To start the period, a deep low pressure trough will be located west of the Appalachian Mountains, with high pressure off the Atlantic coastline. This will provide a southerly flow of moisture deep through the atmosphere, and with a jet streak in the upper levels producing some lift, showers and thunderstorms will be numerous on Friday. They will be possible at any time of the day, but the highest chances will be in the afternoon. I expect that there will be enough rainfall that there will be some delays and stoppages to the day's sessions.
On Saturday the upper trough moves a little farther east, which should move the main axis of rainfall closer to the coast. There will still be a good amount of moisture in the atmosphere, but not much in the way of lift. So I think that the coverage of showers and storms on Saturday will be more scattered, and occur mainly in the afternoon when heating can provide more instability.
On Sunday the trough will be weakening and moving off to the east, which will result in a more westerly flow that will bring drier air to the region. It will be quite a nice day with partly cloudy to mostly sunny skies, and highs in the upper 80s with slightly lower humidity.