A railway line has been closed after debris from a landslip fell onto the track.
The Aberdare line is closed north of Pontypridd following a landslip near Mountain Ash.
A spokesman for Network Rail said about 100 tonnes of debris is currently blocking the route.
Transport for Wales (TfW) said there are no services operating north of Pontypridd and the line is expected to be closed until "at least Wednesday".
Buses are operating between Aberdare and Abercycnon.
Network Rail Wales and Borders shared images of the landslip near Mountain Ash on Twitter.
A spokesman said: "Our teams continue to work around the clock to reopen lines as safely and as swiftly as possible.
"We apologies for any inconvenience and we thank you for your patience."
Storm Jorge has battered Wales with 70mph winds and heavy rain starting on Friday evening.
The Met Office issued a yellow weather warning which started at 12pm on Saturday and is expected to last until 9am on Sunday, March 1.
There has been widespread disruption on Valley line services as a result of Storm Jorge.
The Treherbert line is currently closed with no services operating. TfW said a bus service is being introduced.
Trains are not operating on the Heart of Wales line between Llanelli and Llandrindod Wells, but are still running from Llandrindod Wells to Shrewsbury.
The Rhymney and Merthyr lines remain open.
A train service is also running between Cardiff and Bridgend but with extended journey times.
Bethan Jelfs, customer delivery director for Transport for Wales Rail Services, and Chris Pearce, Network Rail's head of operations for Wales and the Borders, said: "Following flooding at a number of location across Wales caused by heavy and sustained rain failing on already saturated ground, our frontline teams are working around the clock to reopen affected lines as soon as possible.
"A number of lines remain closed however, and with Storm Jorge set to bring strong winds of up to 75mph on Saturday, Transport for Wales and Network Rail are urging all customers to check their journeys prior to travel and allow plenty of time for their journey."
