The threat of severe thunderstorms and flooding has expanded to a wider range of the greater Philadelphia region Thursday as a powerful system approaches.
Torrential rainfall, potentially up to 1 to 3 inches per hour, is possible, and could cause flash flooding in the hardest hit areas. Isolated large hail and even a tornado "cannot be ruled out," the National Weather Service said. But the primary danger will be high winds damaging trees, power lines, and other property.
Storms will hit between 2 p.m. and 10 p.m., and could be most impactful during rush hour.
"Thursday's storms are occurring at a particularly inconvenient time, with the evening commute overlapping with people getting an early start on one of the final big travel weekends of summer," Accuweather meteorologist Elizabeth Danco said. "It doesn't take widespread severe weather to create problems. A torrential downpour over a busy highway can quickly reduce visibility, overwhelm drainage and bring traffic to a crawl."
The region now sits in the second severity zone published by the NOAA, "slight risk," indicating the scattered severe thunderstorms are possible.
A flood watch has also been declared until 4 a.m. Friday for the entire southeastern Pennsylvania region.
Here's the full forecast for the coming week:
Thursday
A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 1 p.m. Mostly cloudy, with a high near 86. South wind around 10 mph. Chance of precipitation is 70 percent. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Thursday Night
A chance of showers and thunderstorms. Mostly cloudy, with a low around 70. South wind around 5 mph becoming calm in the evening. Chance of precipitation is 50 percent. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.
Friday
A chance of showers and thunderstorms, mainly after 4 p.m. Partly sunny, with a high near 86. Calm wind becoming northwest around 5 mph. Chance of precipitation is 30 percent. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.
Friday Night
A chance of showers before 8 p.m. Mostly cloudy, with a low around 69. Calm wind. Chance of precipitation is 30 percent. New precipitation amounts of less than a tenth of an inch possible.
Saturday
Mostly sunny, with a high near 86. North wind around 5 mph becoming calm.
Saturday Night
Partly cloudy, with a low around 68.
Sunday
Mostly sunny, with a high near 88.
Sunday Night
Partly cloudy, with a low around 72.
Monday
Mostly sunny, with a high near 90.
Monday Night
Mostly cloudy, with a low around 73.
Tuesday
A chance of showers. Mostly sunny, with a high near 89. Chance of precipitation is 30 percent.
Tuesday Night
A chance of showers. Mostly cloudy, with a low around 72. Chance of precipitation is 30 percent.
Wednesday
A chance of showers. Partly sunny, with a high near 88. Chance of precipitation is 30 percent.
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