Counties Carlow, Kilkenny, Wexford, Tipperary and Waterford have been placed with Status Orange Warnings, effective until 8pm tonight.
These counties are expected to be hit with slow moving thunderstorms, with very heavy downpours, and hail which is set to bring flash flooding, along with treacherous travelling conditions, and poor visibility. This may lead to "potential damage to power lines".
A further 20 counties are to also be placed with a Status Yellow weather warning, which is expected to bring heavy downpours of rain and thunderstorms. This may lead to spot flooding, poor visibility and difficult travelling conditions.
This warning has been placed for all of Leinster, Connacht Cavan, Donegal, Monaghan, Cork, Clare, Limerick, Tipperary, and Waterford.
Tonight is expected to be cloudy, with heavy showers, and initial isolated thunderstorms. These showers are set to ease, becoming less frequent overnight. Lowest temperatures are to stay between 7 and 11 degrees, with light north-westerly winds.
As for Wednesday, the national forecaster has also predicted cloudy weather, with scattered showers. Although the showers are to be lighter than previous days.
Wednesday evening is to see light rain and drizzle into the northwest. Highest temperatures are to remain between 13 and 17 degrees, with moderate to fresh northwest winds.
The following days are to stay mostly dry, with temperatures moving closer to average, with Saturday to become wetter.
It will remain cloudy and dry for Wednesday, aside from some patchy light rain and drizzle for the northwest. The south is to see a few clear spells developing. Lowest temperatures are to stay between 6 and 9 degrees with moderate to fresh northwest winds.
Met Éireann has predicted dry and cloudy weather in store for Thursday, with scattered showers. Temperatures are to remain between 11 and 15 degrees with moderate northerly winds.
That night is to remain dry, with clear spells developing, and temperatures remaining between 11 and 15 degrees.
The national forecaster has predicted another dry and cloudy day for Friday, with some isolated showers in places. Temperatures are to stay between 12 and 15 degrees with light southwest to west winds.
Saturday to is be overcast and wet, with rain spreading from the west. Temperatures are to hit 14 to 17 degrees, in moderate to fresh southwest winds.
“Current indications suggest that it will gradually turn drier and more settled for Sunday and the start of next week", the forecaster added.