The storm was packing maximum sustained winds of 40 mph as it skirted the coastline of far southern Oman early Wednesday.
At least six people died as flash flooding from Keila surged across the desert region.
But the storm quickly began to dissipate after moving ashore over Oman's arid interior.
Such tropical cyclones form in that area only during two brief periods each year.
A study released this week says that manmade pollution over India is causing storms over the Arabian Sea to become intense in recent years.
Tropical Cyclone Keila Track
Satellite Loop Data: CIMSS