The Met Office has issued a yellow alert for Friday for a second day in a row, warning that thunderstorms, probably accompanied by hail are expected to affect the area today.
Locally, the accumulated precipitation may exceed 35 millimetres per hour, it added.
The alert is in force from 12 noon to 6 pm today.
Be aware that thunderstorms may occur. Take extra care in exposed areas, like mountains, forest and open terrain. Disruption to outdoor activities is possible, the Met Office said.
In its morning forecast, the Met Department said that outside the thunderstorm alert timeframe, we will see some sunny spells amid the cloud. Temperatures today will reach 19 C inland and on the west coast, 20 C on the other coasts and 10 C in the mountains.
Tonight is expected to be mainly fine with some low cloud locally. Temperatures will edge down to 9 C inland and on the south and east coasts, around 11 C on the remaining coasts and 3 C in the mountains where frost may form locally.
The weekend will be mostly fine but cloud that may emerge in the early afternoon may bring some isolated showers mostly in the mountains, without excluding thunderstorms on Saturday.
Monday will be mainly fine with increased cloud locally around noon and in the afternoon in the mountains and inland.
Temperatures will edge up on Saturday to remain near the average for the time of year and will not shift significantly thereafter.