A low pressure system will sit and spin offshore to our southwest Sunday through Tuesday. This will lead to thunderstorms that could produce abundant lightning and gusty outflows.
The upper level low will be centered just off shore of the Bay Area and will increase instability. South, southeast winds aloft are typically are favorable winds for summer time thunderstorms. Monsoon moisture will be in place but not as moist as out last few thunderstorm outbreaks, this could limit rainfall with any thunderstorms that form.
Another concern will be the speed these thunderstorms will be travelling. Upper level steering winds (20,000 ft) are at around 20 knots, which is about 23 mph. Thunderstorms will be moving off to the northwest and rainfall will have limit time to fall on area lightning strikes.
The upper level low will finally lift northeast by Tuesday evening, putting an end to widespread thunderstorms.