Summary
Tropical cyclone Ophelia was a weak cyclone that developed to tlie north of Cocos Island during a period of strong monsoonal activity across the southern equatorial Indian Ocean. Three other cyclones ( Delfininnia at 85°E, Costa at 60°E and an unnamed cyclone at 40°E) were active to the west of the area.
After forming at 8.6°S, 97.6°E (0000 UTC 7 January 1986) the low moved slowly southwest entering the Western region of responsibility at the time the low reached cyclonic strength. At 1800 UTC on 9 January (10.3°S, 95.2°E) the system recurved and began moving generally southeast. The track appears to have been influenced by the flow on the western side of an upper-level high.
Ophelia passed 30 km to the east of Cocos Island. Winds on the island exceeded gale force (63 km/h) for brief periods during 11 January however the strongest wind recorded was a gust of 80 km/h' at 1550 UTC on 10 January. At 0001 UTC on 11 January a ship 110 km south-southwest from the storm reported winds of 66 km/h, however this wind may have resulted from the strong pressure gradients which developed between the cyclone and a high to the south. The lowest central pressure was estimated to be 986 hPa during the period 0000-0600 UTC 11 January.
As the cyclone moved southeast past Cocos Island it was affected by the shear between upper-level northwesterly and low-level southeasterly winds. Under this influence the cyclone decayed rapidly to a low with central pressure of 1004 hPa by 0000 UTC on 12 January.
Track and intensity
All times in WST - subtract 8 hours to convert to UTC.
