A slow-moving upper level low pressure system will bring a slight chance of showers and thunderstorms to portions of southwestern California through Tuesday. Most of the activity will be in the afternoon and evening hours and be confined to the mountains foothills. Any thunderstorms that form could produce brief heavy rain, strong and erratic wind gusts, dangerous cloud-to-ground lightning, and possibly small hail. Keep informed of the forecast and seek shelter from lightning - when thunder roars, go indoors! Plan outdoor activities earlier in the day before storms develop. Be on the lookout for fire starts in dry grasses.