1999–2000 South-West Indian Ocean cyclone season
The same monsoon trough that spawned Connie also produced an area of convection southeast of Diego Garcia on January 28. The circulation slowly organized, and the MFR classified it as a tropical disturbance on January 30. A nearby trough steered the system southeastward initially and later to the southwest. On January 31, the system became a tropical depression, and later Moderate Tropical Storm Damienne the next day, reaching peak winds of 65 km/h (40 mph). Also on February 1, the JTWC initiated warnings on Tropical Cyclone 10S, which estimated 1‑minute winds of 95 km/h (60 mph). Increased wind shear removed the convection on February 2, causing marked weakening, and prompting the JTWC to discontinue advisories that day. This was despite forecasts of strengthening to near tropical cyclone status. As a weak tropical disturbance, Damienne turned to a rapid westward motion, passing north of Rodrigues and Tromelin. The circulation dissipated on February 7 off the northeast coast of Madagascar.
On February 1, a low-pressure area formed within the monsoon trough to the south of Indonesia, which would eventually become Tropical Cyclone Leon in the Australian basin, as well as Tropical Cyclone 11S according to JTWC. The storm tracked westward across much of the Indian Ocean, fluctuating in strength due to changes in the atmosphere. After crossing 90° E, the MFR began tracking the system as Tropical Storm Eline on February 8. The storm continued westward across the Indian Ocean and intensified greatly as it approached the east coast of Madagascar. Late on February 17, Eline made landfall near Mahanoro with 10‑minute winds of 165 km/h (105 mph), making it the strongest storm to hit the country in several decades. The storm rapidly weakened over land, but restrengthened in the Mozambique Channel to reach peak 10‑minute winds of 185 km/h (115 mph). On February 22, Eline made landfall about 80 km (50 mi) south of Beira, Mozambique near peak intensity and quickly weakened over land. The well-defined circulation moved across southern African, finally dissipating over eastern Namibia on February 29. Throughout its duration, Leon–Eline lasted 29 days, a record longevity for a storm in the south-west Indian Ocean. The track was over 11,000 km (6,800 mi), or about 25% of the Earth's circumference.
1999 North Indian Ocean cyclone season
On January 30, an area of disturbed weather began to develop. Convection began to form around the center and a Tropical Cyclone Formation Alert was issued the next day by the JTWC. Development of the storm stalled and the alert was cancelled. The next day, another TCFA was issued but was once more cancelled. Finally, on February 2, after the third TCFA was issued, the low pressure area developed into a tropical storm at 0900Z 370 nm west of Phuket, Thailand. The storm slowly intensified and reached its peak of 45 mph (1-min) on February 3. Shortly after peaking in intensity, vertical wind shear weakened the storm and the low became exposed by 1800Z the same day. The storm later dissipated on February 5 without making landfall.
An area of disturbed weather in the Arabian Sea was monitored in early May for possible development. Over the next two weeks, strong convection would develop before sunrise but dissipate by sunset. By May 16, the convection had become constant and a TCFA was issued at 0100Z. The low became a tropical storm by 0900Z. Tropical Storm 02A intensified as it moved to the northwest and reached cyclone status on May 17 at 0600Z. At that time, a mid-latitude trough weakened the subtropical ridge, allowing 02A to curve into Pakistan. 02A continued to intensify and by May 19, it had reached its peak of 125 mph (205 km/h), just below Category four status on the SSHS. 02A made landfall on May 20 near Karachi, Pakistan at peak intensity. The storm began to dissipate as it continued inland over the Indus River Valley on May 21 and completely dissipated the next day.