yellow weather warning has been announced for Northern Ireland and parts of Scotland amid forecasts of heavy rain and possible thunderstorms.
The Met Office extended its warning on Saturday morning to include parts of central and western Scotland.
The warning is expected to be in place for all of Saturday in Scotland, with 30 to 40mm of rain likely and a low risk of between 80 and 100mm falling, causing localised flooding, according to the Met Office.
A further warning, encompassing Fife, Tayside, the north-east of Scotland and parts of the northern Highlands, has been issued for Sunday, and is expected to be in effect from midnight to 3pm.
In Northern Ireland, a yellow warning for rain is in place until midnight on Saturday and between 2am and 11am on Sunday.
The Met Office also warned “torrential” downpours meant some flooding of homes and businesses was likely while the could also be disruption to power supplies and transport.
There is also the potential for thunderstorm activity and lightning strikes.
The Scottish Environment Protection Agency (Sepa) issued flood alerts for the whole of the country except the Western Isles and parts of the north-west Highlands ahead of the forecast heavy rain over the weekend.
Of the alert in place in west-central Scotland, Sepa said: “Periods of heavy rain on Saturday could cause flooding impacts from surface water and small watercourses. Particularly at risk are urban areas and the transport network.
“Impacts may include flooding to low-lying land and roads, with difficult driving conditions. Isolated properties may also be at risk.
“Due to the localised nature of the heaviest rain, impacts may be isolated, with not all locations being affected.”
The Republic of Ireland’s weather service, Met Eireann, issued an orange warning for intense rainfall up to 50mm expected on Sunday morning, with squalls likely for Carlow, Kildare, Kilkenny, Laois, Longford, Offaly, Westmeath, Cavan, Donegal, Leitrim, Roscommon, Sligo and Waterford.
The orange warning was in place from 4am to 8am on Sunday, with a less severe yellow warning issued for much of the country overnight from Saturday.