The Met Eireann Leitrim, Roscommon, and Sligo added to today’s weather warning as stormy conditions are expected to reach further west than expected.
The forecaster had already issued a yellow thunderstorm and yellow rain warning for Leinster, Cavan, Donegal and Monaghan.
But now 18 counties are under the new warning that begins at midday and runs until 8 p.m.
The forecaster said: “Heavy rain scattered with local thunderstorms will immediately give the risk of flooding.”
The situation is expected to be generally miserable across the country today before starting to flare up in the coming days.
One meteorologist said: “It’s raining in the east and northeast today with sunshine and rain elsewhere. There will be heavy rain with a possibility of thunderstorms and local flooding from about lunchtime until early evening; at-risk areas counties north and east line From Sligo to Wexford, the highest temperatures are from 17 to 20 degrees, with light south winds often deflecting later.
“Tonight, the rain will largely disappear this evening with only scattered rain remaining. Clouds will increase from the west later, with light scattered rain or drizzle appearing in the southwest by morning. Thick fog turning into mist in places with low temperatures from 10 to 13 Degree with light or changing western breezes.
“Sunday will be dry in most areas, with the appearance of sunny periods, best in the East and Northeast. In general, fairly cloudy, with patchy drizzle, in parts of Münster and along the west coast. Highest temperatures from 17 to 17 20 or 21 degrees, at light or variable western breezes.
“Basically dry and stable weather for the rest of the week, with some sunshine and higher-than-normal temperatures.”
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