Met Éireann has issued a Status Yellow thunder warning for 11 counties in the northern half of the country for the afternoon.

Issued earlier today, Tuesday, August 6, the warning will be in place from 2:00pm through to 9:00pm tonight.

The warning is valid for counties: Cavan; Monaghan; Donegal; Longford; Louth; Meath; Leitrim; Roscommon; and Sligo.

In an update at 4:25pm this evening, Met Éireann announced that the warning has been extended to counties Westmeath and Dublin.

In these counties, the national meteorological office warns that there will be heavy thundery downpours this afternoon and evening with a risk of localised flooding.

Meanwhile, for the country in general, there will be showers or longer spells of rain this afternoon and evening with occasional heavy thundery downpours, especially in the affected counties.

Highest temperatures will reach 17° to 21° with moderate south-west breezes, Met Éireann says.

The showers will become isolated later this evening and tonight when there will be long clear periods.

Lowest temperatures of 11° to 13° are expected. A few shallow fog patches will form as the breeze dies off, the national weather forecaster added.

Tomorrow, Wednesday, will start off mainly dry with sunny spells.

Showers will develop in the afternoon, once again mainly over the northern half of the country.

Highest temperatures of 17° to 21° are expected with moderate westerly breezes on the cards.