Torrential rain has left roads in Cardiff flooded as most of south Wales is hit by a yellow weather warning for rain.Roads in parts of Cardiff were flooded by Wednesday afternoon as nearby river levels rose.
The Met Office said there is a "small chance" that homes and businesses could be flooded, as well as the possibility of road closures and some communities becoming cut off.
There are flood alerts and warnings for Wednesday and Thursday, with further rain forecast and a weather warning issued by the Met Office.
Transport was also impacted after train services were suspended between Newport and Hereford and Cardiff and Barry on Wednesday afternoon due to the flooding.
Transport for Wales also said the line between Mountain Ash and Aberdare is blocked with disruption expected until the end of the day.
The warning states that 50 to 70 millimetres of rain could be expected to fall across eastern parts of the country.
South Wales Fire and Rescue Service urged people to "be prepared to act upon advice from emergency services" as heavy rain continued on Wednesday evening.
The Met Office has issued a yellow 'be aware' warning for rain across southern and mid parts of Wales from 6am on Wednesday morning to 2am on Christmas Eve.
Meanwhile, Natural Resources Wales has issued six flood warnings where "flooding is expected" for rivers in south, west, and north Wales.
It has also issued 19 flood alerts where "flooding is possible" for rivers across the country.
Earlier this week, the heavy rainfall caused a second landslip to be triggered in Rhonda Cynon Taf and is currently being investigated by engineers after the bad weather.
Wales has seen a number of flooding incidents across the country this year - a major incident was declared when Storm Dennis brought the worst flooding to hit Wales for more than 40 years back in February.
With rain falling on already saturated ground and into swollen rivers, Natural Resources Wales is warning that further flood alerts or flood warnings may be triggered in some areas of Wales and are asking people to know their flood risk in advance.
Sean Moore, Natural Resources Wales said: “People are advised to keep an eye on the Natural Resources Wales website and Twitter feed to keep up to date with the latest flood warnings for their area, as well as listening for updates on local news and weather reports.
“Due to the recent heavy rainfall experienced across Wales over recent days, the ground is still very saturated and rivers extremely responsive, meaning that further rainfall may cause rivers to rise again quickly.
“Our officers are monitoring forecasts closely and are working with partners to prepare for any impacts and to minimise risk to communities.
“Driving conditions may be poor, so people are asked to take extra time and care while travelling. Flood water is extremely dangerous, and we remind people that they should not walk or drive through floodwater, as it can contain hidden dangers."
What to do in a flood
Check the latest weather forecast and the Natural Resources Wales website for the latest flood alert and warning information;
Call Floodline on 0345 988 1188;
Prepare a bag that includes medicines and insurance documents;
Turn off gas, water and electricity in the event of a flood and move family, pets and car to safety;
Call 999 if in immediate danger.
The bad weather is expected to ease during Christmas Eve with bright skies and sunshine, while the Met Office said it expects Christmas Day to be "dry and chilly".
But the spell of good weather is expected to end as early as Boxing Day, with a yellow warning for wind issued for the whole of Wales from 3pm on December 26 until 12pm the following day.