three storms formed in June. The first struck Oman and later caused devastating flooding in Yemen, killing 338 people and causing $1.2 billion in damage. The other two storms struck opposite sides of India, collectively resulting in 226 deaths after causing widespread flooding. After a brief land depression in July and a weak depression in early October, the season featured four notable cyclones beginning in late October. A low-pressure area moved across southern India, killing 388 people before taking an unusual track in the Arabian Sea. At the end of October, a deep depression killed 14 people in Bangladesh. The strongest cyclone of the season was also the deadliest, killing 1,077 people when it struck Andhra Pradesh in early November. The final storm of the season executed a rare loop in the Bay of Bengal before weakening and striking southern India in early December, killing seven.
Season summary
During the season, the IMD used satellite imagery and surface data to assess and predict storms. The agency also utilized a tropical cyclone forecast model that used climatology and a storm's persistence to forecast future movement. Warnings and advisories were broadcast throughout India by telegraph and news media. The basin's activity is sub-divided between the Arabian Sea and the Bay of Bengal on opposite coasts of India, and is generally split before and after the monsoon season.
The IMD tracked nine tropical disturbances, including one that developed over land, which is below average of 13 systems. Five of the storms formed from October to December, after the end of the monsoon season. In general, storms moved slower than average, and two of the cyclones took unusual tracks near land – one executed a rare loop in the Bay of Bengal, and another turned abruptly away from the Indian state of Gujarat. According to the JTWC, activity in the basin was 60% greater than average, with eight tropical cyclones. Four of these storms attained hurricane intensity – winds of at least 120 km/h (75 mph) – which was a record at the time.
During June, a series of storms affected India in the height of the monsoon season. Two storms on opposite sides of the country contributed to the northward progression of the monsoon. Continued rainfall from the monsoon led to additional flooding. As of July 24, flooding from widespread rains had killed 731 people across India. The floods also wrecked 368,420 houses and ruined 394,000 ha (970,000 acres) of crop fields. The monsoon became reestablished over open waters on October 9, spawning two storms in the basin that month. There were two simultaneous storms on opposite sides of India in October, which would not happen again until May 2010.
Systems
Deep Depression BOB 01 (01B)
In early May, a westerly wind burst spawned two disturbances on both sides of the equator in the eastern Indian Ocean, in association with the monsoon trough. The system in the southern hemisphere eventually became Tropical Storm Jenna, while the system in the northern hemisphere developed an area of convection about 445 km (277 mi) northwest of Sumatra. This disturbance moved generally northward, and initially remained disorganized; the thunderstorms were removed from the circulation. However, the JTWC issued a Tropical Cyclone Formation Alert (TCFA) on May 5 once the system became better organized amid low wind shear. Rounding the periphery of a ridge, the system turned to the northeast. Based on the appearance on satellite imagery, the JTWC classified the system as Tropical Cyclone 01B at 00:00 UTC on May 7. Three hours later, the IMD classified the system as a depression about 400 km (250 mi) south of Kolkata. The storm intensified further while moving toward southeastern Bangladesh. The JTWC upgraded it to a 75 km/h (45 mph) tropical storm, while the IMD upgraded it to a deep depression. Around 00:00 UTC on May 8, the storm made landfall along Cox's Bazar District. Quickly weakening over land, the system dissipated over northern Myanmar later that day.
The system brought rainfall to southeastern India and Bangladesh. Kalapara Upazila in the latter country recorded 60 mm (2.4 in) of precipitation on May 7. A station in Cox's Bazar recorded peak winds of 75 km/h (45 mph). The storm produced high tides that flooded villages on the coast, while one girl was swept away by high waves. High winds knocked down trees and houses. There were 140 fishermen missing following the storm on 10 boats.
Tropical Storm 02A
On May 31, a weak circulation persisted over the warm waters of the Gulf of Aden. It moved east-northeastward along the coast of Yemen and Oman, bringing dry air from the north which decreased the convection. The system moved farther offshore on June 7 into the open Arabian Sea, where it interacted with the south-west monsoon and developed more convection. The convection became more persistent by June 9 about 1,480 km (920 mi) northeast of Somalia by June 9. Moving northwestward, the system organized enough for the JTWC to classify it as Tropical Cyclone 02A about 160 km (99 mi) from the Oman coastline. This marked the first occasion that a tropical cyclone originated from a system in the Gulf of Aden. Later on June 11, it struck Oman's southeast coast. The storm weakened over land, dissipating on June 12, although it continued to produce rainfall – heavy at times – over the next few days. The IMD did not track the system.
Offshore Oman, the storm's rough waves disabled an oil tanker and damaged a fishing boat, killing one person in the latter incident. Striking Oman, the storm produced significant rainfall totals well above the monthly average, peaking at 234 mm (9.2 in) in the Dhofar region. Strong winds where the storm moved ashore damaged buildings and the local water plant. The rains washed out roads and isolated villages, killing two people due to drowning in Al-Ghubra. However, the effects were more severe in Yemen, where the floods were considered the worst on record. The storm produced the heaviest rainfall in 70 years, reaching 189 mm (7.4 in) in Ma'rib. Flood waters washed away or damaged 1,068 km (664 mi) of roads and 21 bridges, some of them dating back 2,000 years to the Roman era. The storm washed away the topsoil or otherwise wrecked 42,800 ha (106,000 acres) of crop fields, accounting for US$100 million in agriculture damage. At least 1,820 houses were destroyed, many of them built on wadis, or dry river beds. Overall damage was estimated at US$1.2 billion, and there were 338 deaths in Yemen. The World Bank assisted in a project to rebuild the damaged infrastructure in Yemen and to mitigate against future floods.
Cyclonic Storm BOB 02 (03B)
On June 9, a disturbance began forming within the monsoon trough off the southeast coast of India. Inflow from the south helped the system organize, and the convection became more defined on June 11. At 06:00 UTC the next day, the JTWC classified the system as Tropical Cyclone 03B, and three hours later the IMD classified it as a depression. A ridge to the east initially steered the system to the northwest, although an approaching trough turned it to the northeast, parallel to the coastline. Early on June 13, the JTWC assessed peak 1-minute winds of 85 km/h (55 mph), and on the next day, the IMD upgraded the system to a cyclonic storm. Both the intensity and the track were unusual for the month of June. At 00:00 UTC on June 16, the IMD estimated peak 3-minute winds of 85 km/h (55 mph), around which time the storm turned back to the northwest. Five hours later, the storm made landfall near Visakhapatnam, Andhra Pradesh, and it rapidly weakened into a remnant low. The JTWC continued tracking the remnants until June 18 when the system was over Madhya Pradesh.
About 3,000 people evacuated ahead of the storm in Andhra Pradesh. When the storm struck the state, the highest winds on land were around 55 km/h (35 mph). However, the most severe effects were due to heavy rainfall, in part due to the storm's interaction with the monsoon. Chennai in northeastern Tamil Nadu recorded 350 mm (14 in) on June 14, breaking the 100 year old record for the greatest June daily rainfall total. Three people died near the city after the rains flooded streets. The highest daily rainfall was 680 mm (27 in) in Khammam district in Telangana. Widespread areas in Andhra Pradesh received over 300 mm (12 in) of precipitation, locally peaking at 1,200 mm (47 in), causing flooding that breached reservoirs and damaged 3,833 canals. In Madanapalle, flood waters reached 6 m (20 ft) deep, forcing 1,500 people to leave their homes. The floods also damaged 13,378 ha (33,060 acres) of crop fields, with damage to bananas, coconuts, and mangroves. The storm damaged or destroyed 1,594 homes, leaving over 3,000 families homeless. Overall damage was estimated at RS$820 million (US$23.5 million) in Andhra Pradesh, and there were 68 deaths in the state, mostly due to flash flooding. Elsewhere in India, the storm killed 111 people, including 44 in Tamil Nadu where 18 boats were damaged or missing. In some areas, the rains helped end a drought. After the storm passed, the Andhra Pradesh government provided each family RS$1,000 (US$30) if their house was destroyed, and RS$100,000 (US$3,000) if they lost a family member.
Severe Cyclonic Storm ARB 01 (04A)
While the previous storm was paralleling the east Indian coastline, another disturbance formed off the west coast on June 15, also associated with the monsoon. The new area of convection persisted, developing a distinct circulation by the next day. Early on June 17, a depression developed about 365 km (227 mi) west of Mumbai. At 18:00 UTC that day, the JTWC classified it as Tropical Cyclone 04A, after the wind field became more defined. The system moved to the northeast within the influence of the monsoon, and quickly intensified due to an anticyclone aloft providing favorable conditions. On June 18, the IMD upgraded the system to a cyclonic storm, and further to a severe cyclonic storm by 18:00 UTC that day. At 23:00 UTC, the storm made landfall on Gujarat near Diu, only the fourth cyclone since 1891 to strike the state in June. An hour later the IMD assessed peak 3-minute winds of 110 km/h (70 mph), based on the appearance of an eye feature. Meanwhile, the JTWC assessed slightly stronger 1-minute winds of 120 km/h (75 mph), equivalent to a minimal hurricane. The storm turned northward and slowly weakened, degenerating into a remnant low over Rajasthan on June 20 before being swept up by an approaching trough.
The storm moved ashore with a high storm surge, estimated at 5 to 6 m (16 to 20 ft) in Bharuch. Winds reached 85 km/h (55 mph) in Veraval, while heavy rainfall spread across the region, totaling over 300 mm (12 in) in some parts of Gujarat. South of the landfall point, high winds and waves washed 10 boats ashore near Mumbai, forcing the crews to be rescued by helicopters. The storm disrupted wheat production and port operations in western India. In Gujarat, the storm uprooted trees and damaged 8,000 ha (20,000 acres) of crop fields, with 2,113 cattle killed between Gujarat and neighboring Maharashtra to the south. The storm damaged 41,134 houses in the two states, and overall damage was estimated at RS$196 million (US$5.6 million). There were 47 deaths related to the cyclone.
Depression LAND 01
Toward the end of July, a well-defined low-pressure area developed in the northwest Bay of Bengal. It moved onshore and developed into a depression over southeastern India near Daltonganj on July 26. Turning to the west, the system moved through central India, bringing heavy rainfall along its path. The system degenerated into a remnant low on July 28 over Rajasthan, and the next day was absorbed by the monsoon trough.
Depression BOB 03
On October 1, a depression formed in the western Bay of Bengal. Moving westward, it failed to intensify beyond 45 km/h (30 mph). Around 00:00 UTC on October 2, the system made landfall near Ongole, Andhra Pradesh. Later that day the system degenerated into a remnant low over Karnataka state. It turned northward and moved through central India, bringing widespread heavy rainfall along its path. Eventually it turned to the northeast, dissipating over the Himalayas on October 5. In southern India, the storm wrecked houses, while flash flooding swept away people into rivers. At least 22 people were killed in the country.