Severe Cyclonic Storm Jal was the fifth named cyclonic storm and the fourth Severe Cyclonic Storm of the 2010 North Indian Ocean cyclone season. Jal developed from a low-pressure area in the South China Sea that organized into a Tropical Depression on . Jal is a Sanskrit word, meaning water. At least 54 people are known to have been killed in India. As a tropical depression, Jal produced torrential rains over parts of Thailand and Malaysia, triggering severe flooding which killed 59 and four people in the two countries respectively. In Sri Lanka, heavy rainfall with strong winds have caused flooding affecting around 80,000 people. In Thailand, Jal was responsible for 78 deaths, being the 4th deadliest tropical cyclone in the country.
Meteorological history
On October 12, a weak tropical disturbance formed within a monsoonal trough of low pressure in the South China Sea, just off the eastern coast of Borneo. For the next few weeks, the system stalled on the eastern coast of Bormeo, remaining disorganized, while the system barely affected the island of Borneo at all. During the last week of October, the storm detached from the moonsonal trough, and began slowly moving east. On , the Japan Meteorological Agency (JMA) and the Joint Typhoon Warning Center (JTWC) both reported that the system had begun to develop, already beginning to organize itself, about 550 km (340 mi), to the southeast of Ho Chi Minh City, Vietnam. During the next few days, the tropical depression strengthened slowly as it slowly moved towards the eastern border of the Indian Ocean. During this time, convection around the disturbance increased, but failed to organize around the storm's low level circulation center. Despite these unfavorable conditions, the storm managed to develop convection around its area of low pressure, and organized itself significantly. On , the Thai and Malaysian meteorological departments (TMD) reported that the disturbance had developed into a tropical depression, and initiated advisories on the system. From continuing into , the storm strengthened slightly as it continued moving towards the Indian Ocean, but not enough for it to become a tropical storm. Late on , the tropical depression crossed the Malay Peninsula, and entered the extreme eastern part of the Indian Ocean, causing the west Pacific agencies to cancel all their advisories on the storm, as it was no longer in the west Pacific Ocean. As soon as the system entered the extreme eastern border of the Indian Ocean, the India Meteorological Agency (IMD) immediately declared the storm a depression, and began issuing advisories on the system, because the system had already organized itself into a tropical depression in the west Pacific Ocean, on , which was a day before the system entered the IMD's area of responsibility. Later on , the system began showing signs of further, but slow organization, as the system continued moving west slowly. Early on , the Malaysian Meteorological Department (MMD) also issued their first advisory on the system, and the IMD simply called it Depression, because the storm had not yet entered the Bay of Bengal. Later on that day, the IMD reported that the system had weakened into an area of low pressure, due to the effects of crossing the Malay Peninsula, but they forecast it to become a depression soon again, as the storm was moving over warm water. Late on , the Joint Typhoon Warning Center (JTWC) issued a Tropical Cyclone Formation Alert on the system, as it began reorganizing itself. Early on , the India Meteorological Department (IMD) upgraded the area of low pressure to a depression again, this time giving it the designation "BOB 05", as the system had now entered the Bay of Bengal. On , the Joint Typhoon Warning Center (JTWC) designated the system as Tropical Cyclone 05B.