LISBON, Portugal (AFP) — Portugal placed most of the country on red alert Saturday as Hurricane Leslie barrelled towards its coastline in what could be the fiercest storm to hit the country since 1842.

Authorities urged those living by the coast to stay indoors and fishermen to return to port while some flights were cancelled over warnings winds could reach up to 120 kilometres per hour (75 miles per hour).

And neighbouring Spain was also making preparations, with meteorologists expecting it to hit early Sunday, although by then it was likely to have been downgraded to a tropical storm.

Global weather forecasting site AccuWeather has dubbed Leslie a “zombie hurricane” as it first formed on September 23 “and has been meandering the waters of the Atlantic Ocean for weeks.”

But it was expected to make landfall in Portugal on Saturday, with strong winds and rain expected in the early evening, with the most serious conditions likely overnight or on Sunday morning.

Meteorological records indicate that only five hurricanes have ever arrived in this part of the Atlantic Ocean, and Leslie could turn out to be the fiercest storm to hit Portugal since 1842.

The exact trajectory of the hurricane, however, remains uncertain due to the presence of another storm approaching the region from the north, Portugal’s meteorological institute said.

Maritime authorities have advised fishermen currently at sea to return to the nearest port and Portugal’s TAP airline cancelled seven flights to and from Lisbon.

“We don’t know what the real and concrete impact will be, so we’re erring on the side of caution,” Lisbon’s mayor Fernando Medina told reporters.

Over the past 176 years, only Hurricane Vince has made landfall on the Iberian Peninsula, hitting southern Spain in 2005, according to weather records cited by experts.

In October 2017, strong winds from Hurricane Ophelia, which travelled north off the coast of Portugal and western Spain, fed forest fires that killed around 40 people during a heat wave.

Ophelia then made landfall in Ireland as a violent storm, killing three people.

While Leslie is likely to be downgraded to storm category when it hits western Spain on Sunday, authorities still warned that it could cause damage as it adds on to other active weather fronts.