Hazardous Weather Outlook Issued: Heavy Rain, Flooding Threat Thursday, Friday

Be sure to bring your umbrella if you're headed out tonight, and also for the morning commute Friday.

The National Weather Service has issued a Hazardous Weather Outlook in Eastern Pennsylvania because heavy rain tonight and into the morning could lead to flooding in poor drainage areas.

Heavy rain is predicted to begin Thursday night. The chance of precipitation is 100 percent, the National Weather Service says. New precipitation amounts between three quarters and one inch are possible.

More heavy rain is expected Friday. The chance of precipitation Friday is 90 percent. New precipitation amounts between three quarters and one inch are possible.

The likely downpours are a result of a "slow-moving" storm, AccuWeather Meteorologist Edward Vallee said.

And just because it has been dry, doesn't mean there is no flooding risk. Flooding can occur despite prior dry conditions, Accuweather warns. "The bulk of the flooding will be restricted to urban areas and along small streams," Valley noted.

Bad news: the wet weather is predicted to continue through the weekend, although the chance of precipitation decreases to 50 percent Saturday and 40 percent Sunday.

Here is the forecast:

Tonight: Rain. The rain could be heavy at times. Low around 56. Breezy, with a northeast wind 18 to 20 mph, with gusts as high as 30 mph. Chance of precipitation is 100%. New precipitation amounts between three quarters and one inch possible.

Friday: Rain. The rain could be heavy at times. High near 62. Breezy, with a northeast wind 16 to 20 mph. Chance of precipitation is 90%. New precipitation amounts between three quarters and one inch possible.

Friday Night: Rain before 8pm, then a chance of showers after 8pm. Low around 59. Northeast wind 10 to 17 mph. Chance of precipitation is 80%. New precipitation amounts between a tenth and quarter of an inch possible.

Saturday: A chance of showers. Cloudy, with a high near 71. East wind around 10 mph. Chance of precipitation is 50%. New precipitation amounts between a tenth and quarter of an inch possible.

Saturday Night: Showers likely. Cloudy, with a low around 60. Chance of precipitation is 60%. New precipitation amounts between a tenth and quarter of an inch possible.

Sunday: A chance of showers. Mostly cloudy, with a high near 73. Chance of precipitation is 40%.