The Portuguese Azores archipelago was on weather alert Saturday as Hurricane Ophelia approached, with heavy rainfall forecast in the region.
The hurricane is expected to move past the island of Santa Maria before approaching Ireland.
The Miami-based US National Hurricane Center said Friday that Ophelia was forecast to produce total rain accumulations of two to four inches (51 to 101 millimetres) over the southeastern Azores through Saturday.
The rainfall could trigger flooding, it said.
Seven of the nine islands that make up the Azores were placed on red alert by the regional civil protection services between 1800 GMT and 2400 GMT due to expected rainfall of 40 millimetres per hour.
The local population, which totals 245,000, was told to stay home if possible during the passage of the hurricane which is now a category two out of five, but still capable of generating winds of more than 100 kilometres (60 miles) per hour.
All 17 firefighting units on the archipelago are on standby to intervene, a spokeswoman for the security services told AFP.
The authorities imposed traffic restrictions on the islands of Sao Miguel and Santa Maria, which are expected to see the worst of the hurricane.
Portugal’s weather centre said the eye of the hurricane was projected to pass Santa Maria some 150 kilometres to the south, without making landfall, before moving north-west.
Ophelia should no longer be a hurricane by the time it reaches Ireland, but will still whip up a powerful storm, the US hurricane centre predicted.
Five counties in the west of Ireland will be placed on red alert for “severe” weather conditions from Monday morning to early Tuesday, the Irish Meteorological Service said.
Mean wind speeds in excess of 80 km per hour and gusts in excess of 130 km per hour are expected, potentially causing structural damage and disruption, with dangerous marine conditions due to high seas and potential flooding, the service said.
Parts of the UK, meanwhile, have been placed on yellow alert for Monday and Tuesday, the lowest warning level triggered by “serious” weather conditions.