A flash flood warning issued by the National Weather Service late Monday afternoon includes the Saucon Valley and southern Northampton County, where thunderstorms have produced torrential rainfall over a short period of time. The warning also includes southeastern Lehigh County and northwestern Bucks County.

According to a NWS statement, one to two inches of rain has fallen in the area covered by the flood warning, with another one to two inches possible this evening. Around 5:30 p.m., weather radar showed a slow-moving line of heavy thunderstorms expanding across much of Lehigh and Northampton counties, with little movement away from the area.

Locally, there are a number of flood-prone areas along the Saucon Creek and its tributaries, which flow through a number of communities including Upper Saucon Township, Lower Saucon Township, Hellertown borough and the city of Bethlehem.

According to the National Weather Service, at 5:25 p.m. flash flooding was ongoing or expected to occur shortly in some areas.

Shortly after 6 p.m. the Lower Saucon Township Police Department shared an advisory message in which they reported that there are “multiple” flooded roadways in the township.

The flash flood warning is in effect until 9:30 p.m. A flash flood watch is also in effect for much of eastern Pennsylvania until 2 a.m. Tuesday.

Lower Saucon Township Police said motorists who encounter flooded roadways should turn around rather than try to drive through the flood waters. According to the NWS, statistically, most flood-related deaths occur in vehicles.