Tropical Storm Fiona is forecast to come within about 260 nautical miles of Bermuda on Wednesday.

As of 6pm today, the Bermuda Weather Service continued to classify the storm as a potential threat to the island, reporting that its closest point of approach to the island within the next 72 hours would be 6pm on Wednesday, when it will pass 233 nautical miles to the south-southwest.

However the US-based National Hurricane Center has forecast that the storm will weaken to a tropical depression by tomorrow afternoon and into a post-tropical system before passing the island.

This afternoon Fiona was 748 nautical miles southeast of Bermuda, with maximum sustained winds of 39mph and higher gusts. It was moving in a west-northwest direction at 17mph, with tropical storm force winds extending outward up to 60 miles from its centre.

• This article was updated to reflect information from the Bermuda Weather Service and the National Hurricane Centre at 6pm. For more information, visit www.weather.bm/maps/TropicalStormInfo.asp?WTNTnum=WTNT21 and www.nhc.noaa.gov/#FIONA