Yellow warning of snow, ice affecting Wales: Blaenau Gwent, Caerphilly, Carmarthenshire, Ceredigion, Conwy, Denbighshire, Flintshire, Gwynedd, Merthyr Tydfil, Monmouthshire, Powys, Rhondda Cynon Taf, Wrexham valid from 0300 Sun 18 Dec to 2100 Sun 18 Dec
