Simon Calder, a travel journalist, says the disruption at London Paddington train station could continue into the weekend.
A number of services, including trains to and from south Wales, were cancelled after signalling problems caused major disruption to a line.
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It will become drier in the early hours setting us up for a fine start to Wednesday
Showers in the north will spread southeastwards overnight. Temperatures will be higher so not as chilly as list night.
Chilly start to Tuesday, turning into a largely fine and dry day.