The heavy rainfall poses a significant risk of flash flooding, particularly in urban areas with poor drainage systems. Major metropolitan areas such as Philadelphia and New York City are vulnerable to roadway flooding, which could disrupt travel and pose safety hazards. Low-lying areas, underpasses, and subway entrances are especially at risk of becoming inundated. Smaller waterways may overflow, and excessive runoff could lead to flooding in rivers, creeks, and streams. Residents in flood-prone areas should remain vigilant, as even a few inches of moving water can be life-threatening. The NWS has emphasized the potential for localized flooding to impact homes, businesses, and transportation routes.