Meteorologists have upgraded their weather warning from yellow to amber as Wales prepares for the arrival of Storm Callum.

An amber warning for rain across a large part of south-west Wales - along with a yellow wind warning - have been issued by the Met Office with some forecasts suggesting as much as 200mm of rain will fall in just 48 hours.

A spokesperson for the Met Office said of Friday’s warnings: "Rainfall totals will reach 40 to 80mm widely, with 120 to 160mm likely over the high ground exposed to the south and south west.

"The rain is expected to be accompanied by strong winds, which when combined with high tides may lead to some coastal impacts due to large waves.

"In addition, leaves and twigs, brought down by the wind, could block drains and culverts, increasing the likelihood of flooding.

"Gusts of 50mph are likely with potential for gusts of 60 mph around exposed coasts and hills.

"High tides are also near their peak, heightening the risk of coastal impacts due to large waves."

Gary White, Natural Resources Wales duty tactical manager, said: “The current forecast rain could cause flooding this week, especially in south and west Wales, and we are urging people to prepare themselves.

“Making sure you know what the situation is like where you live is really important. You can check our website or call Floodline on 0345 988 1188 for any flood warnings that may be in place and keep an eye on weather reports and local news for details of any disruption in your area.

“Our teams are doing all they can to reduce the risk for communities, but if there is flooding we want to make sure people are doing all they can to keep themselves safe.”

People are advised to take extra care and allow extra time for their journey as driving conditions may be hazardous., and those walking or driving through any flood waters as it can be extremely dangerous.

People are also advised to avoid fast-flowing rivers and streams as they could get swept away and avoid coastal areas.Arriva Trains Wales have cancelled all trains along the Aberystwyth to Shrewsbury line from 10am Friday until Monday morning, when new train operators, KeomisAmey, take over.In a statement, Arriva Trains Wales said: "No trains will operate between Machynlleth and Newtown in both directions after 10am until start of service on Monday."The 08:52 Machynlleth - Pwllheli, 10:55 Machynlleth - Pwllheli, 09:34 Pwllheli - Machynlleth and 11:37 Pwllheli - Machynlleth services will be cancelled."No trains will operate between Llandudno Junction and Blaenau Ffestiniog on Friday or Saturday. A rail replacement road service will be put into place, subject to local road conditions.