Flood Watch In 15 PA Counties, Thunderstorms In Forecast: See Timeline

PENNSYLVANIA - Heavy rain and thunderstorms expected across Pennsylvania Saturday have prompted forecasters to issue a flood watch for several eastern counties, the National Weather Service said.

Isolated thunderstorms are set to begin at around 2 p.m., though the “main focus” of the storm system will take place Saturday night into Sunday, the National Weather Service's Mount Holly station said. Scattered flash floods are likely in the northeast region; locally strong winds are also in the cards, the weather service said.

The greatest threat of flash flooding will be in areas that have recently had heavy rain and flooding where soils are already saturated, forecasters added.

“Especially for areas that received the heavy rain yesterday (Carbon, Monroe, Northampton, Warren, and Morris Counties), it won't take much extra rainfall to get flash flooding,” the National Weather Service Mount Holly station said in a statement.

Although isolated storms are possible during the day today, the main focus is on late tonight into Sunday. Highest chance for widespread showers and thunderstorms, along with an increased risk for flash flooding will be late tonight (after midnight) through the day on Sunday. pic.twitter.com/mAlb2iPidt
— NWS Mount Holly (@NWS_MountHolly) July 15, 2023

As of noon on Saturday, 15 Pennsylvania counties are under a flood watch through Sunday evening. The affected counties are:

• Carbon
• Monroe
• Berks
• Lehigh
• Northampton
• Delaware
• Philadelphia
• Chester
• Montgomery
• Bucks
• Sullivan
• Wayne
• Lackawanna
• Luzerne
• Pike

1 to 2 inches of rainfall are expected around the state, though localized amounts of 3 to 5 inches are possible, the National Weather Service said.

“Excessive runoff may result in flooding of rivers, creeks, streams, and other low-lying and flood-prone locations,” the weather service said. “Creeks and streams may rise out of their banks. Flooding may occur in poor drainage and urban areas.”

Pennsylvania residents “should monitor later forecasts and be prepared to take action should Flash Flood Warnings be issued,” the weather service added. “Those living in areas prone to flooding should be prepared to take action should flooding develop.”

The Keystone State is slated for a brief break from wet weather on Monday with sunny skies and a high of 91 before thunderstorms return Monday night.

Here’s the latest forecast around Pennsylvania, per the National Weather Service:

Saturday: Isolated showers and thunderstorms. Some of the storms could produce heavy rain. Partly sunny, with a high near 88. South wind 5 to 10 mph. Chance of precipitation is 20 percent.

Saturday Night: A chance of showers and thunderstorms, mainly after 2 a.m. Some of the storms could produce gusty winds and heavy rain. Mostly cloudy, with a low around 75. South wind around 10 mph. Chance of precipitation is 40 percent. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

Sunday: Showers and thunderstorms likely, mainly after 2 p.m. Some of the storms could produce gusty winds and heavy rain. Mostly cloudy, with a high near 86. South wind 5 to 15 mph. Chance of precipitation is 60 percent. New rainfall amounts between a half and three quarters of an inch possible.

Sunday Night: Showers and thunderstorms likely, mainly before 8 p.m. Patchy fog after 2 a.m. Otherwise, partly cloudy, with a low around 70. South wind around 5 mph becoming west after midnight. Chance of precipitation is 60 percent. New rainfall amounts between a quarter and half of an inch possible.

Monday: Patchy fog before 8 a.m. Otherwise, sunny, with a high near 91. Northwest wind 5 to 10 mph becoming southwest in the afternoon.

Monday Night: A slight chance of showers and thunderstorms after 2 a.m. Mostly clear, with a low around 71. Chance of precipitation is 20 percent.