Hail and sleet are likely to precede heavy rainfall today and tomorrow, according to the Meteorological Service.
A belt of heavy rain from the Atlantic is expected over Ireland before moving on to the coast of Scotland and the rest of the UK where it could fall as sleet and snow. No appreciable snowfalls around Ireland are anticipated.
Most rain is expected to fall during a 12 hour period between today and tomorrow. A Met Service spokesman said the rainfall would be heaviest in the south and floods were possible in all areas.
Rains would be accompanied by strong gusty winds, reaching 80 miles an hour at times.
The heavy rain is likely to abate over the weekend but bursts of squally showers will continue through Saturday and Sunday.
