A low pressure system is expected to stall over the region early tomorrow, bringing heavy rain, triggering yet another flood watch, and slowing the commute.
The National Weather Service says the weather pattern is expected to remain unsettled through the weekend and into next week, with real clearing not expected to Wednesday.
Already, fog is impacting some area's of this morning's commute. And it is sticky out, with humidity reaching 93 percent.
The forecast calls for scattered showers this morning, with more showers likely and possibly a thunderstorm this afternoon.
But Friday will be different, with 1 to 2 inches of rain possible.
Rain should continue into Saturday afternoon, tapering off to showers by nighttime, with another half inch or more possible.
In all, three to four inches of rain are expected to to fall from Friday through Saturday night.
Sunday could bring some relief. The forecast calls for partly sunny skies, a high of 74, and much less chance of rain.
The Philadelphia region has already receive over a foot of rain for the month. The current rain pattern means we're already heading into record territory for September.
The record for September rain was reached in September 1999 when 13.07 inches fell.
The National Weather Service's flood warning notes that, because of that, the grond is very saturated and can't absorb much rain.