Tropical Cyclone Gonu weakened as it passed through the Arabian Sea and headed for the Strait of Hormuz, a major shipping channel for Gulf oil shipments, towards Iran, forecasters said on Wednesday.
The atypical storm, which reached the equivalent of a maximum-force Category Five hurricane on Tuesday, has been downgraded to a Category One hurricane.
This is based on the maximum sustained wind speed of the storm, which is just about 92 miles per hour (mph), a report posted on the U.S. military's Joint Typhoon Warning Center said.
"It is important to note that Tropical Cyclone Gonu will become a very weak tropical cyclone ... therefore regardless of the 48-72 hour track, the system will not be a significant tropical cyclone," the U.S. Navy said in its latest forecast.
The center of the storm is now expected to hit land in southeastern Iran over the next 36 hours. But shipping and port agents in the Middle East were not immediately available to comment on operations through the Strait on Wednesday.
Gonu had disrupted Oman's oil and gas exports, closed its stock exchange as well as private and public institutions until Saturday, while national carrier Oman Air had stopped all flights.
The storm is expected to get weaker due to cooler ocean water, dry air from the Arabian Peninsula and Iran, interaction with land and increasing vertical wind shear, said the Weather Underground Web site
"By the time it reaches the southern coast of Iran, it may have already weakened into a tropical depression. Flash flooding will be a major threat," meteorologist Tom Moore wrote on the company's Web site.
The last hurricane-strength tropical cyclone to hit Iran was in 1945, Moore wrote in his report.
On Tuesday, Oman's Mina al Fahal oil terminal, the only outlet for Oman's 650,000 barrels per day (bpd) of crude oil shipments, was shut as storms hit the area.
It was reopened later as the storm weakened, but shippers said conditions were still not suitable for loading operations.
Exports from the Sur export terminal, which handles 10 million tons per year of liquefied natural gas exports, was also closed.