Morning AFD on heavy rain threat from Mount Holly-
Heavy Rain/Flash flooding: There are a lot of factors increasing our concern with the heavy rain threat. For much of the region, models depict precipitable water values around 2 inches which is above the 90th percentile for this time of year. Additionally, the warm cloud layer should be between 10K and 14K ft through much of this period (meaning storms will be far more efficient with heavy rain rates). While storm motions will be slightly faster than what we`ve seen the last few days (generally 10 to 20 mph), but depending on how quickly the low lifts northeast, there could be potential for training storms as the mean cloud layer flow is expected to be parallel to the front for much of the period. Given the increasing concern for flash flood potential, expanded the flood watch to include the entire area. Although flash flood guidance is generally higher in southern DE, adjacent areas of MD, and SE NJ, concern is for flooding along the more flash flood vulnerable coastal and tidal areas.