A Flood Watch has been issued for much of the Mid-Atlantic as the National Weather Service in Mount Holly upgraded the flash flooding threat to a Moderate Risk for parts of New Jersey, southeastern Pennsylvania, northern Delaware, and northeastern Maryland.
The alert, issued early Monday morning, warns of showers and scattered thunderstorms capable of producing heavy rain, with rates exceeding 2 inches per hour. The greatest risk for flash flooding begins at 2 PM Monday and extends through 2 AM Tuesday.
“Localized rainfall amounts near 3-5 inches possible,” the briefing stated, noting the risk of flooding in urbanized areas, poor drainage zones, small streams, and creeks.
An isolated severe thunderstorm is also possible, mainly between 2 PM and 10 PM Monday. The main threat from these storms will be damaging wind gusts, with the highest potential across the Marginal Risk area, which includes parts of New Jersey and the Philadelphia metro.
The flood threat will continue into Tuesday, with another round of scattered thunderstorms expected, especially south of the Philadelphia area. These storms may again produce intense rainfall and localized flooding. A Slight Risk of flash flooding is forecast for that period.
Additional rounds of storms are possible through the rest of the week, with at least a marginal risk of flash flooding and isolated severe weather each day.
NWS officials plan to issue the next update by 5 PM Monday.