Cyclone Ockhi

The ninth depression, and the third and strongest named storm of the 2017 North Indian Ocean cyclone season, Ockhi originated from an area of low pressure that formed over the southwest Bay of Bengal on November 28.

[2] Due to high atmospheric moisture and warmer oceanic surface temperature between Sri Lanka and Kanyakumari (Cape Comorin) in mainland India, Ockhi intensified into a cyclonic storm on November 30.

[3] Ockhi impacted Lakshadweep on December 2, uprooting coconut trees and causing extensive damage to houses, power lines and other infrastructure on the islands.

[4] Ockhi weakened into a well-marked low near the south coast of Gujarat, India, on December 6, before crossing the coastline and dissipating shortly afterward.

[5] In its entirety, Ockhi left a trail of massive destruction in Sri Lanka, Lakshadweep, South India, and The Maldives, as it strengthened from a depression to a mature cyclone.

[8] On November 28, an area of low pressure from the remnant energy of Tropical Storm Kirogi developed about 425 km (265 mi) to the south-southeast of Colombo, Sri Lanka.

[10] On November 29, the storm organized into a depression just off the southeastern coast of Sri Lanka, and the India Meteorological Department (IMD) gave the system the identifier BOB 07.

[13] The storm tracked along Sri Lanka's southwestern and western coastline, towards the west-northwest, around the southern verge of a subtropical ridge located over India.

[18] On December 4, analysis showed that Ockhi was maintaining a source aloft, but there was restricted outflow on the western edge[further explanation needed], due to a deepening trough advancing rapidly from the west.

[19] Increasing vertical wind shear along with a deep layered subtropical ridge to the east steered it north-northeast, and a dry air intrusion from the west gradually weakened the system.

[21] Dry and cold air from the northern parts of India rapidly weakened the storm, and it was last noted as a well-marked low-pressure area south of the Gulf of Cambay on December 6.

[24] The Maldives Meteorological Centre predicted heavy rain and strong winds across the country's atolls, particularly those in the north and center of the island chain, over the day.

[40] Due to the poor visibility caused by rain and attendant wind, BIA was prompted to divert two SriLankan Airlines flights to Mattala early on November 30.

[43] The National Building Research Organisation issued a warning to Kalutara District and its surroundings, with a focus on Palindanuwara, Bulathsinhala, Ingiriya and Agalawatta in particular, predicting landslides and sinkhole formation.

[26][46] The Maldives National Defence Force was assigned to rescue and flood draining efforts predominantly on islands where the local citizenry could not manage on their own; the police too provided aid.

[50] Torrential overnight rains, accompanied by squally winds lashed the district, uprooted 550 trees and 950 electric poles, disrupting normal life.

[59] In Gujarat, parts of southern region received significant rains, with the highest rainfall in Umargam of 90 mm, causing damage to vegetables and banana crops.

[61] Kerala and Tamil Nadu sent special rescue teams on December 2 to track missing fishermen who were at sea during the onset of the cyclone, due to protests in coastal areas over the unsatisfactory response from government agencies.

[64] 4 tonnes of material, including rice, dal, salt and potatoes, water, blankets, raincoats, disposable clothes, mosquito nets and dhurries, were given to the local government.

[65] Tamil Nadu's government stated on December 6 that as many as 4,501 houses in Cyclone Ockhi-hit Kanyakumari had suffered partial and full damage and relief to the tune of ₹41 lakh had been provided.

[69] The protesters claimed that the Government of Kerala was late in issuing warning to the fishermen on November 29, when the cyclone was in depression state near Sri Lanka.

Map plotting the storm's track and intensity, according to the Saffir–Simpson scale
Map key
Tropical depression (≤38 mph, ≤62 km/h)
Tropical storm (39–73 mph, 63–118 km/h)
Category 1 (74–95 mph, 119–153 km/h)
Category 2 (96–110 mph, 154–177 km/h)
Category 3 (111–129 mph, 178–208 km/h)
Category 4 (130–156 mph, 209–251 km/h)
Category 5 (≥157 mph, ≥252 km/h)
Unknown
Storm type
triangle Extratropical cyclone , remnant low, tropical disturbance, or monsoon depression
Cyclone Ockhi becoming extratropical off the West Indian coast on December 4
Many trees were uprooted due to strong winds in Colombo .