Storm Brendan will bring extreme winds and heavy rain on Monday, with a status orange weather warning in force for all counties and a red warning in operation for marine areas.
Met Éireann is forecasting gale-force southerly winds that will extend countrywide during the morning, with severe and damaging gusts. Heavy rain will extend from the Atlantic, thundery at times.
There will be significant risk of coastal flooding due to a combination of onshore winds, spring tides and storm surge.
Clearer conditions, with squally showers of rain and hail, will follow from the west during the early afternoon, with the ongoing risk of thunder.
Winds will veer southwesterly with the clearance and will ease somewhat, although it will remain windy, with stormy conditions persisting on western coasts. Highest temperatures will be 7°C to 10°C.
Sunny spells to begin the day over some northern parts of the country, with showers, some wintry, in the west gradually giving way to cloudier skies further south, with rain becoming widespread.
Some sleet in places and some hill snow, especially over parts of the midlands.
It will be very cold over the bulk of the country, with afternoon highs of just 2°C to 4°C, but milder near the south and southeast coast.
Light to moderate southerly winds, fresh to strong on north and northwest coasts, will become mainly light to moderate cyclonic in the afternoon as an area of low pressure moves up from the south, but strong and gusty southwesterly on the southeast coast.
It will be very cold over the bulk of the country with afternoon highs of just 2°C to 4°C
Any rain or sleet will clear quickly northwards on Tuesday evening and night, leaving clear spells. A few scattered showers will occur in Atlantic coastal counties overnight, some of them wintry, especially on hills.
Southwest winds will be mostly moderate to fresh at first, but they will become gusty overnight, increasing strong to near gale on coasts. Cold and frosty, with lows of 0°C to 3°C, but increasing to 3°C to 5°C by dawn.
Wednesday will be a bright and breezy day in many areas with sunny spells. Scattered showers will occur, mainly in the west. Top temperatures of 5°C to 8°C.
Moderate to fresh southwest winds will back southeasterly in the evening.
Another area of low pressure looks likely to sweep up from the south on Wednesday night, delivering another spell of heavy rain, especially in the western areas. Southeasterly winds will increasing strong and gusty on Munster and Leinster coasts. Lowest temperatures ranging 2°C to 5°C.
Thursday is looking wet and windy at this stage, according to Met Éireann. Rain will be widespread for a time, potentially rather heavy in western counties with a risk of spot flooding there.
Drying conditions will be poor due to unsettled weather expected this coming week, while spraying opportunities will be limited.
With most soils are currently saturated or waterlogged, there is little prospect of improvement in the coming week with rainfall amounts expected to be generally well above average.