Flood watch in effect for Lehigh, Northampton counties through early Thursday

A flood watch is in effect for much of southeastern Pennsylvania through early Thursday as forecasters warn of heavy rainfall and flash flooding across the region.

The National Weather Service says multiple rounds of thunderstorms are expected to bring significant rain, particularly from Wednesday afternoon into Thursday morning. The watch includes Berks, Bucks, Chester, Delaware, Lancaster, Lehigh, Montgomery, Northampton and surrounding counties.

Forecasters said rainfall rates could exceed 1 inch per hour, especially in areas where storms move repeatedly over the same locations — a phenomenon known as “training.” With soils already saturated from recent rain, there’s an increased risk of creeks and streams quickly overflowing their banks.

“Flash flooding is a serious threat in low-lying and urban areas, especially near small streams and poorly drained roadways,” the weather service said in its advisory.

Drivers are urged to use caution and never attempt to drive through flooded roadways. 6 inches of moving water can sweep a vehicle away.

In addition to flooding, high humidity and temperatures in the upper 80s are expected to persist through Thursday.

The flood watch remains in effect until at least 6 a.m. Thursday, with additional downpours possible later in the day as a cold front moves through.

Residents are encouraged to stay weather-aware, check local alerts and take precautions.