Met Éireann has upgraded its rainfall warnings for the southwest, with up to 30 millimetres expected in the next 24 hours and higher totals likely on upland areas in South Kerry and West Cork.

Frontal systems will bring sustained heavy rain across much of the western half of the country. Counties in the alert zones are forecast to see between 20 and 30 millimetres of rain, with larger amounts on higher ground. With soils already saturated and waterlogged, surface flooding is expected.

Conditions are set to improve through Monday and Tuesday as drier weather develops nationwide. More rain is likely in the second half of the week, but a gradual improvement is expected over the Christmas period as high pressure builds close to or over Ireland. The risk of overnight frosts, mist and fog will increase towards the end of the month.

A status orange rain warning has been issued for Cork and Kerry, valid from 3am to 6pm on Sunday. Met Éireann said significant rainfall accumulations are expected, especially on high ground, with the highest totals in Kerry and West Cork. The warning highlights the risk of river and surface flooding, hazardous travel conditions and poor visibility.

Status yellow warnings are also in place for Clare, Cork, Kerry, Limerick, Donegal and Connacht from Saturday evening until midnight on Monday, and for Tipperary, Waterford and Wexford from midnight on Sunday until 3am on Monday. The UK Met Office has issued a yellow rain warning for Antrim, Armagh, Down, Fermanagh, Tyrone and Derry, valid from midnight on Sunday until 6am on Monday.

Marine warnings are in effect across all coasts, with southwesterly winds reaching force six or higher. Gale warnings have been issued for waters from Fair Head to Wicklow Head to Valentia and on the Irish Sea, where winds may reach gale force eight at times. A small craft warning is also in place from Howth Head to Carnsore Point to Roches Point from Sunday evening until early Monday.