Train services will be suspended for the whole day, with disruption likely to continue into the weekend, so that more than 1000 miles of track can be checked and cleared of debris and fallen trees.
Winds of up to 100mph could hit the most westerly parts of Wales, around the Pembrokeshire coastline, while winds of between 60 and 80mph could impact inland across Wales and the borders area.
Due to the level of extreme weather expected, rail replacement services will not be able to operate as the road network will also be disrupted.
Transport for Wales is allowing passengers with tickets for tomorrow (18 Feb) to travel today or over the weekend, if services have resumed by then. Original tickets will be valid for these journeys.
GWR is also allowing passengers to travel on alternative days with tickets valid today through to and including Monday 21 February.
Avanti West Coast passengers with tickets for Friday can use their tickets today or on Saturday 19 February.
The decision has been made jointly by Network Rail and train operators with the safety of passengers and railway staff paramount.
“The decision to temporarily close the railway in Wales has not been made lightly but the safety of passengers and staff is our top priority.
“Storm Eunice is expected to bring extreme high winds of up to 100mph and in places it is very likely trees and debris will be blown onto train lines.
“We are sorry for the disruption caused by closing the railway and we will continue to work hard, along with our train operator colleagues, to get train services back up and running as soon as it is safe to do so.
“Passengers who are planning to travel over the weekend are strongly advised to check before they travel as the unpredictable nature of storms such as Storm Eunice means the impact on services can change quickly.”
Bill Kelly, Network Rail Wales & Borders route director
Martyn Brennan, Operations Director at Transport for Wales, said: “The safety of our customers and our colleagues sits at the very heart of what we do and for this reason, we have taken the difficult decision to suspend all TfW services Friday until it is safe to re-open. The extreme weather forecast for Storm Eunice is very concerning, so we are strongly advising people not to attempt to travel during this time as services will not be operating.
“For those who have already purchased a ticket to travel during Storm Eunice, they can choose to either travel today, Thursday 17th, on Saturday 19th or on Sunday 20th. Alternatively, customers can claim a full refund in the normal way. I would like to thank customers for their understanding and support.”
“Speed restrictions will be put in place on our network, but the extent of those restrictions can only be determined by conditions on the ground and are likely to change throughout the day.
“We will continue to run as many trains as we can but those who need to travel should be aware that we will have to reduce the number of trains we can run, journey times will take longer, and those trains we can run will be much busier.
“Please do heed the usual advice to check before you travel.”
GWR Managing Director Mark Hopwood