A yellow weather warning for rain and snow on the hills has been issued for a large part of Wales on Thursday.
The Met Office has said that periods of rain and hill snow could bring some disruption, with some areas seeing up to 60mm of rain.
The warning runs from midnight on Thursday morning until 11.45pm on Thursday night.
It covers most of east and north Wales including Cardiff and much of the south Wales Valleys.
The warning says: "Periods of rain are expected to become widespread and locally heavy across parts of England and Wales through Thursday.
"Over western areas, particularly the higher ground of Wales, some snow is also likely, with local accumulations of a few cm possible.
"Rainfall totals of 15-30 mm are likely, with some spots, particularly higher ground, seeing isolated totals of 40-60 mm."
It comes as forecasters warn temperatures are set to drop dramatically across Wales this week.
The lowest temperature forecast for this week is -2C according to the Met Office.
Experts say that is up to 8C below the average for the time of year.
Snow closed mountain roads and disrupted sporting events in Powys, Montgomeryshire and Gwynedd on Saturday.
The weather warning comes into place from midnight on Thursday for nearly 24 hours.
The areas in Wales covered by the warning are:
- Blaenau Gwent
- Caerphilly
- Cardiff
- Conwy
- Denbighshire
- Flintshire
- Gwynedd
- Merthyr Tydfil
- Monmouthshire
- Newport
- Powys
- Rhondda Cynon Taf
- Torfaen
- Vale of Glamorgan
- Wrexham
Parts of England badly affected by flooding last week are also within the warning area.
Warnings for Monday, Tuesday and Thursday all cover the South Yorkshire area and the crucial catchment area of the River Don, which remains high along its length.
The warnings cover the same areas that are still dealing with the aftermath from Thursday and Friday's downpours stretching from Yorkshire to Derbyshire and the East Midlands.
Several areas were deluged with one month's worth of rain in a day, and a woman died after being swept up in floodwaters.
