Friday will start off mainly cloudy with scattered showers and isolated thunderstorms, becoming gradually partly cloudy by the afternoon.
A yellow alert warning of thunderstorms is in force until 11 am.
Temperatures will be 17 C inland and on the coasts and 5 C in the mountains.
The weekend, there will be intervals of mainly fine weather and intervals of cloud with isolated showers possible, mainly in the mountains. Temperatures will edge up to average for the time of year.
Monday will be mainly cloudy with scattered showers and isolated thunderstorms. Temperatures will remain basically unchanged at around average for the time of year.