The National Weather Service has issued a flood watch for 2 p.m. today through Friday afternoon.

Periods of heavy rain will begin over western portions of the area Thursday afternoon with the threat of heavy rainfall progressing eastward Thursday evening into the overnight hours. Rainfall will decrease in intensity Friday morning, but impacts from the earlier heavier rainfall may linger into the day on Friday. Rainfall amounts will generally range from 1.5 to 3 inches over the watch area; however, locally higher amounts will be possible, particularly over the higher terrain of eastern Pennsylvania and northwest New Jersey.

As a result of the rainfall, poor drainage and low-lying flooding may begin late Thursday. Small stream as well as main stem flooding is possible Thursday night into Friday.

The latest forecast:

• Showers, with thunderstorms also possible after 2 p.m. Some of the storms could produce heavy rainfall. High near 61. Breezy, with a southeast wind 15 to 20 mph, with gusts as high as 35 mph. Chance of precipitation is 90 percent. New rainfall amounts between three quarters and one inch possible.

Tonight: Showers and possibly a thunderstorm before 2 a.m., then showers likely. Some of the storms could produce heavy rainfall. Low around 53. Southeast wind 10 to 15 mph becoming light after midnight. Winds could gust as high as 30 mph. Chance of precipitation is 90%. New rainfall amounts between 1 and 2 inches possible.

Friday: Showers likely, then showers and possibly a thunderstorm after 2 p.m. High near 65. Northwest wind 5 to 10 mph. Chance of precipitation is 80%. New rainfall amounts between a quarter and half of an inch possible.

Friday Night: Showers and possibly a thunderstorm before 8 p.m., then a chance of showers. Low around 48. Northwest wind 5 to 10 mph. Chance of precipitation is 80%. New precipitation amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

Saturday: A slight chance of showers before 2 p.m. Mostly sunny, with a high near 65. Northwest wind around 10 mph. Chance of precipitation is 20%.

Saturday Night: Partly cloudy, with a low around 46.

Sunday: A chance of showers after 2 p.m. Partly sunny, with a high near 69. Chance of precipitation is 30%.

Sunday Night: A chance of showers. Mostly cloudy, with a low around 50. Chance of precipitation is 40%.

Monday: Mostly sunny, with a high near 65.

Monday Night: Partly cloudy, with a low around 41.