A flood watch issued for Wednesday through Thursday afternoon for the Philadelphia region remains in effect as periods of heavy rain on Wednesday, combined with melting snow, could produce widespread flooding.
With temperatures on Wednesday in Philadelphia at or near the record of 62 in 2006, between 3/4 to 1 1/2 inches of rain is expected across the area, forecasters said. The extent of the flooding will depend on that rainfall amount. Most of the snow piled up on area lawns and sidewalks will likely be gone by Thursday morning.
There is dual concern about the flooding. Low-lying flooding from poor street drainage is possible as early as Wednesday afternoon, and likely will make the evening commute difficult, forecasters said. Road closures are possible in areas that drain poorly.
Then, as the runoff reaches the area's creeks, streams and rivers, they could exceed flood stage Wednesday into Thursday. Minor to moderate river flooding is also possible in the Schuylkill River basin.
Dense fog could complicate driving, especially Wednesday morning, the National Weather Service said.
The weather service has issued the following forecast through the weekend:
Tuesday afternoon
Sunny, with a high near 50 degrees. Northeast wind around 5 m.p.h.
Tuesday night
Scattered showers, mainly after 5 a.m. Increasing clouds, with a low around 40. East wind 3 to 6 m.p.h. Chance of precipitation is 30 percent. New precipitation amounts of less than a tenth of an inch possible.
Wednesday
Showers, mainly after 7 a.m. The rain could be heavy at times. Areas of fog. High near 63. East wind 7 to 16 m.p.h. becoming south in the afternoon. Chance of precipitation is 100 percent. New precipitation amounts between three-quarters and one inch possible.
Wednesday Night
A chance of showers. Patchy fog before 1 a.m. Otherwise, cloudy, then gradually becoming partly cloudy, with a low around 45. South wind 7 to 11 m.p.h. becoming west after midnight. Chance of precipitation is 50 percent. New precipitation amounts between a tenth and a quarter of an inch possible.
Thursday
Mostly sunny, with a high near 49. Northwest wind 8 to 10 m.p.h.
Thursday Night
Partly cloudy, with a low around 31.
Friday
Mostly sunny, with a high near 43.
Friday Night
Mostly clear, with a low around 29.
Saturday
Mostly sunny, with a high near 47.
Saturday Night
Mostly cloudy, with a low around 32.
Sunday
Mostly sunny, with a high near 45.
Sunday Night
Partly cloudy, with a low around 30.