Northern Ireland on 'tornado watch' as Storm Isha sweeps across UK and Ireland

The Met Office said a tornado could hit western parts of the UK after the research organisation Torro said Ireland, Northern Ireland, parts of Scotland and northern England were under threat.

Flights and ferries were cancelled and disrupted after the storm grew in intensity on Sunday, and thousands of homes were left without electricity.

In Belfast city centre a pedestrian was struck by falling debris after scaffolding became dislodged in Castle Lane. They were treated at the scene by emergency services.

PSNI officers closed the Castle Lane junction with Royal Avenue for a time.

It also said it had received “numerous reports of fallen trees” and urged people to only travel if the journey is necessary.

A Met Office spokesperson said that the province was in for “a rather nasty evening”.

​They said: “The north coast of Northern Ireland looks particularly vulnerable to the worst of the winds tonight.

“The amber [wind] warning is in force right through to six in the morning, with potential gusts up to 80mph in one or two places – especially on the north coast.

“A squally band of rain is moving through this evening.

“It will turn more showery overnight with some clearer spells. It's going to turn more blustery.”

Only a very gradual improvement is expected on Monday, with a risk of gales in exposed areas even in the afternoon around the coast and hills.

The spokesperson added: “These wind speeds aren't uncommon – it's more uncommon that it’s affecting the UK so widely.

“There's a nasty weather system coming in on Tuesday. There are wind warnings for Tuesday and Wednesday for Northern Ireland and Scotland. There could be 60-70mph winds again.”

In Ireland status red wind warnings were issued for counties Donegal, Galway and Mayo, while status orange/amber warnings were in place for all other counties from Sunday evening.

Meanwhile, gusts of up to 90mph were expected across the rest of the UK.

Multiple weather warnings, including two amber wind alerts, were put in place by the Met Office.

Met Office forecaster Marco Petagna told the PA news agency: “There is a potential that we could see the odd isolated tornado largely tied in with the squally cold front mainly in western parts of the UK on Sunday evening.

“They can cause some significant damage but often on a very localised scale, they often don’t tend to last very long.”

Rail, sea and air travellers were hit with disruption, with closures, cancellations and delays expected across a number of services.

Network Rail said 50mph speed restrictions have been imposed across most routes in England to keep passengers and trains safe from falling trees and debris blown onto tracks, with disruption likely to continue into Monday morning.

Scotland’s railway operator cancelled all of its services after 7pm and there will also be no Monday morning rush-hour services.

Storm Isha is the ninth named storm to hit the UK since the season began in September.

Each storm is named when it poses a risk to people and they are given names beginning with consecutive letters of the alphabet.