The Met Office has issued a yellow warning of rain for most of Powys.
Meteorologists say periods of rain and hill snow may bring some disruption to transport from midnight to 11.45pm on Thursday, November 14.
Flooding of a few homes and businesses is "likely", Met Office warns.
Areas affected by the weather warning:
- Llanfyllin
- Llanfair Caereinion
- Welshpool
- Newtown
- Knighton
- Bishops Castle
- Llandrindod Wells
- Builth Wells
- Brecon
- Crickhowell
The Met Office said: "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 centimetres possible."
They added: "Rainfall totals of 15-30mm are likely, with some spots, particularly higher ground seeing isolated totals of 40-60mm."
Natural Resources Wales says there is 'low risk' of flooding however residents and commuters in Powys should be aware that flooding "is possible".
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