The first of a family of weak disturbances in the atmosphere is working through Pennsylvania this evening, with a chance of sprinkles and showers in the forecast as it moves east for portions of the region. As of 5 PM, most of the shower activity is southwest and west of the city, generally moving east-southeast. Even though radar is detecting shower activity in the atmosphere, the fact that dew points are in the 20's and 30's with air temperatures in the 60's would result in little in the way of significant shower activity reaching the surface thanks to the atmosphere going a good job of drying up precipitation.
Odds don't favor much in the way of shower activity as it moves through as computer model projections from the high res NAM (below), with an increase in clouds likely as we work through the Midnight hour and into the early morning hours. Breezes will continue but subside somewhat. Any shower activity that does fall will do little to dampen the fires going on in Berks County and Burlington County forests, with the latter fire already at 1300 acres of scorched woodland.
Shower and sprinkle chances continue through Wednesday before we enter a period of fair weather for the latter half of the week. The next chances for any rain of note will be on Sunday -- perhaps with a cold front approaching the area -- or into next week as the front may stall out. There's a bit of uncertainty about how the front behaves next week...with the Euro hanging the front to our northwest and bringing us some significant warmth (80 possible?) while the GFS blasts the front through pretty quickly. Until then, these showers over tonight, tomorrow, and perhaps Wednesday will be about it for the chances of any noted rainfall.