WILMINGTON, Del. — A flood watch has been issued across a wide swath of the mid-Atlantic region Tuesday afternoon through Tuesday evening, as forecasters warn of possible flash flooding from heavy rainfall.
The National Weather Service said flooding caused by excessive rainfall is possible in parts of Delaware, Maryland, New Jersey and Pennsylvania, with the heaviest downpours expected during afternoon and evening hours.
“A frontal boundary will collide with a tropical airmass and produce widespread showers and thunderstorms,” the weather agency said. Rainfall rates could exceed 2 inches per hour in some areas.
Counties under the flood watch include all of Delaware; northeastern Maryland counties such as Caroline, Kent, Queen Anne’s and Talbot; numerous counties in New Jersey including Camden, Middlesex, Sussex and Atlantic; and parts of southeastern Pennsylvania including Philadelphia, Bucks, Montgomery and Chester.
Excessive runoff may lead to flooding in rivers, creeks, streams and flood-prone urban areas with poor drainage. Forecasters noted that low-lying regions could be particularly vulnerable during intense downpours.
The flood threat stems from a combination of tropical moisture and an approaching front that will increase the intensity and coverage of thunderstorms Tuesday afternoon into the night.
The National Weather Service continues to monitor the situation and advises residents to remain alert for updated forecasts and potential warnings.
A tropical surge colliding with a cold front could bring dangerous flash floods to four states Tuesday afternoon.