Analysis: Heavy rain, storm potential Friday morning
A mid level atmospheric disturbance will approach the area from the southwest later Thursday Night into Friday morning, bringing with it plenty of tropical moisture and lift. As the disturbance shifts toward the Mid Atlantic states and eventually off the coast, a surface low pressure area will develop in the same adjacent areas. This will enhance lift in the atmosphere — allowing heavy rain to develop just to the north of the low pressure area.
Within an airmass characterized by precipitable water values over 2.50″, this lift will support the development of heavy, torrential rains from Thursday Night into Friday. Movement from southwest to northeast of heavy rain, and embedded thunderstorms, is anticipated. Exactly where the heaviest bands fall will depend on a few things; namely convection, and placement of the best mid level lift and vertical velocity.