Accuweather says that a "total washout" is not likely in the east.
However, "there will be enough rain and thunderstorms around to interfere with some outdoor plans, as well as slow travel and perhaps create dangerous conditions in some locations."
A forecast map from the outlet shows downpours across both states Saturday, Aug. 17 into Sunday, Aug. 18.
The National Weather Service says that Saturday will be partly sunny with a high near 83, and a 50 percent chance of showers and thunderstorms in the evening.
On Sunday morning, a chance of showers and thunderstorms are possible with potential for another thunderstorm after 2 p.m. Temps will be near 80 and skies will be mostly cloudy.
Click here to follow Daily Voice Carlisle and receive free news updates.