Storms that could bring flash flooding, damaging winds and cloud-to-ground lightning are possible through Monday in the Lehigh Valley.
Rain is expected overnight Sunday into Monday, and there could be multiple rounds of showers and thunderstorms, according to the National Weather Service in Mount Holly, New Jersey. The Lehigh Valley and surrounding counties are at a marginal risk for flash flooding and severe weather Sunday into Monday.
The Lehigh Valley and Bucks, Berks and Montgomery counties will be under a flash flood watch from 8 p.m. Sunday until 11 p.m. Monday. Forecasters said flash flooding is expected to be the primary threat, however severe thunderstorms could bring wind damage as well.
Multiple rounds of showers and thunderstorms are expected through tomorrow. The main hazards are heavy rain leading to flash flooding, damaging winds, and cloud-to-ground lightning.
For the latest detailed forecast for your location, please visit https://t.co/LgidMZadPn pic.twitter.com/0YHJTrOuSm
— NWS Mount Holly (@NWS_MountHolly) August 2, 2026
“The model trends continue to show a slower arrival of this system, with the bulk of the showers and thunderstorms occurring later tonight and especially on Monday,” meteorologists wrote Sunday in their daily forecast discussion.
The front will continue into Tuesday, and could bring more scattered showers to the area. Rain is possible every day through Saturday.
The latest storm threat comes just days after storms brought more than 4 inches of rain to the Lehigh Valley, causing flash flooding and flooded basements.
Here is the extended forecast from the National Weather Service:
Monday: Showers and thunderstorms before 2 p.m., then showers likely and possibly a thunderstorm 2 p.m. and 5 p.m., then a chance of showers and thunderstorms after 5pm. High near 82. South wind around 5 mph. Chance of precipitation is 80%. New rainfall amounts between a quarter and half of an inch possible.
Tuesday: A chance of showers after 2 p.m. Mostly sunny, with a high near 83. Calm wind becoming northeast around 5 mph. Chance of precipitation is 30%. New precipitation amounts of less than a tenth of an inch possible.
Wednesday: A chance of showers before 8 a.m., then a chance of showers and thunderstorms after 2 p.m. Partly sunny, with a high near 82. Chance of precipitation is 50%.
Thursday: A chance of showers and thunderstorms after 2 p.m. Partly sunny, with a high near 88. Chance of precipitation is 50%.
Friday: Showers likely and possibly a thunderstorm. Partly sunny, with a high near 88. Chance of precipitation is 60%.
Saturday: A chance of showers. Mostly sunny, with a high near 87. Chance of precipitation is 50%.