People from remote villages near the coastal city of Salalah evacuated to safer places ahead of the powerful storm.
Meteorologists in Oman are on alert as forecast models predict the development of a tropical cyclone in the Arabian Sea that is expected to make landfall later this week.
The system is expected to emerge from an area of active thunderstorms across southern India where Kerala and Tamil Nadu states are already seeing torrential rain.
The Indian Meteorological Department has issued warnings of extreme rain for the states over the next few days, with Sunday bringing the worst of the weather.
There are concerns that these downpours could cause further flooding in Kerala, which was hit by the worst flooding in nearly a century in August, killing more than 480 people.
The tropical cyclone is expected to develop to the west of India within this region of severe weather.
The storm is not expected to hit Kerala but is forecast to move northwest towards Oman, making landfall on Thursday or Friday. It is likely to bring damaging winds, rains causing flooding and the risk of landslides.
In weather terms, this is a long way off so the forecast track and the time of impact are likely to change.
Tropical cyclones are not particularly common in the Arabian Sea, usually forming during the onset of the Indian summer monsoon in May or June, or during its withdrawal in September or October.
The most intense tropical cyclone to make landfall in the Arabian Peninsula on record is Cyclone Mekunu which made landfall just to the east of Salalah on May 25 this year.
Oman’s preparations for tropical cyclones were improved after Cyclone Gonu slammed the country in June 2007 and killed 50 people.