Scattered severe storms late Thursday afternoon could bring flooding, damaging winds and hail to the Lehigh Valley.
A strong cold front is moving through the region, already bringing widespread heavy rain and creating a messy evening commute.
Lehigh and Northampton counties, as well as neighboring Berks, Bucks, Carbon and Monroe counties are under a flood watch until 2 a.m. Friday. The Lehigh Valley is also under a severe thunderstorm watch until 10 p.m.
Most of the Lehigh Valley is under a marginal risk for severe weather between 2 and 8 p.m., according to the National Weather Service in Mount Holly, New Jersey.
Areas south of the Lehigh Valley are at a slight risk of severe weather. Forecasters said there is also a slight chance of tornadoes.
Between 1 and 2 inches of rain is expected to fall, but there could be locally higher amounts between 3 and 5 inches. Storms could bring rainfall rates of 2-4 inches per hour. Flooding in urban areas and creeks and streams is also possible.
“We will have efficient rainfall producers where some areas could see multiple rounds, which is not a good combination. This event will also be during the evening commute, with travel disruptions likely,” meteorologists wrote Thursday in their daily forecast discussion. “Have multiple ways to receive warnings.”
An active day is expected for today. Storms begin to develop by the early afternoon, continuing into the evening. Scattered strong to severe thunderstorms that develop are capable of damaging winds, hail, and a few tornadoes. Have multiple ways to receive warnings! pic.twitter.com/apjV7yqGg1
— NWS Mount Holly (@NWS_MountHolly) August 20, 2026
The threat of severe rain and flooding should diminish early Friday morning, forecasters said.
More rain is possible over the weekend.
Here is the extended forecast from the National Weather Service:
Friday: Mostly sunny, with a high near 80. Calm wind becoming northeast around 5 mph.
Saturday: A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 8 a.m. Mostly cloudy, with a high near 78. Calm wind becoming east around 5 mph. Chance of precipitation is 60%. New rainfall amounts between a quarter and half of an inch possible.
Sunday: A chance of showers after 2 p.m. Partly sunny, with a high near 82. Chance of precipitation is 40%.
Monday: Sunny, with a high near 78.
Tuesday: Sunny, with a high near 79.
Wednesday: A chance of showers. Mostly sunny, with a high near 82. Chance of precipitation is 30%.