Repairs to the Cambrian Coast railway will take months, say Network Rail.
The line is closed between Dovey Junction and Pwllheli after recent storms left debris strewn across the tracks.
Engineers intend to have the route open by mid-May.
Winds in the area reached speeds of more than 50mph on Saturday night.
Coastal and flood-prone communities across Wales are preparing themselves for another battering from the weather this weekend
Ceredigion Council estimates that damage in Aberystwyth and elsewhere in the country will top £1.5m.